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  PREFACE TO ~IRST EDITION  Avii-
HUMAN reason has this peculiar fate that in one species
of its knowledge it is burdened by questions which, as pre-
scribed by the very nature of reason itself, it is not able to
ignore, but which, as transcending all its powers, it is also
not able to answer.
  The perplexity into which it thus falls is not due to any
fault of its own. It begins with principles which it has no
option save to employ in the course of experience, and which
this experience at the same time abundantly justifies it in
using. Rising with their aid (since it is determined to this
also by its own nature) to ever higher, ever more remote,
conditions,  it soon becomes  aware that in this way---the A viii.
questions never ceasing ---its work must always remain
incomplete; and it therefore finds itself compelled to resort
to principles which overstep all possible empirical employ-
ment, and which yet seem so unobjectionable that even
ordinary consciousness readily accepts them. But by this
procedure human reason precipitates itself into darkness
and contradictions; and while it may indeed conjecture
that these must be in some way due to concealed errors,
it is not in a position to be able to detect them. For since
the principles of which it is making use transcend the limits
of experience, they are no longer subject to any empirical
test. The battle-field of these endless controversies is called
metaphysics.
  Time was when metaphysics was entitled the Queen of
all the sciences; and if the will be taken for the deed, the pre-
eminent importance of her accepted tasks gives her every
right to this title of honour. Now, however, the changed
fashion of the time brings her only scorn; a matron outcast
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and forsaken, she mourns like Hecuba: <1Modo maxima rerum,>1
A ix. <1tot generis natisque potens---nunc trahor exul, inops.a>1
  Her government, under the administration of the <1dogmat>1
  <1ists,>1 was at first <1despotic.>1 But inasmuch as the legislation
  still bore traces of the ancient barbarism, her empire gradu-
  ally through intestine wars gave way to complete anarchy;
  and the <1sceptics,>1 a species of nomads, despising all settled
  modes of life, broke up from time to time all civil society.
  Happily they were few in number, and were unable to prevent
  its being established ever anew, although on no uniform and
  self-consistent plan. In more recent times, it has seemed as
  if an end might be put to all these controversies and the
  claims of metaphysics receive final judgment, through a
  certain <1physiology>1 of the human understanding---that of the
  celebrated Locke. But it has turned out quite otherwise. For
  however the attempt be made to cast doubt upon the pre-
  tensions of the supposed Queen by tracing her lineage to
  vulgar origins in common experience, this genealogy has,
  as a matter of fact, been fictitiously invented, and she has
A x. still continued to uphold her claims. Metaphysics has accord-
  ingly lapsed back into the ancient time-worn dogmatism, and
  so again suffers that depreciation from which it was to have
  been rescued. And now, after all methods, so it is believed,
  have been tried and found wanting, the prevailing mood is
  that of weariness and complete <1indifferentism->1--the mother,
  in all sciences, of chaos and night, but happily in this case
  the source, or at least the prelude, of their approaching
  reform and restoration. For it at least puts an end to that ill-
  applied industry which has rendered them thus dark, confused,
  and unserviceable.
  But it is idle to feign indifference to such enquiries,
  the object of which can never be indifferent to our human
  nature. Indeed these pretended <1indifferentists,>1 however
  they may try to disguise themselves by substituting a
  popular tone for the language of the Schools, inevitably
  fall back, in so far as they think at all, into those very
  metaphysical assertions which they profess so greatly to
  despise. None the less this indifference, showing itself in the
  midst of flourishing sciences, and affecting precisely those
  a Ovid, <1Metam.>1 [xiii. 508-510].
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sciences, the knowledge of which, if attainable, we should
least of all care to dispense with, is a phenomenon that A xi.
calls for attention and reflection. It is obviously the effect
not of levity but of the matured judgmenta of the age, which
refuses to be any longer put off with illusory knowledge. It is
a call to reason to undertake anew the most difficult of all
its tasks, namely, that of self-knowledge, and to institute
a tribunal which will assure to reason its lawful claims, and
dismiss all groundless pretensions, not by despotic decrees, A xii.
but in accordance with its own eternal and unalterable
laws. This tribunal is no other than the <1critique of pure>1
<1reason.>1
  I do not mean by this a critique of books and systems,
but of the faculty of reason in general, in respect of all know-
ledge after which it may strive <1independently of all experi->1
<1ence.>1 It will therefore decide as to the possibility or impossi-
bility of metaphysics in general, and determine its sources,
its extent, and its limits---all in accordance with principles.
  I have entered upon this path---the only one that has re-
mained unexplored---and flatter myself that in following it I
have found a way of guarding against all those errors which
have hitherto set reason, in its non-empirical employment, at
  a  We often hear complaints of shallowness of thought in our age
and of the consequent decline of sound science. But I do not see
that the sciences which rest upon a secure foundation, such as mathe-
matics, physics, etc., in the least deserve this reproach. On the con-
trary, they merit their old reputation for solidity, and, in the case
of physics, even surpass it. The same spirit would have become
active in other kinds of knowledge, if only attention had first been
directed to the determination of their principles. Till this is done, in-
difference, doubt, and, in the final issue, severe criticism, are them-
selves proofs of a profound habit of thought. Our age is, in especial
degree, the age of criticism, and to criticism everything must sub-
mit. Religion through its sanctity, and law-giving throughits majesty,
may seek to exempt themselves from it. But they then awaken just
suspicion, and cannot claim the sincere respect which reason accords
only to that which has been able to sustain the test of free and open
examination.
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variance with itself. I have not evaded its questions by plead-
ing the insufficiency of human reason. On the contrary, I have
specified these questions exhaustively, according to prin-
ciples; and after locating the point at which, through mis-
understanding, reason comes into conflict with itself, I have
A xiii. solved them to its complete satisfaction. The answer to these
  questions has not, indeed, been such as a dogmatic and vision-
  knowledge might lead us to expect---
  that can be catered for only through magical devices, in which
  I am no adept. Such ways of answering them are, indeed, not
  within the intention of the natural constitution of our reason;
  and inasmuch as they have their source in misunderstanding,
  it is the duty of philosophy to counteract their deceptive in-
  fluence, no matter what prized and cherished dreams may have
  to be disowned. In this enquiry I have made completeness
  my chief aim, and I venture to assert that there is not a single
  metaphysical problem which has not been solved, or for the
  solution of which the key at least has not been supplied. Pure
  reason is, indeed, so perfect a unity that if its principle were
  insufficient for the solution of even a single one of all the
  questions to which it itself gives birth we should have no
  alternative but to reject the principle, since we should then no
  longer be able to place implicit reliance upon it in dealing
  with any one of the other questions.
  While I am saying this I can fancy that I detect in the face
A xiv. of the reader an expression of indignation, mingled with con-
  tempt, at pretensions seemingly so arrogant and vain-glorious.
  Yet they are incomparably more moderate than the claims
  of all those writers who on the lines of the usual programme
  profess to prove the simple nature of the soul or the necessity
  of a first beginning of the world. For while such writers pledge
  themselves to extend human knowledge beyond all limits of
  possible experience, I humbly confess that this is entirely be-
  yond my power. I have to deal with nothing save reason itself
  and its pure thinking; and to obtain complete knowledge of
  these, there is no need to go far afield, since I come upon them
  in my own self. Common logic itself supplies an example, how
  all the simple acts of reason can be enumerated completely
  and systematically. The subject of the present enquiry is the
  [kindred] question, how much we can hope to achieve by
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reason, when all the material and assistance of experience are
taken away.
  So much as regards <1completeness>1 in our determination of
each question, and <1exhaustiveness>1 in our determination of all
the questions with which we have to deal. These questions are
not arbitrarily selected; they are prescribed to us, by the very
nature of knowledge itself, as being the subject-matter of our
critical enquiry.
  As regards the form of our enquiry, <1certainty>1 and <1clearness>1 A xv.
are two essential requirements, rightly to be exacted from any-
one who ventures upon so delicate an undertaking.
  As to <1certainty,>1 I have prescribed to myself the maxim,
that in this kind of investigation it is in no wise permissible to
hold <1opinions.>1 Everything, therefore, which bears any manner
of resemblance to an hypothesis is to be treated as contra-
band; it is not to be put up for sale even at the lowest price,
but forthwith confiscated, immediately upon detection. Any
knowledge that professes to hold <1a priori>1 lays claim to be
regarded as absolutely necessary. This applies still more to any
<1determination>1 of all pure <1apriori>1 knowledge, since such deter-
mination has to serve as the measure, and therefore as the
[supreme] example, of all apodeictic (philosophical) certainty.
Whether I have succeeded in what I have undertaaen must be
left altogether to the reader's judgment; the author's task is
solely to adduce grounds, not to speaa as to the effect which
they should have upon those who are sitting in judgment. But
the author, in order that he may not himself, innocently, be A xvi.
the cause of any weakening of his arguments, may be permitted
to draw attention to certain passages, which, although merely
incidental, may yet occasion some mistrust. Such timely inter-
vention may serve to counteract the influence which even quite
undefined doubts as to these minor matters might otherwise
exercise upon the reader's attitude in regard to the main
issue.
  I know no enquiries which are more important for ex-
ploring the faculty which we entitle understanding, and for
determining the rules and limits of its employment, than those
which I have instituted in the second chapter of the Trans-
cendental Analytic under the title <1Deduction of the Pure>1
<1Concepts of Understanding.>1 They are also those which have
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cost me the greatest labour---labour, as I hope, not unre-
warded. This enquiry, which is somewhat deeply grounded,
has two sides. The one refers to the objects of pure under-
standing, and is intended to expound and render intelligible
the objective validity of its <1a priori>1 concepts. It is therefore
essential to my purposes. The other seeks to investigate the
pure understanding itself, its possibility and the cognitive
A xvii. faculties upon which it rests; and so deals with it in its sub-
  jective aspect. Although this latter exposition is of great
  importance for my chief purpose, it does not form an essential
  part of it. For the chief question is always simply this:---what
  and how much can the understanding and reason know apart
  from all experience? not:---how is the faculty of thought itself
  possible? The latter is, as it were, the search for the cause of
  a given effect, and to that extent is somewhat hypothetical
  in character (though, as I shall show elsewhere, it is not really
  so); and I would appear to be taking the liberty simply of
  expressing an <1opinion,>1 in which case the reader would be free
  to express a different <1opinion.>1 For this reason I must forestall
  the reader's criticism by pointing out that the objective de-
  duction with which I am here chiefly concerned retains its full
  force even if my subjective deduction should fail to produce
  that complete conviction for which I hope. On this matter,
  what has been said on pp. 92-931 should in any case suffice
  by itself.
  As regards <1clearness,>1 the reader has a right to demand, in
  the first place, a <1discursive>1 (logical) clearness, through <1con->1
A xviii. <1cepts,>1 and secondly, an <1intuitive>1 (aesthetic) clearness, through
  <1intuitions,>1 that is, through examples and other concrete
  illustrations. For the first I have sufficiently provided. That
  was essential to my purpose; but it has also been the incidental
  cause of my not being in a position to do justice to the second
  demand, which, if not so pressing, is yet still quite reasonable.
  I have been almost continuously at a loss, during the progress
  of my work, how I should proceed in this matter. Examples
  and illustrations seemed always to be necessary, and so took
  their place, as required, in my first draft. But I very soon
  became aware of the magnitude of my task and of the multi-
  plicity of matters with which I should have to deal; and as
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I perceived that even if treated in dry, purely <1scholastic>1
fashion, the outcome would by itself be already quite suffi-
ciently large in bulk, I found it inadvisable to enlarge it yet
further through examples and illustrations. These are neces-
sary only from a <1popular>1 point of view; and this work can
never be made suitable for popular consumption. Such
assistance is not required by genuine students of the science,
and, though always pleasing, might very well in this case
have been self-defeating in its effects. Abbot Terrasson  has
remarked that if the size of a volume be measured not by the A xix.
number of its pages but by the time required for mastering it,
it can be said of many a book, <1that it would be much shorter>1
<1if it were not so short.>1 On the other hand, if we have in view
the comprehensibility of a whole of speculative knowledge,
which, though wide-ranging, has the coherence that  follows
from unity of principle, we can say with equal justice <1that>1
<1many a book would have been much clearer if it had not made>1
<1such an effort to be clear.>1 For the aids to clearness, though
they may be of assistance  in regard to details, often interfere
with our grasp of the whole. The reader is not allowed to
arrive sufficiently quickly at a conspectus of the whole; the
bright colouring of the illustrative material intervenes to cover
over and conceal the articulation and organisation of the
system, which, if we are to be able to judge of its unity and
solidity, are what chiefly concern us.
  The reader, I should judge, will feel it to be no small
inducement to yield his willing co-operation, when the author
is thus endeavouring, according to the plan here proposed, to
carry through a large and important work in a complete and
lasting manner. Metaphysics, on the view which we are adopt- A xx.
ing, is the only one of all the sciences which dare promise
that through a small but concentrated effort it will attain,
and this in a short time, such completion as will leave no
task to our successors save that of adapting it in a <1didactic>1
manner according to their own preferences, without their
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being able to add anything whatsoever to its content. For it
is nothing but the <1inventory>1 of all our possessions through
<1pure>1 reason, systematically arranged. In this field nothing
can escape us. What reason produces entirely out of itself
cannot be concealed, but is brought to light by reason itself
immediately the common principle has been discovered.
The complete unity of this kind of knowledge, and the fact
that it is derived solely from pure concepts, entirely unin-
fluenced by any experience or by <1special>1 intuition, such as
  might lead to any determinate experience that would enlarge
  and increase it, make this unconditioned completeness not
  only practicable but also necessary. <1Tecum habita, et noris>1
  <1quam sit tibi curta supellex.a>1
  A xxi.  Such a system of pure (speculative) reason I hope myself
  to produce under the title <1Metaphysics of Nature.>1 It will be
  not half as large, yet incomparably richer in content than this
  present <1Critique,>1 which has as its first task to discover the
  sources and conditions of the possibility of such criticism,
  clearing, as it were, and levelling what has hitherto been waste-
  ground. In this present enterprise I look to my reader for the
  patience and impartiality of <1a judge;>1 whereas in the other I
  shall look for the benevolent assistance of a <1fellow-worker.>1
  For however completely all the <1principles>1 of the system are
  presented in this <1Critique,>1 the completeness of the system
  itself likewise requires that none of the <1derivative>1 concepts
  be lacking. These cannot be enumerated by any <1a priori>1 com-
  putation, but must be discovered gradually. Whereas, there-
  fore, in this <1Critique>1 the entire <1synthesis>1 of the concepts has
  been exhausted, there will still remain the further work of
  making their <1analysis>1 similarly complete, a task which is
  rather an amusement than a labour.
  I have only a few remarks to add of a typographical
  character. As the beginning of the printing was delayed, I
  A xxii. was not able to see more than about half of the proof-sheets,
  and I now find some misprints, which do not, however, affect
  the sense except on p. 379, line 4 from the bottom,1 where
  specific has to be read in place of sceptical. The antinomy
  a Persius <1[Sat.>1 iv. 52].
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of pure reason, from p. 425 to p. 461,1 has been so arranged,
in tabular form, that all that belongs to the thesis stands
on the left and what belongs to the antithesis on the right.
This I have done in order that proposition and counter-
proposition may be the more easily compared with one
another.
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WHETHER the treatment of such knowledge as lies within the
province of reason does or does not follow the secure path of a
science, is easily to be determined from the outcome. For if
after elaborate preparations, frequently renewed, it is brought
to a stop immediately it nears its goal; if often it is com-
pelled to retrace its steps and strike into some new line of
approach; or again, if the various participants are unable to
agree in any common plan of procedure, then we may rest
assured that it is very far from having entered upon the secure
path of a science, and is indeed a merely random groping. In
these circumstances, we shall be rendering a service to reason
should we succeed in discovering the path upon which it can
securely travel, even if, as a result of so doing, much that is
comprised in our original aims, adopted without reflection,
may have to be abandoned as fruitless.
  That logic has already, from the earliest times, proceeded B viii.
upon this sure path is evidenced by the fact that since Aris-
totle it has not required to retrace a single step, unless, indeed,
we care to count as improvements the removal of certain need-
less subtleties or the clearer exposition of its recognised teach-
ing, features which concern the elegance rather than the cer-
tainty of the science. It is remarkable also that to the present
day this logic has not been able to advance a single step, and
is thus to all appearance a closed and completed body of doc-
trine. If some of the moderns have thought to enlarge it by
introducing <1psychological>1 chapters on the different faculties of
knowledge (imagination, wit, etc.), <1metaphysical>1 chapters on
the origin of knowledge or on the different kinds of certainty
according to difference in the objects (idealism, scepticism, etc.),
or <1anthropological>1 chapters on prejudices, their causes and
remedies, this could only arise from their ignorance of the
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peculiar nature of logical science. We do not enlarge but
disfigure sciences, if we allow them to trespass upon one
B ix. another's territory. The sphere of logic is quite precisely de-
  limited; its sole concern is to give an exhaustive exposition and
  a strict proof of the formal rules of all thought, whether it be
  <1a priori>1 or empirical, whatever be its origin or its object, and
  whatever hindrances, accidental or natural, it may encounter
  in our minds.
  That logic should have been thus successful is an advan-
  tage which it owes entirely to its limitations, whereby it is
  justified in abstracting---indeed, it is under obligation to do
  so---from all objects of knowledge and their differences, leav-
  ing the understanding nothing to deal with save itself and its
  form. But for reason to enter on the sure path of science is,
  of course, much more difficult, since it has to deal not with
  itself alone but also with objects. Logic, therefore, as a pro-
  paedeutic, forms, as it were, only the vestibule of the sciences;
  and when we are concerned with specific modes of know-
  ledge, while logic is indeed presupposed in any critical
  estimate of them, yet for the actual acquiring of them we
  have to look to the sciences properly and objectively so
  called.
  Now if reason is to be a factor in these sciences, something
  in them must be known <1a priori,>1 and this knowledge may be
  related to its object in one or other of two ways, either as
  merely <1determining>1 it and its concept (which must be supplied
B x. from elsewhere) or as also <1making it actual.>1 The former is
  <1theoretical,>1 the latter <1practical>1 knowledge of reason. In both,
  that part in which reason determines its object completely
  <1a priori,>1 namely, the <1pure>1 part---however much or little this part
  may contain---must be first and separately dealt with, in case
  it be confounded with what comes from other sources. For it
  is bad management if we blindly pay out what comes in, and
  are not able, when the income falls into arrears, to distinguish
  which part of it can justify expenditure, and in which line we
  must make reductions.
  Mathematics and physics, the two sciences in which reason
  yields theoretical knowledge, have to determine their objects
  <1a priori,>1 the former doing so quite purely, the latter having
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to reckon, at least partially, with sources of knowledge other
than reason.
  In the earliest times to which the history of human reason
extends, <1mathematics,>1 among that wonderful people, the
Greeks, had already entered upon the sure path of science. But
it must not be supposed that it was as easy for mathematics as
it was for logic---in which reason has to deal with itself alone---
to light upon, or rather to construct for itself, that royal road. B xi.
On the contrary, I believe that it long remained, especially
among the Egyptians, in the groping stage, and that the trans-
formation must have been due to a <1revolution>1 brought about
by the happy thought of a single man, the experiment which
he devised marking out the path upon which the science must
enter, and by following which, secure progress throughout all
time and in endless expansion is infallibly secured. The his-
tory of this intellectual revolution---far more important than
the discovery of the passage round the celebrated Cape of
Good Hope---and of its fortunate author, has not been pre-
served. But the fact that Diogenes Laertius, in handing down
an account of these matters, names the reputed author of even
the least important among the geometrical demonstrations,
even of those which, for ordinary consciousness, stand in need
of no such proof, does at least show that the memory of the
revolution, brought about by the first glimpse of this new path,
must have seemed to mathematicians of such outstanding im-
portance as to cause it to survive the tide of oblivion. A new light
flashed upon the mind of the first man (be he Thales or some
other) who demonstrated the properties of the isosceles triangle.
The true method, so he found, was not to inspect what he dis- B xii.
cerned either in the figure, or in the bare concept of it, and from
this, as it were, to read off its properties; but to bring out what 1
was necessarily implied in the concepts that he had himself
formed <1apriori,>1 and had put into the figure in the construction
by which he presented it to himself. If he is to know anything
with <1a priori>1 certainty he must not ascribe to the figure any-
thing save what necessarily follows from what he has himself
set into it in accordance with his concept.
  Natural science was very much longer in entering upon the
highway of science. It is, indeed, only about a century and a
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half since Bacon, by his ingenious proposals, partly initiated
this discovery, partly inspired fresh vigour in those who were
already on the way to it. In this case also the discovery can
be explained as being the sudden outcome of an intellectual
revolution. In my present remaras I am referring to natural
science only in so far as it is founded on <1empirical>1 principles.
  When Galileo caused balls, the weights of which he had
himself previously determined, to roll down an inclined plane;
when Torricelli made the air carry a weight which he had cal-
culated beforehand to be equal to that of  a definite column of
water; or in more recent times, when Stahl changed metal
B xiii. into lime, and lime back into metal, by withdrawing some-
  thing and then restoring it,a a light broke upon all students of
  nature. They learned that reason has insight only into that
  which it produces after a plan of its own, and that it must not
  allow itself to be kept, as it were, in nature's leading-strings,
  but must itself show the way with principles of judgment based
  upon fixed laws, constraining nature to give answer to ques-
  tions of reason's own determining. Accidental observations,
  made in obedience to no previously thought-out plan, can
  never be made to yield a necessary law, which alone reason is
  concerned to discover. Reason, holding in one hand its prin-
  ciples, according to which alone concordant appearances can
  be admitted as equivalent to laws, and in the other hand the
  experiment which it has devised in conformity with these prin-
  ciples, must approach nature in order to be taught by it. It
  must not, however, do so in the character of a pupil who
  listens to everything that the teacher chooses to say, but of
  an appointed judge who compels the witnesses to answer
  questions which he has himself formulated. Even physics,
  therefore, owes the beneficent revolution in its point of view
B xiv. entirely to the happy thought, that while reason must seek in
  nature, not fictitiously ascribe to it, whatever as not being
  knowable through reason's own resources has to be learnt,
  if learnt at all, only from nature, it must adopt as its guide,
  in so seeking, that which it has itself put into nature. It is thus
  that the study of nature has entered on the secure path of a
  a  I am not  in my choice of examples, tracing the exact course of
  the history of the experimental method; we have indeed no very pre-
  cise knowledge of its first beginnings.
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science, after having for so many centuries been nothing but
a process of merely random groping.
  Metaphysics is a completely isolated speculative science of
reason, which soars far above the teachings of experience, and
in which reason is indeed meant to be its own pupil. Meta-
physics rests on concepts alone---not, like mathematics, ontheir
application to intuition. But though it is older than all other
sciences, and would survive even if all the rest were swallowed
up in the abyss of an all-destroying barbarism, it has not yet
had the good fortune to enter upon the secure path of a science.
For in it reason is perpetually being brought to a stand, even
when the laws into which it is seeaing to have, as it professes,
an <1apriori>1 insight are those that are confirmed by our most com-
mon experiences. Ever and again we have to retrace our steps,
as not leading us in the direction in which we desire to go. So
far, too, are the students of metaphysics from exhibiting any B xv.
kind of unanimity in their contentions, that metaphysics has
rather to be regarded as a battle-ground quite peculiarly suited
for those who desire to exercise themselves in mock combats,
and in which no participant has ever yet succeeded in gaining
even so much as an inch of territory, not at least in such
manner as to secure him in its permanent possession. This
shows, beyond all questioning, that the procedure of meta-
physics has hitherto been a merely random groping, and,
what is worst of all, a groping among mere concepts.
  What, then, is the reason why, in this field, the sure road
to science has not hitherto been found? Is it, perhaps, im-
possible of discovery? Why, in that case, should nature have
visited our reason with the restless endeavour whereby it is
ever searching for such a path, as if this were one of its most
important concerns. Nay, more, how little cause have we to
place trust in our reason, if, in one of the most important
domains of which we would fain have knowledge, it does
not merely fail us, but lures us on by deceitful promises, and
in the end betrays us! Or if it be only that we have thus far
failed to find the true path, are there any indications to justify
the hope that by renewed efforts we may have better fortune
than has fallen to our predecessors?
  The examples of mathematics and natural science, which
by a single and sudden revolution have become what they B xvi.
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now are, seem to me sufficiently remarkable to suggest our
considering what may have been the essential features in the
changed point of view by which they have so greatly bene-
fited. Their success should incline us, at least by way of experi-
ment, to imitate their procedure, so far as the analogy which,
as species of rational knowledge, they bear to metaphysics may
permit. Hitherto it has been assumed that all our knowledge
must conform to objects. But all attempts to extend our know-
ledge of objects by establishing something in regard to them
<1a priori,>1 by means of concepts, have, on this assumption,
ended in failure. We must therefore make trial whether we
may not have more success in the tasks of metaphysics, if
we suppose that objects must conform to our knowledge. This
would agree better with what is desired, namely, that it should
be possible to have knowledge of objects <1a priori,>1 determining
something in regard to them prior to their being given. We
should then be proceeding precisely on the lines of Copernicus'
primary hypothesis. Failing of satisfactory progress in ex-
plaining the movements of the heavenly bodies on the supposi-
tion that they all revolved round the spectator, he tried whether
he might not have better success if he made the spectator
B xvii- to revolve and the stars to remain at rest. A similar experi-
  ment can be tried in metaphysics, as regards the <1intuition>1
  of objects. If intuition must conform to the constitution of
  the objects, I do not see how we could know anything of
  the latter <1a priori;>1 but if the object (as object of the senses)
  must conform to the constitution of our faculty of intuition,
  I have no difficulty in conceiving such a possibility. Since I
  cannot rest in these intuitions if they are to become known,
  but must relate them as representations to something as their
  object, and determine this latter through them, either I must
  assume that the <1concepts,>1 by means of which I obtain this
  determination, conform to the object, or else I assume that the
  objects, or what is the same thing, that the <1experience>1 in
  which alone, as given objects, they can be known, conform to
  the concepts. In the former case, I am again in the same per-
  plexity as to how I can know anything <1a priori>1 in regard to
  the objects. In the latter case the outlook is more hopeful. For
  experience is itself a species of knowledge which involves
00017
understanding; and understanding has rules which I must pre-
suppose as being in me prior to objects being given to me, and
therefore as being <1a priori.>1 They find expression in <1a priori>1
concepts to which all objects of experience necessarily con- B xviii.
form, and with which they must agree. As regards objects
which are thought solely through reason, and indeed as
necessary, but which can never---at least not in the manner
in which reason thinks them---be given in experience, the
attempts at thinking them (for they must admit of being
thought) will furnish an excellent touchstone of what we are
adopting as our new method of thought, namely, that we can
know <1a priori>1 of things only what we ourselves put into them. a
  This experiment succeeds as well as could be desired, and
promises to metaphysics, in its first part---the part that is
occupied with those concepts <1a priori>1 to which the correspond-
ing objects, commensurate with them, can be given in ex-
perience---the secure path of a science. For the new point of B xix.
view enables us to explain how there can be knowledge
<1a priori;>1 and, in addition, to furnish satisfactory proofs of the
laws which form the <1a priori>1 basis of nature, regarded as the
sum of the objects of experience---neither achievement being
possible on the procedure hitherto followed. But this deduction
of our power of knowing <1a priori,>1 in the first part of metaphysics,
has a consequence which is startling, and which has the appear-
  a This method, modelled on that of the student of nature, con-
sists in looking for the elements of pure reason in <1what admits of con->1
<1firmati-on or refutati-on by experiment.>1 Now the propositions of pure
reason, especially if they venture out beyond all limits of possible
experience, cannot be brought to the test through any experiment
with their <1objects,>1 as in natural science. In dealing with those <1con->1
<1cepts>1 and <1principles>1 which we adopt <1a priori>1, all that we can do is to
contrive that they be used for viewing objects from two different
points of view---on the one hand, in connection with experience, as B xix.
objects of the senses and of the understanding, and on the other
hand, for the isolated reason that strives to transcend all1 limits of
experience, as objects which are thought merely. If, when things are
viewed from this twofold standpoint, we find that there is agreement
with the principle of pure reason, but that when we regard them
only from a single point of view reason is involved in unavoidable
self-conflict, the experiment decides in favour of the correctness of
this distinction.
00018
ance of being highly prejudicial to the whole purpose of meta-
physics, as dealt with in the second part. For we are brought
to the conclusion that we can never transcend the limits of
possible experience, though that is precisely what this science
B xx. is concerned, above all else, to achieve. This situation yields,
  however, just the very experiment by which, indirectly, we
  are enabled to prove the truth of this first estimate of our
  <1a priori>1 knowledge of reason, namely, that such knowledge
  has to do only with appearances, and must leave the thing
  in itself1 as indeed real <1per se,>1 but as not known by us.
  For what necessarily forces us to transcend the limits of
  experience and of all appearances is the <1unconditioned,>1
  which reason, by necessity and by right, demands in things
  in themselves, as required to complete the series of con-
  ditions. If, then, on the supposition that our empirical know-
  ledge conforms to objects as things in themselves, we find
  that the unconditioned <1cannot be thought withoutcontradiction,>1
  and that when, on the other hand, we suppose that our repre-
  sentation of things, as they are given to us, does not conform
  to these things as they are in themselves, but that these objects,
  as appearances, conform to our mode of representation, <1the>1
  <1contradiction vanishes;>1 and if, therefore, we thus find that
  the unconditioned is not to be met with in things, so far as
  we know them, that is, so far as they are given to us, but
  only so far as we do not know them, that is, so far as they
  are things in themselves, we are justified in concluding that
  what we at first assumed for the purposes of experiment is
B xxi. now definitely confirmed.a But when all progress in the field
  of the supersensible has thus been denied to speculative
  reason, it is still open to us to enquire whether, in the practical
  a  This experiment of pure reason bears a great similarity to what
  in chemistry is sometimes entitled the experiment of <1reduction,>1 or
  more usually the <1synthetic>1 process. The <1analygis of the metaphysician>1
  separates pure <1a priori>1 knowledge into two very heterogeneous
  elements, namely, the knowledge of things as appearances, and the
  knowledge of things in themselves; his <1dialectic>1 combines these
  two again, in <1harmony>1 with the necessary idea of the <1unconditioned>1
  demanded by reason, and finds that this harmony can never be ob-
  tained except through the above distinction, which must therefore
  be accepted.
00019
knowledge of reason, data may not be found sufficient to de-
termine reason's transcendent concept of the unconditioned,
and so to enable us, in accordance with the wish of meta-
physics, and by means of knowledge that is possible <1a priori,>1
though only from a practical point of view, to pass beyond
the limits of all possible experience. Speculative reason has
thus at least made room for such an extension; and if it must
at the same time leave it empty, yet none the less we are at B xxii.
liberty, indeed we are summoned, to take occupation of it,
if we can, by practical data of reason.a
  This attempt to alter the procedure which has hitherto
prevailed in metaphysics, by completely revolutionising it
in accordance with the example set by the geometers and
physicists, forms indeed the main purpose of this critique of
pure speculative reason. It is a treatise on the method, nor a
system of the science itself. but at the same time it marks out
the whole plan of the science, both as regards its limits and as
regards its entire internal structure. For pure speculative reason  B xxiii
has this peculiarity, that it can measure its powers according
o the diReffent ways in which it chooses the objects of its
thinking, and can also give an exhaustive enumeration of
the various ways in which it propounds its problems, and so
is able, nay bound, to trace the complete outline of a system
of metaphysics. As regards the first point, nothing in <1a priori>1
knowledge can be ascribed to objects save what the thinking
subject derives from itself; as regards the second point, pure
reason, so far as the principles of its knowledge are concerned,
  a  Similarly, the fundamental laws of the motions of the heavenly
bodies gave established certainty to what Copernicus had at first
assumed only as an hypothesis, and at the same time yielded
proof of the irvisible force (the Newtonian attraction) which holds
the universe together. The latter would have remained for ever un-
discovered if Copernicus had not dared, in a manner contradictory
of the senses, but yet true, to seek the observed movements, not in
the heavenly bodies, but in the spectator. The change in point of
view, analogous to this hypothesis, which is expounded in the
<1Critique>1, I put forward in this preface as an hypothesis only, in order
to draw attention to the character of these first attempts at such a
change, which are always hypothetical. But in the <1Critique>1 itself it
will be proved, apodeictically not hypothetically, from the nature
of our representations of space and time and from the elementary
concepts of the understanding.
00020
is a quite separate self-subsistent unity, in which, as in an
organised body, every member exists for every other, and
all for the sake of each, so that no principle can safely be
taken in <1any one>1 relation, unless it has been investigated in
the <1entirety>1 of its relations to the whole employment of pure
reason. Consequently, metaphysics has also this singular
advantage, such as falls to the lot of no other science which
deals with objects (for <1logic>1 is concerned only with the form
of thought in general), that should it, through this critique,
be set upon the secure path of a science, it is capable of ac-
B xxiv. quiring exhaustive knowledge of its entire field. Metaphysics
  has to deal only with principles, and with the limits of their
  employment as determined by these principles themselves,
  and it can therefore finish its work and bequeath it to posterity
  as a capital to which no addition can be made. Since it is
  a fundamental science, it is under obligation to achieve this
  completeness. We must be able to say of it: <1nil actum re->1
  <1putans, si quid superesset agendum.>1
  But, it will be asked, what sort of a treasure is this that
  we propose to bequeath to posterity? What is the value of
  the metaphysics that is alleged to be thus purified by criti-
  cism and established once for all?  On a cursory view of the
  present work it may seem that its results are merely <1negative,>1
  warning us that we must never venture with speculative reason
  beyond the limits of experience. Such is in fact its primary use.
  But such teaching at once acquires a <1positive>1 value when we
  recognise that the principles with which speculative reason
  ventures out beyond its proper limits do not in effect <1extend>1
  the employment of reason, but, as we find on closer scrutiny,
  inevitably <1narrow>1 it. These principles properly belong [not
  to reason but] to sensibility, and when thus employed they
B xxv. threaten to make the bounds of sensibility coextensive with
  the real, and so to supplant reason in its pure (practical) em-
  ployment. So far, therefore, as our Critique limits speculative
  reason, it is indeed <1negative;>1 but since it thereby removes an
  obstacle which stands in the way of the employment of practi-
  cal reason, nay threatens to destroy it, it has in reality a <1posi->1
  <1tive>1 and very important use. At least this is so, immediately
  we are convinced that there is an absolutely necessary <1prac->1
  <1tical>1 employment of pure reason---the <1moral->1--in which it
00021
inevitably goes beyond the limits of sensibility. Though
[practical] reason, in thus proceeding, requires no assistance
from speculative reason, it must yet be assured against its
opposition, that reason may not be brought into conflict
with itself. To deny that the service which the Critique renders
is <1Positive>1 in character, would thus be like saying that the
police are of no positive benefit, inasmuch as their main busi-
ness is merely to prevent the violence of which citizens stand
in mutual fear, in order that each may pursue his vocation in
peace and security. That space and time are only forms of sens-
ible intuition, and so only conditions of the existence of things
as appearances; that, moreover, we have no concepts of under-
standing, and consequently no elements for the knowledge of
things, save in so far as intuition can be given corresponding B xxvi.
to these concepts; and that we can therefore have no knowledge
of any object as thing in itself, but only in so far as it is an
object of sensible intuition, that is, an appearance---all this is
proved in the analytical part of the Critique. Thus it does in-
deed follow that all possible speculative knowledge of reason
is limited to mere objects of <1experience>1. But our further con-
tention must also be duly borne in mind, namely, that though
We cannot <1know>1 these objects as things in themselves, we
must yet be in position at least to <1think>1 them as things in them-
selves;a otherwise we should be landed in the absurd conclusion
that there can be appearance without anything that appears. B xxvii.
Now let us suppose that the distinction, which our Critique has
shown-to be necessary, between things as objects of experience
and those same things as things in themselves, had not been
made. In that case all things in general, as far as they are
  a  To <1know>1 an object I must be able to prove its possibility, either
from its actuality as attested by experience, or <1a priori>1 by means of
reason. But I can <1think>1 whatever I please, provided only that I do
not contradict myself, that is, provided my concept is a possible
thought. This suffices for the possibility of the concept, even though
I may not be able to answer for there being, in the sum of all possi-
bilities, an object corresponding to it. But something more is re-
quired before I can ascribe to such a concept objective validity, that
is, real possibility; the former possibility is merely logical. This some-
thing more need not, however, be sought in the theoretical sources of
knowledge; it may lie in those tha  are practical.
00022
lity and consequently by the mechanism of nature. I could
not, therefore, without palpable contradiction, say of one and
the same being, for instance the human soul, that its will is free
and yet is subject to natural necessity, that is, is not free. For
I have taken the soul in both propositions <1in one and the same>1
<1sense,>1 namely as a thing in general, that is, as a thing  in itself;
and save by means of a preceding critique, could not have done
otherwise. But if our Critique is not in error in teaching that
the object is to be taken <1in a twofold sense,>1 namely as appear-
ance and as thing in itself; if the deduction of the concepts of
understanding is valid, and the principle of causality there-
fore applies only to things taken in the former sense, namely,
in so far as they are objects of experience-these same objects,
taken in the other sense, not being subject to the principle---
then there is no contradiction in supposing that one and the
B xxviii. same will is, in the appearance, that is, in its visible acts,
  necessarily subject to the law of nature, and so far <1not free,>1
  while yet, as belonging to a thing in itself, it is not subject
  to that law, and is therefore <1free.>1 My soul, viewed from the
  latter standpoint, cannot indeed be known by means of specu-
  lative reason (and still less through empirical observation);
  and freedom as a propertyof a being towhich I attribute effects
  in the sensible world, is therefore also not knowable in any
  such fashion. For I should then have to know such a being as
  determined in its existence, and yet as not determined in time---
  which is impossible, since I cannot support my concept by any
  intuition. But though I cannot <1know,>1 I can yet <1think>1 freedom;
  that is to say, the representation of it is at least not self-con-
  tradictory, provided due account be taken of our critical dis-
  tinction between the two modes of representation, the sensible
  and the intellectual, and of the resulting limitation of the pure
  concepts of understanding and of the principles which flow
  from them.
  If we grant that morality necessarily presupposes freedom
  (in the strictest sense) as a property of our will; if, that is to
 say, we grant that it yields practical principles---original prin-
 ciples, proper to our reason---as <1a priori data>1 of reason, and
  B xxix. that this would be absolutely impossible save on the assump-
00023
tion of freedom; and if at the same time we grant that
speculative reason has proved that such freedom does not
allow of being thought, then the former supposition---that
made on behalf of morality---would have to give way to this
other contention, the opposite of which involves a palpable
contradiction. For since it is only on the assumption of free-
dom that the negation of morality contains any contradiction,
freedom, and with it morality, would have to yield to the
mechanism of nature.
  Morality does not, indeed, require that freedom should be
understood, but only that it should not contradict itself, and
so should at least allow of being thought, and that as thus
thought it should place no obstacle in the way of a free act
(viewed in another relation) likewise conforming to the mechan-
ism of nature. The doctrine of morality and the doctrine of
nature may each, therefore, make good its position. This,
however, is only possible in so far as criticism has previously
established our unavoidable ignorance of things in themselves,
and has limited all that we can theoretically <1know>1 to mere
appearances.
  This discussion as to the positive advantage of critical
principles of pure reason can be similarly developed in regard
to the concept of <1God>1 and of the <1simple nature>1 of our <1soul;>1 but
for the sake of brevity such further discussion may be omitted.
[From what has already been said, it is evident that] even the
<1assumption>1--as made on behalf of the necessary practical em- B xxx.
ployment of my reason---of <1God, freedom,>1 and <1immortality>1 is
not permissible unless at the same time speculative reason be
deprived of its pretensions to transcendent insight. For in order
to arrive at such insight it must make use of principles which,
in fact, extend only to objects of possible experience, and
which, if also applied to what cannot be an object of experience,
always really change this into an appearance, thus rendering
<1all practical extension of>1 pure reason impossible. I have therefore
found it necessary to deny <1knowledge,>1 in order to make room
<1forfaith.1>1 The dogmatism of metaphysics, that is, the precon-
ception that it is possible to make headway in metaphysics with-
out a previous criticism of pure reason, is the source of all that
unbelief, always very dogmatic, which wars against morality.
00024
  Though it may not, then, be very difficult to leave to pos-
terity the bequest of a systematic metaphysic, constructed in
conformity with a critique of pure reason, yet such a gift is
not to be valued lightly. For not only will reason be enabled
to follow the secure path of a science, instead of, as hitherto,
B xxxi. groping at random, without circumspection or self-criticism;
  our enquiring youth will also be in a position to spend
  their time more profitably than in the ordinary dogmatism
  by which they are so early and so greatly encouraged to
  indulge in easy speculation about things of which they
  understand nothing, and into which neither they nor any-
  one else will ever have any insight---encouraged, indeed, to
  invent new ideas and opinions, while neglecting the study
  of the better-established sciences. But, above all, there is
  the inestimable benefit, that all objections to morality and
  religion will be for ever silenced, and this in Socratic fashion,
  namely, by the clearest proof of the ignorance of the objectors.
  There has always existed in the world, and there will always
  continue to exist, some kind of metaphysics, and with it the
  dialectic that is natural to pure reason. It is therefore the first
  and most important task of philosophy to deprive meta-
  physics, once and for all, of its injurious influence, by attack-
  ing its errors at their very source.
  Notwithstanding this important change in the field of the
  sciences, and the <1loss>1 of its fancied possessions which specula-
B xxxii. tive reason must suffer, general human interests remain in the
  same privileged position as hitherto, and the advantages which
  the world has hitherto derived from the teachings of pure
  reason are in no way diminished. The loss affects only the
  <1monopoly of the schools,>1 in no respect the <1interests of humanity.>1
  I appeal to the most rigid dogmatist, whether the proof of the
  continued existence of our soul after death, derived from the
  simplicity of substance, or of the freedom of the will as opposed
  to a universal mechanism, arrived at through the subtle but
  ineffectual distinctions between subjective and objective prac-
  tical necessity, or of the existence of God as deduced from the
  concept of an <1ens realissimum>1 (of the contingency of the
  changeable and of the necessity of a prime mover), have ever,
  upon passing out from the schools, succeeded in reaching the
  public mind or in exercising the slightest influence on its con-
00025
victions? That has never been found to occur, and in view of
the unfitness of the common human understanding for such
subtle speculation, ought never to have been expected. Such
widely held convictions, so far as they rest on rational grounds,
are due to quite other considerations. The hope of <1a future life>1
has its source in that notable characteristic of our nature,
never to be capable of being satisfied by what is temporal (as
insufficient for the capacities of its whole destination); the
consciousness of <1freedom>1 rests exclusively on the clear ex- B xxxiii
hibition of duties, in opposition to all claims of the inclina-
tions; the belief in a wise and great <1Author of the world>1 is
generated solely by the glorious order, beauty, and providen-
tial care everywhere displayed in nature. When the schools
have been brought to recognise that they can lay no claim
to higher and fuller insight in a matter of universal human
concern than thatwhich is equally within the reach of the
great mass of men (ever to be held by us in the highest  -
esteem), and that, as Schools of philosophy, they should limit
themselves to the study of those universally comprehensible,
and, for moral purposes, sufficient grounds of proof, then
not only do these latter possessions remain undisturbed, but
through this very fact they acquire yet greater authority. The
change affects only the arrogant pretensions of the Schools,
which would fain be counted the sole authors and possessors
of such truths (as, indeed, they can justly claim to be in many
other branches of knowledge), reserving the key to themselves,
and communicating to the public their use only---<1quod mecum>1
<1nescit, solus vult scire videri.>1 At the same time due regard is
paid tothe more moderate claims of the speculative philosopher.  B xxxiv.
He still remains the sole authority in regard to a science which
benefits the public without their knowing it, namely, the critique  =
of reason. That critique can never become popular, and indeed
there is no need that it should. Forjust as fine-spun arguments
in favour of useful truths make no appeal to the general mind,
so neither do the subtle objections that can be raised against
them. On the other hand, both inevitably present themselves
to everyone who rises to the height of speculation; and it is
therefore the duty of the Schools, by means of a thorough
investigation of the rights of speculative reason, once for all
to prevent the scandal which, sooner or later, is sure to
00026
break out even among the masses, as the result of the
disputes in which metaphysicians (and, as such, finally also
the clergy) inevitably become involved to the consequent
perversion of their teaching. Criticism alone can sever the
root of <1materialism, fatalism, atheism, free-thinking, fanati->1
<1cism,>1 and <1superstition,>1 which can be injurious universally; as
well as of <1idealism>1 and <1scepticism,>1 which are dangerous chiefly
to the Schools, and hardly allow of being handed on to the
B xxxv. public. If governments think proper to interfere with the
  affairs of the learned, it would be more consistent with a wise
  regard for science as well as for mankind, to favour the free-
  dom of such criticism, by which alone the labours of reason
  can be established on a firm basis, than to support the
  ridiculous despotism of the Schools, which raise a loud cry of
  public danger over the destruction of cobwebs to which the
  public has never paid any attention, and the loss of which it
  can therefore never feel.
  This critique is not opposed to the <1dogmatic procedure>1 of
  reason in its pure knowledge, as science, for that must always
  be dogmatic, that is, yield strict proof from sure principles
  <1a priori.>1 It is opposed only to <1dogmatism,>1 that is, to the pre-
  sumption that it is possible to make progress with pure know-
  ledge, according to principles, from concepts alone (those that
  are philosophical), as reason has long been in the habit of
  doing; and that it is possible to do this without having first in-
  vestigated in what way and by what right reason has come into
  possession of these concepts. Dogmatism is thus the dogmatic
  procedure of pure reason, <1without previous criticism of its own>1
  <1powers.>1 In withstanding dogmatism we must not allow ourselves
  to give free rein to that loquacious shallowness, which assumes
B xxxvi. for itself the name of popularity, nor yet to scepticism, which
  makes short work with all metaphysics. On the contrary, such
  criticism is the necessary preparation for a thoroughly grounded
  metaphysics, which, as science, must necessarily be developed
  dogmatically, according to the strictest demands of system,
  in such manner as to satisfy not the general public but the re-
  quirements of the Schools. For that is a demand to which it
  stands pledged, and which it may not neglect, namely, that it
  carry out its work entirely <1a priori,>1 to the complete satisfaction
  of speculative reason. In the execution of the plan prescribed
00027
by the critique, that is, in the future system of metaphysics
we have therefore to follow the strict method of the celebrated
Wolff, the greatest of all the dogmatic philosophers. He was
the first to show by example (and by his example he awakened
that spirit of thoroughness which is not extinct in Germany)
how the secure progress of a science is to be attained only
through orderly establishment of principles, clear determina-
tion of concepts, insistence upon strictness of proof, and avoid-
ance of venturesome, non-consecutive steps in our inferences.
He was thus peculiarly well fitted to raise metaphysics to the
dignity of a science, if only it had occurred to him to prepare  -
the ground beforehand by a critique of the organ, that is, of
pure reason itself. The blame for his having failed to do so B xxxvii.
lies not so much with himself as with the dogmatic way
of thinaing prevalent in his day, and with which the philo-
sophers of his time, and of all previous times, have no right
to reproach one another. Those who reject both the method
of Wolff and the procedure of a critique of pure reason can
have no other aim than to shaae off the fetters of <1science>1
altogether, and thus to change work into play, certainty into
opinion, philosophy into philodoxy.
  Now, <1as regards this second edition,>1 I have, as is fitting,
endeavoured to profit by the opportunity, in order to remove,
wherever possible, difficulties and obscurity which, not per-
haps without my fault, may have given rise to the many
misunderstandings into which even acute thinaers have fallen
in passing judgment upon my book. In the propositions them-
selves and their proofs, and also in the form and completeness
of the [architectonic] plan, I have found nothing to alter. This
is due partly to the long examination to which I have sub-
jected them, before offering them1 to the public, partly to the
nature of the subject-matter with which we are dealing. For
pure speculative reason has a structure wherein everything
is an <1organ,>1 the whole being for the sake of every part, and
every part for the sake of all the others, so that even the B xxxviii.
smallest imperfection, be it a fault (error) or a deficiency, must
inevitably betray itself in use. This system will, as I hope,
maintain, throughout the future, this unchangeableness. It
is not self-conceit which justifies me in this confidence, but
00028
the evidence experimentally obtained through the parity of
the result, whether we proceed from the smallest elements
to the whole of pure reason or reverse-wise from the whole
(for this also is presented to reason through its final end
in the sphere of the practical) to each part. Any attempt to
change even the smallest part at once gives rise to contradic-
tions, not merely in the system, but in human reason in
general. As to the mode of <1exposition,>1 on the other hand,
much still remains to be done; and in this edition I have
sought to make improvements which should help in removing,
first, the misunderstanding in regard to the Aesthetic, especi-
ally concerning the concept of time; secondly, the obscurity
of the deduction of the concepts of understanding; thirdly, a
supposed want of sufficient evidence in the proofs of the prin-
ciples of pure understanding; and finally, the false interpreta-
tion placed upon the paralogisms charged against rational
psychology. Beyond this point, that is, beyond the end of the
B xxxix. first chapter of the Transcendental Dialectic, I have made no
  B xi. changes in the mode of exposition.a Time was too short to
  a The only addition, strictly so called, though one affecting the
  method of proof only, is the new refutation of psychological <1idealism>1
  (cf. below, p. 244), and a strict (also, as I believe, the only possible)
  proof of the objective reality of outer intuition. However harmless
  idealism may be considered in respect of the essential aims of meta-
  physics (though, in fact, it is not thus harmless), it still remains a
  scandal to philosophy and to human reason in general that the
  existence of things outside us (from which we derive the whole
  material of knowledge, even for our inner sense) must be accepted
  merely <1on faith,>1 and that if anyone thinks good to doubt their exist-
  ence, we are unable to counter his doubts by any satisfactory proof.
  Since there is some obscurity in the expressions used in the proof,
  from the third line to the sixth line, I beg to alter the passage as
  follows: <1"But thispermanent cannot be an intuition in me. For all>1
  <1grounds of determination of my existence which are to be met with>1
  <1in me are representations' and as representations themselves require a>1
  <1permanent distinct from them, in relation to which their change,>1
  <1and so my existence in the time wherein they change, may be deter->1
  <1mined.''>1 To this proof it will probably be objected, that I am im-
  mediately conscious only of that which is in me, that is, of my <1repre->1
  <1sentation>1 of outer things; and consequently that it must still remain
  uncertain whether outside me there is anything corresponding to it,
  B xi. or not. But through inner <1experience>1 I am conscious of <1my existence>1
00029
allow of further changes; and besides, I have not found among B xii.
competent and impartial critics any misapprehension in regard
to the remaining sections. Though I shall not venture to name
these critics with the praise that is their due, the attention B xlii.
which I have paid to their comments will easily be recognised
in the [new] passages [above mentioned]. These improvements
involve, however, a small loss, not to be prevented save by
making the book too voluminous, namely, that I have had
to omit or abridge certain passages, which, though not
indeed essential to the completeness of the whole, may yet
be missed by many readers as otherwise helpful. Only so
could I obtain space for what, as I hope, is now a more
intelligible exposition, which, though altering absolutely
nothing in the fundamentals of the propositions put for-
ward or even in their proofs, yet here and there departs
so far from the previous method of treatment, that mere in-
terpolations could not be made to suffice. This loss, which is
small and can be remedied by consulting the first edition, will,
I hope, be compensated by the greater clearness of the new
in time (consequently also of its determinability in time), and this is
more than to be conscious merely of my representation. It is identical
with the <1empirical consciousness of my existence,>1 which is determin-
able only through relation to something which, while bound up with
my existence, is outside me. This consciousness of my existence in
time is bound up in the way of identity 1 with the consciousness of a
relation to something outside me, and it is therefore experience not
invention, sense not imagination, which inseparably connects this
outside something with my inner sense. For outer sense is already
in itself a relation of intuition to something actual outside me, and
the reality of outer sense, in its distinction from imagination, rests
simply on that which is here found to take place, namely, its being
inseparably bound up with inner experience, as the condition of its
possibility. If, with the <1intellectual consciousness>1 of my existence, in
the representation "I am', which accompanies all my judgments and
acts of understanding, I could at the same time connect a determina-
tion of my existence through <1intellectual intuition,>1 the conscious-
ness of a relation to something outside me would not be required.
But though that intellectual consciousness does indeed come first
the inner intuition, in which my existence can alone be determined,
is sensible and is bound up with the condition of time. This deter-
mination, however, and therefore the inner experience itself, depends
00030
text. I have observed, with pleasure and thankfulness, in
various published works---alike in critical reviews and in in-
dependent treatises---that the spirit of thoroughness is not
extinct in Germany, but has only been temporarily over-
B xliii. shadowed by the prevalence of a pretentiously free manner of
  thinking; and that the thorny paths of the Critique have not
  discouraged courageous and clear heads from setting them-
  selves to master my book---a work which leads to a method-
  ical, and as such alone enduring, and therefore most necessary,
  science of pure reason. To these worthy men, who so happily
  combine thoroughness of insight with a talent for lucid ex-
  position---which  I  cannot  regard  myself  as  possessing---I
  leave the task of perfecting what, here and there, in its
  exposition, is still somewhat defective; for in this regard
  the danger is not that of being refuted, but of not being
  upon something permanent which is not in me, and consequently
B xli. can be only in something outside me, to which I must regard my-
  self as standing in relation. The reality of outer sense is thus neces-
  sarily bound up with inner sense, if experience in general is to be
  possible at all; that is, I am just as certainly conscious that there are
  things outside me, which are in relation to my sense, as I am con-
  scious that I myself exist as determined in time. In order to deter-
  mine to which given intuitions objects outside me actually corre-
  spond, and which therefore belong to outer <1sense>1 (to which, and not
  to the faculty of imagination, they are to be ascribed), we must in
  each single case appeal to the rules according to which experience
  in general, even inner experience, is distinguished from imagination
  ---the proposition that there is such a thing as outer experience being
  always presupposed. This further remark may be added. The repre-
  sentation of something <1permanent>1 in existence is not the same as
  <1permanent representation.>1 For though the representation of [some-
  thing permanent]  may be very transitory and variable like all our
  other representations, not excepting those of matter, it yet refers to
  something permanent. This latter must therefore be an external
  thing distinct from all my representations, and its existence must be
  included in the <1determination>1 of my own existence, constituting with
  it but a single experience such as would not take place even inwardly
  if it were not also at the same time, in part, outer. How this should
  be possible we are as little capable of explaining further as we are of
  accounting for our being able to think the abiding in time, the co-
  existence of which with the changing generates the concept of altera-
  tion.
00031
understood. From now on, though I cannot allow myself to
enter into controversy, I shall take careful note of all sugges-
tions, be they from friends or from opponents, for use, in
accordance with this propaedeutic, in the further elaboration
of the system. In the course of these labours I have advanced
somewhat far in years (this month I reach my sixty-fourth
year), and I must be careful with my time if I am to succeed
in my proposed scheme of providing a metaphysic of nature
and of morals which will confirm the truth of my Critique in
the two fields, of speculative and of practical reason. The
clearing up of the obscurities in the present work---they are B xliv.
hardly to be avoided in a new enterprise---and the defence
of it as a whole, I must therefore leave to those worthy men
who have made my teaching their own. A philosophical work
cannot be armed at all points, like a mathematical treatise,
and may therefore be open to objection in this or that respect,
while yet the structure of the system, taken in its unity, is not
in the least endangered. Few have the versatility of mind to
familiarise themselves with a new system; and owing to the
general distaste for all innovation, still fewer have the inclina-
tion to do so. If we take single passages, torn from their
contexts, and compare them with one another, apparent con-
tradictions are not likely to be lacking, especially in a work
that is written with any freedom of expression. In the eyes of
those who rely on the judgment of others, such contradic-
tions have the effect of placing the work in an unfavourable
light; but they are easily resolved by those who have mastered
the idea of the whole. If a theory has in itself stability, the
stresses and strains which may at first have seemed very
threatening to it serve only, in the course of time, to smooth
away its inequalities; and if men of impartiality, insight, and
true popularity devote themselves to its exposition, it may also,
in a short time, secure for itself the necessary elegance of
statement.
00032
  INTRODUCTION  B1
* I. THE DISTINCTION BETWEEN PURE AND EMPIRICAL
  KNOWLEDGE
THERE can be no doubt that all our knowledge begins with
experience. For how should our faculty of knowledge be
awakened into action did not objects affecting our senses
partly of themselves produce representations, partly arouse
the activity of our understanding to compare these repre-
sentations, and, by combining or separating them, work
up the raw material of the sensible impressions into that
knowledge of objects which is entitled experience? In the
order of time, therefore, we have no knowledge antecedent to
experience, and with experience all our knowledge begins.
  But though all our knowledge begins with experience,
it does not follow that it all arises out of experience. For it
  *  [In B the Introduction is divided into five sections, in place of
the two sections of the original Introduction. The new sections I.
and II. (with their headings) are substituted in B for the original
two opening paragraphs (with their heading), which are as follows:]
  I. THE IDEA OF TRANSCENDENTAL PHILOSOPHY  A 1
  Experience is, beyond all doubt, the first product to which
our understanding gives rise, in working up the raw material
of sensible impressions.1 Experience is therefore our  first
instruction, and in its progress is so inexhaustible in new
information, that in the interconnected lives of all future
generations there will never be any lack of new knowledge
that can be thus ingathered. Nevertheless, it is by no means
00033
may well be that even our empirical knowledge is made up of
what we receive through impressions and of what our own
faculty of knowledge (sensible impressions serving merely as
the occasion) supplies from itself. If our faculty of knowledge
makes any such addition, it may be that we are not in a posi-
B 2 tion to distinguish it from the raw material, until with long
  practice of attention we have become skilled in separating it.
  This, then, is a question which at least calls for closer
  examination, and does not allow of any off-hand answer:---
  whether there is any knowledge that is thus independent of
  experience and even of all impressions of the senses. Such
  knowledge is entitled <1a priori,>1 and distinguished from the
  the sole field to which our understanding is confined. Experi-
  ence tells us, indeed, what is, but not that it must necessarily
  be so, and not otherwise. It therefore gives us no true
  universality; and reason, which is so insistent upon this
A 2  kind of knowledge, is therefore more stimulated by it than
  satisfied. Such universal modes of anowledge,1 which at the
  same time possess the character of inner necessity, must in
  themselves, independently of experience, be clear and certain.
  They are therefore entitled knowledge <1a priori;>1 whereas, on
  the other hand, that which is borrowed solely from experience
  is, as we say, known only <1a posteriori,>1 or empirically.
  Now we find, what is especially noteworthy, that even into
  our experiences there enter modes of knowledge which must
  have their origin <1a priori,>1 and which perhaps serve only to
  give coherence to our sense-representations. For if we elimin-
  ate from our experiences everything which belongs to the
  senses, there still remain certain original concepts and certain
  judgments derived from them, which must have arisen com-
  pletely <1a priori,>1 independently of experience, inasmuch as
  they enable us to say, or at least lead us to believe that we can
  say, in regard to the objects which appear to the senses, more
  than mere experience would teach---giving to assertions true
  universality and strict necessity, such as mere empirical know-
  ledge cannot supply.
00034
<1empirical,>1 which has its sources <1a posteriori,>1 that is, in experi-
ence.
  The expression <1"a priori'>1 does not, however, indicate with
sufficient precision the full meaning of our question. For it
has been customary to say, even of much knowledge that is
derived from empirical sources, that we have it or are capable
of having it <1a priori,>1 meaning thereby that we do not derive
it immediately from experience, but from a universal rule---a
rule which is itself, however, borrowed by us from experience.
Thus we would say of a man who undermined the foundations
of his house, that he might have known <1a priori>1 that it would
fall, that is, that he need not have waited for the experience of
its actual falling. But still he could not know this completely
<1a priori.>1 For he had first to learn through experience that
bodies are heavy, and therefore fall when their supports are
withdrawn.
  In what follows, therefore, we shall understand by <1a priori>1
knowledge, not knowledge independent of this or that experi-
ence, but knowledge absolutely independent of all experience.  B 3
Opposed to it is empirical knowledge, which is knowledge
possible only <1a posteriori,>1 that is, through experience. <1A>1
<1priori>1 modes of knowledge are entitled pure when there is
no admixture of anything empirical. Thus, for instance, the
proposition, "every alteration has its cause', while an <1a priori>1
proposition, is not a pure proposition, because alteration is a
concept which can be derived only from experience.1
II.  WE ARE IN POSSESSION OF CERTAIN MODES OF A PRIORI
  KNOWLEDGE, AND EVEN THE COMMON UNDERSTAND-
  ING IS NEWER WITHOUT THEM
  What we here require is a criterion by which to distinguish
with certainty between pure and empirical knowledge. Ex-
perience teaches us that a thing is so and so, but not that it
cannot be otherwise. First, then, if we have a proposition
which in being thought is thought as <1necessary,>1 it is an <1a priori>1
judgment; and if, besides, it is not derived from any proposi-
tion except one which also has the validity of a necessary
judgment, it is an absolutely <1a priori>1 judgment. Secondly,
00035
may well be that even our empirical knowledge is made up of
what we receive through impressions and of what our own
faculty of knowledge (sensible impressions serving merely as
the occasion) supplies from itself. If our faculty of knowledge
makes any such addition, it may be that we are not in a posi-
B 2  tion to distinguish it from the raw material, until with long
  practice of attention we have become skilled in separating it.
  This, then, is a question which at least calls for closer
  examination, and does not allow of any off-hand answer:---
  whether there is any knowledge that is thus independent of
  experience and even of all impressions of the senses. Such
  knowledge is entitled <1a priori,>1 and distinguished from the
  the sole field to which our understanding is confined.  Experi-
  ence tells us, indeed, what is, but not that it must necessarily
  be so, and not otherwise. It therefore gives us no true
  universality; and reason, which is so insistent upon this
A 2 kind of knowledge, is therefore more stimulated by it than
  satisfied. Such universal modes of anowledge, which at the
  same time possess the character of inner necessity, must in
  themselves, independently of experience, be clear and certain.
  They are therefore entitled knowledge <1a priori;>1 whereas, on
  the other hand, that which is borrowed solely from experience
  is, as we say, known only <1a posteriori,>1 or empirically.
  Now we find, what is especially noteworthy, that even into
  our experiences there enter modes of knowledge which must
  have their origin <1a priori,>1 and which perhaps serve only to
  give coherence to our sense-representations. For if we elimin-
  ate from our experiences everything which belongs to the
  senses, there still remain certain original concepts and certain
  judgments derived from them, which must have arisen com-
  pletely <1a priori,>1 independently of experience, inasmuch as
  they enable us to say, or at least lead us to believe that we can
  say, in regard to the objects which appear to the senses, more
  than mere experience would teach---giving to assertions true
  universality and strict necessity, such as mere empirical know-
  ledge cannot supply.
00036
<1empirical,>1 which has its sources <1a posteriori,>1 that is, in experi-
ence.
  The expression <1"a priori'>1 does not, however, indicate with
sufficient precision the full meaning of our question. For it
has been customary to say, even of much knowledge that is
derived from empirical sources, that we have it or are capable
of having it <1a priori,>1 meaning thereby that we do not derive
it immediately from experience, but from a universal rule---a
rule which is itself, however, borrowed by us from experience.
Thus we would say of a man who undermined the foundations
of his house, that he might have known <1a priori>1 that it would
fall, that is, that he need not have waited for the experience of
its actual falling. But still he could not know this completely
<1a priori.>1 For he had first to learn through experience that
bodies are heavy, and therefore fall when their supports are
withdrawn.
  In what follows, therefore, we shall understand by <1a priori>1
knowledge, not knowledge independent of this or that experi-
ence, but knowledge absolutely independent of all experience.  B 3
Opposed to it is empirical knowledge, which is knowledge
possible only <1a posteriori,>1 that is, through experience. <1A>1
<1priori>1 modes of knowledge are entitled pure when there is
no admixture of anything empirical. Thus, for instance, the
proposition, "every alteration has its cause', while an <1a priori>1
proposition, is not a pure proposition, because alteration is a
concept which can be derived only from experience.1
II.  WE ARE IN POSSESSION OF CERTAIN MODES OF A PRIORI
  KNOWLEDGE, AND EVEN THE COMMON UNDERSTAND-
  ING IS NEWER WITHOUT THEM
  What we here require is a criterion by which to distinguish
with certainty between pure and empirical knowledge. Ex-
perience teaches us that a thing is so and so, but not that it
cannot be otherwise. First, then, if we have a proposition
which in being thought is thought as <1necessary,>1 it is an <1apriori>1
judgment; and if, besides, it is not derived from any proposi-
tion except one which also has the validity of a necessary
judgment, it is an absolutely <1a priori>1 judgment. Secondly,
00037
experience never confers on its judgments true or strict  but
only assumed and comparative <1universality,>1 through induc-
tion. We can properly only say, therefore, that so far as
B4 we have hitherto observed, there is no exception to this or
  that rule. If, then, a judgment is thought with strict univer-
  sality, that is, in such manner that no exception is allowed as
  possible, it is not derived from experience, but is valid abso-
  lutely <1a priori.>1 Empirical universality is only an arbitrary ex-
  tension of a validity holding in most cases to one which holds
  in all, for instance, in the proposition, "all bodies are heavy'.
  When, on the other hand, strict universality is essential to a
  a judgment, this indicates a special source of knowledge,
  namely, a faculty of <1a priori>1 knowledge. Necessity and strict
  universality are thus sure criteria of <1a priori>1 knowledge, and
  are inseparable from one another. But since in the employ-
  ment of these criteria the contingency of judgments is some-
  times more easily shown than their empirical limitation, or,
  as sometimes also happens, their unlimited universality can
  be more convincingly proved than their necessity, it is advis-
  able to use the two criteria separately, each by itself being
  infallible.
  Now it is easy to show that there actually are in human
  knowledge judgments which are necessary and in the strictest
  sense universal, and which are therefore pure <1a priori>1 judg-
  ments. If an example from the sciences be desired, we have
  only to look to any of the propositions of mathematics; if we
  seek an example from the understanding in its quite ordinary
B 5 employment, the proposition, "every alteration must have a
  cause', will serve our purpose. In the latter case, indeed, the
  very concept of a cause so manifestly contains the concept of
  a necessity of connection with an effect and of the strict uni-
  versality of the rule, that the concept would be altogether lostif
  we attempted to derive it, as Hume has done, from a repeated
  association of that which happens with that which precedes,
  and from a custom of connecting representations, a custom
  originating in this repeated association, and constituting
  therefore a merely subjective necessity. Even without appeal-
00038
ing to such examples, it is possible to show that pure <1a priori>1
principles are indispensable for the possibility of experience,
and so to prove their existence <1a priori.>1  For whence could
experience derive its certainty, if all the rules, according to
which it proceeds, were always themselves empirical, and
therefore contingent? Such rules could hardly be regarded as
first principles. At present, however, we may be content to
have established the fact that our faculty of knowledge does
have a pure employment, and to have shown what are the
criteria of such an employment.
  Such <1a priori>1 origin is manifest in certain concepts, no
less than in judgments. If we remove from our empirical
concept of a body, one by one, every feature in it which is
[merely] empirical, the colour, the hardness or softness, the
weight, even  the impenetrability, there still remains the
space which the body (now entirely vanished) occupied, and
this cannot be removed. Again, if we remove from our em-  B6
pirical concept of any object, corporeal or incorporeal, all
properties which experience has taught us, we yet cannot take
away that property through which the object is thought as
substance or as inhering in a substance (although this concept
of substance is more determinate than that of an object in
general). Owing, therefore, to the necessity with which this
concept of substance forces itself upon us, we have no option
save to admit that it has its seat in our faculty of <1a priori>1
knowledge.
III. PHILOSOPHY STANDS IN NEED OF A SCIENCE WHICH
  SHALL DETERMINE THE POSSIBILITY, THE PRINCIPLES,
  AND THE EXTENT OF ALL A PRIORI KNOWLEDGE
  But what is still more extraordinary than all the preceding
is this, that certain modes of knowledge leave the field of all
possible experiences and have the appearance of extending A3
the scope of our judgments beyond all limits of experience,
and this by means of concepts to which no corresponding
object can ever be given in experience.
  It is precisely by means of the latter modes of knowledge,
in a realm beyond the world of the senses, where experience
00039
can yield neither guidance nor correction, that our reason
carries on those enquiries which owing to their importance
B7  we consider to be far more excellent, and in their purpose
  far more lofty, than all that the understanding can learn in
  the field of appearances. Indeed we prefer to run every risk
  of error rather than desist from such urgent enquiries, on the
  ground of their dubious character, or from disdain and in-
  difference. These unavoidable problems set by pure reason
  itself are <1God, freedom,>1 and <1immortality.>1 The science which,
  with all its preparations, is in its final intention directed
  solely to their solution is metaphysics ; and its procedure
  is at first dogmatic, that is, it confidently sets itself to this
  task without any previous examination of the capacity or
  incapacity of reason for so great an undertaking.
  Now it does indeed seem natural that, as soon as we have
  left the ground of experience, we should, through careful en-
  quiries, assure ourselves as to the foundations of any building
  that we propose to erect, not making use of any knowledge
  that we possess without first determining whence it has come,
  and not trusting to principles without knowing their origin.
  It is natural, that is to say, that the question should first be
  considered, how the understanding can arrive at all this know-
  ledge <1a priori,>1 and what extent, validity, and worth it may
A 4  have. Nothing, indeed, could be more natural, if by the term
B 8  "natural'  we signify what fittingly and reasonably ought to
  happen. But if we mean by "natural' what ordinarily happens,
  then on the contrary nothing is more natural and more in-
  telligible than the fact that this enquiry has been so long neg-
  lected. For one part of this knowledge, the mathematical, has
  longbeen of established reliability, and so gives rise to a favour-
  able presumption as regards the other part, which may yet be of
  quite different nature. Besides, once we are outside the circle
  of experience, we can be sure of not being <1contradicted>1 by
  experience. The charm of extending our knowledge is so
  great that nothing short of encountering a direct contra-
  diction can suffice to arrest us in our course; and this can be
  avoided, if we are careful in our fabrications---which none the
  less will still remain fabrications. Mathematics gives us a shin-
00040
ing example of how far, independently of experience, we can
progress in <1a priori>1 knowledge. It does, indeed, occupy itself
with objects and with knowledge solely in so far as they allow
of being exhibited in intuition. But this circumstance is easily
overlooked, since the intuition, in being thought, can itself be
given <1a priori,>1 and is therefore hardly to be distinguished from
a bare and pure concept. Misled1 by such a proof of the power
of reason, the demand for the extension of knowledge recog-  A 5
nises no limits. The light dove, cleaving the air in her free
flight, and feeling its resistance, might imagine that its flight
would be still easier in empty space. It was thus that Plato  B9
left the world of the senses, as setting too narrow limits to
the understanding, and ventured out beyond it on the wings
of the ideas, in the empty space of the pure understanding.
He did not observe that with all his efforts he made no ad-
vance---meeting no resistance that might, as it were, serve
as a support upon which he could take a stand, to which
he could apply his powers, and so set his understanding
in motion. It is, indeed, the common fate of human reason
to complete its speculative structures as speedily as may
be, and only afterwards to enquire whether the foundations
are reliable. All sorts of excuses will then be appealed to, in
order to reassure us of their solidity, or rather indeed  to
enable us to dispense altogether with so late and so dangerous
an enquiry. But what keeps us, during the actual building,
free from all apprehension and suspicion, and flatters us with
a seeming thoroughness, is this other circumstance, namely,
that a great, perhaps the greatest, part of the business of our
reason consists in analysis of the concepts which we already
have of objects. This analysis supplies us with a consider-
able body of knowledge, which, while nothing but explanation
or elucidation of what has already been thought in our con-  A6
cepts, though in a confused manner, is yet prized as being,
at least as regards its form, new insight. But so far as the
matter or content is concerned, there has been no extension of
our previously possessed concepts, but only an analysis of them.
Since this procedure yields real knowledge <1a priori,>1 which  B 10
00041
progresses in an assured and useful fashion, reason is so far
misled as surreptitiously to introduce, without itself being
aware of so doing, assertions of an entirely different order, in
which it attaches to given concepts others completely foreign
to them, and moreover attaches them <1a priori.1>1 And yet it is
not anown how reason can be in position to do this. Such a
question is never so much as thought of. I shall therefore
at once proceed to deal with the difference between these two
kinds of knowledge.
   IV. THE DISTINCTION BETWEEN ANALYTIC AND
  SYNTHETIC JUDGMENTS
  In all judgments in which the relation of a subject to the
predicate is thought (I take into consideration affirmative
judgments only, the subsequent application to negative judg-
ments being easily made), this relation is possible in two
different ways. Either the predicate B belongs to the subject
A, as something which is (covertly) contained in this concept
A; or B lies outside the concept A, although it does indeed
stand in connection with it. In the one case I entitle the judg-
A 7 ment analytic, in the other synthetic. Analytic judgments
  (affirmative) are therefore those in which the connection of the
  predicate with the subject is thought through identity; those
  in which this connection is thought without identity should
B 11  be entitled synthetic. The former, as adding nothing through
  the predicate to the concept of the subject, but merely break-
  ing it up into those constituent concepts that have all along
  been thought in it, although confusedly, can also be entitled
  explicative. The latter, on the other hand, add to the concept
  of the subject a predicate which has not been in any wise thought
  in it, and which no analysis could possibly extract from it; and
  they may therefore be entitled ampliative. If I say, for instance,
  "All bodies are extended', this is an analytic judgment. For I
  do not require to go beyond the concept which I connect with
  "body' in order to find extension as bound up with it.  To
00042
meet with this predicate, I have merely to analyse the concept,
that is, to become conscious to myself  of the manifold which
I always think in that concept. The judgment is therefore
analytic. But when I say, "All bodies are heavy', the predi-
cate is something quite different from anything that I think in
the mere concept of body in general; and the addition of such
a predicate therefore yields a synthetic judgment.
  * Judgments of experience, as such, are one and all synthetic.
For it would be absurd to found an analytic judgment on ex-
perience. Since, in framing the judgment, I must not go out-
side my concept, there is no need to appeal to the testimony
of experience in its support. That a body is extended is a pro-
position that holds <1a priori>1 and is not empirical. For, before  B 12
appealing to experience, I have already in the concept of body
all the conditions required for myjudgment. I have only to ex-
tract from it, in accordance with the principle of contradiction,
the required predicate, and in so doing can at the same time
become conscious of the necessity of the judgment---and that
is what experience could never have taught me. On the other
hand, though I do not include in the concept of a body in
general the predicate "weight', none the less this concept indi-
cates an object of experience through one of its parts, and I
can add to that part other parts of this same experience, as in
this way belonging together with the concept. From the start
  *  [""Judgments of experience'' to end of paragraph substituted in
B in place of the following:]
  Thus it is evident: I. that through analytic judgments our
knowledge is not in any way extended, and that the concept  A8
which I already have is merely set forth and made intelligible
to me; 2. that in synthetic judgments I must have besides the
concept of the subject something else (X), upon which the un-
derstanding may rely, if it is to know that a predicate, not
contained in this concept, nevertheless belongs to it.
  In the case of empirical judgments, judgments of experi-
ence, there is no difficulty whatsoever in meeting this demand.
This X is the complete experience of the object which I think
through the concept A---a concept which forms only one part
of this experience. For though I do not include in the concept
00043
I can apprehend the concept of body analytically through the
characters of extension, impenetrability, figure, etc., all of
which are thought in the concept. Now, however, looking
back on the experience from which I have derived this con-
cept of body, and finding weight to be invariably connected
with the above characters, I attach it as a predicate to the
concept; and in doing so I attach it synthetically, and am
therefore extending my knowledge. The possibility of the syn-
  thesis of the predicate "weight' with the concept of "body' thus
  rests upon experience. While the one concept is not contained
  in the other, they yet belong to one another, though only con-
  tingently, as parts of a whole, namely, of an experience which
  is itself a synthetic combination of intuitions.
  A 9   But in <1a priori>1 synthetic judgments this help is entirely
  B 13  lacking. [I do not here have the advantage of looking around
  in the field of experience.] Upon what, then, am I to rely, when
  I seek to go beyond the concept A, and to know that another
  concept B is connected with it? Through what is the syn-
  thesis made possible?  Let us take the proposition,  "Every-
  thing which happens has its cause'. In the concept of "some-
  thing which happens', I do indeed think an existence which is
  preceded by a time, etc., and from this concept analytic judg-
  ments may be obtained. But the concept of a "cause' lies entirely
  outside the other concept, and signifies something different
  of a body in general the predicate "weight', the concept none
  the less indicates the complete experience through one of its
  parts; and to this part, as belonging to it, I can therefore add
  other parts of the same experience. By prior analysis I can ap-
  prehend the concept of body through the characters of exten-
  sion, impenetrability, figure, etc., all of which are thought in
  this concept. To extend my knowledge, I then look back to the
  experience from which I have derived this concept of body, and
  find that weight is always connected with the above characters.
  Experience is thus the X which lies outside the concept A,
  and on which rests the possibility of the synthesis of the
  predicate "weight' (B) with the concept (A).
00044
from "that which happens', and is not therefore1 in any way
contained in this latter representation. How come I then to
predicate of that which happens something quite different,
and to apprehend that the concept of cause, though not con-
tained in it, yet belongs, and indeed necessarily belongs  to it?
What is here the unknown =X which gives support to the
understanding when it believes that it can discover outside
the concept A a predicate B foreign to this concept, which
it yet at the same time considers to be connected with it?
It cannot be experience, because the suggested principle has
connected the second representation with the first, not only
with greater universality, but also with the character of
necessity, and therefore completely <1a priori>1 and on the basis
of mere concepts. Upon such synthetic, that is, ampliative
principles, all our <1a priori>1 speculative knowledge must ulti-  A 10
mately rest; analyticjudgments are very important, and indeed
necessary, but only for obtaining that clearness in the con-  B 14
cepts which is requisite for such a sure and wide synthesis as
will lead to a genuinely new addition to all previous know-
ledge.*
  * [In A there follows the passage, omitted in B:]
  A certain mystery lies here concealed;a and only upon
its solution can the advance into the limitless field of the
knowledge yielded by pure understanding be made sure and
trustworthy. What we must do is to discover, in all its proper
universality, the ground of the possibility of <1a priori>1 synthetic
judgments, to obtain insight into the conditions which make
  a If it had occurred to any of the ancients even to raise this
question, this by itself would, up to our own time, have been a power-
ful influence against all systems of pure reason, and would have
saved us so many of those vain attempts, which have been blindly
undertaken without knowledge of what it is that requires to be done.
00045
V.INAL
  I.  <1All mathematical judgments,  without  exception,  are>1
<1synthetic.>1 This fact, though incontestably certain and in
its consequences very important, has hitherto escaped the
notice of those who are engaged in the analysis of human
reason, and is, indeed, directly opposed to all their conjectures.
For as it was found that all mathematical inferences proceed
in accordance with the principle of contradiction (which the
nature of all apodeictic certainty requires), it was supposed that
the fundamental propositions of the science can themselves be
known to be true through that principle. This is an erroneous
view. For though a synthetic proposition can indeed be dis-
cerned in accordance with the principle of contradiction, this
can only be if another synthetic proposition is presupposed,
and if it can then be apprehended as following from this other
proposition; it can never be so discerned in and by itself.
  First of all, it has to be noted that mathematical proposi-
tions, strictly so called, are always judgments <1a priori,>1 not
empirical; because they carry with them necessity, which
B 15  cannot be derived from experience. If this be demurred to,
  I am willing to limit my statement to <1pure>1 mathematics, the
  very concept of which implies that it does not contain empirical,
  but only pure <1a priori>1 knowledge.
  We might, indeed, at first suppose that the proposition
  7+ 5= 12  is  a merely analytic proposition,  and follows by
  the principle of contradiction from the concept of a sum of
  7 and 5. But if we look more closely we find that the concept
  of the sum of 7 and 5 contains nothing save the union of the
  two numbers into one, and in this no thought is being taken
  each kind of such judgments possible, and to mark out all this
  knowledge, which forms a genus by itself, not in any cursory
  outline, but in a system, with completeness and in a manner
  sufficient for any use, according to its original sources, divi-
  sions, extent, and limits. So much, meantime, as regards
  what is peculiar in synthetic judgments.
00046
as to what that single number may be which combines both.
The concept of 12 is by no means already thought in merely
thinking this union of 7 and 5; and I may analyse my concept
of such a possible sum as long as I please, still I shall never
find the 12 in it. We have to go outside these concepts, and
call in the aid of the intuition which corresponds to one of
them, our five fingers, for instance, or, as Segner 1 does in his
<1Arithmetic,>1 five points, adding to the concept of 7, unit by
unit, the five given in intuition. For starting with the number
7, and for the concept of 5 calling in the aid of the fingers of
my hand as intuition, I now add one by one to the number 7
the units which I previously took together to form the number  B 16
5, and with the aid of that figure 2 [the hand] see the number 12
come into being. That 5 should be added to 7, I have indeed
already thought in the concept of a sum =7+ 5, but not that
this sum is equivalent to the number 12. Arithmetical pro-
positions are therefore always synthetic. This is still more
evident if we take larger numbers. For it is then obvious that,
however we might turn and twist our concepts, we could
never, by the mere analysis of them, and without the aid of
intuition, discover what [the number is that] is the sum.
  Just as little is any fundamental proposition of pure
geometry analytic. That the straight line between two points
is the shortest, is a synthetic proposition. For my concept of
<1straight>1 contains nothing of quantity, but only of quality. The
concept of the shortest is wholly an addition, and cannot be
derived, through any process of analysis, from the concept of
the straight line. Intuition, therefore, must here be called in;
only by its aid is the synthesis possible. What here causes  B 17
us commonly to believe that the predicate of such apodeictic
judgments is already contained in our concept, and that the
judgment is therefore analytic, is merely the ambiguous
character of the terms used. We are required to join in
thought a certain predicate to a given concept, and this neces-
00047
sity is inherent in the concepts themselves. But the question is
not what we <1ought>1 to join in thought to the given concept, but
what we <1actually>1 think in it, even if only obscurely; and it is
then manifest that, while the predicate is indeed attached
necessarily to the concept,1 it is so in virtue of an intuition
which must be added to the concept, not as thought in the
concept itself.
B 16  Some few fundamental propositions, presupposed by the
  geometrician, are, indeed, really analytic, and rest on the
  principle of contradiction. But, as identical propositions, they
B 17  serve only as links in the chain of method and not as prin-
  ciples; for  instance, <1a>1 =a; the whole is equal to itself; or
  (a + <1b)>a,>1 that is, the whole is greater than its part. And even
  these propositions, though they are valid according to pure
  concepts, are only admitted in mathematics because they can
  be exhibited in intuition.
  2. <1Natural science <1(Physics) contains>1 a priori <1synthetic>1
  <1judgments asprinciples.>1 I need cite only two such judgments:
  that in all changes of the material world the quantity of matter
  remains unchanged; and that in all communication of motion,
  action and reaction must always be equal. Both propositions,
  it is evident, are not only necessary, and therefore in their origin
B 18  <1a priori,>1 but also synthetic. For in the concept of matter I do
  not think its permanence, but only its presence in the space
  which it occupies. I go outside and beyond the concept of
  matter, joining to it <1a priori>1 in thought something which l
  have not thought <1in>1 it. The proposition is not, therefore, ana-
  lytic, but synthetic, and yet is thought <1a priori;>1 and so likewise
  are the other propositions of the pure part of natural science.
  3.  <1Metaphysics,>1 even if we look upon it as having hitherto
  failed in all its endeavours, is yet, owing to the nature of
  human reason, a quite indispensable science, and <1ought to>1
  <1contain>1 a priori <1synthetic knowledge.>1 For its business is not
  merely to analyse concepts which we make for ourselves <1a>1
  <1priori>1 of things, and thereby to clarify them analytically, but
  to extend our <1a priori>1 knowledge. And for this purpose we
  must employ principles which add to the given concept some-
  thing that was not contained in it, and through <1a priori>1 syn-
  thetic judgments venture out so far that experience is quite
00048
unable to follow us, as, for instance, in the proposition, that
the world must have a first beginning, and such like. Thus
metaphysics consists, at least <1in intention,>1 entirely of <1a priori>1
synthetic propositions.
  VI. THE GENERAL PROBLEM OF PURE REASON  B 19
  Much is already gained if we can bring a number of in-
vestigations under the formula of a single problem. For we
not only lighten our own task, by defining it accurately, but
make it easier for others, who would test our results, to judge
whether or not we have succeeded in what we set out to do.
Now the proper problem of pure reason is contained in the
question: How are <1a Priori>1 synthetic judgments possible?
  That metaphysics has hitherto remained in so vacillating
a state of uncertainty and contradiction, is entirely due to the
fact that this problem, and perhaps even the distinction be-
tween analytic and synthetic judgments, has never previously
been considered. Upon the solution of this problem, or upon
a sufficient proof that the possibility which it desires to have
explained does in fact not exist at all, depends the success or
failure of metaphysics. Among philosophers, David Hume
came nearest to envisaging this problem, but still was very far
from conceiving it with sufficient definiteness and universality.
He occupied himself exclusively with the synthetic proposi-
tion regarding the connection of an effect with its cause
<1(principium causalitatis),>1 and he believed himself to have  B 20
shown that such an <1a Priori>1 proposition is entirely impos-
sible. If we accept his conclusions, then all that we call
metaphysics is a mere delusion whereby we fancy ourselves to
have rational insight into what, in actual fact, is borrowed
solely from experience, and under the influence of custom has
taken the illusory semblance of necessity. If he had envisaged
our problem in all its universality, he would never have been
guilty of this statement, so destructive of all pure philosophy.
For he would then have recognised that, according to his own
argument, pure mathematics, as certainly containing <1a priori>1
synthetic propositions, would also not be possible; and from
such an assertion his good sense would have saved him.
  In the solution of the above problem, we are at the same
00049
time deciding as to the possibility of the employment of pure
reason in establishing and developing all those sciences which
contain a theoretical <1a priori>1 knowledge of objects, and have
therefore to answer the questions:
  How is pure mathematics possible?
  How is pure science of nature possible?
  Since these sciences actually exist, it is quite proper to ask
<1how>1 they are possible; for that they must be possible is proved
B 21  by the fact that they exist.a But the poor progress which has
  hitherto been made in metaphysics, and the fact that no
  system yet propounded can, in view of the essential purpose
  of metaphysics, be said really to exist, leaves everyone suffi-
  cient ground for doubting as to its possibility.
  Yet, in a certain sense, this <1kind of knowledge>1 is to be
  looked upon as given; that is to say, metaphysics actually
  exists, if not as a science, yet still as natural disposition <1(meta->1
  <1physica naturalis).>1 For human reason, without being moved
  merely by the idle desire for extent and variety of knowledge,
  proceeds impetuously, driven on by an inward need, to ques-
  tions such as cannot be answered by any empirical employ-
  ment of reason, or by principles thence derived. Thus in all
  men, as soon as their reason has become ripe for speculation,
  there has always existed and will always continue to exist
  some kind of metaphysics. And so we have the question:
B 22  <1How is metaphysics, as natural disposition, possible?>1
  that is, how from the nature of universal human reason do
  those questions arise which pure reason propounds to itself,
  and which it is impelled by its own need to answer as best it
  can?
  But since all attempts which have hitherto been made
  to answer these natural questions---for instance, whether the
  a Many may still have doubts as regards pure natural science.
  We have only, however, to consider the various propositions that are
  to be found at the beginning of (empirical) physics, properly so
  called, those, for instance, relating to the permanence in the quantity
  of matter, to inertia, to the equality of action and reaction, etc., in
  order to be soon convinced that they constitute a <1physica pura,>1 or
  <1rationalis,>1 which well deserves, as an independent science, to be
  separately dealt with in its whole extent, be that narrow or wide.
00050
world has a beginning or is from eternity---have always met
with unavoidable contradictions, we cannot rest satisfied with
the mere natural disposition to metaphysics, that is, with the
pure faculty of reason itself, from which, indeed, some sort of
metaphysics (be it what it may) always arises. It must be
possible for reason to attain to certainty whether we know or
do not know the objects of metaphysics, that is, to come to
a decision either in regard to the objects of its enquiries or in
regard to the capacity or incapacity of reason to pass any
judgment upon them, so that we may either with confidence
extend our pure reason or set to it sure and determinate
limits. This last question, which arises out of the previous
general problem, may, rightly stated, take the form:
  <1How is metaphysics, as science, possible?>1
  Thus the critique of reason, in the end, necessarily leads to
scientific knowledge; while its dogmatic employment, on the
other hand, lands us in dogmatic assertions to which other  B23
assertions, equally specious, can always be opposed---that is,
in <1scepticism.>1
  This science cannot be of any very formidable prolixity,
since it has to deal not with the objects of reason, the variety
of which is inexhaustible, but only with itself and the prob-
lems which arise entirely from within itself, and which are
imposed upon it by its own nature, not by the nature of things
which are distinct from it. When once reason has learnt com-
pletely to understand its own power in respect of objects which
can be presented to it in experience, it should easily be able to
determine, with completeness and certainty, the extent and
the limits of its attempted employment beyond the bounds of
all experience.
  We may, then, and indeed we must, regard as abortive all
attempts, hitherto made, to establish a metaphysic <1dogmatic->1
<1ally.>1 For the analytic part in any such attempted system,
namely, the mere analysis of the concepts that inhere in our
reason <1apriori,>1 is by no means the aim of, but only a prepara-
tion for, metaphysics proper, that is, the extension of its <1a>1
<1priori>1 synthetic knowledge. For such a purpose, the analysis
of concepts is useless, since it merely shows what is contained
in these concepts, not how we arrive at them <1apriori.>1 A solution
  C2
00051
of this latter problem is required, that we may be able to de-
B 24  termine the valid employment of such concepts in regard to
  the objects of all knowledge in general. Noris much self-denial
  needed to give up these claims, seeing that the undeniable,
  and in the dogmatic procedure of reason also unavoidable,
  contradictions of reason with itself have long since undermined
  the authority of every metaphysical system yet propounded.
  Greater firmness will be required if we are not to be deterred
  by inward difficulties and outward opposition from endeavour-
  ing, through application of a method entirely different from
  any hitherto employed, at last to bring to a prosperous and
  fruitful growth a science indispensable to human reason---a
  science whose every branch may be cut away but whose root
  cannot be destroyed.1
  VII. THE IDEA AND DIVISION OF A SPECIAL SCIENCE,
  UNDER THE TITLE ""CRITIQUE OF PURE REASON'' 2
  In view of all these considerations, we arrive at the idea of
  a special science which can be entitled the Critique of Pure
A 11  Reason.* For reason is the faculty which supplies the principles
  of <1a priori>1 knowledge. Pure reason is, therefore, that which
  contains the principles whereby we know anything absolutely
  <1apriori.>1 An organon of pure reason would be the sum-total of
B 25  those principles according to which all modes of pure <1a Priori>1
  knowledge can be acquired and actually brought into being.
  The exhaustive application of such an organon would give
  rise to a system of pure reason. But as this would be asking
  rather much, and as it is still doubtful whether, and in what
  cases, any extension of our knowledge be here possible, we
  * [In A follow two sentences, omitted in B]:
  Any knowledge is entitled pure, if it be not mixed with any-
  thing extraneous. But knowledge is more particularly to be
  called absolutely pure, if no experience or sensation whatso-
  ever be mingled with it, and if it be therefore possible com-
  pletely <1a priori.>1
00052
can regard a science of the mere examination of pure reason,
of its sources and limits, as the <1Propaedeutic>1 to the system of
pure reason. As such, it should be called a critique, not a
doctrine, of pure reason. Its utility, in speculation, ought
properly to be only negative, not to extend, but only to clarify
our reason, and keep it free from errors---which is already
a very great gain. I entitle <1transcendental>1 all knowledge
which is occupied not so much with objects as with the
mode of our knowledge of objects in so far as this mode of  A 12
knowledge is to be possible <1apriori.>1  A system of such con-
cepts might be entitled transcendental philosophy. But that
is still, at this stage, too large an undertaaing. For since
such a science must contain, with completeness, both kinds
of <1apriori>1 knowledge, the analytic no less than the synthetic,
it is, so far as our present purpose is concerned, much too
comprehensive. We have to carry the analysis so far only
as is indispensably necessary in order to comprehend, in
their whole extent, the principles of <1a priori>1 synthesis, with
which alone we are called upon to deal. It is upon this B 26
enquiry, which should be entitled not a doctrine, but only
a transcendental critique, that we are now engaged. Its pur-
pose is not to extend knowledge, but only to correct it, and to
supply a touchstone of the value, or lack of value, of all <1a priori>1
knowledge. Such a critique is therefore a preparation, so far
as may be possible, for an organon; and should this turn out
not to be possible, then at least for a canon, according to which,
in due course, the complete system of the philosophy of pure
reason---be it in extension or merely in limitation of its know-
ledge---may be carried into execution, analytically as well as
synthetically. That such a system is possible, and indeed that
it may not be of such great extent as to cut us off from the hope
of entirely completing it, may already be gathered from the
fact that what here constitutes our subject-matter is not the
nature of things, which is inexhaustible, but the understand-  A 13
ing which passes judgment upon the nature of things; and this
understanding, again, only in respect of its <1apriori>1 knowledge.
These <1a Priori>1 possessions of the understanding, since they
00053
have not to be sought for without, cannot remain hidden from
of our apprehending them in their completeness of judging
them. Still less may the reader here expect a critique of
books and systems of pure reason; we are concerned only with
the critique of the faculty of pure reason itself. Only in so far
as we build upon this foundation do we have a reliable touch-
stone for estimating the philosophical value of old and new
works in this field. Otherwise the unqualified historian or critic
is passing judgments upon the groundless assertions of others
by means of his own, which are equally groundless.
  Transcendental philosophy is only the idea of a science,
for which the critique of pure reason has to lay down the
complete architectonic plan. That is to say, it has to guaran-
tee, as following from principles, the completeness and cer-
tainty of the structure in all its parts. It is the system of
all principles of pure reason. And if this critique is not
itself to be entitled a transcendental philosophy, it is solely be-
cause, to be a complete system, it would also have to contain
an exhaustive analysis of the whole of <1a priori>1 human know-
ledge. Our critique must, indeed, supply a complete enumera-
tion of all the fundamental concepts that go to constitute such
pure knowledge. But it is not required to give an exhaustive
analysis of these concepts, nor a complete review of those
that can be derived from them. Such a demand would be
A 14 unreasonable, partly because this analysis would not be
B 28 appropriate to our main purpose, inasmuch as there is no
  such uncertainty in regard to analysis as we encounter in the
  case of synthesis, for the sake of which alone ourwhole critique
  is undertaken; and partly because it would be inconsistent
  with the unity of our plan to assume responsibility for the com-
  pleteness of such an analysis and derivation, when in view of our
  purposewe can be excused from doing so. The analysis of these
  <1apriori>1 concepts, which later we shall have to enumerate, and
  the derivation of other concepts from them, can easily, how-
00054
ever, be made complete when once they have been established
as exhausting the principles of synthesis, and if in this essen-
tial respect nothing be lacking in them.
  The critique of pure reason therefore will contain all that
is essential in transcendental philosophy. While it is the com-
plete idea of transcendental philosophy, it is not equivalent
to that latter science; for it carries the analysis only so far as
is requisite for the complete examination of knowledge which
is <1a priori>1 and synthetic.
  What has chiefly to be kept in view in the division of such
a science, is that no concepts be allowed to enter which con-
tain in themselves anything empirical, or, in other words,
that it consist in knowledge wholly <1a priori.>1 Accordingly,
although the highest principles and fundamental concepts of
morality are <1a priori>1 knowledge, they have no place in tran-  A 15
scendental philosophy, because,1 although they do not lay at  B 29
the foundation of their precepts the concepts of pleasure
and pain, of the desires and inclinations, etc., all of which
are of empirical origin, yet in the construction of a system
of pure morality these empirical concepts must necessarily
be brought into the concept of duty, as representing either a
hindrance, which we have to overcome, or an allurement, which
must not be made into a motive. Transcendental philosophy is
therefore a philosophy of pure and merely speculative reason.
All that is practical, so far as it contains motives, relates to
feelings, and these belong to the empirical sources of know-
ledge.
  If we are to make a systematic division of the science
which we are engaged in presenting, it must have first a
<1doctrine of the elements,>1 and secondly, a <1doctrine of the method>1
<1of pure reason.>1 Each of these chief divisions will have its
subdivisions, but the grounds of these we are not yet in a
position to explain. By way of introduction or anticipation
we need only say that there are two stems of human know-
ledge, namely, <1sensibility>1 and <1understanding,>1 which perhaps
spring from a common, but to us unknown, root.  Through the
former, objects are given to us; through the latter, they are
00055
thought.  Now in so far as sensibility may be found to contain
B 30 <1a priori>1 representations constituting the condition under
  which objects are given to us, it will belong to transcendental
A 16  philosophy. And since the conditions under which alone the
  objects of human knowledge are given must precede those
  under which they are thought, the transcendental doctrine
  of sensibility will constitute the first part of the science of the
  elements.
00056
TRANSCENDENTAL DOCTRINE OF  A19
  ELEMENTS
  FIRST PART
  TRANSCENDENTAL AESTHETIC
  S11
IN whatever manner and by whatever means a mode of know-
ledge may relate to objects, <1intuition>1 is that through which it
is in immediate relation to them, and to which all thought as a
means is directed. But intuition takes place only in so far as the
object is given to us. This again is only possible, to man at least,
in so far as the mind is affected in a certain way. The capacity
(receptivity) for receiving representations through the mode
in which we are affected by objects, is entitled <1sensibility.>1
Objects are <1given>1 to us by means of sensibility, and it alone
yields us <1intuitions;>1 they are <1thought>1 through the understand-
ing, and from the understanding arise <1concepts.>1 But all thought
must, directly or indirectly, by way of certain characters
relate ultimately to intuitions, and therefore, with us, to sensi-
bility, because in no other way can an object be given to us.
  The effect of an object upon the faculty of representation,  B 34
so far as we are affected by it, is <1sensation.>1 That intuition  A20
which is in relation to the object through sensation, is entitled
<1empirical.>1 The undetermined object of an empirical intuition
is entitled <1appearance.>1
  That in the appearance which corresponds to sensation
00057
I term its <1matter;>1 but that which so determines1 the manifold
of appearance that it allows of being ordered in certain re-
lations, I term the <1form>1 of appearance. That in which alone
the sensations can be posited and ordered in a certain form,
cannot itself be sensation; and therefore, while the matter of
all appearance is given to us <1a posteriori>1 only, its form must
lie ready for the sensations <1apriori>1 in the mind, and so must
allow of being considered apart from all sensation.
  I term all representations <1pure>1 (in the transcendental
sense) in which there is nothing that belongs to sensation. The
pure form of sensible intuitions in general, in which all the
manifold of intuition is intuited in certain relations, must be
found in the mind <1a priori.>1 This pure form of sensibility may
B 35  also itself be called <1pure intuition.>1 Thus, if I take away from
  the representation of a body that which the understanding
  thinas in regard to it, substance, force, divisibility, etc., and
A 21  likewise what belongs to sensation, impenetrability, hardness,
  colour, etc., something still remains over from this empirical
  intuition, namely, extension and figure.  These belong to pure
  intuition, which, even without any actual object of the senses
  or of sensation, exists in the mind <1a priori>1 as a mere form
  of sensibility.
  The science of all principles of <1a priori>1 sensibility I call
  <1transcendental aesthetic.a>1 There must be such a science, form-
  a The Germans are the only people who currently make use of
  the word "aesthetic' in order to signify what others call the critique
  of taste. This usage originated in the abortive attempt made by
  Baumgarten, that admirable analytical thinker, to bring the critical
  treatment of the beautiful under rational principles, and so to raise its
  rules to the rank of a science. But such endeavours are fruitless.
  The said rules or criteria are, as regards their chief sources, merely
  empirical, and consequently can never serve as determinate <1a>1
  <1priori->1 laws by which our judgment of taste must be directed. On
  the contrary, our judgment is the proper test of the correctness
B 36  of the rules. For this reason it is advisable either to give up
  using the name in this sense of critique of taste, and to reserve
  it for that doctrine of sensibility which is true science--thus ap-
00058
ing the first part of the transcendental doctrine of elements,  B 36
in distinction from that part which deals with the principles
of pure thought, and which is called transcendental logic.
  In the transcendental aesthetic we shall, therefore, first A 22
<1isolate>1 sensibility, by taking away from it everything which the
understanding thinks through its concepts, so that nothing
may be left save empirical intuition. Secondly, we shall also
separate off from it everything which belongs to sensation, so
that nothing may remain save pure intuition and the mere
form of appearances, which is all that sensibility can supply
<1a priori.>1 In the course of this investigation it will be found
that there are two pure forms of sensible intuition, serving as
principles of <1a priori>1 knowledge, namely, space and time. To
the consideration of these we shall now proceed.
  THE TRANSCENDENTAL AESTHETIC  B 37
  SECTION I
  SPACE
  S2
  <1Metaphysical Exposition of this Concept>1
  By means of outer sense, a property of our mind, we repre-
sent to ourselves objects as outside us, and all without excep-
tion in space. In space their shape, magnitude, and relation to
one another are determined or determinable. Inner sense,
by means of which the mind intuits itself or its inner state,
yields indeed no intuition of the soul itself as an object; but
there is nevertheless a determinate form [namely, time] in A 23
which alone the intuition of inner states is possible, and every-
thing which belongs to inner determinations is therefore
proximating to the language and sense of the ancients, in their
far-famed division of knowledge into                      else
to share the name with speculative philosophy, employing it partly
in the transcendental and partly in the psychological sense.
00059
represented in relations of time. Time cannot be outwardly
intuited, any more than space can be intuited as something
in us. What, then, are space and time? Are they real exist-
ences? Are they only determinations or relations of things, yet
such as would belong to things even if they were not intuited?
Or are space and time such that they belong only to the form
B 38  of intuition, and therefore to the subjective constitution of our
  mind, apart from which they could not be ascribed to anything
  whatsoever? In order to obtain light upon these questions,
  let us first give an exposition of the concept of space. By
  <1exposition (expositio)>1 I mean the clear, though not necessarily
  exhaustive, representation of that which belongs to a concept:
  the exposition is <1metaphysical>1 when it contains that which
  exhibits the concept <1as given a priori.>1
  1. Space is not an empirical concept which has been de-
  rived from outer experiences. For in order that certain sensa-
  tions be referred to something outside me (that is, to something
  in another region of space from that in which I find myself),
  and similarly in order that I may be able to represent them as
  outside and alongside  one another, and accordingly as not
  only different but as in different places, the representation of
  space must be presupposed. The representation of space can-
  not, therefore, be empirically obtained from the relations of
  outer appearance. On the contrary, this outer experience is
  itself possible at all only through that representation.
  A 24  2. Space is a necessary <1a priori>1 representation, which
  underlies all outer intuitions. We can never represent to our-
  selves the absence of space, though we can quite well think it
  B 39  as empty of objects. It must therefore be regarded as the con-
  dition of the possibility of appearances, and not as a determina-
  tion dependent upon them. It is an <1a priori>1 representation,
  which necessarily underlies outer appearances.*
  * [In A there is here inserted the following argument:]  iti
  and the possibility of their <1a priori>1 construction  is grounded
  in this <1a priori>1 necessity of space. Were this representation of
00060
3.1  Space is not discursive or, as we say, general concept
of relations of things in general, but a pure intuition. For, inthe  A 25
first place, we can represent to ourselves only one space; and
if we speak of diverse spaces, we mean thereby only parts of
one and the same unique space. Secondly, these parts cannot
precede the one all-embracing space, as being, as it were,
constituents out of which it can be composed; on the contrary,
they can be thought only as <1in>1 it. Space is essentially one;
the manifold in it, and therefore the general concept of spaces,
depends solely on [the introduction of] limitations. Hence it
follows that an <1a priori,>1 and not an empirical, intuition under-
lies all concepts of space. For kindred reasons, geometrical
propositions, that, for instance, in a triangle two sides
together are greater than the third, can never be derived
from the general concepts of line and triangle, but only
from intuition, and this indeed <1a priori,>1 with apodeictic
certainty.
  4.* Space is represented as an infinite <1given>1 magnitude.
Now every concept must be thought as a representation B 40
which is contained in an infinite number of different possible
space a concept acquired <1a posteriori,>1 and derived from outer
experience in general, the first principles of mathematical
determination would be nothing but perceptions. They would
therefore all share in the contingent character of perception;
rat there should be only one straight line between two points
would not be necessary, but only what experience always
teaches. What is derived from experience has only compara-
tive universality, namely, that which is obtained through in-
duction. We should therefore only be able to say that, so far
as hitherto observed, no space has been found which has more
than three dimensions.
  * [In A this paragraph runs:]
  5. Space is represented as an infinite given magnitude.
A general concept of space, which is found alike in a foot and
in an ell, cannot determine anything in regard to magnitude.
If there were no limitlessness in the progression of intuition,
no concept of relations could yield a principle of their infini-
tude.
00061
representations (as their common character), and which
therefore contains these <1under>1 itself; but no concept, as such,
can be thought as containing an infinite number of representa-
tions <1within>1 itself. It is in this latter way, however, that space
is thought; for all the parts of space coexist <1ad infinitum.>1
Consequently, the original representation of space is an <1a>1
<1Priori>1 intuition, not a concept.
  S31
  <1The Transcendental Exposition of the Concept of Space>1
  I understand by a transcendental exposition the explana-
tion of a concept, as a principle from which the possibility
of other <1a priori>1 synthetic knowledge can be understood.
For this purpose it is required (1) that such knowledge does
really flow from the given concept, (2) that this knowledge is
possible only on the assumption of a given mode of explaining
the concept.
  Geometry is a science which determines the properties
of space synthetically, and yet <1a priori.>1 What, then, must be
our representation of space, in order that such knowledge
of it may be possible? It must in its origin be intuition; for
  B41  from a mere concept no propositions can be obtained which
  go beyond the concept---as happens in geometry (Introduc-
  tion, V). Further, this intuition must be <1a priori,>1 that is,
  it must be found in us prior to any perception of an object,
  and must therefore be pure, not empirical, intuition. For
  geometrical propositions are one and all apodeictic, that is,
  are bound up with the consciousness of their necessity; for
  instance, that space has only three dimensions. Such pro-
  positions cannot be empirical or, in other words, judgments
  of experience, nor can they be derived from any such judg-
  ments (Introduction, II).
  How, then, can there exist in the mind an outer intui-
  tion which precedes the objects themselves, and in which
  the concept of these objects can be determined <1a priori?>1
  Manifestly, not otherwise than in so far as the intuition has
  its seat in the subject only, as the formal character of the
00062
subject, in virtue of which, in being affected by objects, it
obtains <1immediate representation,>1 that is, <1intuition,>1 of them;
and only in so far, therefore, as it is merely the form of outer
<1sense>1 in general.
  Our explanation is thus the only explanation that makes
intelligible the <1possibility>1 of geometry, as a body of <1a priori>1
synthetic knowledge. Any mode of explanation which fails to
do this, although it may otherwise seem to be somewhat
similar, can by this criterion1 be distinguished from it with
the greatest certainty.
  <1Conclusionsfrom the above Concepts>1  A 26
  (B 42
  (a) Space does not represent any property of things in
themselves, nor does it represent them in their relation to
one another. That is to say, space does not represent any
determination that attaches to the objects themselves, and
which remains even when abstraction has been made of all
the subjective conditions of intuition. For no determina-
tions, whether absolute or relative, can be intuited prior to
the existence of the things to which they belong, and none,
therefore, can be intuited <1a priori.>1
  (b) Space is nothing but the form of all appearances
of outer sense. It is the subjective condition of sensibility,
under which alone outer intuition is possible for us. Since,
then, the receptivity of the subject, its capacity to be affected
by objects, must necessarily precede all intuitions of these
objects, it can readily be understood how the form of all
appearances can be given prior to all actual perceptions, and
so exist in the mind <1a priori,>1 and how, as a pure intuition, in
which all objects must be determined, it can contain, prior
to all experience, principles which determine the relations
of these objects.
  It is, therefore, solely from the human standpoint that
we can speak of space, of extended things, etc. If we depart
from the subjective condition under which alone we can have
outer intuition, namely, liability to be affected by objects,
the representation of space stands for nothing whatsoever.  B 43
00063
A 27  This predicate can be ascribed to things only in so far as they
  appear to us, that is, only to objects of sensibility. The con-
  stant form of this receptivity, which we term sensibility, is a
  necessary condition of all the relations in which objects can
  be intuited as outside us; and if we abstract from these
  objects, it is a pure intuition, and bears the name of space.
  Since we cannot treat the special conditions of sensibility as
  conditions of the possibility of things, but only of their appear-
  ances, we can indeed say that space comprehends all things
  that appear to us as external, but not all things in themselves,
  by whatever subject they are intuited, or whether they be
  intuited or not. For we cannot judge in regard to the intui-
  tions of other thinking beings, whether they are bound by
  the same conditions as those which limit our intuition and
  which for us are universally valid. If we add to the concept of
  the subject of a judgment the limitation under which the judg-
  ment is made, the judgment is then unconditionally valid.
  The proposition, that all things are side by side in space, is
  valid under the limitation that these things are viewed as
  objects of our sensible intuition. If, now, I add the condition
  to the concept, and say that all things, as outer appearances,
  are side by side in space, the rule is valid universally and
B 44 without limitation. Our exposition therefore establishes the
A 28 <1reality,>1 that is, the objective validity, of space in respect of
  whatever can be presented to us outwardly as object, but also
  at the same time the <1ideality>1 of space in respect of things when
  they are considered in themselves through reason, that is,
  without regard to the constitution of our sensibility. We
  assert, then, the <1empirical reality>1 of space, as regards all
  possible outer experience; and yet at the same time we
  assert its <1transcendental ideality>1--in other words, that it
  is nothing at all, immediately we withdraw the above con-
  dition, namely, its limitation to possible experience, and so
  look upon it as something that underlies things in them-
  selves.
  With the sole exception of space there is no subjective
  representation, referring to something <1outer,>1 which could be
00064
entitled [at once] objective [and] <1a priori->1 For * there is no other
subjective representation from which we can derive <1a priori>1
synthetic propositions, as we can from intuition in space (S 3 1).
Strictly speaking, therefore, these other representations have no
ideality, although they agree with the representation of space in
this respect, that they belong merely to the subjective constitu-
tion of our manner of sensibility, for instance, of sight, hearing,
touch, as in the case of the sensations of colours, sounds, and
heat, which, since they are mere sensations and not intuitions,
do not of themselves yield knowledge of any object, least of
all any <1a priori>1 knowledge.
  The above remark is intended only to guard anyone from  B 45
supposing that the ideality of space as here asserted can be
illustrated by examples so altogether insufficient as colours,
taste, etc. For these cannot rightly be regarded as properties
of things, but only as changes in the subject, changes which
may, indeed, be different for different men. In such examples
as these, that which originally is itself only appearance, for
instance, a rose, is being treated by the empirical understand-
ing as a thing in itself, which, nevertheless, in respect of its  A 30
colour, can appear differently to every observer. The tran-
scendental concept of appearances in space, on the other hand,
is a critical reminder that nothing intuited in space is a thing
in itself, that space is not a form inhering in things in them-
  * [""For there is . . .'' to end of paragraph, substituted in B for
the following:]
  This subjective condition of all outer appearances cannot,
therefore, be compared to any other. The taste of a wine does
not belong to the objective determinations of the wine, not
even if by the wine as an object we mean the wine as appear-
ance, but to the special constitution of sense in the subject that
tastes it. Colours are not properties of the bodies to the in-
tuition of which they are attached, but only modifications of
the sense of sight, which is affected in a certain manner by
light. Space, on the other hand, as condition of outer objects,
necessarily belongs to their appearance or intuition. Taste and
colours are not necessary conditions under which alone objects  A 29
can be for us objects of the senses. They are connected with
00065
selves as their intrinsic property, that objects in themselves are
quite unknown to us, and that what we call outer objects are
nothing but mere representations of our sensibility, the form
of which is space. The true correlate of sensibility, the thing
in itself, is not known, and cannot be known, through these
representations; and in experience no question is ever asked
in regard to it.
B 46  TRANSCENDENTAL AESTHETIC
  SECTION II
  TIME
  S4
  <1Metaphysical exposition of the Concept of Time>1
  1. Time is not an empirical concept that  has  been
  derived from any experience. For neither coexistence nor
  succession would ever come within our perception, if the repre-
  sentation of time were not presupposed as underlying them
  <1a Priori.>1 Only on the presupposition of time can we represent
  to ourselves a number of things as existing at one and the
  same time (simultaneously) or at different times (successively).
A 31  2. Time is a necessary representation that underlies all
  the appearances only as effects accidentally added by the par-
  ticular constitution of the sense organs. Accordingly, they are
  not <1a priori>1 representations, but are grounded in sensation,
  and, indeed, in the case of taste, even upon feeling (pleasure
  and pain), as an effect of sensation. Further, no one can have
  <1a priori>1 a representation of a colour or of any taste; whereas,
  since space concerns only the pure form of intuition, and
  therefore involves no sensation whatsoever, and nothing em-
  pirical, all kinds and determinations of space can and must be
  represented <1a priori,>1 if concepts of figures and of their rela-
  tions are to arise. Through space alone is it possible that
  things should be outer objects to us.
00066
intuitions. We cannot, in respect of appearances in general,
remove time itself, though we can quite well think time as void
of appearances. Time is, therefore, given <1a priori.>1 In it alone
is actuality of appearances possible at all. Appearances may,
one and all, vanish; but time (as the universal condition of
their possibility) cannot itself be removed.
  3. The possibility of apodeictic principles concerning the  B 47
relations of time, or of axioms of time in general, is also
grounded upon this <1a priori>1 necessity. Time has only one
dimension; different times are not simultaneous but successive
(just as different spaces are not successive but simultaneous).
These principles cannot be derived from experience, for ex-
perience would give neither strict universality nor apodeictic
certainty. We should only be able to say that common experi-
ence teaches us that it is so; not that it must be so. These
principles are valid as rules under which alone experiences are
possible; and they instruct us in regard to the experiences,
not by means of them.
  4.  Time is not a discursive, or what is called a general con-
cept, but a pure form of sensible intuition. Different times are
but parts of one and the same time; and the representation A 32
which can be given only through a single object is intuition.
Moreover, the proposition that different times cannot be
simultaneous is not to be derived from a general concept.
The proposition is synthetic, and cannot have its origin in
concepts alone.  It is immediately contained in the intuition
and representation of time.
  5.  The infinitude of time signifies nothing more than that
every determinate magnitude of time is possible only through  B 48
limitations of one single time that underlies it. The original
representation, <1time,>1 must therefore be given as unlimited.
But when an object is so given that its parts, and every quan-
tity of it, can be determinately represented only through
limitation, the whole representation cannot be given through
concepts, since they contain only partial representations; on
the contrary, such concepts must themselves rest on immediate
intuition.
00067
  S51
  <1The Transcendental exposition of the Concept of Time>1
  I may here refer to No. 3,2 where, for the sake of brevity,
I have placed under the title of metaphysical exposition what
is properly transcendental. Here I may add that the concept
of alteration, and with it the concept of motion, as alteration
of place, is possible only through and in the representation
of time; and that if this representation were not an <1a priori>1
(inner) intuition, no concept, no matter what it might be, could
render comprehensible the possibility of an alteration, that is,
of a combination of contradictorily opposed predicates in one
and the same object, for instance, the being and the not-being
of one and the same thing in one and the same place. Only in
B 49  time can two contradictorily opposed predicates meet in one
  and the same object, namely, <1one after the other.>1 Thus our
  concept of time explains the possibility of that body of <1apriori>1
  synthetic knowledge which is exhibited in the general doc-
  trine of motion, and which is by no means unfruitful.
  S64
  <1Conclusions from these Concepts>1
  (a) Time is not something which exists of itself, or which
  inheres in things as an objective determination, and it does
  not, therefore, remain when abstraction is made of all sub-
  jective conditions of its intuition. Were it self-subsistent, it
  would be something which would be actual and yet not an
A 33  actual object. Were it a determination or order inhering in
  things themselves, it could not precede the objects as their
  condition, and be known and intuited <1a priori>1 by means of
  synthetic propositions. But this last is quite possible if time
  is nothing but the subjective condition under which alone
  intuition can take place in us. For that being so, this form
  of inner intuition can be represented prior to the objects, and
  therefore <1a priori.>1
00068
(b) Time is nothing but the form of inner sense, that is, of
the intuition of ourselves and of our inner state. It cannot be a
determination of outer appearances; it has to do neither with
shape nor position, but with the relation of representations in  B 50
our inner state. And just because this inner intuition yields no
shape, we endeavour to make up for this want by analogies.
We represent the time-sequence by a line progressing to in-
finity, in which the manifold constitutes a series of one dimen-
sion only; and we reason from the properties of this line to all
the properties of time, with this one exception, that while the
parts of the line are simultaneous the parts of time are always
successive. From this fact also, that all the relations of time
allow of being expressed in an outer intuition, it is evident that
the representation is itself an intuition.
  (c) Time is the formal <1apriori>1 condition of all appearances  A 34
whatsoever. Space, as the pure form of all <1outer>1 intuition, is so
far limited; it serves as the <1a priori>1 condition only of outer
appearances. But since all representations, whether they have
for their objects outer things or not, belong, in themselves, as
determinations of the mind, to our inner state; and since this
inner state stands under the formal condition of inner intui-
tion, and so belongs to time, time is an <1a priori>1 condition of
all appearance whatsoever. It is the immediate condition of
inner appearances (of our souls), and thereby the mediate con-
dition of outer appearances. Just as I can say <1a priori>1 that  B 51
all outer appearances are in space, and are determined <1a priori>1
in conformity with the relations of space, I can also say, from
the principle of inner sense, that all appearances whatsoever,
that is, all objects of the senses, are in time, and necessarily
stand in time-relations.
  If we abstract from <1our>1 mode of inwardly intuiting our-
selves---the mode of intuition in terms of which we likewise
take up into our faculty of representation all outer intuitions---
and so take objects as they may be in themselves, then time is
nothing. It has objective validity only in respect of appear-
ances, these being things which we take <1as objects of our>1
<1senses.>1 It is no longer objective, if we abstract from the sensi-  A 35
bility of our intuition, that is, from that mode of representation
which is peculiar to us, and speak of <1things in general.>1 Time is
00069
therefore a purely subjective condition of our (human) intuition
(which is always sensible, that is, so far as we are affected by
objects), and in itself, apart from the subject, is nothing.
Nevertheless, in respect of all appearances, and therefore of
all the things which can enter into our experience, it is neces-
sarily objective. We cannot say that all things are in time, be-
B 52  cause in this concept of things in general we are abstracting
  from every mode of their intuition and therefore from that
  condition under which alone objects can be represented as
  being in time. If, however, the condition be added to the
  concept, and we say that all things as appearances, that is, as
  objects of sensible intuition, are in time, then the proposition
  has legitimate objective validity and universality <1a priori.>1
  What we are maintaining is, therefore, the <1empirical>1
  <1reality>1 of time, that is, its objective validity in respect of all
  objects which allow of ever being given to our senses. And
  since our intuition is always sensible, no object can ever be
  given to us in experience which does not conform to the
  condition of time. On the other hand, we deny to time all
  claim to absolute reality; that is to say, we deny that it belongs
A 36  to things absolutely, as their condition or property, independ-
  ently of any reference to the form of our sensible intuition;
  properties that belong to things in themselves can never be
  given to us through the senses. This, then, is what constitutes
  the <1transcendental ideality>1 of time. What we mean by this
  phrase is that if we abstract from the subjective conditions of
  sensible intuition, time is nothing, and cannot be ascribed to
  the objects in themselves (apart from their relation to our in-
  tuition) in the way either of subsistence or of inherence. This
B 53  ideality, like that of space, must not, however, be illustrated
  by false analogies with sensation, because it is then assumed
  that the appearance, in which the sensible predicates inhere,
  itself has objective reality. In the case of time, such objective
  reality falls entirely away, save in so far as it is merely empir-
  ical, that is, save in so far as we regard the object itself merely
  as appearance. On this subject, the reader may refer to what
  has been said at the close of the preceding section
00070
S71
<1Elucidation>1
Against this theory, which admits the empirical reality of
time, but denies its absolute and transcendental reality, I have
heard men of intelligence so unanimously voicing an objection,
that I must suppose it to occur spontaneously to every reader
to whom this way of thinking is unfamiliar. The objection is
this. Alterations are real, this being proved by change of our  A 37
own representations---even if all outer appearances, together
with their alterations, be denied. Now alterations are possible
only in time, and time is therefore something real. There is no
difficulty in meeting this objection. I grant the whole argument.
Certainly time is something real, namely, the real form of inner
intuition. It has therefore subjective reality in respect of inner
experience; that is, I really have the representation of time and  B 54
of my determinations in it. Time is therefore to be regarded
as real, not indeed as object but as the mode of representation
of myself as object. If without this condition of sensibility I
could intuit myself, or be intuited by another being, the very
same determinations which we now represent to ourselves as
alterations would yield knowledge into which the representa-
tion of time, and therefore also of alteration, would in no
way enter. Thus empirical reality has to be allowed to time, as
the condition of all our experiences; on our theory, it is only
its absolute reality that has to be denied. It is nothing but the
form of our inner intuition.a If we take away from our inner
intuition the peculiar condition of our sensibility, the concept
of time likewise vanishes; it does not inhere in the objects, but  A 38
merely in the subject which intuits them.
  But the reason why this objection is so unanimously urged,
  a I can indeed say that my representations follow one another;
but this is only to say that we are conscious of them as in a time-
sequence, that is, in conformity with the form of inner sense. Time
is not, therefore, something in itself, nor is it an objective determina-
tion inherent in things.
00071
B 55  and that too by those who have nothing very convincing to say
  against the doctrine of the ideality of space, is this. They have
  no expectation of being able to prove apodeictically the abso-
  lute reality of space; for they are confronted by idealism,
  which teaches that the reality of outer objects does not allow
  of strict proof. On the other hand, the reality of the object of
  our inner sense (the reality of myself and my state) is, [they
  argue,] immediately evident through consciousness. The
  former may be merely an illusion; the latter is, on their view,
  undeniably something real. What they have failed, how-
  ever, to recognise is that both are in the same position; in
  neither case can their reality as representations be questioned,
  and in both cases they belong only to appearance, which
  always has two sides, the one by which the object is viewed in
  and by itself (without regard to the mode of intuiting it---its
  nature therefore remaining always problematic), the other
  by which the form of the intuition of this object is taken into
  account. This form is notto be looked for in the objectin it-
  self, but in the subject to which the object appears; neverthe-
  less, it belongs really and necessarily to the appearance of this
  object.
  Time and space are, therefore, two sources of knowledge,
  from which bodies of <1a priori>1 synthetic knowledge can be
A 39 derived. (Pure mathematics is a brilliant example of such
  knowledge, especially as regards space and its relations.)
B 56 Time and space, taken together, are the pure forms of all
  sensible intuition, and so are what make <1a priori>1 synthetic
  propositions possible. But these <1a priori>1 sources of know-
  ledge, being merely conditions of our sensibility, just by
  this very fact determine their own limits, namely, that they
  apply to objects only in so far as objects are viewed as appear-
  ances, and do not present things as they are in themselves.  This
  is the sole field of their validity; should we pass beyond it, no
  objective use can be made of them. This ideality1 of space
  and time leaves, however, the certainty of empirical know-
  ledge unaffected, for we are equally sure of it, whether these
  forms necessarily inhere in things in themselves or only
  in our intuition of them. Those, on the other hand, who
  Maintain the absolute reality of space and time, whether as
00072
subsistent or only as inherent, must come into conflict with
the principles of experience itself. For if they decide for the
former alternative (which is generally the view taken by
mathematical students of nature), they have to admit two
eternal and infinite self-subsistent non-entities (space and
time), which are there (yet without there being anything real)
only in order to contain in themselves all that is real. If they
adopt the latter alternative (as advocated by certain meta-  A40
physical students of nature), and regard space and time as
relations of appearances, alongside or in succession to one B 57
another---relations abstracted from experience, and in this
isolation confusedly represented---they are obliged to deny
that <1a priori>1 mathematical doctrines have any validity in
respect of real things (for instance, in space), or at least to
deny their apodeictic certainty. For such certainty is not to
be found in the <1a posteriori.>1 On this view, indeed, the <1a priori>1
concepts of space and time are merely creatures of the im-
agination, whose source must really be sought in experience,
the imagination framing out of the relations abstracted from
experience something that does indeed contain what is
general in these relations, but which cannot exist without
the restrictions which nature has attached to them. The
former thinkers obtain at least this advantage, that they keep
the field of appearances open for mathematical propositions.
On the other hand, they have greatly embarrassed them-
selves by those very conditions [space and time, eternal,
infinite, and self-subsistent], when with the understanding
they endeavour to go out beyond this field. The latter have
indeed an advantage, in that the representations of space
and time do not stand in their way if they seek to judge
of objects, not as appearances but merely in their relation
to the understanding. But since they are unable to appeal to
a true and objectively valid <1a priori>1 intuition, they can neither
account for the possibility of <1a priori>1 mathematical know-
ledge, nor bring the propositions of experience into necessary A 41
agreement with it. On our theory of the true character of B 58
these two original forms of sensibility, both difficulties are
removed.
  Lastly, transcendental aesthetic cannot contain more than
00073
these two elements, space and time. This is evident from the
fact that all other concepts belonging to sensibility, even
that of motion, in which both elements are united, presuppose
something empirical. Motion presupposes the perception of
something movable. But in space, considered in itself, there
is nothing movable; consequently the movable must be
something that is found <1in space only through experience,>1
and must therefore be an empirical datum. For the same
reason, transcendental aesthetic cannot count the concept
of alteration among its <1a priori>1 data. Time itself does not
alter, but only something which is in time. The concept of
time thus presupposes the perception of something existing
and of the succession of its determinations; that is to say, it
presupposes experience.
B59  581
  <1General Observations on Transcendental Aesthetic>1
  I.1 To avoid all misapprehension, it is necessary to ex-
  plain, as clearly as possible, what our view is regarding the
A 42  fundamental constitution of sensible knowledge in general.
  What we have meant to say is that all our intuition is
  nothing but the representation of appearance; that the things
  which we intuit are not in themselves what we intuit them
  as being, nor their relations so constituted in themselves as
  they appear to us, and that if the subject, or even only the
  subjective constitution of the senses in general, be removed,
  the whole constitution and all the relations of objects in
  space and time, nay space and time themselves, would vanish.
  As appearances, they cannot exist in themselves, but only
  in us. What objects may be in themselves, and apart from
  all this receptivity of our sensibility, remains completely
  unknown to us. We know nothing but our mode of perceiving
  them---a mode which is peculiar to us, and not necessarily
  shared in by every being, though, certainly, by every human
  being. With this alone have we any concern. Space and time
B 60  are its pure forms, and sensation in general its matter. The
  former alone can we know <1a priori,>1 that is, prior to all actual
  perception; and such knowledge is therefore called pure
00074
intuition. The latter is that in our knowledge which leads to
its being called <1a posteriori>1 knowledge, that is, empirical
intuition. The former inhere in our sensibility with absolute
necessity, no matter of what kind our sensations may be; the
latter can exist in varying modes. Even if we could bring our  A 43
intuition to the highest degree of clearness, we should not
thereby come any nearer to the constitution of objects in
themselves. We should still know only our mode of intuition,
that is, our sensibility. We should, indeed, know it completely,
but always only under the conditions of space and time---
conditions which are originally inherent in the subject.
What the objects may be in themselves would never be-
come known to us even through the most enlightened
knowledge of that which is alone given us, namely, their
appearance.
  The concept of sensibility and of appearance would be
falsified, and our whole teaching in regard to them would be
rendered empty and useless, if we were to accept the view that
our entire sensibility is nothing but a confused representation
of things, containing only what belongs to them in themselves,
but doing so under an aggregation of characters and partial
representations that we do not consciously distinguish. For
the difference between a confused and a clear representation  B61
is merely logical, and does not concern the content. No doubt
the concept of "right', in its common-sense usage, contains all
that the subtlest speculation can develop out of it, though in
its ordinary and practical use we are not conscious of the
manifold representations comprised in this thought  But we
cannot say that the common concept is therefore sensible, con-
taining a mere appearance. For "right' can never be an appear-  A 44
ance; it is a concept in the understanding, and represents a
property (the moral property) of actions, which belongs to
them in themselves. The representation of a body in intuition,
on the other hand, contains nothing that can belong to an
object in itself, but merely the appearance of something, and
the mode in which we are affected by that something; and this
receptivity of our faculty of knowledge is termed sensibility.
Even if that appearance could become completely transparent
00075
to us, such knowledge would remain <1toto coelo>1 different from
knowledge of the object in itself.
  The philosophy of Leibniz and Wolff, in thus treating the
difference between the sensible and the intelligible as merely
logical, has given a completely wrong direction to all in-
vestigations into the nature and origin of our knowledge. This
difference is quite evidently transcendental. It does not merely
B 62  concern their [logical] form, as being either clear or confused.
  It concerns their origin and content. It is not that by our
  sensibility we cannot know the nature of things in themselves
  in any save a confused fashion; we do not apprehend them in
  any fashion whatsoever. If our subjective constitution be re-
  moved, the represented object, with the qualities which sen-
  sible intuition bestows upon it, is nowhere to be found, and
  cannot possibly be found. For it is this subjective constitution
  which determines its form as appearance.
A 45  We commonly distinguish in appearances that which is
  essentially inherent in their intuition and holds for sense in all
  human beings, from that which belongs to their intuition
  accidentally only, and is valid not in relation to sensibility in
  general but only in relation to a particular standpoint or to a
  peculiarity of structure in this or that sense. The former kind
  of knowledge is then declared to represent the object in itself,
  the latter its appearance only. But this distinction is merely
  empirical. If, as generally happens, we stop short at this point,
  and do not proceed, as we ought, to treat the empirical in-
  tuition as itself mere appearance, in which nothing that belongs
  to a thing in itself can be found, our transcendental distinction
  is lost. We then believe that we know things in themselves,
  and this in spite of the fact that in the world of sense, how-
B63  ever deeply we enquire into its objects, we have to do with
  nothing but appearances. The rainbow in a sunny shower may
  be called a mere appearance, and the rain the thing in itself.
  This is correct, if the latter concept be taken in a merely
  physical sense. Rain will then be viewed only as that which,
  in all experience and in all its various positions relative to the
  senses, is determined thus, and not otherwise, in our intuition.
  But if we take this empirical object in its general character,
A46  and ask, without considering whether or not it is the same
  for all human sense, whether it represents an object in
00076
itself (and by that we cannot mean the drops of rain, for these
are already, as appearances, empirical objects), the question
as to the relation of the representation to the object at once
becomes transcendental. We then realise that not only are the
drops of rain mere appearances, but that even their round
shape, nay even the space in which they fall, are nothing in
themselves, but merely modifications or fundamental forms of
our sensible intuition, and that the transcendental object
remains unknown to us.
  The second important concern of our Transcendental Aes-
thetic is that it should not obtain favour merely as a plausible
hypothesis, but should have that certainty and freedom from
doubt which is required of any theory that is to serve as an
organon. To make this certainty completely convincing, we
shall select a case by which the validity of the position adopted
will be rendered obvious, and which will serve to set what has  B 64
been said in S 3 in a clearer light.
  Let us suppose that space and time are in themselves
objective, and are conditions of the possibility of things in
themselves. In the first place, it is evident that in regard to
both there is a large number of <1a priori>1 apodeictic and syn-
thetic propositions. This is especially true of space, to which
our chief attention will therefore be directed in this enquiry.
Since the propositions of geometry are synthetic <1a priori,>1 and
are known with apodeictic certainty, I raise the question,  A 47
whence do you obtain such propositions, and upon what does
the understanding rely in its endeavour to achieve such abso-
lutely necessary and universally valid truths? There is no
other way than through concepts or through intuitions; and
these are given either <1a priori>1 or <1a posteriori.>1 In their latter
form, namely, as <1empirical>1 concepts, and also as that upon
which these are grounded, the <1empirical>1 intuition, neither the
concepts nor the intuitions can yield any synthetic proposition
except such as is itself also merely empirical (that is, a pro-
position of experience), and which for that very reason can
never possess the necessity and absolute universality which are
characteristic of all geometrical propositions. As regards the
first and sole means of arriving at such knowledge, namely,
in <1a priori>1 fashion through mere concepts or through in-
tuitions, it is evident that from mere concepts only analytic
00077
B 65  knowledge, not synthetic knowledge, is to be obtained. Take,
  for instance, the proposition, ""Two straight lines cannot en-
  close a space, and with them alone no figure is possible'',
  and try to derive it from the concept of straight lines and of
  the number two. Or take the proposition, "" Given three straight
  lines, a figure is possible'', and try, in like manner, to derive
  it from the concepts involved. All your labour is vain; and you
  find that you are constrained to have recourse to intuition, as is
  always done in geometry. You therefore give yourself an object
A48  in intuition. But of what kind is this intuition? Is it a pure <1a>1
  <1priori>1 intuition or an empirical intuition? Were it the latter,
  no universally valid proposition could ever arise out of it---
  still less an apodeictic proposition---for experience can never
  yield such. You must therefore give yourself an object <1a priori>1
  in intuition, and ground upon this your synthetic proposition.
  If there did not exist in you a power of <1apriori>1 intuition; and
  if that subjective condition were not also at the same time, as
  regards its form, the universal <1a priori>1 condition under which
  alone the object of this outer intuition is itself possible; if the
  object (the triangle) were something in itself, apart from any
  relation to you, the subject, how could you say that what
  necessarily exist in you as subjective conditions for the con-
  struction of a triangle, must of necessity belong to the triangle
  itself? You could not then add anything new (the figure) to
B 66  your concepts (of three lines) as something which must neces-
  sarily be met with in the object, since this object is [on that
  view] given antecedently to your knowledge, and not by means
  of it. If, therefore, space (and the same is true of time) were
  not merely a form of your intuition, containing conditions <1a>1
  <1priori,>1 under which alone things can be outer objects to you,
  and without which subjective conditions outer objects are in
  themselves nothing, you could not in regard to outer objects
  determine anything whatsoever in an <1a priori>1 and synthetic
  manner. It is, therefore, not merely possible or probable, but
  A 49 indubitably certain, that space and time, as the necessary
  conditions of all outer and inner experience, are merely sub-
  jective conditions of all our intuition, and that in relation to
  these conditions all objects are therefore mere appearances,
  and not given us as things in themselves which exist in this
00078
manner. For this reason also, while much can be said <1a priori>1
as regards the form of appearances, nothing whatsoever can
be asserted of the thing in itself, which may underlie these
appearances.
  II. In confirmation of this theory of the ideality of both
outer and inner sense, and therefore of all objects of the senses,
as mere appearances, it is especially relevant to observe that
everything in our knowledge which belongs to intuition---
feeling of pleasure and pain, and the will, not being know-
ledge, are excluded---contains nothing but mere relations;
namely, of locations in an intuition (extension), of change  B 67
of location (motion), and of laws according to which this
change is determined (moving forces).  What it is that is
present in this or that location, or what it is that is operative
in the things themselves apart from change of location, is not
given through intuition. Now a thing in itself cannot be
known through mere relations; and we may therefore conclude
that since outer sense gives us nothing but mere relations, this
sense can contain in its representation only the relation of an
object to the subject, and not the inner properties of the object
in itself. This also holds true of inner sense, notonly because
the representations of the <1outer senses>1 constitute the proper
material with which we occupy our mind, but because the
time in which we set these representations, which is itself ante-
cedent to the consciousness of them in experience, and which
underlies them as the formal condition of the mode in which
we posit them in the mind, itself contains [only] relations of
succession, coexistence, and of that which is coexistent with
succession, the enduring. Now that which, as representation,
can be antecedent to any and every act of thinking any-
thing, is intuition; and if it contains nothing but relations, it
is the form of intuition. Since this form does not represent
anything save in so far as something is posited in the mind, it
can be nothing but the mode in which the mind is affected
through its own activity (namely, through this positing of its  B 68
representation), and so is affected by itself; in other words, it is
added in B.]
00079
nothing but an inner sense in respect of the form of that sense.
Everything that is represented through a sense is so far always
appearance, and consequently we must either refuse to admit
that there is an inner sense, or we must recognise that the sub-
ject, which is the object of the sense, can be represented through
it only as appearance, not as that subject would judge of itself
if its intuition were self-activity only, that is, were intellectual.
The whole difficulty is as to how a subject can inwardly intuit
itself; and this is a difficulty common to every theory. The con-
sciousness of self (apperception) is the simple representation
of the "I', and if all that is manifold in the subject were given
by the <1activity of the self,>1 the inner intuition would be intel-
lectual.  In man this consciousness demands inner perception
of the manifold which is antecedently given in the subject,
and the mode in which this manifold is given in the mind
must, as non-spontaneous, be entitled sensibility. If the
faculty of coming to consciousness of oneself is to seek out (to
apprehend) that which lies in the mind, it must affect the mind,
and only in this way can it give rise to an intuition of itself.
But the form of this intuition, which exists antecedently in the
B 69  mind, determines, in the representation of time, the mode in
  which the manifold is together in the mind, since it then in-
  tuits itself not as it would represent itself if immediately self-
  active, but as it is affected by itself, and therefore as it appears
  to itself, not as it is.
  III. When I say that the intuition of outer objects and the
  self-intuition of the mind alike represent the objects and the
  mind, in space and in time, as they affect our senses, that is, as
  they appear, I do not mean to say that these objects are a mere
  <1illusion.>1 For in an appearance the objects, nay even the pro-
  perties that we ascribe to them, are always regarded as some-
  thing actually given. Since, however, in the relation of the
  given object to the subject, such properties depend upon the
  mode of intuition of the subject, this object as <1appearance>1 is to
  be distinguished from itself as object <1in itself.>1 Thus when I
  maintain that the quality of space and of time, in conformity
  with which, as a condition of their existence, I  posit both bodies
  and my own soul, lies in my mode of intuition and not in those
  objects in themselves, I am not saying that bodies merely <1seem>1
00080
to be outside me, or that my soul only <1seemsto>1 be given in my self-
consciousness. It would be my own fault, if out of that which
I ought to reckon as appearance, I made mere illusion.a That
does not follow as a consequence of our principle of the ideality  B 70
of all our sensible intuitions---quite the contrary. It is only if we
ascribe <1objective reality>1 to these forms of representation, that
it becomes impossible for us to prevent everything being
thereby transformed into Mere <1illusion.>1 For if we regard space
and time as properties which, if they are to be possible at all,1
must be found in things in themselves, and if we reflect on the
absurdities in which we are then involved, in that two infinite
things, which are not substances, nor anything actually in-
hering in substances, must yet have existence, nay, must
be the necessary condition of the existence of all things, and  B <171>1
moreover must continue to exist, even although all existing
things be removed,---we cannot blame the good Berkeley
for degrading bodies to mere illusion. Nay, even our own
existence, in being made thus dependent upon the self-sub-
sistent reality of a non-entity, such as time, would necessarily
be changed with it into sheer illusion---an absurdity of which
no one has yet been guilty.
  IV. In natural theology, in thinking an object [God],
who not only can never be an object of intuition to us but
  a  The predicates of the appearance can be ascribed to the object
itself, in relation to our sense, for instance, the red colour or the  B 70
scent to the rose. [But what is illusory can never be ascribed as
predicate to an object (for the sufficient reason that we then attribute
to the object, taken by itself, what belongs to it only in relation to
the senses, or in general to the subject), for instance, the two handles
which were formerly ascribed to Satum].a That which, while in-
separable from the representation of the object, is not to be met
with in the object in itself, but always in its relation to the subject,
is appearance. Accordingly the predicates of space and ti1ne are
rightly ascribed to the objects of the senses, as such; and in this there
is no illusion. On the other hand, if I describe redness to the rose <1in>1
<1itself>1 [handles to Satum], or extension to all outer objects <1in them->1
<1selves,>1 without paying regard to the determinate relation of these
objects to the subject, and without limiting my judgment to that
relation, illusion then first arises.
00081
  cannot be an object of sensible intuition even to himself, we
  are careful to remove the conditions of time and space from
  his intuition---for all his knowledge must be intuition, and not
  <1thought,>1 which always involves limitations. But with what
  right can we do this if we have previously made time and space
  forms of things in themselves, and such as would remain, as
  <1a priori>1 conditions of the existence of things, even though the
  things themselves were removed? As conditions of all existence
  in general, they must also be conditions of the existence of
  God. If we do not thus treat them as objective forms of all
  B 72  things, the only alternative is to view them as subjective forms
  of our inner and outer intuition, which is termed sensible, for
  the very reason that it is <1not original,>1 that is, is not such as can
  itself give us the existence of its object---a mode of intuition
  which, so far as we can judge, can belong only to the prim-
  ordial being. Our mode of intuition is dependent upon the
  existence of the object, and is therefore possible only if the
  subject's faculty of representation is affected by that object.
  This mode of intuiting in space and time need not be
  limited to human sensibility. It may be that all finite, thinking
  we are not in a position to judge whether this is actually so. But
  however universal this mode of sensibility may be, it does
  not therefore cease to be sensibility. It is derivative <1(intuitus>1
  <1derivativus),>1 not original <1(intuitus originarius),>1 and therefore
  not an intellectual intuition. For the reason stated above, such
  intellectual intuition seems to belong solely to the primordial
  being, and can never be ascribed to a dependent being,
  dependent in its existence as well as in its intuition, and
  which through that intuition determines its existence solely
  in relation to given objects. This latter remark, however,
  must be taken only as an illustration of our aesthetic theory,
  not as forming part of the proof.
  B 73  <1Conclusion of the Transcendental Aesthetic>1
  Here, then, in pure <1a priori>1 intuitions, space and time,
  we have one of the factors required for solution of the general
00082
problem of transcendental philosophy:  <1how are synthetic>1
<1a priori judgments possible?>1 When in <1a priori>1 judgment
we seek to go out beyond the given concept, we come in the
<1a priori>1 intuitions upon that which cannot be discovered in
the concept but which is certainly found <1a priori>1 in the in-
tuition corresponding to the concept, and can be connected
with it synthetically. Such judgments, however, thus based
on intuition, can never extend beyond objects of the senses;
they are valid only for objects of possible experience.
00083
  ELEMENTS
  SECOND PART
  TRANSCENDENTAL LOGIC
  INTRODUCTION
  IDEA OF A TRANSCENDENTAL LOGIC
  LOGIC IN GENERAL
  OUR knowledge springs from two fundamental sources of the
  mind; the first is the capacity of receiving representations
  (receptivity for impressions), the second is the power of know-
  ing an object through these representations (spontaneity [in
  the production] of concepts). Through the first an object <1is given>1
  to us, through the second the object is <1thought>1 in relation to
  that [given] representation (which is a mere determination of
  the mind). Intuition and concepts constitute, therefore, the ele-
  ments of all our knowledge, so that neither concepts without an
  intuition in some way corresponding to them, nor intuition with-
  out concepts, can yield knowledge. Both may be either pure or
  empirical. When they contain sensation (which presupposes the
  actual presence of the object), they are empirical. When there is
  no mingling of sensationwith the representation,they are pure.
  Sensation may be entitled the material of sensible knowledge.
  B 75  Pure intuition, therefore, contains only the form under which
  A 51  something is intuited; the pure concept only the form of the
  thought of an object in general. Pure intuitions or pure con-
  cepts alone are possible <1a priori,>1 empirical intuitions and
  empirical concepts only <1a posteriori.>1
  92
00084
  TRANSCENDENTAL LOGIC  93
If the <1receptivity>1 of our mind, its power of receiving re-
presentations in so far as it is in any wise affected, is to be
entitled sensibility, then the mind's power of producing repre-
sentations from itself, the <1spontaneity>1 of knowledge, should be
called the understanding. Our nature is so constituted that
our <1intuition>1 can never be other than sensible; that is, it con-
tains only the mode in which we are affected by objects. The
faculty, on the other hand, which enables us to <1think>1 the
object of sensible intuition is the understanding. To neither
of these powers may a preference be given over the other.
Without sensibility no object would be given to us, without
understanding no object would be thought. Thoughts without
content are empty, intuitions without concepts are blind. It
is, therefore, just as necessary to make our concepts sensible,
that is, to add the object to them in intuition, as to make
our intuitions intelligible, that is, to bring them under con-
cepts. These two powers or capacities cannot exchange their
functions. The understanding can intuit nothing, the senses
can think nothing. Only through their union can know-
ledge arise. But that is no reason for confounding the B 76
contribution of either with that of the other; rather is it
a strong reason for carefully separating and distinguishing  A 52
the one from the other. We therefore distinguish the science
of the rules of sensibility in general, that is, aesthetic, from
the science of the rules of the understanding in general, that
is, logic.
  Logic, again, can be treated in a twofold manner, either
as logic of the general or as logic of the special employment
of the understanding. The former contains the absolutely
necessary rules of thought without which there can be no
employment whatsoever of the understanding. It therefore
treats of understanding without any regard to difference in
the objects to which the understanding may be directed. The
logic of the special employment of the understanding contains
the rules of correct thinking as regards a certain kind of
objects. The former may be called the logic of elements, the
latter the organon of this or that science. The latter is com-
monly taught in the schools as a propaedeutic to the sciences,
though, according to the actual procedure of human reason,
it is what is obtained last of all, when the particular science
00085
under question has been already brought to such completion
that it requires only a few finishing touches to correct and
perfect it. For the objects under consideration must already
be known fairly completely before it can be possible to pre-
====  B77 scribe the rules according to which a science of them is to
  A53  a  General logic 1s either pure or applied. In the former we
  standing is exercised, <1i.e.>1 from the influence of the senses, the
  play of imagination, the laws of memory, the force of habit,
  inclination, etc., and so from all sources of prejudice, indeed
  from all causes from which this or that knowledge may arise
  or seem to arise. For they concern the understanding only in
  so far as it is being employed under certain circumstances,
  and to become acquainted with these circumstances experi-
  ence is required. Pure general logic has to do, therefore, only
  with principles <1a priori,>1 and is a <1canon of understanding>1 and
  of reason, but only in respect of what is formal in their em-
  ployment, be the content what it may, empirical or tran-
  scendental. General logic is called applied, when it is directed
  to the rules of the employment of understanding under the
  subjective empirical conditions dealt with by psychology.
  Applied logic has therefore empirical principles, although it
  is still indeed in so far general that it refers to the employ-
  ment of the understanding without regard to difference in the
  objects. Consequently it is neither a canon of the under-
  B 78 standing in general nor an organon of special sciences, but
  merely a cathartic of the common understanding.
  In general logic, therefore, that part which is to constitute
  the pure doctrine of reason must be entirely separated from
  A 54 that which constitutes applied (though always still general)
  logic. The former alone is, properly speaking, a science,
  though indeed concise and dry, as the methodical exposition
  of a doctrine of the elements of the understanding is bound
  to be. There are therefore two rules which logicians must
  always bear in mind, in dealing with pure general logic:
  1. As general logic, it abstracts from all content of the
  knowledge of understanding and from all differences in its
  objects, and deals with nothing but the mere form of
  thought.
00086
2.  As pure logic, it has nothing to do with empirical prin-
ciples, and does not, as has sometimes been supposed, borrow
anything from psychology, which therefore has no influence
whatever on the canon of the understanding. Pure logic is a
body of demonstrated doctrine, and everything in it must be
certain entirely <1a priori.>1
  What I call applied logic (contrary to the usual meaning
of this title, according to which it should contain certain
exercises for which pure logic gives the rules) is a representa-
tion of the understanding and of the rules of its necessary
employment <1in concreto,>1 that is, under the accidental sub-
jective conditions which may hinder or help its application,  B 79
and which are all given only empirically. It treats of attention,
its impediments and consequences, of the source of error, of
the state of doubt, hesitation, and conviction, etc. Pure general
logic stands to it in the same relation as pure ethics, which
contains only the necessary moral laws of a free will in general,  A 55
stands to the doctrine of the virtues strictly so called---the
doctrine which considers these laws under the limitations of
the feelings, inclinations, and passions to which men are
more or less subject. Such a doctrine can never furnish a
true and demonstrated science, because, like applied logic,
it depends on empirical and psychological principles.
  TRANSCENDENTAL LOGIC
  General logic, as we have shown, abstracts from all con-
tent of knowledge, that is, from all relation of knowledge to
the object, and considers onlythe logical form in the relation of
any knowledge to other knowledge; that is, it treats of the form
of thought in general. But since, as the Transcendental Aes-
thetic has shown, there are pure as well as empirical intuitions,
a distinction might likewise be drawn between pure and em-
pirical thought of objects. In that case we should have a logic  B 80
in which we do not abstract from the entire content of know-
ledge. This other logic, which should contain solely the rules
of the pure thought of an object, would exclude only those
00087
modes of knowledge which have empirical content. It would
also treat of the origin of the modes in which we know objects,
A 56  in so far as that origin cannot be attributed to the objects.
  General logic, on the other hand, has nothing to do with the
  origin of knowledge, but only considers representations, be
  they originally <1a priori>1 in ourselves or only empirically given,
  according to the laws which the understanding employs when,
  in thinking, it relates them to one another. It deals therefore
  only with that form which the understanding is able to impart
  to the representations, from whatever source they may have
  arisen.
  And here I make a remark which the reader must bear
  well in mind, as it extends its influence over all that follows.
  Not every kind of knowledge <1a Priori>1 should be called tran-
  scendental, but that only by which we know that---and how---
  certain representations (intuitions or concepts) can be em-
  ployed or are possible purely <1a priori.>1 The term "transcend-
  ental', that is to say, signifies such knowledge as concerns the
  B 81 <1a priori>1 possibility of knowledge, or its <1a priori>1 employment.
  Neither space nor any <1apriori>1 geometrical determination of it
  is a transcendental representation; what can alone be entitled
  transcendental is the knowledge that these representations are
  not of empirical origin, and the possibility that they can yet
  relate <1a priori>1 to objects of experience. The application of
  space to objects in general would likewise be transcendental,
  but, if restricted solely to objects of sense, it is empirical.
  A 57  The distinction between the transcendental and the empirical
  belongs therefore only to the critique of knowledge; it does
  not concern the relation of that knowledge to its objects.
  In the expectation, therefore, that there may perhaps be
  concepts which relate <1a priori>1 to objects, not as pure or sen-
  sible intuitions, but solely as acts of pure thought---that is, as
  concepts which are neither of empirical nor of aesthetic
  origin---we form for ourselves by anticipation the idea of a
  science of the knowledge which belongs to pure understanding
  and reason, whereby we think objects entirely <1a priori.>1 Such
  a science, which should determine the origin, the scope, and
00088
the objective validity of such knowledge, would have to be
called <1transcendental logic,>1 because, unlike general logic,  B 82
which has to deal with both empirical and pure knowledge of
reason, it concerns itself with the laws of understanding and
of reason solely in so far as they relate <1a Priori>1 to objects.
  III
  THE DIVISION OF GENERAL LOGIC INTO ANALYTIC
  AND DIALECTIC
  The question, famed of old, by which logicians were
supposed to be driven into a corner, obliged either to have
recourse to a pitiful sophism, or to confess their ignorance
and consequently the emptiness of their whole art, is the A 58
question: What is truth? The nominal definition of truth,
that it is the agreement of knowledge with its object, is
assumed as granted; the question asked is as to what is
the general and sure criterion of the truth of any and every
knowledge.
  To know what questions may reasonably be asked is
already a great and necessary proof of sagacity and insight.
For if a question is absurd in itself and calls for an answer
where none is required, it not only brings shame on the pro-
pounder of the question, but may betray an incautious listener
into absurd answers, thus presenting, as the ancients said. the  B 83
ludicrous spectacle of one man milking a he-goat and the
other holding a sieve underneath.
  If truth consists in the agreement of knowledge with its
object, that object must thereby be distinguished from other
objects; for knowledge is false, if it does not agree with the
object to which it is related, even although it contains some-
thing which may be valid of other objects. Now a general
criterion of truth must be such as would be valid in each and
every instance of knowledge, however their objects may vary.  It
is obvious, however, that such a criterion [being general] cannot
take account of the [varying] content of knowledge (relation
to its [specific] object). But since truth concerns just this very  A 59
content, it is quite impossible, and indeed absurd, to ask for a
00089
general test of the truth of such content. A sufficient and at the
same time general criterion of truth cannot possibly be given.
Since we have already entitled the content of knowledge its
matter, we must be prepared to recognise that of the truth
of knowledge, so far as its matter is concerned, no general
  criterion can be demanded. Such a criterion would by its
  very nature be self-contradictory.
  But, on the other hand, as regards knowledge in respect
  of its mere form (leaving aside all content), it is evident that
  B 84 logic, in so far as it expounds the universal and necessary
  rules of the understanding, must in these rules furnish criteria
  of truth. Whatever contradicts these rules is false. For the
  understanding would thereby be made to contradict its own
  general rules of thought, and so to contradict itself. These
  criteria, however, concern only the form of truth, that is, of
  thought in general; and in so far they are quite correct, but
  are not by themselves sufficient. For although our knowledge
  may be in complete accordance with logical demands, that is,
  may not contradict itself, it is still possible that it may be in
  contradiction with its object. The purely logical criterion of
  truth, namely, the agreement of knowledge with the general
  and formal laws of the understanding and reason, is a <1conditio>1
  <1sine qua non,>1 and is therefore the negative condition of all
  A 60 truth. But further than this logic cannot go. It has no touch-
  stone for the discovery of such error as concerns not the
  form but the content.
  General logic resolves the whole formal procedure of the
  understanding and reason into its elements, and exhibits them
  as principles of all logical criticism of our knowledge. This
  part of logic, which may therefore be entitled <1analytic,>1 yields
  what is at least the negative touchstone of truth. Its rules
  must be applied in the examination and appraising of the
  form of all knowledge before we proceed to determine whether
  B 85  their content contains positive truth in respect to their object.
  But since the mere form of knowledge, however completely
  it may be in agreement with logical laws, is far from being
  sufficient to determine the material (objective) truth of know-
  ledge, no one can venture with the help of logic alone to
  judge regarding objects, or to make any assertion. We must
  first, independently of logic, obtain reliable information; only
00090
  TRANSCENDENTAL LOGIC
then are we in a position to enquire, in accordance with logical
laws, into the use of this information and its connection in a
coherent whole, or rather to test it by these laws. There is,
however, something so tempting in the possession of an art so
specious, through which we give to all our knowledge, how-
ever uninstructed we may be in regard to its content, the form
of understanding, that general logic, which is merely a <1canon>1  A 61
of judgment, has been employed as if it were an <1organon>1 for
the actual production of at least the semblance of objective
assertions, and has thus been misapplied. General logic, when
thus treated as an organon, is called <1dialectic.>1
  However various were the significations in which the ancients
used "dialectic' as the title for a science or art, we can safely
conclude from their actual employment of it that with them
it was never anything else than the <1logic of illusion.>1 It was a  B 86
sophistical art of giving to ignorance, and indeed to intentional
sophistries, the appearance of truth, by the device of imitat-
ing the methodical thoroughness which logic prescribes, and
of using its "topic' to conceal the emptiness of its pretensions.
Now it may be noted as a sure and useful warning, that general
logic, if viewed as an organon, is always a logic of illusion,
that is, dialectical. For logic teaches us nothing whatsoever
regarding the content of knowledge, but lays down only the
formal conditions of agreement with the understanding; and
since these conditions can tell us nothing at all as to the
objects concerned, any attempt to use this logic as an instru-
ment (organon) that professes to extend and enlarge our
knowledge can end in nothing but mere talk---in which, with
a certain plausibility, we maintain, or, if such be our choice,  A62
attack, any and every possible assertion.
  Such instruction is quite unbecoming the dignity of philo-
sophy. The title "dialectic' has therefore come to be otherwise
employed, and has been assigned to logic, as a <1critique of>1
<1dialectical illusion.>1 This is the sense in which it is to be under-
stood in this work.
00091
  IV
B 87  THE DIVISION OF TRANSCENDENTAL LOGIC INTO
  TRANSCENDENTAL ANALYTIC AND DIALECTIC
  In a transcendental logic we isolate the understanding---
  as above, in the Transcendental Aesthetic, the sensibility---
  separating out from our knowledge that part of thought which
  has its origin solely in the understanding. The employment of
  this pure knowledge depends upon the condition that objects
  to which it can be applied be given to us in intuition. In the
  absence of intuition all our knowledge is without objects,
  and therefore remains entirely empty. That part of transcen-
  dental logic which deals with the elements of the pure know-
  ledge yielded by understanding, and the principles without
  which no object can be thought, is transcendental analytic. It
  is a logic of truth. For no knowledge can contradict it without
  A 63  at once losing all content, that is, all relation to any object, and
  therefore all truth. But since it is very tempting to use these
  pure modes of knowledge of the understanding and these prin-
  ciples by themselves, and even beyond the limits of experience,
  B 88 which alone can yield the matter (objects) to which those pure
  concepts of understanding can be applied, the understanding is
  led to incur the risk of making, with a mere show of rationality,
  passing judgments upon objects without distinction---upon
  objects which are not given to us, nay, perhaps cannot in any
  way be given. Since, properly, this transcendental analytic
  should be used only as a canon for passing judgment upon the
  empirical employment of the understanding, it is misapplied
  if appealed to as an organon of its general and unlimited
  application, and if consequently we venture, with the pure
  understanding alone, to judge synthetically, to affirm, and to
  decide regarding objects in general. The employment of the
  pure understanding then becomes dialectical. The second part
  of transcendental logic must therefore form a critique of this
  dialectical illusion, and is called transcendental dialectic, not
  as an art of producing such illusion dogmatically (an art un-
  fortunately very commonly practised by metaphysical jugglers),
  but as a critique of understanding and reason in respect of
00092
their hyperphysical employment. It will expose the false, illu-
sory character of those groundless pretensions, and in place  A 64
of the high claims to discover and to extend knowledge merely
by means of transcendental principles, it will substitute what is
no more than a critical treatment of the pure understanding,
for the guarding of it against sophistical illusion.
00093
  TRANSCENDENTAL ANALYTIC
  TRANSCENDENTAL analytic consists in the dissection of all
  our <1a priori>1 knowledge into the elements that pure under-
  standing by itself yields. In so doing, the following are the
  points of chief concern: (1) that the concepts be pure and
  not empirical; (2) that they belong, not to intuition and
  sensibility, but to thought and understanding; (3) that
  they be fundamental and be carefully distinguished from
  those which are derivative or composite; (4) that our table
  of concepts be complete, covering the whole field of the pure
  understanding. When a science is an aggregate brought into
  existence in a merely experimental manner, such completeness
  can never be guaranteed by any kind of mere estimate. It is
  possible only by means of <1an idea of the totality>1 of the <1apriori>1
  knowledge yielded by the understanding; such an idea can
  furnish an exact classification of the concepts which compose
  A 65 that totality, exhibiting their <1interconnection in a system.>1
  Pure understanding distinguishes itself not merely from all
  that is empirical but completely also from all sensibility. It
  B 90 is a unity self-subsistent, self-sufficient, and not to be increased
  by any additions from without. The sum of its knowledge thus
  constitutes a system, comprehended and determined by one
  idea. The completeness and articulation of this system can at
  the same time yield a criterion of the correctness and genuine-
  ness of all its components. This part of transcendental logic
  requires, however, for its complete exposition, two books, the
  one containing the <1concepts,>1 the other the <1principles>1 of pure
  understanding.
  102
00094
TRANSCENDENTAL ANALYTIC
  BOOK I
ANALYTIC OF CONCEPTS
By "analytic of concepts' I do not understand their ana-
lysis, or the procedure usual in philosophical investigations,
that of dissecting the content of such concepts as may present
themselves, and so of rendering them more distinct; but the
hitherto rarely attempted <1dissection of thefaculty of the under->1
<1standing>1 itself, in order to investigate the possibility of con-  A 66
cepts <1a priori>1 by looking for them in the understanding alone,
as their birthplace, and by analysing the pure use of this
faculty. This is the proper task of a transcendental philosophy;  B 91
anything beyond this belongs to the logical treatment of con-
cepts in philosophy in general. We shall therefore follow up
the pure concepts to their first seeds and dispositions in the
human understanding, in which they lie prepared, till at last,
on the occasion of experience, they are developed, and by the
same understanding are exhibited in their purity, freed from
the empirical conditions attaching to them.
00095
  THE CLUE TO THE DISCOVERY OF ALL PURE
  CONCEPTS OF THE UNDERSTANDING
  WHEN we call a faculty of knowledge into play, then,
  as the occasioning circumstances differ, various concepts
  stand forth and make the faculty known, and allow of
  their being collected with more or less completeness, in
  proportion as observation has been made of them over a longer
  time or with greater acuteness. But when the enquiry is
  carried on in this mechanical fashion, we can never be sure
  whether it has been brought to completion. Further, the con-
  A67 cepts which we thus discover only as opportunity offers, ex-
  B 92 hibit no order and systematic unity, but are in the end merely
  arranged in pairs according to similarities, and in series accord-
  ing to the amount of their contents, from the simple on to the
  more composite---an arrangement which is anything but sys-
  tematic, although to a certain extent methodically instituted.
  Transcendental philosophy, in seeking for its concepts, has
  the advantage and also the duty of proceeding according to a
  single principle. For these concepts spring, pure and unmixed,
  out of the understanding which is an absolute unity; and must
  therefore be connected with each other according to one con-
  cept or idea. Such a connection supplies us with a rule, by
  which we are enabled to assign its proper place to each pure
  concept of the understanding, and by which we can determine
  in an <1a priori>1 manner their systematic completeness. Other-
  wise we should be dependent in these matters on our own
  discretionary judgment or merely on chance.
00096
THE TRANSCENDENTAL CLUE TO THE DISCOVERY OF
  ALL PURE CONCEPTS OF THE UNDERSTANDING
  Section I
  THE LOGICAL EMPLOYMENT OF THE UNDERSTANDING
  The understanding has thus far been explained merely
negatively, as a non-sensible faculty of knowledge. Now since
without sensibility we cannot have any intuition, understand-  A 68
ing cannot be a faculty of intuition. But besides intuition there
is no other mode of anowledge except by means of concepts.  B 93
The knowledge yielded by understanding, or at least by the
human understanding, must therefore be by means of concepts,
and so is not intuitive, but discursive. Whereas all intuitions,
as sensible, rest on affections, concepts rest on functions. By
"function' I mean the unity of the act of bringing various repre-
sentations under one common representation. Concepts are
based on the spontaneity of thought, sensible intuitions on the
receptivity of impressions. Now the only use which the under-
standing can make of these concepts is to judge by means of
them. Since no representation, save when it is an intuition,
is in immediate relation to an object, no concept is ever
related to an object immediately, but to some other representa-
tion of it, be that other representation an intuition, or itself
a concept. Judgment is therefore the mediate knowledge of an
object, that is, the representation of a representation of it. In
every judgment there is a concept which holds of many repre-
sentations, and among them of a given representation that is
immediately related to an object. Thus in the judgment, "all
bodies are divisible', the concept of the divisible applies to
various other concepts, but is here applied in particular to
the concept of body, and this concept again to certain appear-  A 69
ances that present themselves to us. These objects, therefore,
are mediately represented through the concept of divisibility.
Accordingly, all judgments are functions of unity among our
00097
B 94 representations; instead of an immediate representation, a
  <1higher>1 representation, which comprises the immediate repre-
  sentation and various others, is used in knowing the object,
  and thereby much possible knowledge is collected into one.
  Now we can reduce all acts of the understanding to judg-
  ments, and the <1understanding>1 may therefore be represented
  as a <1faculty of judgment.>1 For, as stated above, the under-
  standing is a faculty of thought. Thought is knowledge by
  means of concepts. But concepts, as predicates of possible
  judgments, relate to some representation of a not <1yet>1 deter-
  mined object. Thus the concept of body means something, for
  instance, metal, which can be known by means of that con-
  cept. It is therefore a concept solely in virtue of its com-
  prehending other representations, by means of which it can
  relate to objects. It is therefore the predicate of a possible
  judgment, for instance, "every metal is a body'. The functions
  of the understanding can, therefore, be discovered if we can
  give an exhaustive statement of the functions of unity in
  judgments. That this can quite easily be done will be shown
  in the next section.
  CONCEPTS OF THE UNDERSTANDING
  Section 2
  591
  THE LOGICAL FUNCTION OF THE UNDERSTANDING IN
  JUDGMENTS
  If we abstract from all content of a judgment, and con-
  sider only the mere form of understanding, we find that the
  function of thought in judgment can be brought under four
  heads, each of which contains three moments. They may be
  conveniently represented in the following table:
00098
  I
  <1Quantity of Judgments>1
  Universal
  Particular
II  Singular  III
<1Quality  Relation>1
Affirmative  Categorical
Negative  Hypothetical
Infinite  Disjunctive
  IV
  <1Modality>1
  Problematic
  Assertoric
  Apodeictic

As this division appears to depart in some, though not in  B 96
any essential respects, from the technical distinctions ordin-
arily recognised by logicians, the following observations may  A 71
serve to guard against any possible misunderstanding.
  I. Logicians are justified in saying that, in the employ-
ment of judgments in syllogisms, singular judgments can
be treated like those that are universal. For, since they
have no extension at all, the predicate cannot relate to part
only of that which is contained in the concept of the subject,
and be excluded from the rest. The predicate is valid of that
concept, without any such exception, just as if it were a
general concept and had an extension to the whole of which
the predicate applied. If, on the other hand, we compare a
singular with a universal judgment, merely as knowledge,
in respect of quantity, the singular stands to the universal as
unity to infinity, and is therefore in itself essentially different
from the universal. If, therefore, we estimate a singular judg-
ment <1(judicium singulare),>1 not only according to its own inner
validity, but as knowledge in general, according to its quantity
in comparison with other knowledge, it is certainly different
from general judgments <1(judicia communia),>1 and in a com-
plete table of the moments of thought in general deserves a
separate place---though not, indeed, in a logic limited to the
use of judgments in reference to each other.  B 97
00099
  2. In like manner <1infinite judgments>1 must, in trans-
cendental logic, be distinguished from those that are <1affirm->1
A 72 <1ative,>1 although in general logic they are rightly classed with
  them, and do not constitute a separate member of the division.
  General logic abstracts from all content of the predicate (even
  though it be negative); it enquires only whether the predicate
  be ascribed to the subject or opposed to it. But transcendental
  logic also considers what may be the worth or content of a
  logical affirmation that is thus made by means of a merely
  negative predicate, and what is thereby achieved in the way
  of addition to our total knowledge. If I should say of the soul,
  "It is not mortal', by this negative judgment I should at least
  have warded off error. Now by the proposition, "The soul
  is non-mortal', I have, so far as the logical form is concerned,
  really made an affirmation.  I locate the soul in the unlimited
  sphere of non-mortal beings. Since the mortal constitutes
  one part of the whole extension of possible beings, and the
  non-mortal the other, nothing more is said by my proposition
  than that the soul is one of the infinite number of things which
  remain over when I take away all that is mortal. The infinite
  sphere of all that is possible is thereby only so far limited that
1398 the mortal is excluded from it, and that the soul is located
  in the remaining part of its extension. But, even allowing
  for such exclusion, this extension still remains infinite, and
  several more parts of it may be taken away without the con-
A73  cept of the soul being thereby in the least increased, or de-
  termined in an affirmative manner. These judgments, though
  infinite in respect of their logical extension, are thus, in respect
  of the content of their knowledge, limitative only, and cannot
  therefore be passed over in a transcendental table of all
  moments of thought in judgments, since the function of the
  understanding thereby expressed may perhaps be of import-
  3. All relations of thought in judgments are (a) of the
  predicate to the subject, (b) of the ground to its consequence,
  (c) of the divided knowledge and of the members of the
  division, taken together, to each other.  In the first kind of
00100
judgments we consider only two concepts, in the second
two judgments, in the third several judgments in their relation
t  each other. The hypothetical proposition, "If there is a
perfect justice, the obstinately wicked are punished', really
contains the relation of two propositions, namely, "There is
a perfect justice', and "The obstinately wicked are punished'.
Whether both these propositions are in themselves true, here
remains undetermined.  It is only the logical sequence which
is thought by this judgment. Finally, the disjunctive judgment  1399
contains a relation of two or more propositions to each other,
a relation not, however, of logical sequence, but of logical
opposition, in so far as the sphere of the one excludes the
sphere of the other, and yet at the same time of community,
in so Far as the propositions taken together occupy the whole
sphere of the knowledge in question. The disjunctive judg-
ment expresses, therefore, a relation of the parts of the sphere  A 74
of such knowledge, since the sphere of each part is a com-
plement of the sphere of the others, yielding together the
sum-total of the divided knowledge. Take, for instance, the
judgment, "The world exists either through blind chance,
or through inner necessity, or through an external cause'.
Each of these propositions occupies a part of the sphere of
the possible knowledge concerning the existence of a world in
general; all of them together occupy the whole sphere. To
take the knowledge out of one of these spheres means placing
it in one of the other spheres, and to place it in one sphere
means taking it out of the others. There is, therefore, in a
disjunctive judging a certain community of the known
  that they mutually exclude each other,
and yet thereby determine <1in their totality>1 the true know-
ledge. For, when taken together, they constitute the whole
content of one given knowledge. This is all that need here
be considered, so far as concerns what follows.
  4.  The <1modality>1 of judgments is a quite peculiar function.
Its distinguishing characteristic is that it contributes nothing 13 100
to the content of the judgment (for, besides quantity, quality,
and relation, there is nothing that constitutes the content of
a judgment), but concerns only the value of the copula in
relation to thought in general. Problematic judgments are
those in which affirmation or negation is taken as merely
00101
A 75 possible (optional). In assertoric judgments affirmation or
  negation is viewed as real (true), and in apodeictic judgments
  as necessary.a Thus the two judgments, the relation of which
  constitutes the hypothetical judgment <1(antecedens et con->1
  <1sequens),>1 and likewise the judgments the reciprocal relation
  of which forms the disjunctive judgment (members of the
  division), are one and all problematic only. In the above
  example, the proposition, "There is a perfect justice', is not
  stated assertorically, but is thought only as an optional judg-
  ment, which it is possible to assume; it is only the logical
  sequence which is assertoric. Such judgments may therefore
  be obviously false, and yet, taken problematically, may be con-
  ditions of the knowledge of truth. Thus the judgment'  The
  world exists by blind chance', has in the disjunctive judgment
  only problematic meaning, namely, as a proposition that may
  13 101  for a moment be assumed. At the same time, like the indica-
  tion of a false road among the number of all those roads that
  can be taken, it aids in the discovery of the true proposition.
  The problematic proposition is therefore that which expresses
  only logical (which is not objective) possibility---a free choice
  of admitting such a proposition, and a purely optional
  admission of it into the understanding. The assertoric pro-
  position deals with logical reality or truth. Thus, for instance,
  A 76 in a hypothetical syllogism the antecedent is in the major
  premiss problematic, in the minor assertoric, and what the
  syllogism shows is that the consequence follows in accordance
  with the laws of the understanding. The apodeictic proposi-
  tion thinks the assertoric as determined by these laws of the
  understanding, and therefore as affirming <1a priori;>1 and in
  this manner it expresses logical necessity. Since everything
  is thus incorporated in the understanding step by step---inas-
  much as we first judge something problematically, then
  maintain its truth assertorically, and finally affirm it as in-
  separably united with the understanding, that is, as necessary
  and apodeictic---we are justified in regarding these three
  functions of modality as so many moments of thought.
  a just as if thought were in the problematic a function of the
  understanding; in the assertoric, of the faculty of judgment; in
  the apodeictic, of reason.  This is a remark which will be explained
  in the sequel.
00102
  TABLE OF CATEGORIES
THE CLUE TO THE DISCOVERY OF ALL PURE  B 102
  CONCEPTS OF THE UNDERSTANDING
  Section 3
  S101
THE PURE CONCEPTS OF THE UNDERSTANDING, OR
  CATEGORIES
General logic, as has been repeatedly said, abstracts from
all content of knowledge, and looks to some other source,
whatever that may be, for the representations which it is
to transform into concepts by process of analysis. Tran-
scendental logic, on the other hand, has lying before it a mani-
fold of <1a priori>1 sensibility, presented by transcendental aes-  A 77
thetic, as material for the concepts of pure understanding.
In the absence of this material those concepts would be with-
out any content, therefore entirely empty. Space and time
contain a manifold of pure <1a priori>1 intuition, but at the same
time are conditions of the receptivity of our mind---conditions
under which alone it can receive representations of objects, and
which therefore must also always affect the concept of these
objects. But if this manifold is to be known, the spontaneity
of our thought requires that it be gone through in a certain
way, taken up, and connected. This act I name <1synthesis.>1
  By <1synthesis,>1 in its most general sense, I understand the  B 103
act of putting different representations together, and of grasp-
ing what is manifold in them in one [act of] knowledge. Such
a synthesis is <1pure,>1 if the manifold is not empirical but is given
<1a priori,>1 as is the manifold in space and time. Before we can
analyse our representations, the representations must them-
selves be given, and therefore as regards <1content>1 no concepts
can first arise by way of analysis. Synthesis of a manifold (be
it given empirically or <1a priori)>1 is what first gives rise to know-
ledge. This knowledge may, indeed, at first, be crude and con-
fused, and therefore in need of analysis. Still the synthesis is
that which gathers the elements for knowledge, and unites
them to [form] a certain content. It is to synthesis, therefore,  A 78
00103
that we must first direct our attention, if we would determine
the first origin of our knowledge.
  Synthesis in general, as we shall hereafter see, is the mere
result of the power of imagination, a blind but indispensable
function of the soul, without which we should have no know-
ledge whatsoever, but of which we are scarcely ever conscious.
To bring this synthesis <1to concepts>1 is a function which belongs
to the understanding, and it is through this function of the
understanding that we first obtain knowledge properly so
called.
  13 104  Pure synthesis, <1represented in its mostgeneral aspect,>1 gives
  thesis I understand that which rests upon a basis of <1a priori>1
  synthetic unity. Thus our counting, as is easily seen in the case
  of larger numbers, is a synthesis according to concepts, be-
  cause it is executed according to a common ground of unity,
  as, for instance, the decade. In terms of this concept, the unity
  of the synthesis of the manifold is rendered necessary.
  By means of analysis different representations are brought
  under one concept---a procedure treated of in general logic.
  What transcendental logic, on the other hand, teaches, is how
  we bring to concepts, not representations, but the <1pure syn->1
  <1thesis>1 of representations. What must first be given---with a
  view to the <1a priori>1 knowledge of all objects---is the <1manifold>1
  A 79  of pure intuition; the second factor involved is the <1synthesis>1 of
  this manifold by means of the imagination. But even this does
  not yet yield knowledge. The concepts which give <1unity>1 to this
  pure synthesis, and which consist solely in the representation
  of this necessary synthetic unity, furnish the third requisite for
  the knowledge of an object; and they rest on the under-
  standing.
  The same function which gives unity to the various repre-
  sentations <1in a judgment>1 also gives unity to the mere syn-
  13 10f thesis of various representations <1in an intuition;>1 and this
  unity, in its most general expression, we entitle the pure con-
  cept of the understanding. The same understanding, through
  the same operations by which in concepts, by means of ana-
  lytical unity, it produced the logical form of a judgment,
  also introduces a transcendental content into its representa-
  tions, by means of the synthetic unity of the manifold in intui-
00104
  TABLE OF CATEGORIES  I13
tion in general. On this account we are entitled to call these
representations pure concepts of the understanding, and to
regard them as applying <1a priori>1 to objects---a conclusion
which general logic is not in a position to establish.
  In this manner there arise precisely the same number of
pure concepts of the understanding which apply <1a priori>1 to
objects of intuition in general, as, in the preceding table, there
have been found to be logical functions in all possible judg-
ments. For these functions specify the understanding com-
pletely, and yield an exhaustive inventory of its powers. These
concepts we shall, with Aristotle, call <1categories,>1 for our A 80
primary purpose is the same as his, although widely diverging
from it in manner of execution.
  TABLE OF CATEGORIES  13106
  <1Of Quantity>1
  Unity
  Plurality
  Totality
  II  III
  <1Of Quality  Of Relation>1
  Reality  Of Inherence and Subsistence
  Negation  <1(substantia et accidens)>1
  Limitation  Of Causality and Dependence
  <1(cause and effect)>1
  Of Community (reciprocity
  between agent and patient)
  IV
  <1Of Modality>1
  Possibility---Impossibility
  Existence---Non-existence
  Necessitu---Contingency
  This then is the list of all original pure concepts of syn-
thesis that the understanding contains within itself <1a priori.>1
00105
  Indeed, it is because it contains these concepts that it is
  called pure understanding; for by them alone can it <1under->1
  <1stand>1 anything in the manifold of 1ntuition, that is, think an
  object of intuition. This division is develo ed s stematicall
  A 81  from a common principle, namely, the faculty of judgment
  (which is the same as the faculty of thought)  It has not arisen
  rhapsodically, as the result of a haphazard search after pure
  concepts, the complete enumeration of which as based on
  B 107 induction only, could never be guaranteed. Nor could we, if
  this were our procedure, discover why just these concepts, and
  no others, have their seat in the pure understanding. It was
  an enterprise worthy of an acute thinker like Aristotle to make
  search for these fundamental concepts. But as he did so on no
  principle, he merely picked them up as they came his way,
  and at first procured ten of them, which he called <1categories>1
  (predicaments). Afterwards he believed that he had discovered
  five others, which he added under the name of post-predica-
  ments. But his table still remained defective. Besides, there
  are to be found in it some modes of pure sensibility <1(quando,>1
  <1ubi, situs,>1 also <1prius, simul),>1 and an empirical concept <1(motus),>1
  none of which have any place in a table of the concepts that
  trace their origin to the understanding. Aristotle's list also
  cepts <1(actio, passio);>1 and of the original concepts some are
  entirely lacking.
  In this connection, it is to be remarked that the categories,
  as the true primary concepts of the pure understanding, have
  also their pure derivative concepts. These could not be passed
  over in a complete system of transcendental philosophy, but
  A 82  in a merely critical essay the simple mention of the fact may
  suffice.
  B 108  I beg permission to entitle these pure but derivative con-
  cepts of the understanding the <1predicables>1 of the pure under-
  standing---to distinguish them from the predicaments <1[i.e.>1 the
  categories]. If we have the original and primitive concepts, it
  is easy to add the derivative and subsidiary, and so to give a
  complete picture of the family tree of the [concepts of] pure
  understanding. Since at present we are concerned not with the
  completeness of the system, but only with the principles to be
  followed in its construction, I reserve this supplementary work
00106
for another occasion. It can easily be carried out, with the
aid of the ontological manuals---for instance, by placing under
the category of causality the predicables of force, action,
passion; under the category of community the predicables
of presence, resistance; under the predicaments of modality
the predicables of coming to be, ceasing to be, change, etc.
The categories, when combined with the modes of pure sen-
sibility, or with one another, yield a large number of derivative
<1a priori>1 concepts. To note, and, where possible, to give a com-
plete inventory of these concepts, would be a useful and not
unpleasant task, but it is a task from which we can here be
absolved.
  In this treatise, I purposely omit the definitions of the cate-
gories, although I may be in possession of them. I shall pro-  A 83
ceed to analyse these concepts only so far as is necessary in
connection with the doctrine of method which I am propound-  B 109
ing. In a system of pure reason, definitions of the categories
would rightly be demanded, but in this treatise they would
merely divert attention from the main object of the enquiry,
arousing doubts and objections which, without detriment to
what is essential to our purposes, can very well be reserved for
another occasion. Meanwhile, from the little that I have said,
it will be obvious that a complete glossary, with all the requisite
explanations, is not only a possible, but an easy task. The divi-
sions are provided; all that is required is to fill them; and a
systematic "topic', such as that here given, affords sufficient
guidance as to the proper location of each concept, while at
the same time indicating which divisions are still empty.
  SIII
  This table of categories suggests some nice points, which
may perhaps have important consequences in regard to the
scientific form of all modes of knowledge obtainable by reason.
For that this table is extremely useful in the theoretical part of
philosophy, and indeed is indispensable as supplying the <1com->1
<1plete plan of a whole science,>1 so far as that science rests on <1a>1
<1priori>1 concepts, and as dividing it systematically <1according to>1
00107
  <1determinate principles,>1 is already evident from the fact that
  the table contains all the elementary concepts of the under-
  standing in their completeness, nay, even the form of a system
  B 110  of them in the human understanding, and accordingly indi-
  cates all the <1momenta>1 of a projected speculative science, and
  even their <1order,>1 as I have elsewhere * shown.
  The first of the considerations suggested by the table is
  that while it contains four classes of the concepts of under-
  standing, it may, in the first instance, be divided into two
  groups; those in the first group being concerned with objects
  of intuition, pure as well as empirical, those in the second
  group with the existence of these objects, in their relation
  either to each other or to the understanding.
  The categories in the first group I would entitle the <1mathe->1
  <1matical,>1 those in the second group the <1dynamical.>1 The former
  have no correlates; these are to be met with only in the second
  group. This distinction must have some ground in the nature
  of the understanding.
  Secondly, in view of the fact that all <1a priori>1 division of
  concepts must be by dichotomy, it is significant that in each
  class the number of the categories is always the same, namely,
  three. Further, it may be observed that the third category in
  each class always arises from the combination of the second
  category with the first.
  B 111  Thus <1allness>1 or <1totality>1 is just plurality considered as unity;
  <1limitation>1 is simply reality combined with negation; <1commun->1
  <1ity>1 is the causality of substances reciprocally determining one
  another; lastly, <1necessity>1 is just the existence which is given
  through possibility itself. It must not be supposed, however,
  that the third category is therefore merely a derivative, and
  nota primary, concept of the pure understanding. For the com-
  bination of the first and second concepts, in order that the third
  may be produced, requires a special act of the understand-
  ing, which is not identical with that which is exercised in the
  case of the first and the second. Thus the concept of a <1number>1
  (which belongs to the category of totality) is not always possible
  simply upon the presence of concepts of plurality and unity
  * <1Metaphysical First Principles of Natural Science.>1 [In the
  Introduction by which Kant prefaces this treatise.]
00108
(for instance, in the representation of the infinite); nor can I,
by simply combining the concept of a cause and that of a sub-
stance, at once have understanding of <1influence,>1 that is, how a
substance can be the cause of something in another substance.
Obviously in these cases, a separate act of the understanding
is demanded; and similarly in the others.
  Thirdly, in the case of one category, namely, that of <1com->1
<1munity,>1 which is found in the third group, its accordance with
the form of a disjunctive judgment---the form which corre- B 112
sponds to it in the table of logical functions---is not as evident
as in the case of the others.
  To gain assurance that they do actually accord, we must
observe that in all disjunctive judgments the sphere (that is,
the multiplicity which is contained in any one judgment) is
represented as a whole divided into parts (the subordinate con-
cepts), and that since no one of them can be contained under
any other, they are thought as co-ordinated with, not sub-
ordinated to, each other, and so as determining each other,
not in one direction only, as in a series, but reciprocally, as in
an aggregate---if one member of the division is posited, all
the rest are excluded, and conversely.
  Now in a <1whole>1 which is made up of <1things,>1 a similar com-
bination is being thought; for one thing is not subordinated,
as effect, to another, as cause of its existence, but, simultane-
ously and reciprocally, is co-ordinated with it, as cause of the
determination of the other (as, for instance, in a body the
parts of which reciprocally attract and repel each other). This
is a quite different kind of connection from that which is found
in the mere relation of cause to effect (of ground to conse-
quence), for in the latter relation the consequence does not in
its turn reciprocally determine the ground, and therefore does
not con titute with it a whole---thus the world, for instance,
does not with its Creator serve to constitute a whole. The
procedure which the understanding follows in representing to  B 113
itself the sphere of a divided concept it likewise follows when
it thinks a thing as divisible; and just as, in the former case,
the members of a division exclude each other, and yet are com-





































00001
bined in one sphere, so the understanding represents to itself
the parts of the latter as existing (as substances) in such a way
that, while each exists independently of the others, they are
yet combined together in one whole.
    #12
  In the transcendental philosophy of the ancients there is
included yet another chapter containing pure concepts of the
understanding which, though not enumerated among the cate-
gories, must, on their view, be ranked as <1a priori>1 concepts of
objects. This, however, would amount to an increase in the
number of the categories, and is therefore not feasible. They
are propounded in the proposition, so famous among the
Schoolmen, <1quodlibet ens est unum, verum, bonum.>1 Now,
although the application of this principle has proved very
meagre in consequences, and has indeed yielded only proposi-
tions that are tautological, and therefore in recent times has
retained its place in metaphysics almost by courtesy only, yet,
on the other hand, it represents a view which, however empty
it may seem to be, has maintained itself over this very long
period. It therefore deserves to be investigated in respect of
its origin, and we are justified in conjecturing that it has its
ground in some rule of the understanding which, as often
happens, has only been wrongly interpreted. These supposedly
B 114 transcendental predicates of <1things>1 are, in fact, nothing but
  logical requirements and criteria of all <1knowledge>1 of things in
  general, and prescribe for such knowledge the categories of
  quantity, namely, <1unity, plurality,>1 and <1totality.>1 But these
  categories, which, properly regarded, must be taken as material,
  belonging to the possibility of the things themselves [empirical
  objects], have, in this further application, been used only in
  their formal meaning, as being of the nature of logical requis-
  ites of all knowledge, and yet at the same time have been
  incautiously converted from being criteria of thought to be pro-
  perties of things in themselves. In all knowledge of an object
  there is <1unity>1 of concept, which may be entitled <1qualitative>1
  <1unity,>1 so far as we think by it only the unity in the combination
  of the manifold of our knowledge: as, for example, the unity
  of the theme in a play, a speech, or a story. Secondly, there is
00002
<1truth,>1 in respect of its consequences. The greater the number
of true consequences that follow from a given concept, the
more criteria are there of its objective reality. This might be
entitled the <1qualitative plurality>1 of characters, which belong to
a concept as to a common ground (but are not thought in it, as
quantity). Thirdly, and lastly, there is <1perfection,>1 which con-
sists in this, that the plurality together leads back to the unity
of the concept, and accords completely with this and with no
other concept. This may be entitled the <1qualitative complete->1
<1ness>1 (totality). Hence it is evident that these logical criteria of  B 115
the possibility of knowledge in general are the three categories
of quantity, in which the unity in the production of the quantum
has to be taken as homogeneous throughout; and that these
categories are here being transformed so as also to yield con-
nection of <1heterogeneous>1 knowledge in one consciousness, by
means of the quality of the knowledge as the principle of the
connection. Thus the criterion of the possibility of a concept
(not of an object) is the definition of it, in which the <1unity>1 of
the concept, the <1truth>1 of all that may be immediately deduced
from it, and finally, the <1completeness>1 of what has been thus de-
duced from it, yield all that is required for the construction of
the whole concept. Similarly, the criterion of an hypothesis
consists in the intelligibility of the assumed ground of explana-
tion, that is,1 in its <1unity>1 (without any auxiliary hypothesis);
in the <1truth>1 of the consequences that can be deduced from it
(their accordance with themselves and with experience); and
finally, in the <1completeness>1 of the ground of explanation of
these consequences, which carry us back to neither more nor
less than was assumed in the hypothesis, and so in an <1a pos->1
<1teriori>1 analytic manner give us back and accord with what
has previously been thought in a synthetic <1a priori>1 manner.
We have not, therefore, in the concepts of unity, truth, and per-
fection, made any addition to th transcendental table of the  - .
  spect imperfect. All that we
have done is to bring the employment of these concepts under
general logical rules, for the agreement of knowledge with
itself---the question of their relation to objects not being in any  B 116
way under discussion.
00003
     CHAPTER II
  THE DEDUCTION OF THE PURE CONCEPTS OF
  UNDERSTANDING
  Section 1
  # 13
  THE PRINCIPLES OF ANY TRANSCENDENTAL DEDUCTION
  JURISTS, when speaking of rights and claims, distinguish in a
  legal action the question of right <1(quidjuris)>1 from the question
  of fact <1(quid facti);>1 and they demand that both be proved.
  Proof of the former, which has to state the right or the legal
  claim, they entitle the <1deduction.>1 Many empirical concepts are
  employed without question from anyone. Since experience is
  always available for the proof of their objective reality, we be-
  lieve ourselves, even without a deduction, to be justified in ap-
B 117  propriating to them a meaning, an ascribed significance. But
  there are also usurpatory concepts, such as <1fortune, fate,>1
  which, though allowed to circulate by almost universal indul-
  gence, are yet from time to time challenged by the question:
  <1quidjuris.>1 This demand for a deduction involves us in con-
A 85  siderable perplexity, no clear legal title, sufficient to justify
  their employment, being obtainable either from experience or
  from reason.
  Now among the manifold concepts which form the highly
00004
complicated web of human knowledge, there are some which
are marked out for pure <1a priori>1 employment, in complete in-
dependence of all experience; and their right to be so em-
ployed always demands a deduction. For since empirical proofs
do not suffice to justify this kind of employment, we are faced
by the problem how these concepts can relate to objects which
they yet do not obtain from any experience. The explanation
of the manner in which concepts can thus relate <1a priori>1 to
objects I entitle their transcendental deduction; and from it I
distinguish empirical deduction, which shows the manner in
which a concept is acquired through experience and through
reflection upon experience, and which therefore concerns, not
its legitimacy, but only its <1de facto>1 mode of origination.
  We are already in possession of concepts which are of two  B 118
quite different kinds, and which yet agree in that they relate
to objects in a completely <1a priori>1 manner, namely, the con-
cepts of space and time as forms of sensibility, and the cate-
gories as concepts of understanding. To seek an empirical de-
duction of either of these types of concept would be labour
entirely lost. For their distinguishing feature consists just in
this, that they relate to their objects without having borrowed  A 86
from experience anything that can serve in the representation
of these objects. If, therefore, a deduction of such concepts is
indispensable, it must in any case be transcendental.
  We can, however, with regard to these concepts, as with
regard to all knowledge, seek to discover in experience, if
not the principle of their possibility, at least the occasioning
causes 1 of their production. The impressions of the senses
supplying the first stimulus, the whole faculty of knowledge
opens out to them, and experience is brought into exist-
ence. That experience contains two very dissimilar elements,
namely, the <1matter>1 of knowledge [obtained] from the senses,
and a certain <1form>1 for the ordering of this matter, [obtained]
from the inner source of the pure intuition and thought
which, on occasion of the sense-impressions, are first brought
into action and yield concepts. Such an investigation of the
first strivings of our faculty of knowledge, whereby it advances
from particular perceptions to universal concepts,  is un-  B 119
doubtedly of great service. We are indebted to the celebrated
00005
Locae for opening out this new line of enquiry. But a <1deduc->1
<1tion>1 of the pure <1a priori>1 concepts can never be obtained in
this manner; it is not to be looked for in any such direction.
For in view of their subsequent employment, which has to be
entirely independent of experience, they must be in a position
to show a certificate of birth quite other than that of descent
A 87  from experiences. Since this attempted physiological deriva-
  tion concerns a <1quaestio facti,>1 it cannot strictly be called
  deduction; and I shall therefore entitle it the explanation of
  the <1possession>1 of pure knowledge. Plainly the only deduction
  that can be given of this 1 knowledge is one that is transcen-
  dental, not empirical. In respect to pure <1a priori>1 concepts
  the latter type of deduction is an utterly useless enterprise
  which can be engaged in only by those who have failed to
  grasp the quite peculiar nature of these modes of know-
  ledge.
  But although it may be admitted that the only kind of
  deduction of pure <1a priori>1 knowledge which is possible is on
  transcendental lines, it is not at once obvious that a deduc-
  tion is indispensably necessary.  e have already, by means of
  a transcendental deduction, traced the concepts of space and
  time to their sources, and have explained and determined
B 12o  their <1a priori>1 objective validity. Geometry, however, proceeds
  with security in knowledge that is completely <1apriori,>1 and has
  no need to beseech philosophy for any certificate of the pure
  and legitimate descent of its fundamental concept of space.
  But the concept is employed in this science only in its reference
  to the outer sensible world---of the intuition of which space
  is the pure form---where all geometrical knowledge, grounded
  as it is in <1a priori>1 intuition, possesses immediate evidence.
  The objects, so far as their form is concerned, are given,
A88 through the very knowledge of them, <1a priori>1 in intuition.
  In the case of the <1pure concepts of understanding,>1 it is quite
  otherwise; it is with them that the unavoidable demand for a
  transcendental deduction, not only of themselves, but also
  of the concept of space, first originates. For since they speak
  of  objects through predicates not of intuition and sensibility
  but of pure <1a priori>1 thought, they relate to objects universally,
00006
that is, apart from all conaitions of sensibility. Also,1 not being
grounded in experience, they cannot, in <1a priori>1 intuition,
exhibit any object such as might, prior to all experience,
serve as ground for their synthesis. For these reasons, they
arouse suspicion not- merely in regard to the objective
validity and the limits of their own employment, but owing
to their tendency to employ the <1concept of space>1 beyond the
conditions of sensible intuition, that concept also they render
ambiguous; and this, indeed, is why we have already found  B 121
a transcendental deduction of it necessary. The reader must
therefore be convinced of the unavoidable necessity of such
a transcendental deduction before he has taken a single step
in the field of pure reason. Otherwise he proceeds blindly,
and after manifold wanderings must come back to the same
ignorance from which he started. At the same time, if he is
not to lament over obscurity in matters which are by their
very nature deeply veiled, or to be too easily discouraged in
the removal of obstacles, he must have a clear foreknowledge
of the inevitable difficulty of the undertaking. For we must A 89
either completely surrender all claims to make judgments of
pure reason ina the most highly esteemed of all fields, that
which transcends the limits of all possible experience, or else
bring this critical enquiry to completion.
  We have already been able with but little difficulty to
explain how the concepts of space and time, although <1apriori>1
modes of knowledge, must necessarily relate to objects, and
how independently of all experience they make possible a
synthetic knowledge of objects. For since only by means of
such pure forms of sensibility can an object appear to us,
and so be an object of empirical intuition, space and time
are pure intuitions which contain <1a priori>1 the condition of the
possibility of objects as appearances, and the synthesis which  B 122
takes place in them has objective validity.
  The categories of understanding, on the other hand, do
not represent the conditions under which objects are given
in intuition. Objects may, therefore, appear to us without
00007
their being under the necessity of being related to the functions
of understanding; and understanding need not, therefore,
contain their <1a priori>1 conditions. Thus a difficulty such as
we did not meet with in the field of sensibility is here
presented, namely, how <1subjective conditions of thought>1 can
have <1objective validity,>1 that is, can furnish conditions of the
A9o  possibility of all knowledge of objects. For appearances can
  certainly be given in intuition independently of functions of
  the understanding. Let us take, for instance, the concept of
  cause, which signifies a special kind of synthesis, whereby
  upon something, A, there is posited something quite different,
  B, accordding to a rule. Is not manifest <1apriori>1 why appear-
  ances should contain anything of this kind (experiences
  cannot be cited in its proof, for what has to be established
  is the objective validity of a concept that is <1a priori);>1 and it
  is therefore <1a priori>1 doubtful whether such a concept be
  not perhaps altogether empty, and have no object anywhere
  among appearances. That objects of sensible intuition must
B 123 conform to the formal conditions of sensibility which lie
  <1a priori>1 in the mind is evident, because otherwise they would
  not be objects for us. But that they must likewise conform
  to the conditions which the understanding requires for the
  synthetic unity1 of thought, is a conclusion the grounds of
  which are by no means so obvious. Appearances might very
  well be so constituted that the understanding should not find
  them to be in accordance with the Conditions of its unity.
  Everything might be in such confusion that, for instance,
  in the series of appearances nothing presented itself which
  1night yield a rule of synthesis and so answer to the concept
  of cause and effect. This concept would then be altogether
  empty, null, and meaningless. But since intuition stands in
A 91  no need whatsoever of the functions of thought, appearances
  would none the less present objects to our intuition.
  If we thought to escape these toilsome enquiries by saying
  that experience continually presents examples of such regu-
  larity among appearances and so affords abundant oppor-
  tunity of abstracting the concept of cause, and at the same
  time of verifying the objective validity of such a concept, we
  should be overlooking the fact that the concept of cause can
00008
never arise in this manner. It must either be grounded com-
pletely <1a priori>1 in the understanding, or must be entirely given
up as a mere phantom of the brain. For this concept makes  B 124
strict demand that something, A, should be such that some-
thing else, B, follows from it <1necessarily and in accordance>1
<1with an absolutely universal rule.>1 Appearances do indeed pre-
sent cases from which a rule can be obtained according to
which something usually happens, but they never prove the
sequence1 to be <1necessary.>1 To the synthesis of cause and
effect there belongs a dignity which cannot be empirically
expressed, namely that the effect not only succeeds upon the
cause, but that itis posited <1through>1 it and arises <1out of>1 it.a
This strict universality of the rule is never a characteristic of
empirical rules; they can acquire through induction only com-
parative universality, that is, extensive applicability. If we A 92
were to treat pure concepts of understanding as merely em-
pirical products, we should be making a complete change in
[the manner of] their employment.
  # I43
  <1Transition to the Transcendental Deduction of the>1
  <1Categories>1
  There are only two possible ways in which synthetic re-
presentations and  their objects   can establish connection,
obtain necessary relation to one another, and, as it were, meet
one another. Either the object alone must make the repre-
sentation possible, or the representation alone must make the
object possible. In the former case, this relation is only em-  B 125
pirical, and the representation is never possible <1a priori.>1 This
is true of appearances, as regards that [element] in them
which belongs to sensation. In the latter case, representation
in itself does not produce its object in so far as <1existence>1 is
concerned, for we are not here speaking of its causality by
means of the will. None the less the representation is <1a priori>1
determinant of the object, if it be the case that only through
00009
Now- there are two conditions under which alone the know-
ledge of an object is possible, first, <1intuition,>1 through which
it is given though only as appearance; secondly, <1concept,>1
A 93  through which an object is thought corresponding to this in-
  tuition. It is evident from the above that the first condition,
  namely, that under which alone objects can be intuited, does
  actually lie1 <1a priori>1 in the mind as the formal ground of the
  objects. All appearances necessarily agree with this formal
  condition of sensibility, since only through it can they appear,
  that is, be empirically intuited and given. The question now
  arises whether <1a priori>1 concepts do not also serve as ante-
  cedent conditions under which alone anything can be, if not
  intuited, yet thought as object in general. In that case all em-
B 126  pirical knowledge of objects would necessarily conform to such
  concepts, because only as thus presupposing them is anything
  possible as <1object of experience.>1 Now all experience does indeed
  contain, in addition to the intuition of the senses through
  which something is given, a <1concept>1 of an object as being
  thereby given, that is to say, as appearing.  Concepts of objects
  in general thus underlie all empirical knowledge as its <1a priori>1
  conditions. The objective validity of the categories as <1a priori>1
  concepts rests, therefore, on the fact that, so far as the form
  of thought is concerned, through them alone does experience
  become possible. They relate of necessity and <1a priori>1 to
  objects of experience, for the reason that only by means of
  them can any object whatsoever of experience be thought.
A 94  The transcendental deduction of all <1a priori>1 concepts has
  thus a principle according to which the whole enquiry must
  be directed, namely, that they must be recognised as <1a priori>1
  conditions of the possibility of experience, whether of the
  intuition which is to be met with in it or of the thought. Con-
  cepts which yield the objective ground of the possibility of
  experience are for this very reason necessary. But the unfold-
  ing of the experience wherein they are encountered is not
==  their deduction; it is only their illustration. For on any such
00010
exposition they would be merely accidental. Save through
their original relation to possible experience, in which all B 127
objects of knowledge are found,1 their relation to any one
object would be quite incomprehensible.
  * The illustrious Locke, failing to take account of these con-
siderations, and meeting with pure concepts of the understand-
ing in experience, deduced them also from experience, and
yet proceeded so <1inconsequently>1 that he attempted with their
aid to obtain knowledge which far transcends all limits of ex-
perience. David Hume recognised that, in order to be able to
do this, it was necessary that these concepts should have an
a <1priori>1 origin. But since he could not explain how it can be
possible that the understanding must think concepts, which
are not in themselves connected in the understanding, as being
necessarily connected in the object, and since it never occurred
to him that the understanding might itself, perhaps, through
these concepts, be the author of the experience in which its
objects are found, he was constrained to derive them from
experience, namely, from a subjective necessity (that is, from
<1custom),>1 which arises from repeated association in experience,
and which comes mistakenly to be regarded as objective. But
from these premisses he argued quite consistently. It is im-
possible, he declared, with these concepts and the principles to
which they give rise, to pass beyond the limits of experience.
  * [The next three paragraphs are substituted in B for the
following:]
  There are three original sources (capacities or faculties of
the soul) which contain the conditions of the possibility of all
experience, and cannot themselves be derived from any other
faculty of the mind, namely, <1sense, imagination,>1 and <1appercep->1
<1tion.>1 Upon them are grounded (I) the <1synopsis>1 of the manifold
<1a priori>1 through sense; (2) the <1synthesis>1 of this manifold
through imagination; finally (3) the <1unity>1 of this synthesis
through original apperception. All these <1faculties>1 have a
transcendental (as well as an empirical) employment which
concerns the form alone, and is possible <1a priori.>1 As regards
sense, we have treated of this above in the first part; we shall  A 95
now endeavour to comprehend the nature of the other two.
00011
B 128 Now this <1empirical>1 derivation, in which both philosophers
  agree, cannot be reconciled with the scientific <1a priori>1 know-
  ledge which we do actually possess, namely, <1pure mathematics>1
  and <1general science of nature;>1 and this fact therefore suffices
  to disprove such derivation.
  While the former of these two illustrious men opened a wide
  door to <1enthusiasm>1---for if reason once be allowed such rights,
  it will no longer allow itself to be kept within bounds by
  vaguely defined recommendations of moderation---the other
  gave himself over entirely to <1scepticism,>1 having, as he believed,
  discovered that what had hitherto been regarded as reason
  was but an all-prevalent illusion infecting our faculty of know-
  ledge. We now propose to make trial whether it be not possible
  to find for human reason safe conduct between these two rocks,
  assigning to her determinate limits, and yet keeping open for
  her the whole field of her appropriate activities.
  But first I shall introduce a word of explanation in regard
  to the categories. They are concepts of an object in general, by
  means of which the intuition of an object is regarded as deter-
  mined in respect of one of the logical functions of judgment.
  Thus the function of the categorical judgment is that of the
  relation of subject to predicate; for example, "All bodies are
  divisible'.  But as regards the merely logical employment of
  the understanding, it remains undetermined to which of the
  two concepts the function of the subject, and to which the
B 129  function of predicate, is to be assigned. For we can also say,
  "Something divisible is a body'. But when the concept of body
  is brought under the category of substance, it is thereby de-
  termined that its empirical intuition in experience must always
  be considered as subject and never as mere predicate. Simi-
===  larly with all the other categories.
00012
  Section 2
  THE A PRIORI GROUNDS OF THE POSSIBILITY OF
  EXPERIENCE
THAT a concept, although itself neither contained in the con-
cept of possible experience nor consisting of elements of a
possible experience, should be produced completely <1a priori>1
and should relate to an object, is altogether contradictory and
impossible. For it would then have no content, since no intui-
tion corresponds to it; and intuitions in general, through which
objects can be given to us, constitute the field, the whole ob-
ject, of possible experience.  An <1a priori>1 concept which did
not relate to experience would be only the logical form of a
concept, not the concept itself through which something is
thought.
  Pure <1a priori>1 concepts, if such exist, cannot indeed con-
tain anything empirical; yet, none the less, they can serve
solely as <1a priori>1 conditions of a possible experience. Upon
this ground alone can their objective reality rest.
  If, therefore, we seek to discover how pure concepts of
understanding are possible, we must enquire what are the
<1a priori>1 conditions upon which the possibility of experience  A 96
rests, and which remain as its underlying grounds when every-
thing empirical is abstracted from appearances. A concept
which universally and adequately expresses such a normal and
00013
objective condition of experience would be entitled a pure con-
cept of understanding. Certainly, once I am in possession of
pure concepts of understanding, I can think objects which may
be impossible, or which, though perhaps in themselves possible,
cannot be given in any experience. For in the connecting of
these concepts something may be omitted which yet neces-
sarily belongs to the condition of a possible experience (as in
the concept of a spirit). Or, it may be, pure concepts are ex-
tended further than experience can follow (as with the concept
of God). But the <1elements>1 of all modes of <1a priori>1 knowledge,
even of capricious and incongruous fictions, though they
cannot, indeed, be derived from experience, since in that case
they would not be knowledge <1a priori,>1 must none the less
always contain the pure <1a priori>1 conditions of a possible ex-
perience and of an empirical object. Otherwise nothing would
be thought through them, and they themselves, being without
data, could never arise even in thought.
  The concepts which thus contain <1apriori>1 the pure thought
involved in every experience, we find in the categories. If we
A 97  can prove that by their means alone an object can be thought,
  this will be a sufficient deduction of them, and will justify their
  the faculty of thought, the understanding, is brought 1nto Pla is'
  meant to relate to objects, calls for explanation in regard to the
  possibility of such relation  we must first of all consider, not in
  their empirical but in their transcendental constitution, the
  subjective sources which form the <1a priori>1 foundation of the
  possibility of experience.
  If each representation were completely foreign to every
  other, standing apart in isolation, no such thing as knowledge
  would ever arise. For knowledge is [essentially] a whole in
  which representations stand compared and connected.  As sense
  contains a manifold in its intuition, I ascribe to it a synopsis.
  But to such synopsis a synthesis must always correspond; re-
  ceptivity can make knowledge possible only when combined
  with spontaneity. Now this spontaneity is the ground of a
  threefold synthesis which must necessarily be found in all
  knowledge; namely, the <1apprehension>1 of representations as
  modifications of the mind in intuition, their <1reproduction>1 in
00014
imagination, and their <1recognition>1 in a concept. These point
to three subjective sources of knowledge which make possible
the understanding itself---and consequently all experience as  A 98
its empirical product.
  <1Preliminary Remark>1
  The deduction of the categories is a matter of such ex-
treme difficulty, compelling us to penetrate so deeply into the
first grounds of the possibility of our knowledge in general,
that in order to avoid the elaborateness of a complete theory,
and yet at the same time to omit nothing in so indispensable
an enquiry, I have found it advisable in the four following pass-
ages rather to prepare than to instruct the reader. System-
atic exposition of these elements of the understanding is first
given in Section , immediately following. The reader must
nottherefore be deterred by obscurities in these earlier sections.
They are unavoidable in an enterprise never before attempted.
They will, as I trust, in the section referred to, finally give way
to complete insight.
  1.  <1The Synthesis of Apprehension in intuition>1
  Whatever the origin of our representations, whether they
are due to the influence of outer things, or are produced
through inner causes, whether they arise <1a priori,>1 or being
appearances have an empirical origin, they must all, as modi-
fications of the mind, belong to inner sense. All our know-  A 99
ledge is thus finally subject to time, the formal condition of
inner sense. In it they must all be ordered, connected, and
brought into relation. This is a general observation which,
throughout what follows, must be borne in mind as being
quite fundamental.
  Every intuition contains in itself a manifold which can
be represented as a manifold only in so far as the mind distin-
guishes the time in the sequence of one impression upon another;
for each representation, <1in so far as it is contained in a single>1
<1moment,>1 can never be anything but absolute unity. In order
that unity of intuition may arise out of this manifold (as is
required in the representation of space) it must first be run
through, and held together. This act I name the <1synthesis of>1
<1apprehension,>1 because it is directed immediately upon intuition,
which does indeed offer a manifold, but a manifold which can
00015
never be represented as a manifold, and as contained <1in a>1
<1single representation,>1 save in virtue of such a synthesis.
  This synthesis of apprehension must also be exercised
<1a priori,>1 that is, in respect of representations which are not
empirical. For without it we should never have <1a priori>1 the
representations either of space or of time. They can be pro-
A 100  duced only through the synthesis of the manifold which sen-
  sibility presents in its original receptivity. We have thus a pure
  synthesis of apprehension.
  2.  <1The Synthesis of Reproduction in imagination>1
  It is a merely empirical law, that representations which
  have often followed or accompanied one another finally be-
  come associated, and so are set in a relation whereby, even in
  the absence of the object, one of these representations can, in
  accordance with a fixed rule, bring about a transition of the
  mind to the other. But this law of reproduction presupposes
  that appearances are themselves actually subject to such a
  rule, and that in the manifold of these representations a co-
  existence or sequence takes place in conformity with certain
  rules. Otherwise our empirical imagination would never find
  opportunity for exercise appropriate to its powers, and so
  would remain concealed within the mind as a dead and to us
  unknown faculty. If cinnabar were sometimes red, sometimes
  black, sometimes light, sometimes heavy, if a man changed
  sometimes into this and sometimes into that animal form, if
  the country on the longest day were sometimes covered with
A 1o1  fruit, sometimes with ice and snow, my empirical imagina-
  tion would never find opportunity when representing red
  colour to bring to mind heavy cinnabar. Nor could there be
  an empirical synthesis of reproduction, if a certain name were
  sometimes given to this, sometimes to that object, or were one
==  and the same thing named sometimes in one way, sometimes
  inreain themselves subject.
  There must then be something which, as the <1a priori>1
  ground of a necessary synthetic unity of appearances, makes
  their reproduction possible. What that something is we
00016
soon discover, when we reflect that appearances arc not
things in themselves, but are the mere play of our representa-
tions, and in the end reduce to determinations of inner sense.
For if we can show that even our purest <1a priori>1 intuitions
yield no knowledge, save in so far as they contain a com-
bination of the manifold such as renders a thoroughgoing
synthesis of reproduction possible, then this synthesis of im-
agination is likewise grounded, antecedently to all experi-
ence, upon <1a priori>1 principles; and we must assume a pure
transcendental synthesis of imagination as conditioning the
very possibility of all experience. For experience as such neces-
sarily presupposes the reproducibility of appearances. When  A 1o2
I seek to draw1 a line in thought, or to think of the time from
one noon to another, or even to represent to myself some par-
ticular number, obviously the various manifold representa-
tions that are involved must be apprehended by me in thought
one after the other. But if I were always to drop out of thought
the preceding representations (the first parts of the line, the
antecedent parts of the time period, or the units in the order
represented), and did not reproduce them while advancing to
those that follow, a complete representation would never be
obtained: none of the above-mentioned thoughts, not even the
purest and most elementary representations of space and time,
could arise.
  The synthesis of apprehension is thus inseparably bound
up with the synthesis of reproduction. And as the former con-
stitutes the transcendental ground of the possibility of all
modes of knowledge whatsoever---of those that are pure
<1a priori>1 no less than of those that are empirical---the repro-
ductive synthesis of the imagination is to be counted among
the transcendental acts of the mind. We shall therefore entitle
this faculty the transcendental faculty of imagination.
  3. <1The Synthesis of Recognition in a Concept>1  A 103
  If we were not conscious that what we think is the same
as what we thought a moment before, all reproduction in the
series of representations would be useless. For it would in its
present state be a new representation which would not in any
way belong to the act whereby it was to be gradually gener-
00017
ated. The manifold of the representation would never, there-
fore, form a whole, since it would lack that unity which only
consciousness can impart to it. If, in counting, I forget that
the units, which now hover before me,1 have been added to
one another in succession, I should never know that a total
is being produced through this successive addition of unit to
unit, and so would remain ignorant of the number. For the
concept of the number is nothing but the consciousness of
this unity of synthesis.
  The word "concept' might of itself suggest this remark.
For this unitary consciousness is what combines the mani-
fold, successively intuited, and thereupon also reproduced,
into one representation. This consciousness may often be only
faint, so that we do not connect it with the act itself, that
is, not in any direct manner with the <1generation>1 of the repre-
A 104  sentation, but only with the outcome [that which is thereby
  represented]. But notwithstanding these variations, such con-
  sciousness, however indistinct, must always be present; with-
  out it, concepts, and therewith knowledge of objects, are
  altogether impossible.
  At this point we must make clear to ourselves what we
  mean by the expression "an object of representations'. We
  have stated above that appearances are themselves nothing
  but sensible representations, which, as such and in themselves,
  must not be taken as objects capable of existing outside our
  power of representation. What, then, is to be understood when
  we speak of an object corresponding to, and consequently
  also distinct from, our knowledge? It is easily seen that this
  object must be thought only as something in general  <1x,>1 since
  outside our knowledge we have nothing which we could set
  over against this knowledge as corresponding to it.
  Now we find that our thought of the relation of all know-
  ledge to its object carries with it an element of necessity; the
  object is viewed as that which prevents our modes of know-
  ledge from being haphazard or arbitrary, and which deter-
  mines them <1a priori>1 in some definite fashion.  For in so far
  as they are to relate to an object, they must necessarily agree
00018
with one another, that is, must possess that unity which con-  A 1o5
stitutes the concept of an object.
  But it is clear that, since we have to deal only with the
manifold of our representations, and since that <1x>1 (the object)
which corresponds to them is nothing to us---being, as it is,
something that has to be distinct from all our representations
---the unity which the object makes necessary can be nothing
else than the formal unity of consciousness in the synthesis of
the manifold of representations. It is only when we have thus
produced synthetic unity in the manifold of intuition that we  "
are in a position to say that we know the object. But this unity
is impossible if the intuition cannot be generated in accord-
ance with a rule by  ans of such a function of synthesis as
makes the reproducti  of the manifold <1a priori>1 necessary,
  concept in which it is united. Thus we
think a triangle as an object, in that we are conscious of the
combination of three straight lines according to a rule by
which such an intuition can always be represented. This <1unity>1
<1of rule>1 determines all the manifold, and limits it to conditions
which make unity of apperception possible. The concept of
this unity is the representation  of the object = <1x,>1 which  I
think through the predicates, above mentioned, of a triangle.
  All knowledge demands a concept, though that concept A 106
may, indeed, be quite imperfect or obscure. But a concept
is always, as regards its form, something universal which
serves as a rule. The concept of body, for instance, as the
unity of the manifold which is thought through it, serves as
a rule in our knowledge of outer appearances. But it can be
a rule for intuitions only in so far as it represents in any given
appearances the necessary reproduction of their manifold,
and thereby the synthetic unity in our consciousness of them.
The concept of body, in the perception of something outside
us, necessitates the representation of extension, and there-
with representations of impenetrability, shape, etc.
  All necessity, without exception, is grounded in a tran-
scendental condition. There must, therefore, be a transcend-
ental ground of the unity of consciousness in the synthesis
of the manifold of all our intuitions, and consequently also
of the concepts of objects in general, and so of all objects
of experience, a ground without which it would be impossible
00019
00020
to think any object for our intuitions; for this object is no
more than that something, the concept of which expresses
such a necessity of synthesis.
  This original and transcendental condition is no other
A 107 than <1transcendental apperception.>1  Consciousness of self
  according to the determinations of our state in inner percep-
  tion is merely empirical, and always changing.  No fixed
  and abiding self can present itself in this flux of inner appear-
  ances. Such consciousness is usually named <1inner sense,>1 or
  <1empirical apperception.>1 What has <1necessarily>1 to be repre-
  sented as numerically identical cannot be thought as such
  through empirical data. To render such a transcendental
  presupposition valid, there must be a condition which
  precedes all experience, and which makes experience itself
  possible.
  There can be in us no modes of knowledge, no connection
  or unity of one mode of knowledge with another, without that
  unity of consciousness which precedes all data of intuitions,
  and by relation to which representation of objects is alone
  possible. This pure original unchangeable consciousness I
  shall name <1transcendental apperception.>1 That it deserves this
  name is clear from the fact that even the purest objective
  unity, namely, that of the <1a priori>1 concepts (space and time),
  is1 only possible through relation of the intuitions to such
  unity of consciousness. The numerical unity of this appercep-
  tion is thus the <1a priori>1 ground of all concepts, just as the
  manifoldness of space and time is the <1a priori>1 ground of
  the intuitions of sensibility.
A 1o8  This transcendental unity of apperception forms out of
  all possible appearances, which can stand alongside one
  another in one experience, a connection of all these repre-
  sentations according to laws. For this unity of consciousness
  would be impossible if the mind in knowledge of the manifold
  could not become conscious of the identity of function whereby
  it synthetically combines it in one knowledge. The original
  and necessary consciousness of the identity of the self is thus
  at the same time a consciousness of an equally necessary unity
  of the synthesis of all appearances according to concepts, that
00021
is, according to rules, which not only make them necessarily
reproducible but also in so doing determine an object for their
intuition, that is, the concept of something wherein they are
necessarily interconnected. For the mind could never think
its identity in the manifoldness of its representations, and
indeed think this identity <1a priori,>1 if it did not have before
its eyes the identity of its act, whereby it subordinates all
synthesis of apprehension (which is empirical) to a transcend-
ental unity, thereby rendering possible their interconnection
according to <1a priori>1 rules.
  Now, also, we are in a position to determine more ade-
quately our concept1 of an <1object>1 in general. All representations
have, as representations, their object, and can themselves in
turn become objects of other representations. Appearances are
the sole objects which can be given to us immediately, and A 1e9
that in them which relates immediately to the object is called
intuition. But these appearances are not things in themselves;
they are only representations, which in turn have their object
---an object which cannot itself be intuited by us, and which
may, therefore, be named the non-empirical, that is, transcend-
ental  object = <1x.>1
  The pure concept of this transcendental object, which in
reality throughout all our knowledge is always one and the
same, is what can alone confer upon all our empirical con-
cepts in general relation to an object, that is, objective reality.
This concept cannot contain any determinate intuition, and
therefore refers only to that unity which must be met with
in any manifold of knowledge which stands in relation to an
object. This relation is nothing but the necessary unity of
consciousness, and therefore also of the synthesis of the mani-
fold, through a common function of the mind, which com-
bines it in one representation. Since this unity must be re-
garded as necessary <1a priori>1---otherwise knowledge would
be without an object---the relation to a transcendental object,
that is, the objective reality of our empirical knowledge, rests  A 110
on the transcendental law, that all appearances, in so far as
through them objects are to be given to us, must stand under
those <1a priori>1 rules of synthetical unity whereby the inter-
00022
relating of these appearances in empirical intuition is alone
possible. In other words, appearances in experience must
stand under the conditions of the necessary unity of apper-
ception, just as in mere intuition they must be subject to the
formal conditions of space and of time. Only thus can any
knowledge become possible at all.
  <1Categories, as knowledge>1 a priori
  There is one single experience in which all perceptions
are represented as in thoroughgoing and orderly connection,
just as there is only one space and one time in which all
modes1 of appearance and all relation of being or not being
occur. When we speak of different experiences, we can refer
only to the various perceptions, all of which, as such, belong
to one and the same general experience. This thoroughgoing
synthetic unity of perceptions is indeed the form of experience;
it is nothing else than the synthetic unity of appearances in
accordance with concepts.
A 111  Unity of synthesis according to empirical concepts would
  be altogether accidental, if these latter were not based on a
  transcendental ground of unity. Otherwise it would be possible
  for appearances to crowd in upon the soul, and yet to be such
  as would never allow of experience.  Since connection in accord-
  ance with universal and necessary laws would be lacking, all
  relation of knowledge to objects would fall away. The appear-
  ances might, indeed, constitute intuition without thought,a
  but not knowledge; and consequently would be for us as good
  as nothing.
  The <1a priori>1 conditions of a possible experience in general
  are at the same time conditions of the possibility of objects
  of experience. Now I maintain that the categories, above
  cited, are nothing but the conditions of thought in a possible
  experience, just as space and time are  the conditions of in-
  tuition for that same experience. They are fundamental con-
  cepts by which we think objects in general for appearances,
  and have therefore <1a priori>1 objective validity. This is exactly
  what we desired to prove.
00023
00024
00025
00026
00027
But the possibility, indeed the necessity, of these cate-
gories rests on the relation in which our entire sensibility,
and with it all possible appearances, stand to original apper-
ception. In original apperception everything must necessarily
conform to the conditions of the thoroughgoing unity of self-
consciousness, that is, to the universal functions of synthesis,  A 112
namely, of that synthesis according to concepts in which
alone apperception can demonstrate <1a priori>1 its complete and
necessary identity. Thus the concept of a cause is nothing but
a synthesis (of that which follows in the time-series, with other
appearances) <1according to concepts;>1 and without such unity,
which has its <1a priori>1 rule, and which subjects the appear-
ances to itself, no thoroughgoing, universal, and therefore
necessary, unity of consciousness would be met with in the
manifold of perceptions. These perceptions would not then
belong to any experience, consequently would be without an
object, merely a blind play of representations, less even than
a dream.
  All attempts to derive these pure concepts of understand-
ing from experience, and so to ascribe to them a merely em-
pirical origin, are entirely vain and useless. I need not insist
upon the fact that, for instance, the concept of a cause involves
the character of necessity, which no experience can yield.
Experience does indeed show that one appearance customarily
follows upon another, but not that this sequence is necessary,
nor that we can argue <1apriori>1 and with complete universality
from the antecedent, viewed as a condition, to the consequent.
But as regards the empirical rule of <1association,>1 which we
must postulate throughout when we assert that everything in
the series of events is so subject to rule that nothing ever A 113
happens save in so far as something precedes it on which it
universally follows---upon what I ask, does this rule, as a law
of nature, rest? How is this association itself possible? The
ground of the possibility of the association of the manifold, so
far as it lies in the object, is named the <1affinity>1 of the manifold.
I therefore ask, how are we to make comprehensible to our-
selves the thoroughgoing affinity of appearances, whereby
they stand and <1must>1 stand under unchanging laws?
  On my principles it is easily explicable. All possible ap-
pearances, as representations, belong to the totality of a pos-
00028
sible self-consciousness.1 But as self-consciousness is a tran-
scendental representation, numerical identity is inseparable
from it, and is <1a priori>1 certain. For nothing can come to our
knowledge save in terms of this original apperception. Now,
since this identity must necessarily enter into the synthesis of
all the manifold of appearances, so far as the synthesis is to
yield empirical anowledge, the appearances are subject to
<1a priori>1 condition, with which the synthesis of their apprehen-
sion must be in complete accordance. The representation of
a universal condition according to which a certain manifold
can be posited in uniform fashion is called a <1rule,>1 and, when
it <1must>1 be so posited, a <1law.>1 Thus all appearances stand in
A 114 thoroughgoing connection according to necessary laws, and
  therefore in a transcendental affinity, of which the empirical
  is a mere consequence.
  That nature should direct itself according to our sub-
  jective ground of apperception, and should indeed depend
  upon it in respect of its conformity to law, sounds very strange
  and absurd.  But when we consider that this nature is not a
  thing in itself but is merely an aggregate of appearances, so
  many representations of the mind, we shall not be surprised
  that we can discover it only in the radical faculty of all our
  knowledge, namely, in transcendental apperception, in that
  unity on account of which alone it can be entitled object of all
  possible experience, that is, nature. Nor shall we be surprised
  that just for this very reason this unity can be known <1a priori,>1
  and therefore as necessary. Were the unity given in itself in-
  dependently of the first sources of our thought, this would
  never be possible. We should not then know of any source
  from which we could obtain the synthetic propositions assert-
  ing such a universal unity of nature.  For they would then have
  to be derived from the objects of nature themselves; and as this
  could take place only empirically, none but a merely accidental
  unity could be obtained, which would fall far short of the
  necessary interconnection that we have in mind when we speak
  of nature.
00029
  UNDERSTANDING
  Section 3
  GENERAL, AND THE POSSIBILITY OF KNOWING THEM
  A PRIORI
  What we have expounded separately and singly in the
preceding section, we shall now present in systematic inter-
connection. There are three subjective sources of knowledge
upon- which rests the possibility of experience in general and
of knowledge of its objects---<1sense, imagination,>1 and <1appercep->1
<1tion.>1 Each of these can be viewed as empirical, namely, in its
application to given appearances. But all of them are likewise
a <1priori>1 elements or foundations, which make this empirical
employment itself possible. <1Sense>1 represents appearances em-
pirically in <1perception, imagination>1 in <1association>1 (and repro-
duction), <1apperception>1 in the <1empirical consciousness>1 of the
identity of the reproduced representations with the appear-
ances whereby they were given, that is, in recognition.
  But all perceptions are grounded <1apriom->1 in pure intuition
(in time, the form of their inner intuition as representations),
association in pure synthesis of imagination, and empirical A 116
consciousness in pure apperception, that is, in the thorough-
going identity of the self in all possible representations.
  If, now, we desire to follow up the inner ground of this
connection of the representations to the point upon which  -=
they have all to converge in order that they may therein for
the first time acquire the unity of knowledge necessary for
a possible experience, we must begin with pure appercep-
tion. Intuitions are nothing to us, and do not in the least
concern us if they cannot be taken up into consciousness, in
which they may participate- either directly or indirectly.  In
this way alone is any knowledge possible. We are conscious
a <1priori>1 of the complete identity of the self in respect of all
representations which can even belong to our knowledge, as
being a necessary condition of the possibility of all representa-
00030
tions. For in me they can represent something only in so far
as they belong with all others 1 to one consciousness,  and
therefore must be at least capable of being so connected.
This principle holds <1a priori,>1 and may be called the tran-
scendental principle of the <1unity>1 of all that is manifold in our
representations, and consequently also in intuition. Since this
unity of the manifold in one subject is synthetic, pure apper-
A 117  ception supplies a principle of the synthetic unity of the mani-
  fold in all possible intuition a
A 118  This synthetic unity presupposes or includes a synthesis,
  and if the former is to be <1apriori>1 necessary, the synthesis must
  also be <1apriori.>1 The transcendental unity of apperception thus
  relates to the pure synthesis of imagination, as an <1a priori->1
  condition of the possibility of all combination of the manifold
  in one knowledge. But only the <1productive>1 synthesis of the
  a This proposition is of great importance and calls for careful
  consideration. All representations have a necessary relation to a
  <1possible>1 empirical consciousness. For if they did not have this, and
  if it were altogether impossible to become conscious of them, this
  would practically amount to the admission of their non-existence.
  But all empirical consciousness has a necessary relation to a tran-
  scendental consciousness which precedes all special experience,
  namely, the consciousness of myself as original apperception. It is
  therefore absolutely necessary that in my knowledge all conscious-
  ness should belong to a single consciousness, that of myself. Here,
  then, is a synthetic unity of the manifold (of consciousness), which
  is known <1a priori,>1 and so yields the ground for synthetic <1a priori>1
  propositions which concem pure thought, just as do space and time
  for the propositions which refer to the form of pure intuition. The
  synthetic proposition, that all the variety of <1empirical consciousness>1
  must be combined in one single a self-consciousness, is the <1abso->1
  <1lutely>1 first and synthetic principle of our thought in general. But
  it must not be forgotten that the bare representation "I' in relation
  to all other representations (the collective unity of which it makes
  possible) is transcendental consciousness. Whether this representa-
  tion is clear (empirical consciousness)  or obscure, or even whether
  it ever actually occurs, does not here concem us. But the possibility
  of the logical form of all knowledge is necessarily conditioned by
  relation to this apperception <1as afaculty.>1
00031
imagination can take place <1a priori;>1 the reproductive rests
upon empirical conditions. Thus the principle of the necessary
unity of pure (productive) synthesis of imagination, prior to
apperception, is the ground of the possibility of all know-
ledge, especially of experience.
  We entitle the synthesis of the manifold in imagination
transcendental, if without distinction of intuitions it is directed
exclusively to the <1a priori>1 combination of the manifold; and
the unity of this synthesis is called transcendental, if it is repre-
sented as <1a priori>1 necessary in relation to the original unity
of apperception. Since this unity of apperception underlies
the possibility of all knowledge, the transcendental unity of
the synthesis of imagination is the pure form of all possible
knowledge; and by means of it all objects of possible experi-
ence must be represented <1a priori.>1
  <1The unity of apperception in relation to the synthesis of>1 A 119
<1imagination>1 is the <1understanding;>1 and this same unity, with
reference to the <1transcendental synthesis>1 of the imagination,
the <1pure understanding.>1 In the understanding there are then
pure <1a priori>1 modes of knowledge1 which contain the neces-
sary unity of the pure synthesis of imagination in respect of all
possible appearances. These are the <1categories,>1 that is, the pure
concepts of understanding. The empirical faculty of know-
ledge in man must therefore contain an understanding which
relates to all objects of the senses, although only by means of
intuition and of its synthesis through imagination. All appear-
ances, as data for a possible experience, are subject to this
understanding. This relation of appearances to possible ex-
perience is indeed necessary, for otherwise they would yield
no knowledge and would not in any way concern us. We have,
therefore, to recognise that pure understanding, by means of
the categories, is a formal and synthetic principle of all ex-
periences, and that appearances have <1a necessary relation to>1
<1the understanding.>1  -
  We will now, starting from below, namely, with the em-
pirical, strive to make clear the necessary connection in which
understanding, by means of the categories, stands to appear-
ances. What is first given to us is appearance. When combined  A 120
with consciousness, it is called perception. (Save through its
00032
relation to a consciousness that is at least possible, appear-
ance could never be for us an object of knowledge, and so
would be nothing to us; and since it has in itself no objective
reality, but exists only in being known, it would be nothing
at all.) Now, since every appearance contains a manifold,
and since different perceptions therefore occur in the mind
separately and singly, a combination of them, such as they
cannot have in sense itself, is demanded. There must therefore
exist in us an active faculty for the synthesis of this manifold.
To this faculty I give the title, imagination. Its action, when
immediately directed upon perceptions, I entitle apprehen-
sion. Since imagination has to bring the manifold of intuition
into the form of an image, it must previously have taken the
impressions up into its activity, that is, have apprehended them.
A 121  But it is clear that even this apprehension of the manifold
  would not by itself produce an image and a connection of the
  impressions, were it not that there exists a subjective ground
  which leads the mind to reinstate a preceding perception
  alongside the subsequent perception to which it has passed,
  and so to form whole series of perceptions.  This is the repro-
  ductive faculty of imagination, which is merely empirical.
  If, however, representations reproduced one another in any
  order, just as they happened to come together, this would not
  lead to any determinate connection of them, but only to acci-
  dental collocations;1 and so would not give rise to any know-
  ledge. Their reproduction must, therefore, conform to a
  rule, in accordance with which a representation connects in
  the imagination with some one representation in preference
  to another. This subjective and <1empirical>1 ground of repro-
  duction according to rules is what is called the <1association>1 of
  representations.
  Now if this unity of association had not also an objective
  a Psychologists have hitherto failed to realise that imagination
  is a necessary ingredient of perception itself. This is due partly to
  the fact that that faculty has been limited to reproduction, partly to
  the belief that the senses not only supply impressions but also com-
  bine them so as to generate images of objects. For that purpose some-
  thing more than the mere receptivity of impressions is undoubtedly
  required, namely, a function for the synthesis of them.
00033
ground which makes it impossible that appearances should
be apprehended by the imagination otherwise than under the
condition of a possible synthetic unity of this apprehension, it
would be entirely accidental that appearances should fit into a
connected whole of human knowledge. For even though we
should have the power of associating perceptions, it would
remain entirely undetermined and accidental whether they A 122
would themselves be associable; and should they not be associ-
able, there might exist a multitude of perceptions, and indeed
an entire sensibility, in which much empirical consciousness
would arise in my mind, but in a state of separation, and without
belonging to a consciousness of myself. This, however, is im-
possible. For it is only because I ascribe all perceptions to one
consciousness (original apperception) that I can say of all per-
ceptions that I am conscious of them. There must, therefore,
be an objective ground (that is, one that can be comprehended
<1apriori,>1 antecedently to all empirical laws of the imagination)
upon which rests the possibility, nay, the necessity, of a law
that extends to all appearances---a ground, namely, which
constrains us to regard all appearances as data of the senses
that must be associable in themselves and subject to universal
rules of a thoroughgoing connection in their reproduction.
This objective ground of all association of appearances I
entitle their <1affinity.>1 It is nowhere to be found save in the
principle of the unity of apperception, in respect of all know-
ledge which is to belong to me. According to this principle all
appearances, without exception, must so enter the mind or be
apprehended, that they conform to the unity of appercep-
tion. Without synthetic unity in their connection, this would
be impossible; and such synthetic unity is itself, therefore,
objectively necessary.
  The objective unity of all empirical consciousness in one  A 123
consciousness, that of original apperception, is thus the neces-
sary condition of all possible perception; and [this being recog-
nised we can prove that] the affinity of all appearances, near or
remote, is a necessary consequence of a synthesis in imagina-  -=
tion which is grounded <1a priori>1 on rules.
  Since the imagination is itself a faculty of <1a priori>1 syn-  ==
thesis, we assign to it the title, productive imagination. In so
far as it aims at nothing but necessary unity in the synthesis of

00034
experience, they are only special determinations of still higher
laws, and the highest of these, under which the others all1
stand, issue <1a priori>1 from the understanding itself. They are
not borrowed from experience; on the contrary, they have to
confer upon appearances their conformity to law, and so to
make experience possible. Thus the understanding is some-
thing more than a power of formulating rules through com-
parison of appearances; it is itself the lawgiver of nature.
Save through it, nature, that is, synthetic unity of the mani-
A 127 fold of appearances according to rules, would not exist at
  all (for appearances, as such, cannot exist outside us---they
  exist only in our sensibility); and this nature, as object of
  knowledge in an experience, with everything which it may
  contain, is only possible in the unity of apperception. The
  unity of apperception is thus the transcendental ground of
  the necessary conformity to law of all appearances in one ex-
  perience. This same unity of apperception in respect to a
  manifold of representations (determining it out of a unity)
  acts as the rule, and the faculty of these rules is the under-
  standing. All appearances, as possible experiences, thus lie
  <1a priori>1 in the understanding, and receive from it their
  formal possibility, just as, in so far as they are mere in-
  tuitions, they lie in the sensibility, and are, as regards their
  form, only possible through it.
  However exaggerated and absurd it may sound, to say that
  the understanding is itself the source of the laws of nature,
  and so of its formal unity, such an assertion is none the less
  correct, and is in keeping with the object to which it refers,
  namely, experience. Certainly, empirical laws, as such, can
  never derive their origin from pure understanding. That is
  as little possible as to understand completely the inexhaust-
  ible multiplicity of appearances merely by reference to the
  pure form of sensible intuition. But all empirical laws are
A 128  only special determinations of the pure laws of understanding,
  under which, and according to the norm of which, they first
  become possible. Through them appearances take on an
  orderly character, just as these same appearances, despite
00035
the differences of their empirical form, must none the less
always be in harmony with the pure form of sensibility.
  Pure understanding is thus in the categories the law of
the synthetic unity of all appearances, and thereby first and
originally makes experience, as regards its form, possible.
This is all that we were called upon to establish in the tran-
scendental deduction of the categories, namely, to render
comprehensible this relation of understanding to sensibility,
and, by means of sensibility, to all objects of experience. The
objective validity of the pure <1a priori>1 concepts is thereby made
intelligible, and their origin and truth determined.
<1Summary Representation of the Correctness of this Deduction>1
  <1of the Pure Concepts of Understanding, and of its being>1
  <1the only Deduction possible>1
  If the objects with which our knowledge has to deal were
things in themselves, we could have no <1a priori>1 concepts of
them.  For from what source could we obtain the concepts?  If we
derived them from the object (leaving aside the question how
the object could become known to us), our concepts would A 129
be merely empirical, not <1a priori.>1 And if we derived them from
the self, that which is merely in us could not determine the
character of an object distinct from our representations, that
is, could not be a ground why a thing should exist character-
ised by that which we have in our thought, and why such a
representation should not, rather, be altogether empty. But
if, on the other hand, we have to deal only with appearances,
it is not merely possible, but necessary, that certain <1a priori>1
concepts should precede empirical knowledge of objects.
For since a mere modification of our sensibility can never be
met with outside us, the objects, as appearances, constitute an
object which is merely in us. Now to assert in this manner,
that all these appearances, and consequently all objects with
which we can occupy ourselves, are one and all in me, that
is, are determinations of my identical self, is only another
way of saying that there must be a complete unity of them
in one and the same apperception. But this unity of possible
consciousness also constitutes the form of all knowledge of
objects; through it the manifold is thought as belonging to a
00036
single object. Thus the mode in which the manifold of sensible
representation (intuition) belongs to one consciousness pre-
cedes all knowledge of the object as the intellectual form of
such knowledge, and itself constitutes a formal <1a priori>1 know-
A 13o ledge of all objects, so far as they are thought (categories).
  The synthesis of the manifold through pure imagination,
  the unity of all representations in relation to original apper-
  ception, precede all empirical knowledge. Pure concepts of
  understanding are thus <1a priori>1 possible, and, in relation to
  experience, are indeed necessary; and this for the reason
  that our knowledge has to deal solely with appearances, the
  possibility of which lies in ourselves, and the connection and
  unity of which (in the representation of an object) are to be
  met with only in ourselves. Such connection and unity must
  therefore precede all experience, and are required for the
  very possibility of it in its formal aspect. From this point of
  view, the only feasible one, our deduction of the categories
  has been developed.
00037
DEDUCTION OF THE PURE CONCEPTS OF THE
  UNDERSTANDING1
  [As <1restated in 2nd edition]>1
  Section 2
TRANSCENDENTAL DEDUCTION OF THE PURE CONCEPTS
  OF THE UNDERSTANDING
    #I5
  <1The Possibility of Combination in General>1
THE manifold of representations can be given in an intuition
which is purely sensible, that is, nothing but receptivity; and
the form of this intuition can lie <1a priori>1 in our faculty of
representation, without being anything more than the mode in
which the subject is affected. But the combination <1(conjunction)>1
of a manifold in general can never come to us through the
senses, and cannot, therefore, be already contained in the pure
form of sensible intuition. For it is an act of spontaneity of the  B 130
faculty of representation; and since this faculty, to distinguish
it from sensibility, must be entitled understanding, all com-
bination---be we conscious of it or not, be it a combination of
the manifold of intuition, empirical or non-empirical, or of
various concepts---is an act of the understanding. To this act
the general title "synthesis' may be assigned, as indicating
that we cannot represent to ourselves anything as combined in
the object which we have not ourselves previously combined,
and that of all representations <1combination>1 is the only one which
00038
words, the <1analytic>1 unity of apperception is possible only under
the presupposition of a certain <1synthetic>1 unity a
B 134  The thought that the representations given in intuition one
-=-=  and all belong to me, is therefore equivalent to the thought
  that I unite them in one self-consciousness, or can at least
so unite them; and although this thought is not itself the
  consciousness of the <1synthesis>1 of the representations, it pre-
- supposes the possibility of that synthesis. In other words, only
  in so far as I can grasp the manifold of the representations in
  one consciousness, do I call them one and all <1mine.>1 For other-
  wise I should have as many-coloured and diverse a self as I
  have representations of which I am conscious to myself. Syn-
  thetic unity of the manifold of intuitions, as generated1 <1a>1
  <1priori,>1 is thus the ground of the identity of apperception itself,
  which precedes <1a priori>1 all <1my>1 determinate thought. Com-
  bination does not, however, lie in the objects, and cannot be
  borrowed from them, and so, through perception, first taken up
  into the understanding. On the contrary, it is an affair of the
  B 135 understanding alone, which itself is nothing but the faculty
  of combining <1a priori,>1 and of bringing the manifold of given
  representations under the unity of apperception. The principle
  of apperception is the highest principle in the whole sphere of
  human knowledge.
  This principle of the necessary unity of apperception is
  a  The analytic unity of consciousness belongs to all general con-
  cepts, as such. If, for instance, I think red in general, I thereby repre-
  sent to myself a property which (as a characteristic) can be found in
  something, or can he combined with other representations; that is,
  only by means of a presupposed possible synthetic unity can I repre-
  sent to myself the analytic unity. A representation which is to be
  thought as common to <1different>1 representations is regarded as be-
  B 134 longing to such as have, in addition to it, also something <1different.>1
  Consequently it must previously be thought in synthetic unity with
-  other (though, it may be, only possible) representations, before I can
  think in it the analytic unity of consciousness, which makes it a <1con->1
  <1ceptus communis.>1 The synthetic unity of apperception is therefore
  that highest point, to which we must ascribe all employment of the
  understanding, even the whole of logic, and conformably therewith,
  transcendental philosophy. Indeed this faculty of apperception is the
  understanding itself.
00039
  TRANSCENDENTAL DEDUCTION (B)  155
itself, indeed, an identical, and therefore analytic, proposi-
tion; nevertheless it reveals the necessity of a synthesis of the
manifold given in intuition, without which the thoroughgoing
identity of self-consciousness cannot be thought. For through
the "I', as simple representation, nothing manifold is given;
only in intuition, which is distinct from the "I', can a manifold
be given; and only through <1combination>1 in one conscious-
ness can it be thought. An understanding in which through
self-consciousness all the manifold would <1eo lyso>1 be given,
would be <1intuitive;>1 our understanding can only <1think,>1 and
for intuition must look to the senses. I am conscious of the
self as identical in respect of the manifold of representations
that are given to me in an intuition, because I call them one
and all <1my>1 representations, and so apprehend them as con-
stituting <1one>1 intuition. This amounts to saying, that I am
conscious to myself <1a priori>1 of a necessary synthesis of re-
presentations---to be entitled the original synthetic unity of
apperception---under which all representations that are given
to me must stand, but under which they have also first to
be brought by means of a synthesis-  B 136
  #I7
  <1The Principle of the Synthetic Unity is the Supreme>1
  <1Principle of all employment of the  Understanding>1
  The supreme principle of the possibility of all intuition in
its relation to sensibility is, according to the Transcendental
Aesthetic, that all the manifold of intuition should be subject
to the formal conditions of space and time. The supreme prin-
ciple of the same possibility, in its relation to understanding,
is that all the manifold of intuition should be subject to con-
ditions of the original synthetic unity of apperception.a In so
  a Space and time, and all their parts, are <1intuitions,>1 and are,
therefore, with the manifold which they contain, singular representa-
tions <1(vide>1 the Transcendental Aesthetic). Consequently they are not
mere concepts through which one and the same consciousness is
found to be contained in a number of representations. On the con-
tra1y, through them many representations are found to be contained
in one representation, and in the consciousness of that representa-
tion ; and they are thus composite. The unity of that consciousness
00040
far as the manifold representations of intuition are <1given>1 to us,
they are subject to the former of these two principles; in so far
as they must allow of being <1combined>1 in one consciousness,
B 137  they are subject to the latter. For without such combination
  nothing can be thought or known, since the given repre-
  sentations would not have in common the act of the apper-
  ception "I think', and so could not be apprehended together in
  <1knowledge.>1 This knowledge consists in the determinate re-
  lation of given representations to an object; and an <1object>1 is
  that in the concept of which the manifold of a given intuition
  is <1united.>1 Now all unification of representations demands
  unity of consciousness in the synthesis of them. Consequently
  it is the unity of consciousness that alone constitutes the
  relation of representations to an object, and therefore their
  objective validity and the fact that they are modes of know-
  ledge; and upon it therefore rests the very possibility of the
  understanding.
  The first pure knowledge of understanding, then, upon
  which all the rest of its employment is based, and which also
  at the same time is completely independent of all conditions
  of sensible intuition, is the principle of the original <1synthetic>1
  unity of apperception. Thus the mere form of outer sensible
  intuition, space, is not yet [by itself] knowledge; it supplies
  only the manifold of <1a priori>1 intuition for a possible know-
  ledge. To know anything in space (for instance, a line), l
B 138  must <1draw>1 it, and thus synthetically bring into being a de-
  terminate combination of the given manifold, so that the unity
  of this act is at the same time the unity of consciousness (as
  in the concept of a line); and it is through this unity of con-
  sciousness that an object (a determinate space) is first known.
:  The synthetic unity of consciousness is, therefore, an objective
  condition of all knowledge. It is not merely a condition that
  I myself require in knowing an object, but is a condition
  under which every intuition must stand in order <1to become>1
  <1an object for me.>1 For otherwise, in the absence of this
  is therefore synthetic and yet is also <1original.The singularity>1 of such
  intuitions is found to have important consequences <1(vide S>1 25)-
00041
synthesis, the manifold would <1not>1 be united in one con-
sciousness.
  Although this proposition makes synthetic unity a con-
dition of all thought, it is, as already stated, itself analytic.
For it says no more than that all <1my>1 representations in any
given intuition must be subject to that condition under which
alone I can ascribe them to the identical self as <1my>1 representa-
tions, and so can comprehend them as synthetically com-
bined in one apperception through the general expression,
"I <1think'.>1
  This principle is not, however, to be taken as applying
to every possible understanding, but only to that understand-
ing through whose pure apperception, in the representation
"I am', nothing manifold is given. An understanding which
through its self-consciousness could supply to itself the mani-
fold of intuition---an understanding, that is to say, through  B 139
whose representation the objects of the representation should
at the same time exist---would not require, for the unity of
consciousness, a special act of synthesis of the manifold. For
the human understanding, however, which thinks only, and
does not intuit, that act is necessary.  It is indeed the first
principle of the human understanding, and is so indispensable
to it that we cannot form the least conception of any other
possible understanding, either of such as is itself intuitive or
of any that may possess an underlying mode of sensible in-
tuition which is different in kind from that in space and time.
  #18
  <1The Objective Unity of Self-Consciousness>1
  The transcendental unity of apperception is that unity
through which all the manifold given in an intuition is united
in a concept of the object. It is therefore entitled <1objective,>1
and must be distinguished from the <1subjective>1 unity of con-
sciousness, which is a <1determination>1 of <1inner sense->1--through
which the manifold of intuition for such [objective] c mbina-
tion is empirically given. Whether I can become <1em irically>1
conscious of the manifold as simultaneous or as s  cessive
depends on circumstances or empirical conditions. Therefore
00042
B 140 the empirical unity of consciousness, through association of
  representations, itself concerns an appearance, and is wholly
  contingent. But the pure form of intuition in time, merely
  as intuition in general, which contains a given manifold, is
  subject to the original unity of consciousness, simply through
  the necessary relation of the manifold of the intuition to
  the one "I <1think',>1 and so through the pure synthesis of
  understanding which is the <1a priori>1 underlying ground of
  the empirical synthesis. Only the original unity is objectively
  valid; the empirical unity of apperception, upon which we
  are not here dwelling, and which besides is merely derived
  from the former under given conditions <1in concreto,>1 has only
  subjective validity. To one man, for instance; a certain word
  suggests one thing, to another some other thing; the unity
  of consciousness in that which is empirical is not, as regards
  what is given, necessarily and universally valid.
  #19
  <1The Logical Form of all Judgments consists in the Objective>1
  <1Unity of the Apperception of the Concepts which they>1
  <1contain>1
  I have never been able to accept the interpretation which
  logicians give of judgment in general. It is, they declare,
  the representation of a relation between two concepts. I do
  B 141  not here dispute with them as to what is defective in this
  interpretation---that in any case it applies only to <1categorical,>1
  not to hypothetical and disjunctive judgments (the two latter
  containing a relation not of concepts but of judgments), an
  oversight from which many troublesome consequences have
  o owe. -  nee  n y po1n out that the definition does not
  a The lengthy doctrine of the four syllogistic figures concems
  categorical syllogisms only; and although it is indeed nothing more
  than an artificial method of securing, through the surreptitious
  introduction of immediate inferences <1(consequentiae i-mmediatae)>1
=    among the premisses of a pure syllogism, the appearance that there
  are more kinds of inference than that of the first figure, this would
  hardly have met with such remarkable acceptance, had not its
  authors succeeded in bringing categorical judgments into such ex-
00043
But if I investigate more precisely the relation of the given
modes of knowledge1 in any judgment, and distinguish it,
as belonging to the understanding, from the relation accord-
ing to laws of the reproductive imagination, which has
only subjective validity, I find that a judgment is nothing
but the manner in which given modes of knowledge are
brought to the objective unity of apperception. This is what
is intended by the copula "is'. It is employed to distinguish  B 142
the objective unity of given representations from the sub-
jective. It indicates their relation to original apperception,
and its <1necessary unity.>1 It holds good even if the judgment
is itself empirical, and therefore contingent, as, for example,
in the judgment, "Bodies are heavy'. I do not here assert that
these representations <1necessarily>1 belong <1to one another>1 in the
empirical intuition, but that they belong to one another <1in>1
<1virtue of the necessary unity>1 of apperception in the synthesis
of intuitions, that is, according to principles of the object-
ive determination of all representations, in so far as know-
ledge can be acquired by means of these representations---
principles which are all derived from the fundamental prin-
ciple of the transcendental unity of apperception. Only in this
way does there arise from this relation a <1judgment,>1 that is, a
relation which is <1objectively valid,>1 and so can be adequately
distinguished from a relation of the same representations
that would have only subjective validity---as when they are
connected according to laws of association. In the latter case,
all that I could say would be, "If I support a body, I feel an
impression of weight';  I could not say, "It, the body, is heavy'.
Thus to say "The body is heavy' is not merely to state that
the two representations have always been conjoined in my
perception, however often that perception be repeated; what
we are asserting is that they are combined <1in the object,>1 no
matter what the state of the subject may be.
clusive respect, as being those to which all others must allow of
being reduced---teaching which, as indicated in # 9, is none the less
erroneous.
00044
B143  3 20
  <1fall Sensible Intuitions are subject to the Categories, as Con->1
  <1gether in one Consciousness>1
  The manifold given in a sensible intuition is necessarily
  subject to the original synthetic unity of apperception, be-
  cause in no other way is the <1unity>1 of intuition possible (# I7).
  But that act of understanding by which the manifold of given
  representations (be they intuitions or concepts) is brought
  under one apperception, is the logical function of judgment
  (cf. # I9). All the manifold, therefore, so far as it is given in a
  single empirical intuition, is <1determined>1 in respect of one of
  the logical functions of judgment, and is thereby brought into
  one consciousness. Now the <1categories>1 are just these functions
  of judgment, in so far as they are employed in determination
  of the manifold of a given intuition (cf. # 13). Consequently,
  the manifold in a given intuition is necessarily subject to the
  categories.
  B144 #2I
  <1Observation>1
  A manifold, contained in an intuition which I call mine, is
  represented, by means of the synthesis of the understanding, as
  belonging to the <1necessary>1 unity of self-consciousness; and this
  is effected by means of the category.a This [requirement of a]
  category therefore shows that the empirical consciousness of a
  given manifold in a single intuition is subject to a pure self-
  consciousness <1a priori,>1 just as is empirical intuition to a pure
  sensible intuition, which likewise takes place <1apriori.>1 Thus in
  the above proposition a beginning is made of a <1deduction>1 of
  the pure concepts of understanding; and in this deduction,
  since the categories have their source in the understanding
  alone, <1independently of sensibility,>1 I must abstract from the
  a  The proof of this rests on the represented <1unity of intuition,>1 by
  which an object is given. This unity of intuition always includes in
  itself a synthesis of the manifold given for an intuition, and so
  already contains the relation of this manifold to the unity of apper-
  ception.
00045
mode in which the manifold for an empirical intuition is given,
and must direct attention solely to the unity which, in terms of
the category, and by means of the understanding, enters into
the intuition. In what follows (cf. # 26) it will be shown, from
the mode in which the empirical intuition is given in sensibil-
ity, that its unity is no other than that which the category  B 145
(according to # 20) prescribes to the manifold of a given in-
tuition in general. Only thus, by demonstration of the <1apriori>1
validity of the categories in respect of all objects of our senses,
will the purpose of the deduction be fully attained.
  But in the above proof there is one feature from which I
could not abstract, the feature, namely, that the manifold to be
intuited must be given prior to the synthesis of understanding,
and independently of it.  How this takes place, remains here
undetermined. For were I to think an understanding which is
itself intuitive (as, for example, a divine understanding which
should not represent to itself given objects, but through whose
representation the objects should themselves be given or pro-
duced), the categories would have no meaning whatsoever in
respect of such a mode of knowledge. They are merely rules for
an understanding whose whole power consists in thought, con-
sists, that is, in the act whereby it brings the synthesis of a mani-
fold, given to it from elsewhere in intuition, to the unity of ap-
perception---a faculty, therefore, which by itself knows nothing
whatsoever, but merely combines and arranges the material of
knowledge, that is, the intuition, which must be given to it by
the object. This peculiarity of our understanding, that it can
produce <1a priori>1 unity of apperception solely by means of the
categories, and only by such and so many, is as little capable  B 146
of further explanation as why we have just these and no other
functions of judgment, or why space and time are the only
forms of our possible intuition.
  # 22
  <1The Category has no other Application in knowledge>1
  <1than to Objects of Experience>1
  To <1think>1 an object and to <1know>1 an object are thus by no
means the same thing  Knowledge involves two factors: first,
00046
be applied. We could not, for instance, apply to it the concept
of substance, meaning something which can exist as subject
and never as mere predicate. For save in so far as empirical
:=  intuition provides the instance to which to apply it, I do not
  know whether there can be anything that corresponds to such
  a form of thought. But of this more hereafter.
  B150  #24
  <1The Application of the Categories to Objects of the Senses>1
  <1in General>1
  The pure concepts of understanding relate, through the
=====::===  mere understanding, to objects of intuition in general, whether
  that intuition be our own or any other, provided only it be
  - sensible. The concepts are, however, for this very reason, mere
  <1forms of thought,>1 through which alone no determinate object is
  known.  The synthesis or combination of the manifold in them
  relates only to the unity of apperception, and is thereby the
  ground of the possibility of <1apriori>1 knowledge, so far as such
  knowledge rests on the understanding. This synthesis, there-
=  fore, is at once transcendental and also purely intellectual. But
  since there lies in us a certain form of <1a priori>1 sensible intui-
  tion, which depends on the receptivity of the faculty of repre-
  sentation (sensibility),the understanding, as spontaneity, is able
  to determine inner sense through the manifold of given repre-
  sentations, in accordance with the synthetic unity of apper-
  ception, and so to think synthetic unity of the apperception
  of the manifold of <1a priori sensible intuition->1--that being the
  condition under which all objects of our human intuition must
  necessarily stand. In this way the categories, in themselves
  mere forms of thought, obtain objective reality, that is, ap-
  B 151  plication to objects which can be given us in intuition. These
  objects, however, are only appearances, for it is solely of
  appearances that we can have <1a priori>1 intuition.
  This synthesis of the manifold of sensible intuition, which
  is possible and necessary <1a priori,>1 may be entitled <1fgurative>1
  synthesis <1(synthesis speciosa),>1 to distinguish it from the syn-
  thesis which is thought in the mere category in respect of the
  manifold of an intuition in general, and which is entitled
  combination through the understanding <1(synthesis intellectua->1
00047
<1lis).>1 Both are <1transcendental,>1 not merely as taking place 1
<1a priori,>1 but also as conditioning the possibility of other
<1a priori>1 knowledge.
  But the figurative synthesis, if it be directed merely
to the original synthetic unity of apperception, that is, to
the transcendental unity which is thought in the categories,
must, in order to be distinguished from the merely intellec-
tual combination, be called the <1tramscendental synthesis of>1
<1magination. Imagination>1 is the faculty of representing in
intuition an object that is <1not itseifpresent.>1 Now since all our
intuition is sensible, the imagination, owing to the subjective
condition under which alone it can give to the concepts of
understanding a corresponding intuition, belongs to <1sen->1
<1sibility.>1 But inasmuch as its synthesis is an expression of
spontaneity, which is determinative and not, like sense, deter-
minable merely, and which  is therefore able to determine  B 152
sense <1a priori>1 in respect of its form in accordance with the
unity of apperception, imagination is to that extent a faculty
which determines the sensibility <1apriori;>1 and its synthesis of
intuitions, conforming as it does to the <1categories,>1 must be
the transcendental synthesis of <1imagination.>1 This synthesis is
an action of the understanding on the sensibility; and is
its first application---and thereby the ground of all its other
applications---to the objects of our possible intuition. As
figurative, it is distinguished from the intellectual synthesis,
which is carried out by the understanding alone, without the
aid of the imagination. In so far as imagination is spontaneity,
I sometimes also entitle it the <1productive>1 imagination, to dis-
tinguish it from the <1reproductive>1 imagination, whose synthesis
is entirely subject to empirical laws, the laws, namely, of
association, and which therefore contributes nothing to the
explanation of the possibility of <1apriori>1 knowledge. The repro-
ductive synthesis falls within the domain, not of transcendental
hilosophy, but of psychology.
  *  :  *
  This is a suitable place for explaining the paradox which
must have been obvious to everyone in our exposition of the
00048
form of inner sense (# 6): namely, that this sense represents
B 153 to consciousness even our own selves only as we appear to
  ourselves, not as we are in ourselves. For we intuit ourselves
  only as we are inwardly <1affected,>1 and this would seem to be
  contradictory, since we should then have to be in a passive
  relation [of active affection] to ourselves. It is to avoid this
  contradiction that in systems of psychology <1inner sense,>1
  which we have carefully distinguished from the faculty
  of <1apperception,>1 is commonly regarded as being identical
  with it.
  What determines inner sense is the understanding and its
  original power of combining the manifold of intuition, that is,
  of bringing it under an apperception, upon which the possi-
  bility of undestanding itself rest. Nowthe understanding in us men is not  a faculty o intiutions,
 and cannot,
  even if intuitions be given in sensibility, take them up <1into>1
  <1itself in>1 such manner as to combine them as the manifold of
  its <1own>1 intuition. Its synthesis, therefore, if the synthesis be
  viewed by itself alone, is nothing but the unity of the act,
  of which, as an act, it is conscious to itself, even without
  [the aid of] sensibility, but through which it is yet able to
  determine the sensibility. The understanding, that is to say,
  in respect of the manifold which may be given to it in accord-
  ance with the form of sensible intuition, is able to deter-
  mine sensibility inwardly. Thus the understanding, under
  the title of a <1transcendental synthesis of imagination,>1 performs
  this act upon the <1passive>1 subject, whose <1faculty>1 it is, and we
  B 154 are therefore justified in saying that inner sense is affected
  thereby. Apperception and its synthetic unity is, indeed, very
"  far from being identical with inner sense. The former, as the
  source of all <1combination,>1 applies to the manifold of <1intui->1
  <1tions in general,>1 and in the guise of the <1categories,>1 prior
 (  to all sensible intuition, to <1objects in general.>1 Inner sense,
  on the other hand, contains the mere form of intuition, but
  without combination of the manifold in it, and therefore so
  far contains no <1determinate>1 intuition, which is possible only
  through the consciousness of the determination of the manifold
  by the transcendental act of imagination (synthetic influence
00049
of the understanding upon inner sense), which I have entitled
figurative synthesis.
  This we can always perceive in ourselves. We cannot think
a line without <1drawing>1 it in thought, or a circle without
<1describing>1 it. We cannot represent the three dimensions of
space save by <1setting>1 three lines at right angles to one another
from the same point. Even time itself we cannot represent,
save in so far as we attend, in the <1drawing>1 of a straight line
(which has to serve as the outer figurative representation of
time), merely to the act of the synthesis of the manifold where-
by we successively determine inner sense, and in so doing
attend to the succession of this determination in inner sense.
Motion, as an act of the subject (not as a determination of
an object),a and therefore the synthesis of the manifold in  B 155
space, first produces the concept of succession---if we abstract
from this manifold and attend solely to the act through which
we determine the <1inner>1 sense according to its form. The
understanding does not, therefore, find in inner sense such
a combination of the manifold, but <1produces>1 it, in that it
<1affects>1 that sense.
  How the "I' that thinks1 can be distinct from the "I' that
intuits itself (for I can represent still other modes of intuition
as at least possible), and yet, as being the same subject, can be
identical with the latter; and how, therefore, I can say: ""I, as
intelligence and <1thinking>1 subject, know myself as an object
that is <1thought,>1 in so far as I am given to myself (as some-
thing other or] beyond that [I] which is [given to myself] in
intuition, and yet know myself, like other phenomena, only
as I appear to myself, not as I am to the understanding''---
these are questions that raise no greater nor less difficulty
than how I can be an object to myself at all, and, more
particularly, an object of intuition and of inner perceptions.  B 156
  a  Motion of an object in space does not belong to a pure science,
and consequently not to geometry. For the fact that something is
movable cannot be known <1a priori,>1 but only through experience.
Motion, however, considered as the describing of a space, is a pure
act of the successive synthesis of the manifold in outer intuition in
general by means of the productive imagination, and belongs not
only to geometry, but even to transcendental philosophy.
00050
Indeed, that this is how it must be, is easily shown---if we
admit that space is merely a pure form of the appearances of
outer sense---by the fact that we cannot obtain for ourselves
a representation of time, which is not an object of outer in-
tuition, except under the image of a line, which we draw, and
that by this mode of depicting it alone could we know the
singleness1 of its dimension; and similarly by the fact that
for all inner perceptions we must derive the determination of
lengths of time or of points of time from the changes which
are exhibited to us in outer things, and that the determina-
tions of inner sense have therefore to be arranged as appear-
ances in time in precisely the same manner in which we
arrange those of outer sense in space. If, then, as regards the
latter, we admit that we know objects only in so far as we
are externally affected, we must also recognise, as regards
inner sense, that by means of it we intuit ourselves only as
we are inwardly affected <1by ourselves;>1 in other words, that,
so far as inner intuition is concerned, we know our own
subject only as appearance, not as it is in itself a
B157  #25
  On the other hand, in the transcendental synthesis of the
  manifold of representations in general, and therefore in the
  synthetic original unity of apperception, I am conscious of
  myself, not as I appear to myself, nor as I am in myself, but
  only that I am. This <1representation>1 is a <1thought,>1 not an <1intui->1
  <1tion.>1 Now in order to <1know>1 ourselves, there is required in
  addition to the act of thought, which brings the manifold
  of every possible intuition to the unity of apperception, a de-
  terminate mode of intuition, whereby this manifold is given;
  it therefore follows that although my existence is not indeed
  a I do not see why so much difficulty should be found in admit-
  ting that our inner sense is affected by ourselves. Such affection finds
  B 157 exemplification in each and every act of <1attention.>1 In every act of
  attention the understanding determines inner sense, in accordance
  with the combination which it thinks, to that inner intuition which
  corresponds to the manifold in the synthesis of the understanding.
  How much the mind is usually thereby affected, everyone will be
'  able to perceive in himself.
00051
appearance (still less mere illusion), the determination of my
existencea can take place only in conformity with the form of  B 158
inner sense, according to the special mode in which the mani-
fold, which I combine, is given in inner intuition. Accordingly
I have no <1knowledge>1 of myself as I am but merely as I appear
to myself. The consciousness of self is thus very far from being
a knowledge of the self, notwithstanding all the categories
which [are being employed to] constitute the thought of an
<1object in general,>1 through combination of the manifold in one
apperception. Just as for knowledge of an object distinct from
me I require, besides the thought of an object in general
(in the category), an intuition by which I determine that
general concept, so for knowledge of myself I require, besides
the consciousness, that is, besides the thought of myself, an
intuition of the manifold in me, by which I determine this
thought. I exist as an intelligence which is conscious solely
of its power of combination; but in respect of the manifold  B 159
which it has to combine I am subjected to a limiting condition
(entitled inner sense), namely, that this combination can be
made intuitable only according to relations of time, which
lie entirely outside the concepts of understanding, strictly re-
garded. Such an intelligence, therefore, can know itself only
as it appears to itself in respect of an intuition which is not
intellectual and cannot be given by the understanding itself,
not as it would know itself if its <1intuition>1 were intellectual.
  a The "I think' expresses the act of determining my existence.
Existence is already given thereby, but the mode in which I am to
determine this existence, that is, the manifold belonging to it, is not
thereby given. In order that it be given, self-intuition is required;
and such intuition is conditioned by a given <1a priori>1 form, namely,
time, which is sensible and belongs to the receptivity of the deter-
minable [in me]. Now since I do not have another self-intuition B 158
which gives the <1determining>1 in me (I am conscious only of the
spontaneity of it) prior to the act of <1determi-nation,>1 as time does
in the case of the determinable, I cannot determine my existence
as that of a self-active being; all that I can do is to represent to
myself the spontaneity of my thought, that is, of the determination;
and my existence is still only determinable sensibly, that is, as the
existence of an appearance. But it is owing to this spontaneity that
I entitle myself an <1intelligence.>1
00052
00053
00054
to sensibility, simply in order to emphasise that it precedes any con-  B 161
00055
 # 26
  <1Transcendental Deduction of the Universally Possible Em->1
  <1ployment in experience of the Pure Concepts of the>1
  <1Understanding>1
  In the <1metaphysical deduction>1 the <1a priori>1 origin of the
  categories has been proved through their complete agreement
  with the general logical functions of thought; in the <1transcen->1
  <1dental deduction>1 we have shown their possibility as <1a priori>1
  modes of knowledge of objects of an intuition in general
  (cf. ## 2o, 21)- We have now to explain the possibility of
  knowing <1a priori,>1 by means of <1categories,>1 whatever objects
  may <1present themselves to our senses,>1 not indeed in respect
  of the form of their intuition, but in respect of the laws of
  their combination, and so, as it were, of prescribing laws to
  B 160  nature, and even of making nature possible. For unless the cate-
  gories discharged this function, there could be no explaining
  why everything that can be presented to our senses must be
  subject to laws which have their origin <1a priori>1 in the under-
  standing alone.
  First of all, I may draw attention to the fact that by <1syn->1
==  <1thesis of apprehension>1 I understand that combination of the
  manifold in an empirical intuition, whereby perception, that
  is, empirical consciousness of the intuition (as appearance),
  .  .  . .
  In the representations of space and time we have <1a priori->1
  <1forms>1 of outer and inner sensible intuition; and to these the
  synthesis of apprehension of the manifold of appearance must
  always conform, because in no other way can the synthesis
  ====  take place at all. But space and time are represented <1a priori->1
  not merely as <1forms>1 of sensible intuition, but as themselves
  =  <1intuitions>1 which contain a manifold [of their own], and there-
  fore are represented with the determination of the <1unity>1
  of this manifold <1(vide>1 the Transcendental Aesthetic). Thus
  a Space represented as <1object>1 (as we are required to do in geo-
  metry), contains more than mere form of intuition; it also contains
  <1combination>1 of the manifold, given according to the form of sensi-
  bility, in an <1intuitive>1 representation, so that the <1form of intuition>1
  gives only a manifold, <1the formal intuition>1 gives unity of representa-
    tion. In the Aesthetic I have treated this unity as belonging merely
00056
<1unity of the synthesis>1 of the manifold, without or within us,  B 161
and consequently also a <1combination>1 to which everything that
is to be represented as determined in space or in time must
conform, is given <1a priori>1 as the condition of the synthesis
of all <1apprehension-->1-not indeed in, but with these intuitions.
This synthetic unity can be no other than the unity of the
combination of the manifold of a given <1intuition in general>1
in an original consciousness, in accordance with the cate-
gories, in so far as the combination is applied to our <1sensible>1
<1intuition.>1 All synthesis, therefore, even that which renders
perception possible, is subject to the categories; and since
experience is knowledge by means of connected perceptions,
the categories are conditions of the possibility of experience,
and are therefore valid <1a priori>1 for all objects of experience.
  *  *  *
  When, for instance, by apprehension of the manifold of a  B 162
house I make the empirical intuition of it into a perception,
the <1necessary unity>1 of space and of outer sensible intuition in
general lies at the basis of my apprehension, and I draw as it
were the outline of the house in conformity with this synthetic
unity of the manifold in space. But if I abstract from the form
of space, this same synthetic unity has its seat in the under-
standing, and is the category of the synthesis of the homogene-
ous in an intuition in general, that is, the category of <1quantity.>1
To this category, therefore, the synthesis of apprehension, that
is to say, the perception, must completely conform
to sensibility, simply in order to emphasise that it precedes any con-  B 161
cept, although, as a Matter of fact, it presupposes a synthesis which
does not belong to  e senses but through which all concepts of
space and time first become possible. For since by its means (in that
the understanding determines the sensibility) space and time are
first <1given>1 as intuitions, the unity of this <1apriori>1 intuition belongs to
space and time, and not to the concept of the understanding (cf.
# 24)-
which is empirical, must necessarily be in conformity with the syn-
thesis of apperception, which is intellectual and is contained in the
category completely <1a priori.>1 It is one and the same spontaneity,
00057
  When, to take another example, I perceive the freezing of
water, I apprehend two states, fluidity and solidity, and these
as standing to one another in a relation of time. But in time,
B 163 which I place at the basis of the appearance [in so far] as
  [it is] inner <1intuition,>1 I necessarily represent to myself synthetic
  <1unity>1 of the manifold, without which that relation of time could
  not be given in an intuition as being <1determined>1 in respect of
  time-sequence. Now this synthetic unity, as a condition
  <1a priori>1 under which I combine the manifold of an <1intui>1-
  <1tion in general,>1 is---if I abstract from the constant form of
  my inner intuition, namely, time---the category of <1cause,>1 by
  means of which, when I apply it to my sensibility, I deter-
  mine <1everything that happens>1 in accordance with the relation
  which it prescribes, and I do so <1in time in general.>1 Thus my
  apprehension of such an event, and therefore the event itself,
  considered as a possible perception, is subject to the con-
  cept of the <1relation>1 of <1effects>1 and <1causes,>1 and so in all other
  cases.
  Categories are concepts which prescribe laws <1a priori>1 to
  appearances, and therefore to nature, the sum of all appear-
  ances <1(natura materialiter spectata).>1 The question therefore
  arises, how it can be conceivable that nature should have to
  proceed in accordance with categories which yet are not de-
  rived from it, and do not model themselves upon its pattern;
  that is, how they can determine <1a priori>1 the combination of
  the manifold of nature, while yet they are not derived from it.
  The solution of this seeming enigma is as follows.
B 164  That the <1laws>1 of appearances in nature must agree with the
  understanding and its <1a priori>1 form, that is, with its faculty
  of <1combining>1 the manifold in general, is no more surprising
  than that the appearances themselves must agree with the form
  of <1a priori>1 sensible intuition. For just as appearances do not
  exist in themselves but only relatively to the subject in which,
  so far as it has senses, they inhere, so the laws do not exist in
  the appearances but only relatively to this same being, so far as
  it has understanding. Things in themselves would necessarily,
  which in the one case, under the title of imagination, and in the other
  case, under the title of understanding, brings combination into the
  manifold of intuition.
00058
apart from any understanding that knows them, conform to
laws of their own. But appearances are only representations of
things which are unknown as regards what they may be in
themselves. As mere representations, they are subject to no
law of connection save that which the connecting faculty pre-
scribes. Now it is imagination that connects the manifold of
sensible intuition; and imagination is dependent for the unity
of its intellectual synthesis upon the understanding, and for
the manifoldness of its apprehension upon sensibility. All
possible perception is thus dependent upon synthesis of appre-
hension, and this empirical synthesis in turn upon transcen-
dental synthesis, and therefore upon the categories. Conse-
quently, all possible perceptions, and therefore everything that
can come to empirical consciousness, that is, all appearances
of nature, must, so far as their connection is concerned, be sub-  B 165
ject to the categories. Nature, considered merely as nature in
general, is dependent upon these categories as the original
ground of its necessary conformity to law <1(natura formaliter>1
<1spectata).>1 Pure understanding is not, however, in a position,
through mere categories, to prescribe to appearances any
<1a pm-ori>1 laws other than those which are involved in a <1nature>1
<1in general,>1 that is, in the conformity to law of all appearances
in space and time. Special laws, as concerning those appear-
ances which are empirically determined, cannot in their specific
character be <1derived>1 from the categories, although they are
one and all subject to them. To obtain any knowledge what-
soever of these special laws, we must resort to experience; but
it is the <1a priori>1 laws that alone can instruct us in regard to
experience in general, and as to what it is that can be known
as an object of experience.
  #27
  <1Outcome of this Deduction of the Concepts of>1
  <1Understanding>1
  We cannot think an object save through categories; we
cannot <1know>1 an object so thought save through intuitions
corresponding to these concepts. Now all our intuitions are
sensible; and this knowledge, in so far as its object is given, is
empirical. But empirical knowledge is experience. <1Conse->1 B 166
00059
<1quently, there can be no>1 a priori <1knowledge, except of objects>1
<1of possible experience.a>1
  But although this knowledge is limited to objects of ex-
perience, it is not therefore all derived from experience. The
pure intuitions [of receptivity] and the pure concepts of under-
standing are elements in knowledge, and both are found in us
<1apriori.>1 There are only two ways in which we can account for
a <1necessary>1 agreement of experience with the concepts of its
objects: either experience makes these concepts possible or these
concepts make experience possible. The former supposition
B 167  does not hold in respect of the categories (nor of pure sensible
  intuition); for since they are <1a priori>1 concepts, and there-
  fore independent of experience, the ascription to them of an
  empirical origin would be a sort of <1generatio aequivoca.>1 There
  remains, therefore, only the second supposition---a system, as
  it were, of the <1epigenesis>1 of pure reason---namely, that the cate-
  gories contain, on the side of the understanding, the grounds
  of the possibility of all experience in general. How they make
  experience possible, and what are the principles of the possi-
  bility of experience that they supply in their application to
  appearances, will be shown more fully in the following chapter
  on the transcendental employment of the faculty of judgment.
  A middle course may be proposed between the two above
  mentioned, namely, that the categories are neither <1self-thought1>1
  first principles <1a priori>1 of our knowledge nor derived from ex-
  perience, but subjective dispositions of thought, implanted in
  us from the first moment of our existence, and so ordered by
  our Creator that their employment is in complete harmony
  with the laws of nature in accordance with which experience
00060
proceeds---a kind of <1preformation-system>1 of pure reason.
Apart, however, from the objection that on such an hypo-
thesis we can set no limit to the assumption of predetermined
dispositions to future judgments, there is this decisive objec-
tion against the suggested middle course, that the <1necessity>1  B 168
of the categories, which belongs to their very conception,
would then have to be sacrificed. The concept of cause, for
instance, which expresses the necessity of an event under a
presupposed condition, would be false if it rested only on an
arbitrary subjective necessity, implanted in us, of connecting
certain empirical representations according to the rule of
causal relation. I would not then be able to say that the effect
is connected with the cause in the object, that is to say, neces-
sarily, but only that I am so constituted that I cannot thina
this representation otherwise than as thus connected. This is
exactly what the sceptic most desires. For if this be the situa-
tion, all our insight, resting on the supposed objective validity
of Our judgments, is nothing but sheer illusion; nor would
there be wanting people who would refuse to admit this sub-
jective necessity, a necessity which can only be felt. Certainly
a man cannot dispute with anyone regarding that which de-
pends merely on the mode in which he is himself organised.
  <1Brief Outline of this Deduction>1
  The deduction is the exposition1 of the pure concepts of the
understanding, and therewith of all theoretical <1a priori>1 know-
ledge, as principles of the possibility of experience---the prin-
ciples being here taken as the <1determination>1 of appearances in
space and time <1in general,>1 and this determination, in turn, as  B 169
ultimately following from the <1original>1 synthetic unity of apper-
ception, as the form of the understanding in its relation to
space and time, the original forms of sensibility.
  I consider the division by numbered paragraphs as neces-
sary up to this point, because thus far we have had to treat
of the elementary concepts. We have now to give an account
of their employment, and the exposition may therefore pro-
ceed in continuous fashion, without such numbering.
00061
TRANSCENDENTAL ANALYTIC
  BOOK II
GENERAL logic is constructed upon a ground plan which
exactly coincides with the division of the higher faculties of
knowledge. These are: <1understanding,judgment,1>1 and <1reason.>1
A 131  In accordance with the functions and order of these mental
  powers, which in current speech are comprehended under the
  general title of understanding, logic in its analytic deals with
  <1concepts, judgments,>1 and <1inferences.>1
B 170  Since this merely formal logic abstracts from all content
  of knowledge, whether pure or empirical, and deals solely with
  the form of thought in general (that is, of discursive know-
  ledge), it can comprehend the canon of reason in its analytic
  portion. For the form of reason possesses its established rules,
  which can be discovered <1a priori,>1 simply by analysing the
  actions of reason into their components, without our requir-
  ing to take account of the special nature of the knowledge
  involved.
  As transcendental logic is limited to a certain determinate
  content, namely, to the content of those modes of knowledge
  which are pure and <1apriori,>1 it cannot follow general logic in
  this division. For the transcendental employment of reason is
  not, it would seem, objectively valid, and consequently does
  not belong to the <1logic of truth, i.e.>1 to the Analytic. As a
  <1logic of illusion,>1 it calls for separate location in the scholastic
  edifice, under the title of Transcendental Dialectic.
  176
00062
  ANALYTIC OF PRINCIPLES
Understanding and judgment find, therefore, in tran-
scendental logic their canon of objectively valid and correct
employment; they belong to its analytic portion. Reason, on
the other hand, in its endeavours to determine something <1a>1
<1priori>1 in regard to objects and so to extend knowledge beyond  B 171
the limits of possible experience, is altogether <1dialectical.>1 Its  A 132
illusory assertions cannot find place in a canon such as the
analytic is intended to contain.
  The <1Analytic of Principles>1 will therefore be a canon solely
<1forjudgment,>1 instructing it how to apply to appearances the
concepts of understanding, which contain the condition for
<1a priori>1 rules. For this reason, while adopting as my theme
the <1principles of the understanding,>1 strictly so called, I shall
employ the title <1doctrine ofjudgment>1 as more accurately in-
dicating the nature of our task.
  INTRODUCTION
  TRANSCENDENTAL JUDGMENT IN GENERAL
  If understanding in general is to be viewed as the faculty of
rules, judgment will be the faculty of subsuming under rules;
that is, of distinguishing whether something does or does not
stand under a given rule <1(casus datae legis).>1 General logic con-
tains, and can contain, no rules for judgment. For since general
logic abstracts from all content of knowledge, the sole task that
remains to it is to give an analytical exposition of the form of (B 172
knowledge [as expressed] in concepts, in judgments, and in
inferences, and so to obtain formal rules for all employment of
understanding. If it sought to give general instructions how we
are to subsume under these rules, that is, to distinguish whether
something does or does not come under them, that could only
be by means of another rule. This in turn, for the very reason
that it is a rule, again demands guidance from judgment.
And thus it appears that, though understanding is capable of
being instructed, and of being equipped with rules, judgment
is a peculiar talent which can be practised only, and cannot
be taught. It is the specific quality of so-called mother-wit;
and its lack no school can make good. For although an
abundance of rules borrowed from the insight of others may

00063
indeed be proffered to, and as it were grafted upon, a limited
understanding, the power of rightly employing them must
belong to the learner himself; and in the absence of such a
natural gift no rule that may be prescribed to him for this pur-
A 134) pose can ensure against misuse. A physician, a judge, or a
  ruler may have at command many excellent pathological,
  legal, or political rules, even to the degree that he may become
  a profound teacher of them, and yet, none the less, may easily
  stumble in their application. For, although admirable in
  understanding, he may be wanting in natural power of judg-
  ment. He may comprehend the universal <1in abstracto,>1 and yet
  not be able to distinguish whether a case <1in concreto>1 comes
  under it. Or the error may be due to his not having received,
  through examples and actual practice, adequate training for
  this particular act of judgment. Such sharpening of the judg-
  ment is indeed the one great benefit of examples. Correctness
  and precision of intellectual insight, on the other hand, they
  more usually somewhat impair. For only very seldom do they
  adequately fulfil the requirements of the rule (as <1casus in ter->1
  <1minis).>1 Besides, they often weaken that effort which is re-
  quired of the understanding to comprehend properly the rules
  in their universality, in independence of the particular circum-
  stances of experience, and so accustom us to use rules rather
  as formulas than as principles. Examples are thus the go-cart
B 174  of judgment; and those who are lacking in the natural talent
  can never dispense with them.
A 135  But although general logic can supply no rules for judg-
  ment, the situation is entirely different in transcendental logic.
  and securing of judgment, by means of determinate rules, in
=  the use of the pure inderstanding. For as a doctrine, that is,
  a Deficiency in judgment is just what is ordinarily called stupid-
  ity, and for such a failing there is no remedy. An obtuse or narrow-
  minded person to whom nothing is wanting save a proper degree of
  understanding and the concepts appropriate thereto, may indeed be
  trained through study, even to the extent of becoming learned. But
  B 173 as such people are commonly still lacking in judgment <1(secunda>1
  <1Petri),>1 it is not unusual to meet leamed men who in the application
  of their scientific knowledge betray that original want, which can
  never be made good.
00064
as an attempt to enlarge the sphere of the understanding in
the field of pure <1apriori>1 knowledge, philosophy is by no means
necessary, and is indeed ill-suited for any such purpose, since
in all attempts hitherto made, little or no ground has been won.
On the other hand, if what is designed be a critique to guard
against errors of judgment <1(lapsus judicii)>1 in the employment
of the few pure concepts of understanding that we possess,
the task, merely negative as its advantages must then be, is
one to which philosophy is called upon to devote all its re-
sources of acuteness and penetration.
  Transcendental philosophy has the peculiarity that besides
the rule (or rather the universal condition of rules), which is
given in the pure concept of understanding, it can also specify
<1a priori>1 the instance to which the rule1 is to be applied. The  B 175
advantage which in this respect it possesses over all other
didactical sciences, with the exception of mathematics, is due
to the fact that it deals with concepts which have to relate to
objects <1a priori,>1 and the objective validity of which cannot
therefore be demonstrated <1a posteriori,>1 since that would mean  A 136
the complete ignoring of their peculiar dignity. It must
formulate by means of universal but sufficient marks the con-
ditions under which objects can be given in harmony with
these concepts. Otherwise the concepts would be void of all  ===
content, and therefore mere logical forms, not pure concepts
of the understanding.
  This transcendental doctrine of judgment will consist of
two chapters. The first will treat of the sensible condition under
which alone pure concepts of understanding can be employed,
that is, of the schematism of pure understanding.The second
will deal with the synthetic judgments which under these con-
ditions follow <1a priori>1 from pure concepts of understanding,
and which lie <1a priori>1 at the foundation of all other modes of
knowledge---that is, with the principles of pure understanding.
00065
A 137) TRANSCENDENTAL DOCTRINE OF JUDGMENT
  (OR ANALYTIC OF PRINCIPLES)
  CHAPTER I
  THE SCHEMATISM OF THE PURE CONCEPTS OF
  UNDERSTANDING
  In all subsumptions of an object under a concept the repre-
  sentation of the object must be <1homogeneous>1 with the concept;
  in other words, the concept must contain something which is
  represented in the object that is to be subsumed under it.
  This, in fact, is what is meant by the expression, "an object is
  contained under a concept'. Thus the empirical concept of a
  <1Plate>1 is homogeneous with the pure geometrical concept of a
  <1circle.>1 The roundness which is thought in the latter can be
  intuited in the former.1
  But pure concepts of understanding being quite hetero-
  geneous from empirical intuitions, and indeed from all
  sensible intuitions, can never be met with in any intuition.
  For no one will say that a category, such as that of causality,
  A 1778  can be intuited through sense and is itself contained in appear-
  ance. How, then, is the <1subsumption>1 of intuitions under pure
  concepts, the <1application>1 of a category to appearances, pos-
  sible? A transcendental doctrine of judgment is necessary just
  because of this natural and important question. We must be
  able to show how pure concepts can be applicable to appear-
  ances. In none of the other sciences is this necessary. For since
  in these sciences the concepts through which the object is
  thought in [its] general [aspects] are not so utterly distinct
00066
as given, no special discussion of the applicability of the1
former to the latter is required.
  Obviously there must be some third thing, which is homo-
geneous on the one hand with the category, and on the other
hand with the appearance, and which thus makes the appli-
cation of the former to the latter possible. This mediating
representation must be pure, that is, void of all empirical
content, and yet at the same time, while it must in one
respect be <1intellectual,>1 it must in another be <1sensible.>1 Such a
representation is the <1transcendental schema.>1
  The concept of understanding contains pure synthetic
unity of the manifold in general. Time, as the formal con-
dition of the manifold of inner sense, and therefore of the
connection of all representations, contains an <1a priori>1 manifold
in pure intuition. Now a transcendental determination of
time is so far homogeneous with the category, which con-
stitutes its unity, in that it is universal and rests upon an  B 178
<1a priori>1 rule. But, on the other hand, it is so far homogeneous  A 139
with appearance, in that time is contained in every empirical
representation of the manifold. Thus an application of the
category to appearances becomes possible by means of the
transcendental determination of time, which, as the schema
of the concepts of understanding, mediates the subsumption
of the appearances under the category.
  After what has been proved in the deduction of the cate-
gories, no one, I trust, will remain undecided in regard to
the question whether these pure concepts of understanding
are of merely empirical or also of transcendental employ-
ment; that is, whether as conditions of a possible experience
they relate <1a pori>1 solely to appearances, or whether, as
conditions of the possibility of things in general, they can be
extended to objects in themselves, without any restriction
to our sensibility. For we have seen that concepts are alto-
gether impossible, and can have no meaning, if no object
is given for them, or at least for the elements of which they
are composed. They cannot, therefore, be viewed as appli-
cable to things in themselves, independent of all question
as to whether and how these may be given to us. We
00067
have also proved that the only manner in which objects
can be given to us is by modification of our sensibility; and
B 179  finally, that pure <1a priori>1 concepts, in addition to the function
A 140 of understanding expressed in the category, must contain
  <1a priori>1 certain formal conditions of sensibility, namely, those
  of inner sense. These conditions of sensibility constitute the
  universal condition under which alone the category can be
  applied to any object. This formal and pure condition of
  sensibility to which the employment of the concept of under-
  standing is restricted, we shall entitle the <1schema>1 of the
  concept. The procedure of understanding in these schemata
  we shall entitle the <1schematism>1 of pure understanding.
  The schema is in itself always a product of imagination.
  Since, however, the synthesis of imagination aims at no
  special intuition, but only at unity in the determination of
  sensibility, the schema has to be distinguished from the image.
  If five points be set alongside one another, thus, . . . . ., I
  have an image of the number five. But if, on the other hand,
  I think only a number in general, whether it be five or a
  hundred, this thought is rather the representation of a method
  whereby a multiplicity, for instance a thousand, may be re-
  presented in an image in conformity with a certain concept,
  than the image itself. For with such a number as a thousand
  the image can hardly be surveyed and compared with the
  concept. This representation of a universal procedure of
B 180  imagination in providing an image for a concept, I entitle the
  schema of this concept.
  Indeed it is schemata, not images of objects, which underlie
A 141  our pure sensible concepts. No image could ever be adequate
  to the concept of a triangle in general. It would never attain
:==  that universality of the concept which renders it valid of all
  triangles, whether right-angled, obtuse-angled, or acute-
  angled; it would always be limited to a part only of this
  sphere. The schema of the triangle can exist nowhere but in
  thought. It is a rule of synthesis of the imagination, in respect
  to pure figures in space. Still less is an object of experience or
  its image ever adequate to the empirical concept; for this latter
  always stands in immediate relation to the schema of imagina-
  tion, as a rule for the determination of our intuition, in accord-
  ance with some specific universal concept. The concept "dog'
00068
signifies a rule according to which my imagination can
delineate the figure of a four-footed animal in a general
manner, without limitation to any single determinate figure
such as experience, or any possible image that I can repre-
sent <1in concreto,>1 actually presents. This schematism of our
understanding, in its application to appearances and their
mere form, is an art concealed in the depths of the human
soul, whose real modes of activity nature is hardly likely ever  B 181
to allow us to discover, and to have open to our gaze. This
much only we can assert: the <1image>1 is a product of the
empirical faculty of reproductive1 imagination; the <1schema>1 of
sensible concepts, such as of figures in space, is a product and,  A 142
as it were, a monogram, of pure <1a priori>1 imagination, through
which, and in accordance with which, images themselves first
become possible. These images can be connected with the
concept only by means of the schema to which they belong.
In themselves they are never completely congruent with the
concept. On the other hand, the schema of a <1pure>1 concept of
understanding can never be brought into any image whatso-
ever. It is simply the pure synthesis, determined by a rule of
that unity, in accordance with concepts, to which the category
gives expression. It is a transcendental product of imagina-
tion, a product which concerns the determination of inner
sense in general according to conditions of its form (time), in
respect of all representations, so far as these representations
are to be connected <1a priori>1 in one concept in conformity with
the unity of apperception.
  That we may not be further delayed by a dry and tedious
analysis of the conditions demanded by transcendental
schemata of the pure concepts of understanding in general,
we shall now expound them according to the order of the
categories and in connection with them.
  The pure image of all magnitudes <1(quantorum)>1 for outer  B 182
sense is space; that of all objects of the senses in general is
time. But the pure <1schema>1 of magnitude <1(quantitatis),>1 as a
concept of the understanding, is <1number,>1 a representation
which comprises the successive addition of homogeneous
00069
imagination is simply the unity of all the manifold of intuition
  as a function corresponds to the receptivity of inner sense.
  the true and sole conditions under which these concepts ob-
00070
imagination is simply the unity of all the manifold of intuition
in inner sense, and so indirectly the unity of apperception which
as a function corresponds to the receptivity of inner sense.
A 146  The schemata of the pure concepts of understanding are thus
  the true and sole conditions under which these concepts ob-
  tain relation to objects and so possess <1signifcance.>1 In the end,
  therefore, the categories have no other possible employment
  than the empirical. As the grounds of an <1a priori>1 necessary
  unity that has its source in the necessary combination of all
  consciousness in one original apperception, they serve only to
  subordinate appearances to universal rules of synthesis, and
  thus to fit them for thoroughgoing connection in one ex-
  perience.
==  All our knowledge falls within the bounds of possible ex-
  perience, and just in this universal relation to possible experi-
  ence consists that transcendental truth which precedes all
  empirical truth and makes it possible.
  But it is also evident that although the schemata of sensibility first realise the catagories, the
y at the same time restrict
  them, that is, limit them to conditions which lie outside the
'  understanding, and are due to sensibility. The schema is, pro-
  perly, only the phenomenon, or sensible concept, of an object
=  in agreement with the category. (Numerus <1estquantitasphaeno->1
  <1menon,>1 sensatio <1realitas phaenomenon,>1 constans et perdurabile
  rerum <1substantia phaenomenon,>1 aeternitas <1necessitas phaeno->1
  <1menon,1 etc.)>1 If we omit a restricting condition, we would seem
  A 147  to extend the scope of the concept that was previously limited.
  Arguing from this assumed fact, we conclude that the cate-
.  gories in their pure significance, apart from all conditions of
  sensibility, ought to apply to things in general, <1as they are,>1
  and not, like the schemata, represent them only <1as they appear.>1
  They ought, we conclude, to possess a meaning independent
  of all schemata, and of much wider application. Now there
  certainly does remain in the pure concepts of understanding,
  even after elimination of every sensible condition, a meaning;
  but it is purely logical, signifying only the bare unity of the
  representations. The pure concepts can find no object, and so
00071
can acquire no meaning which might yield a concept1 of some
object. Substance, for instance, when the sensible determina-
tion of permanence is omitted, would mean simply a something
which can be thought only as subject, never as a predicate of
something else. Such a representation I can put to no use, for
it tells me nothing as to the nature of that which is thus to  B 187
be viewed as a primary subject. The categories, therefore,
without schemata, are merely functions of the understanding
for concepts; and represent no object. This [objective] mean-
ing they acquire from sensibility, which realises the under-
standing in the very process of restricting it.
00072
==  A 148 TRANSCENDENTAL DOCTRINE OF JUDGMENT
  (OR ANALYTIC OF PRINCIPLES)
  CHAPTER II
  SYSTEM OF ALL PRINCIPLES OF PURE UNDERSTANDING
  In the preceding chapter we have considered transcendental
  judgment with reference merely to the universal conditions
  under which it is alone justified in employing pure concepts
  of understanding for synthetic judgments. Our task now is
  to exhibit, in systematic connection, the judgments which
  understanding, under this critical provision, actually achieves
  <1a priori>1. There can be no question that in this enquiry our
  table of categories is the natural and the safe guide. For since
  it is through the relation of the categories to possible experi-
  ence that all pure <1a priori>1 knowledge of understanding has
  to be constituted, their relation to sensibility in general will
  B 188 exhibit completely and systematically all the transcendental
  principles of the use of the understanding.
     Principles <1a priori>1 are so named not merely because they
  contain in themselves grounds of other judgements, but also because they   are not themselves grou
nded in higher and more
  universal modes of knowledge. But this characteristic does not
  A 149  remove them beyond the sphere of proof. This proof cannot,
  indeed, be carried out in any objective fashion, since such
  principles [do not rest on objective considerations but]  lie at
  the foundation of all <1knowledge>1 of objects. This does not,
  however, prevent our attempting a proof, from the subjective
  sources of the possibility of knowledge of an object in general.
  Such proof is, indeed, indispensable, if the propositions are not
  to incur the suspicion of being merely surreptitious assertions.
00073
Secondly, we shall limit ourselves merely to those prin-
ciples which stand in relation to the categories. The principles
of the Transcendental Aesthetic, according to which space and
time are the conditions of the possibility of all things as ap-
pearances, and likewise the restriction of these principles,
namely, that they cannot be applied to things in themselves,
are matters which do not come within the range of our present
enquiry. For similar reasons mathematical principles form
no part of this system. They are derived solely from intuition,
not from the pure concept of understanding. Nevertheless,
since they too are synthetic <1a priori>1 judgments, their possi-  B 189
bility must receive recognition in this chapter. For though
their correctness and apodeictic certainty do not indeed re-
quire to be established, their possibility, as cases of evident
<1a priori>1 knowledge, has to be rendered conceivable, and to be
deduced.
  We shall also have to treat of the principle of analytic
judgments, in so far as it stands in contrast with that of syn-  A 150
thetic judgments with which alone strictly we have to deal.
For by thus contrasting them we free the theory of synthetic
judgments from all misu  erstanding, and have them in their
own peculiar nature clear before us.
  THE SYSTEM OF THE PRINCIPLES OF PURE
  UNDERSTANDING
  Section 1
THE HIGHEST PRINCIPLE OF ALL ANALYTIC JUDGMENTS
  The universal, though merely negative, condition of all our
judgments in general, whatever be the content of our know-
ledge, and however it may relate to the object, is that they be
not self-contradictory; for if self-contradictory, these judgments
are in themselves, even without reference to the object, null and
void. But even if ourjudgment contains no contradiction, it may  B 190
connect concepts in a manner not borne out by the object, or
else in a manner for which no ground is given, either <1a priori>1
or <1a posteriori,>1 sufficient to justify such judgment, and so may
00074
still, in spite of being free from all inner contradiction, be
either false or groundless.
A 151  The proposition that no predicate contradictory of a thing
  can belong to it, is entitled the principle of contradiction, and
  is a universal, though merely negative, criterion of all truth.
  merely as knowledge in general, irrespective of content; and
  asserts that the contradiction completely cancels and in-
  validates it.
  But it also allows of a positive employment, not merely,
  that is, to dispel falsehood and error (so far as they rest on
  contradiction), but also for the knowing of truth. For, if
  <1the judgment is analytic,>1 whether negative or affirmative, its
  truth can always be adequately known in accordance with the
  principle of contradiction. The reverse of that which as con-
  cept is contained and is thought in the knowledge of the object,
  B 191  is always rightly denied. But since the opposite of the concept
  would contradict the object, the concept itself must neces-
  sarily be affirmed of it.
  <1Theprincliple of contradiction>1 must therefore be recognised
  as being the universal and completely sufficient <1principle of>1
  <1all analytic knowledge;>1 but beyond the sphere of analytic
  knowledge it has, as a <1sufficient>1 criterion of truth, no authority
  and no field of application. The fact that no knowledge can
  be contrary to it without self-nullification, makes this prin-
  A 152  ciple a <1conditio sine qua non,>1 but not a determining ground,
  of the truth of our (non-analytic? knowledge. Now in our
  critical enquiry it is only with the synthetic portion of our
  knowledge that we are concerned; and in regard to the truth
  of this kind of knowledge we can never look to the above
  principle for any positive information, though, of course, since
  it is inviolable, we must always be careful to conform to it-
    Although this famous principle is thus without content and merely    formal, it has sometimes be
en carelessly formulated in a manner which involves the quite unnecessary admixture of
  a synthetic element. The formula runs: It is impossible that
  something should <1at one and the same time>1 both be and not be
  Apart from the fact that the apodeictic certainty, expresse
  through the word "impossible', is superfluously added---sinc
00075
it is evident of itself from the [very nature of the] proposition
---the proposition is modified by the condition of time. It then,
as it were, asserts: A thing=A, which is something= B, can-  B 192
not at the same time be not-B, but may very well in succession
be both B and not-B.  For instance, a man who is young cannot
at the same time be old, but may very well at one time be young
and at another time not-young, that is, old. The principle of
contradiction, however, as a merely logical principle, must not
in any way limit its assertions to time-relations. The above
formula is therefore completely contrary to the intention of the  A 153
principle. The misunderstanding results from our first of all
separating a predicate of a thing from the concept of that
thing, and afterwards connecting this predicate with its op-
posite---a procedure which never occasions a contradiction with
the subject but only with the predicate which has been syn-
thetically connected with that subject, and even then only
when both predicates are affirmed at one and the same time.
If I saythat a man who is unlearned is not learned, the con-
dition, <1at one and the same time,>1 must be added; for he who
is at one time unlearned can very well at another be learned.
But if I say, no unlearned man is learned, the proposition is
analytic, since the property, unlearnedness, now goes to make
up the concept of the subject, and the truth of the negative
judgment then becomes evident as an immediate consequence
of the principle of contradiction, without requiring the supple-
mentary condition, <1at one and the same time.>1 This, then, is
the reason why I have altered its formulation, namely, in order  B 193
that the nature of an analytic proposition be clearly expressed
through it.
  THE SYSTEM OF THE PRINCIPLES OF PURE  A 154
  UNDERSTANDING
  Section 2
THE HIGHEST PRINCIPLE OF ALL SYNTHETIC JUDGMENTS
  The explanation of the possibility of synthetic judgments
is a problem with which general logic has nothing to do. It
need not even so much as know the problem by name. But in
00076
transcendental logic it is the most important of all questions;
and indeed, if in treating of the possibility of synthetic <1apriori>1
judgments we also take account of the conditions and scope of
their validity, it is the only question with which it is concerned.
For upon completion of this enquiry, transcendental logic is
in a position completely to fulfil its ultimate purpose, that of
determining the scope and limits of pure understanding.
  In the analytic judgment we keep to the given concept,
and seek to extract something from it. If it is to be affirmative,
I ascribe to it only what is already thought in it. If it is to be
negative, I exclude from it only its opposite. But in synthetic
judgments I have to advance beyond the given concept,
B 194  viewing as in relation with the concept something altogether
  different from what was thought in it. This relation is con-
  sequently never a relation either of identity or of contradiction;
A 155  and from the judgment, taken in and by itself, the truth or
  falsity of the relation can never be discovered.
  Granted, then, that we must advance beyond a given
  concept in order to compare it synthetically with another, a
  third something 1 is necessary, as that wherein alone the syn-
  thesis of two concepts can be achieved. What, now, is this
  third something that is to be the medium of all synthetic
  judgments? There is only one whole in which all our re-
  presentations are contained, namely, inner sense and its
  <1a priori>1 form, time. The synthesis of representations rests on
  imagination; and their synthetic unity, which is required for
  judgment, on the unity of apperception. In these, therefore,
  [in inner sense, imagination, and apperception], we must
  look for the possibility of synthetic judgments; and since all
  three contain the sources of <1a priori>1 representations, they
  must also account for the possibility of <1pure>1 synthetic judg-
  ments. For these reasons they are, indeed, indispensably
  necessary for any knowledge of objects, which rests entirely
  on the synthesis of representations.
  If knowledge is to have objective reality, that is, to re-
  late to an object, and is to acquire meaning and significance
  in respect to it, the object must be capable of being in some
00077
manner given. Otherwise the concepts are empty; through
them we have indeed thought, but in this thinking we have  B 195
really known nothing; we have merely played with repre-
sentations. That an object be given (if this expression be A 156
taken, not as referring to some merely mediate process, but as
signifying immediate presentation in intuition), means simply
that the representation through which the object is thought
relates to actual or possible experience. Even space and time,
however free1 their concepts are from everything empirical,
and however certain it is that they are represented in the mind
completely <1a priori,>1 would yet be without objective validity,
senseless and meaningless, if their necessary application to
the objects of experience were not established. Their repre-
sentation is a mere schema which always stands in relation
to the reproductive imagination that calls up and assembles
the objects of experience. Apart from these objects of ex-
perience, they would be devoid of meaning. And so it is with
concepts of every kind.
  The <1possibility of experience>1 is, then, what gives objective
reality to all our <1a priori>1 modes of knowledge. Experience,
however, rests on the synthetic unity of appearances, that is,
on a synthesis according to concepts of an object of appear-
ances in general. Apart from such synthesis it would not be
knowledge, but a rhapsody of perceptions that would not fit
into any context according to rules of a completely intercon-
nected (possible) consciousness, and so would not conform to
the transcendental and necessary unity of apperception. Ex-  B 196
perience depends, therefore, upon <1a priori>1 principles of its
form, that is, upon universal rules of unity in the synthesis of  A 157
appearances. Their objective reality, as necessary conditions
of experience, and indeed of its very possibility, can always
be shown in experience. Apart from this relation synthetic
<1a priori>1 principles are completely impossible. For they have
then no third something, that is, no object, in which the
synthetic unity can exhibit the objective reality of its concepts.
  Although we know <1a priori>1 in synthetic judgments a great
deal regarding space in general and the figures which produc-
00078
tive imagination describes in it, and can obtain such judg-
ments without actually requiring any experience, yet even this
knowledge would be nothing but a playing with a mere fig-
ment of the brain, were it not that space has to be regarded as
a condition of the appearances which constitute the material
for outer experience. Those pure synthetic judgments there-
fore relate, though only mediately, to possible experience, or
rather to the possibility of experience; and upon that alone is
founded the objective validity of their synthesis.
  Accordingly, since experience, as empirical synthesis, is,
in so far as such experience is possible, the one species of
knowledge which is capable of imparting reality to any non-
00079
tive imagination describes in it, and can obtain such judg-
ments without actually requiring any experience, yet even this
knowledge would be nothing but a playing with a mere fig-
ment of the brain, were it not that space has to be regarded as
a condition of the appearances which constitute the material
for outer experience. Those pure synthetic judgments there-
fore relate, though only mediately, to possible experience, or
rather to the possibility of experience; and upon that alone is
founded the objective validity of their synthesis.
  Accordingly, since experience, as empirical synthesis, is,
in so far as such experience is possible, the one species of
knowledge which is capable of imparting reality to any non-
empirical synthesis, this latter [type of synthesis], as know-
B 197  ledge <1a priori,>1 can possess truth, that is, agreement with the
  object, only in so far as it contains nothing save what is  -
A 155  necessary to synthetic unity of experience in general.
  The highest principle of all synthetic judgments is there-
  fore this: every object stands under the necessary conditions of           synthetic unity of the
manifold of intuition in a possible experience.

      Synthetic <1a priori>1 judgements are thus possible when we relate the formal conditions of <1
a priori>1 intuition, the synthesis of
  imagination and the necessary unity of this synthesis in a tran-
  scendental apperception, to a possible empirical knowledge in
  <1of experience>1 in general are likewise conditions of the <1possi->1-
  have objective validity in a synthetic <1a priori>1 judgment
  THE SYSTEM OF THE PRINCIPLES OF PURE
  UNDERSTANDING
  Section 3
  SYSTEMATIC REPRESENTATION OF ALL THE SYNTHETIC
  PRINCIPLES OF PURE UNDERSTANDING
  That there should be principles at all is entirely due to the
  pure understanding. Not only is it the faculty of rules in re-
00080
spect ofthatwhich happens, but is itself the source of principles  B 198
according to which1 everything that can be presented to us as  A 159
an object must conform to rules. For without such rules ap-
pearances would never yield knowledge of an object corre-
sponding to them. Even natural laws, viewed as principles of
the empirical employment of understanding, carry with them
an expression of necessity, and so contain at least the sugges-
tion of a determination from grounds which are valid <1a priori>1
and antecedently to all experience. The laws of nature, in-
deed, one and all, without exception, stand under higher prin-
ciples of understanding. They simply apply the latter to special
cases [in the field] of appearance. These principles alone supply
the concept which contains the condition, and as it were the
exponent, of a rule in general. What experience gives is the
instance which stands under the rule.
  There can be no real danger of our regarding merely em-
pirical principles as principles of pure understanding, or con-
versely. For the necessity according to concepts which distin-
guishes the principles of pure understanding, and the lack
of which is evident in every empirical proposition, however
general its application, suffices to make this confusion easily
preventable. But there are pure <1a priori>1 principles that we
may not properly ascribe to the pure understanding, which is
the faculty of concepts. For though they are mediated by the  A 160
understanding, they are not derived from pure concepts but  B 199
from pure intuitions. We find such principles in mathematics.
The question, however, of their application to experience, that
is, of their objective validity, nay, even the deduction of the
possibility of such synthetic <1a priori>1 knowledge, must always
carry us back to the pure understanding.
  While, therefore, I leave aside the principles of mathe-
matics, I shall none the less include those [more fundamental]
principles upon which the possibility and <1a priori>1 objective
validity of mathematics are grounded. These latter must be
regarded as the foundation of all mathematical principles.
They proceed from concepts to intuition, not from intuition to
concepts.
  In the application of pure concepts of understanding to
00081
possible experience, the employment of their synthesis is either
<1mathematical>1 or <1dynamical;>1 for it is concerned partly with the
mere <1intuition>1 of an appearance in general, partly with its
<1existence.>1 The <1a priori>1 conditions of intuition are absolutely
necessary conditions of any possible experience; those of the
existence of the objects of a possible empirical intuition are in
themselves only accidental. The principles of mathematical
employment will therefore be unconditionally necessary, that
is, apodeictic. Those of dynamical employment will also in-
B 200  deed possess the character of <1a priori>1 necessity, but only under
  the condition of empirical thought in some experience, there-
  fore only mediately and indirectly. Notwithstanding their un-
  doubted certainty throughout experience, they will not con-
A 161  tain that immediate evidence which is peculiar to the former.
  But of this we shall be better able to judge at the conclusion of
  this system of principles.
  The table of categories is quite naturally our guide in the
  construction of the table of principles. For the latter are simply
  rules for the objective employment of the former. All principles
  of pure understanding are therefore---
  Axioms
  of intuition.
  2  3
  Anticipations  Analogies
  of perception.  of experience.
  4
  Postulates
  of empirical thought in general.
  These titles I have intentionally chosen in order to give
  prominence to differences in the evidence and in the applica-
  tion of the principles. It will soon become clear that the
B 201  principles involved in the <1a priori>1 determination of appear-
  ances according to the categories of quantity and of quality
  (only the formal aspect of quantity and quality being con-
  sidered) allow of intuitive certainty, alike as regards their
  evidential force and as regards their <1a priori>1 application to
00082
  AXIOMS OF INTUITION  197
appearances. They are thereby distinguished from those of A 162
the other two groups, which are capable only of a merely
discursive certainty. This distinction holds even while we
recognise that the certainty is in both cases complete. I shall
therefore entitle the former principles <1mathematical,>1 and
the latter <1dynamical.>1 But it should be noted that we are as
little concerned in the one case with the principles of mathe-  B 202
matics as in the other with the principles of general physical
dynamics. We treat only of the principles of pure understand-
ing in their relation to inner sense (all differences among the
given representations being ignored). It is through these
principles of pure understanding that the special principles of
mathematics and of dynamics become possible. I have named
them, therefore, on account rather of their application than
of their content. I now proceed to discuss them in the order
in which they are given in the above table.
  AXIOMS OF INTUITION *
  Their principle is: All intuitions are extensive magnitudes.
  <1Proof>1 1
  Appearances, in their formal aspect, contain an intuition
in space and time, which conditions them, one and all, <1a>1
  * [In A:]
    <1The Axioms of intuition.>1
  Principle of the pure understanding: All appearances
are, in their intuition, extensive magnitudes.
  a  [Note added in B.] All combination <1(conjuncti->1o) is either com-
position <1(compositi->1o) or connection <1(nexus).>1 The former is the syn-
thesis of the manifold where its constituents do not necessarily be-
long to one another. For example, the two triangles into which a
square is divided by its diagonal do not necessarily belong to one
another. Such also is the synthesis of the <1homogeneous>1 in everything
which can be <1mathematically>1 treated. This synthesis can itself be
divided into that of <1aggregation>1 and that of <1coalition,>1 the former
00083
<1priori.>1 They cannot be apprehended, that is, taken up into
empirical consciousness, save through that synthesis of the
manifold whereby the representations of a determinate space
or time are generated, that is, through combination of the
B 203 homogeneous manifold and consciousness of its synthetic
  unity. Consciousness of the synthetic unity1 of the manifold
  [and] homogeneous in intuition in general, in so far as the
  representation of an object first becomes possible by means
  of it, is, however, the concept of a magnitude <1(quantum).>1
  Thus even the perception of an object, as appearance, is only
  possible through the same synthetic unity of the manifold of
  the given sensible intuition as that whereby the unity of the
  combination of the manifold [and] homogeneous is thought
  in the concept of a <1magnitude.>1 In other words, appearances
  are all without exception <1magnitudes,>1 indeed <1extensive mag->1
  <1nitudes.>1 As intuitions in space or time, they must be repre-
  sented through the same synthesis whereby space and time
  in general are determined.
  I entitle a magnitude extensive when the representation
  of the parts makes possible, and therefore necessarily precedes,
  the representation of the whole. I cannot represent to myself
  a line, however small, without drawing it in thought, that
A 163 is, generating from a point all its parts one after another.
  Only in this way can the intuition be obtained. Similarly
  with all times, however small. In these I think to myself
  only that successive advance from one moment to another,
  whereby through the parts of time and their addition a de-
  terminate time-magnitude is generated. As the [element of]
  applying to <1extensive>1 and the latter to <1intensive>1 quantities. The
  second mode of combination <1(nexus)>1 is the synthesis of the manifold
  so far as its constituents <1necessari>1ly <1belong to one another,>1 as, for
  example, the accident to some substance, or the effect to the cause.
  It is therefore synthesis of that which, though <1heterogeneous,>1 is yet
  represented as combined <1a priori->1. This combination, as not being
  arbitrary and as concerning the connection of the <1existence>1 of the
B202  manifold, I entitle <1dynamical.>1 Such connection can itself, in turn.
  be divided into the <1physical>1 connection of the appearances with one
  another, and their <1metaphysical>1 connection in the <1apriori>1 faculty of
  knowledge.
00084
pure intuition in all appearances is either space or time, every
appearance is as intuition an extensive magnitude; only B 204
through successive synthesis of part to part in [the process of]
its apprehension can it come to be known. All appearances
are consequently intuited as aggregates, as complexes of
previously given parts. This is not the case with magnitudes
of every kind, but only with those magnitudes which are
represented and apprehended by us in this <1extensive>1 fashion.
  The mathematics of space 1 (geometry) is based upon this
successive synthesis of the productive imagination in the
generation of figures. This is the basis of the axioms which
formulate the conditions of sensible <1a priori>1 intuition under
which alone the schema of a pure concept of outer appear-
ance can arise---for instance, that between two points only
one straight line is possible, or that two straight lines cannot
enclose a space, etc. These are the axioms which, strictly,
relate only to magnitudes <1(quanta)>1 as such.
  As regards magnitude <1(quantitas),>1 that is, as regards
the answer to be given to the question, "What is the magnitude
of a thing?' there are no axioms in the strict meaning of the  A 164
term, although there are a number of propositions which are
synthetic and immediately certain <1(indemonstrabilia).>1 The
propositions, that if equals be added to equals the wholes
are equal, and if equals be taken from equals the remainders
are equal, are analytic propositions; for I am immediately
conscious of the identity of the production of the one magni-
tude with the production of the other. [Consequently, they  B 205
are not] axioms, [for these] have to be <1a priori synthetic>1 pro-
positions. On the other hand, the evident propositions of
numerical relation are indeed synthetic, but are not general
like those of geometry, and cannot, therefore, be called axioms
but only numerical formulas. The assertion that 7 + 5 is equal
to 12 is not an analytic proposition. For neither in the repre-
sentation of 7, nor in that of 5, nor in the representation of the
combination of both, do I think the number 12. (That I must
do so in the <1addition>1 of the two numbers is not to the point,
since in the analytic proposition the question is only whether
I actually think the predicate in the representation of the
subject.) But although the proposition is synthetic, it is also
00085
only singular. So far as we are here attending merely to the
synthesis of the homogeneous (of units), that synthesis can
take place only in one way, although the <1employment>1 of
these numbers is general. If I assert that through three
lines, two of which taken together are greater than the
third, a triangle can be described, I have expressed merely
A 165 the function of productive imagination whereby the lines
  can be drawn greater or smaller, and so can be made to
  meet at any and every possible angle. The number 7, on the
  other hand, is possible only in one way. So also is the
  number  12, as thus generated through the synthesis of 7
  with 5. Such  propositions  must not, therefore, be called
B 206  axioms (that would involve recognition of an infinite number
  of axioms), but numerical formulas.
  This transcendental principle of the mathematics of ap-
  pearances greatly enlarges our <1a priori>1 knowledge. For it alone
  can make pure mathematics, in its complete precision, appli-
  cable to objects of experience. Without this principle, such
  application would not be thus self-evident; and there has indeed
  been much confusion of thought in regard to it. Appear-
  ances are not things in themselves. Empirical intuition is
  possible only by means of the pure intuition of space and of
  time. What geometry asserts of pure intuition is therefore
  undeniably valid of empirical intuition. The idle objections,
  that objects of the senses may not conform to such rules of
  construction in space as that of the infinite divisibility of lines
  or angles, must be given up. For if these objections hold good,
  we deny the objective validity of space, and consequently of
  all mathematics, and no longer know why and how far
  mathematics can be applicable to appearances. The synthesis
  of spaces and times, being a synthesis of the essential forms
A 166  of all intuition, is what makes possible the apprehension of
  appearance, and consequently every outer experience and all
  knowledge of the objects of such experience. Whatever pure
  mathematics establishes in regard to the synthesis of the form
  of apprehension is also necessarily valid of the objects appre-
  hended. All objections are only the chicanery of a falsely
00086
instructed reason, which, erroneously professing to isolate the  B 207
objects of the senses from the formal condition of our sen-
sibility, represents them, in spite of the fact that they are mere
appearances, as objects in themselves, given to the understand-
ing. Certainly, on that assumption, no synthetic knowledge
of any kind could be obtained of them <1a priori,>1 and nothing
therefore could be known of them synthetically through pure
concepts of space.  Indeed, the science which determines these
concepts, namely geometry, would not itself be possible.
  2
  ANTICIPATIONS OF PERCEPTION
  In all appearances, the real that is an object of sensation
has intensive magnitude, that is, a degree.
  <1Proof>1 1
  Perception is empirical consciousness, that is, a conscious-
ness in which sensation is to be found. Appearances, as objects
of perception, are not pure, merely formal, intuitions, like space
and time. For in and by themselves these latter cannot be per-
ceived. Appearances contain in addition to intuition the matter
for some object in general (whereby something existing in space
or time is represented); they contain, that is to say, the real
of sensation as merely subjective representation, which gives
us only the consciousness that the subject is affected, and
which we relate to an object in general. Now from empirical  B 208
consciousness to pure consciousness a graduated transition
is possible, the real in the former completely vanishing and a
merely formal <1a priori>1 consciousness of the manifold in space
and time remaining. Consequently there is also possible a
  * [InA:]
  <1The Anticipations of Perception>1
  The principle which anticipates all perceptions, as such, is
as follows: In all appearances sensation, and the <1real>1 which
corresponds to it in the object <1(realitas phaenomenon),>1 has an
<1intensive magnitude,>1 that is, a degree.
00087
sation from its  beginning  in  pure  intuition = 0,  up to any
required magnitude. Since, however, sensation is not in itself
an objective representation, and since neither the  intuition
of space nor that of time is to be met with in it, its mag-
nitude is not extensive but <1intensive.>1 This magnitude is
generated in the act of apprehension whereby the empirical
consciousness of it can in a certain time increase from nothing
=0 to the given measure. Corresponding to this intensity
of sensation, an <1intensive magnitude,>1 that is, a degree of
influence on the sense <1[i.e.>1 on the special sense involved],
must be ascribed to all objects of perception, in so far as
the perception contains sensation.
  All knowledge by means of which I am enabled to know
and determine <1a priori>1 what belongs to empirical knowledge
may be entitled an anticipation; and this is undoubtedly the
A 167  sense in which Epicurus employed the term 7rp~~7Wcs. But as
B 209 there is an element in the appearances (namely, sensation, the
  matter of perception) which can never be known <1apriori,>1 and
  which therefore constitutes the distinctive difference between
  empirical and <1a priori>1 knowledge, it follows that sensation is
  just that element which cannot be anticipated. On the other
  hand, we might very well entitle the pure determinations in
  space and time, in respect of shape as well as of magnitude,
  anticipations of appearances, since they represent <1apriori>1 that
  which may always be given <1a posteriori>1 in experience. If,
  however, there is in every sensation, as sensation in general
  (that is, without a particular sensation having to be given),
  something that can be known <1a priori,>1 this will, in a quite
  especial sense, deserve to be named anticipation. For it does
  indeed seem surprising that we should forestall experience,
  precisely in that which concerns what is only to be obtained
  through it, namely, its matter. Yet, none the less, such is
  actually the case.
  Apprehension by means merely of sensation occupies only
  an instant, if, that is, I do not take into account the succes-
  sion of different sensations. As sensation is that element in
00088
the [field of] appearance the apprehension of which does not
involve a successive synthesis proceeding from parts to the
whole representation, it has no extensive magnitude. The
absence of sensation at that instant would involve the re-
presentation of the instant as empty, therefore as=0. Now  A 168
what corresponds in empirical intuition to sensation is reality
<1(realitas phaenomenon);>1 what corresponds to its absence is
negation =0. Every sensation, however, is capable of diminu-  B 210
tion, so that it can decrease and gradually vanish. Between
reality in the [field of] appearance and negation there is there-
fore a continuity1 of many possible intermediate sensations,
the difference between any two of which is always smaller than
the difference between the given sensation and zero or com-
plete negation. In other words, the real in the [field of] ap-
pearance has always a magnitude. But since its apprehension
by means of mere sensation takes place in an instant and not
through successive synthesis of different sensations, and there-
fore does not proceed from the parts to the whole, the mag-
nitude is to be met with onlyin the apprehension. The real
has therefore magnitude, but not extensive magnitude.
  A magnitude which is apprehended only as unity, and
in which multiplicity can be represented only through ap-
proximation to negation=0, I entitle an <1intensive>1 magnitude.
Every reality in the [field of] appearance has therefore inten-
sive magnitude or degree. If this reality is viewed as cause,
either of sensation or of some other reality in the [field of]
appearance, such as change, the degree of the reality as cause
is then entitled a moment, the moment of gravity. It is so
named for the reason that degree signifies only that magnitude  A 169
the apprehension of which is not successive, but instan-
taneous. This, however, I touch on only in passing; for with
causality I am not at present dealing.


  every sensation, therefore, and likewise every reality in  B 211
the [field of] appearance, however small it may be, has a
degree, that is, an intensive magnitude which can always be
diminished. Between reality and negation there is a con-
tinuity of possible realities and of possible smaller perceptions.
00089
Every colour, as for instance red, has a degree which, how-
ever small it may be, is never the smallest; and so with heat,
the moment of gravity, etc.
  The property of magnitudes by which no part of them is
the smallest possible, that is, by which no part is simple, is
called their continuity. Space and time are <1quanta continua,>1
because no part of them can be given save as enclosed between
limits (points or instants), and therefore only in such fashion
that this part is itself again a space or a time. Space therefore
consists solely of spaces, time solely of times.  Points and instants
are only limits, that is, mere positions which limit space and
time. But positions always presuppose the intuitions which
they limit or are intended to limit; and out of mere positions,
A 170  viewed as constituents capable of being given prior to space
or time, neither space nor time can be constructed. Such mag-
nitudes may also be called <1flowing,>1 since the synthesis of
  productive imagination involved in their production is a pro-
B 212 gression in time, and the continuity of time is ordinarily
  designated by the term flowing or flowing away.
  -All appearances, then, are continuous magnitudes, alike in
  their intuition, as extensive, and in their mere perception
  (sensation, and with it reality) as intensive. If the synthesis of
  the manifold of appearance is interrupted, we have an aggre-
  gate of different appearances, and not appearance as a genuine
  quantum. Such an aggregate1 is not generated by continuing
  without break productive synthesis of a certain kind, but
  through repetition of an ever-ceasing synthesis. If I called
  thirteen thalers a quantum of money, I should be correct, pro-
  vided my intention is to state the value of a mark of fine silver.
  smallest, and in which every part can constitute a piece of coin
  that always contains material for still smaller pieces. But if
  I understand by the phrase thirteen round thalers, so many
  coins, quite apart from the question of what their silver
  standard may be, I then use the phrase, quantum of thalers,
  inappropriately. It ought to be entitled an aggregate, that is,
A 171  a number of pieces of money. But as unity must be presup-
  posed in all number, appearance as unity is a quantum, and
  as a quantum is always a continum.
00090
Since all appearances, alike in their extensive and in their
intensive aspect, are thus continuous magnitudes, it might  .
seem to be an easy matter to prove with mathematical con-
clusiveness the proposition that all alteration (transition of a  B 213
thing from one state to another), is continuous. But the caus-
ality of an alteration in general, presupposing, as it does, em-
pirical principles, lies altogether outside the limits of a tran-
scendental philosophy. For upon the question as to whether
a cause capable of altering the state of a thing, that is, of
determining it to the opposite of a certain given state, may
be possible, the <1a priori>1 understanding casts no light; and
this not merely becaus  it has no insight into its possibility
(such insight is lacking to us in many other cases of <1a priori>1
knowledge), but because  alterableness  is to be met with
only in certain determinations of appearances, and because,
whereas [in fact] the cause of these determinations lies
in the unalterable, experience alone can teach what they are.
Since in our present enquiry we have no data of which we
can make use save only the pure fundamental concepts of all
possible experience, in which there must be absolutely nothing
that is empirical, we cannot, without destroying the unity of
our system, anticipate general natural science, which is based  A 172
on certain primary experiences.1
  At the same time, there is no lack of proofs of the great
value of our principle in enabling us to anticipate perceptions,
and even to some extent to make good their absence, by
placing a check upon all false inferences which might be
drawn from their absence.
  If all reality in perception has a degree, between which  B 214
and negation there exists an infinite gradation of ever smaller
degrees, and if every sense must likewise possess some par-
ticular degree of receptivity of sensations, no perception, and
consequently no experience, is possible that could prove,
either immediately or mediately (no matter how far-ranging
the reasoning may be), a complete absence of all reality in the
[field of] appearance. In other words, the proof of an empty
space or of an empty time can never be derived from experi-
ence. For, in the first place, the complete absence of reality
00091
from a sensible intuition can never be itself perceived; and,
 secondly, there is no appearance whatsoever and no difference
  in the degree of reality of any appearance from which it can
  be inferred. It is not even legitimate to postulate it in order
  to explain any difference. For even if the whole intuition of a
  certain determinate space or time is real through and through,
  that is, though no part of it is empty, none the less, since every
  A 173 reality has its degree, which can diminish to nothing (the
  void) through infinite gradations without in any way altering
  the extensive magnitude of the appearance, there must be
  infinite different degrees in which space and time may be filled.
  Intensive magnitude can in different appearances be smaller
  or greater, although the extensive magnitude of the intuition
  remains one and the same.
  B 215  Let us give an example. Almost all natural philosophers,
  observing---partly by means of the moment of gravity or
  weight, partly by means of the moment of opposition to other
  matter in motion---a great difference in the quantity of various
  kinds of matter in bodies that have the same volume, unani-
  mously conclude that this volume, which constitutes the ex-
  tensive magnitude of the appearance, must in all material
  bodies be empty in varying degrees. Who would ever have
  dreamt of believing that these students of nature, most of
  whom are occupied with problems in mathematics and
  mechanics, would base such an inference solely on a meta-
  physical presupposition---the sort of assumption they so stoutly
  profess to avoid? They assume that the real in space (I May
  not here name it impenetrability or weight, since these are
  empirical concepts) is everywhere uniform and varies only
  in extensive magnitude, that is, in amount. Now to this pre-
  supposition, for which they could find no support in experi-
  A 174 ence, and which is therefore purely metaphysical, I oppose a
  transcendental proof, which does not indeed explain the
  difference in the filling of spaces, but completely destroys the
  supposed necessity of the above presupposition, that the
  difference is only to be explained on the assumption of empty
  space. My proof has the merit at least of freeing the under-
  standing, so that it is at liberty to think this difference in
  B 216 some other manner, should it be found that some other
  hypothesis is required for the explanation of the natural
00092
  th t there is no  oint in either where matter is not present,
nevertheless every reality has, while keeping its quality un-
changed  some specific degree (of resistance or weight) which
can, without diminution of its extensive magnitude or amount,
00093
appearances. For we then recognise that although two equal
spaces can be completely filled with different kinds of matter,
so that there is no point in either where matter is not present,
nevertheless every reality has, while keeping its quality un-
changed, some specific degree (of resistance or weight) which
can, without diminution of its extensive magnitude or amount,
become smaller and smaller <1in infinitum,>1 before it passes
into the void and [so] vanishes [out of existence]. Thus a
radiation which fills a space, as for instance heat, and
similarly every other reality in the [field of] appearance,
can diminish in its degree <1in infnitum,>1 without leaving
the smallest part of this space in the least empty. It may
fill the space just as completely with these smaller degrees as
another appearance does with greater degrees. I do not at all
intend to assert that this is what actually occurs when material
bodies differ in specific gravity, but only to establish from a
principle of pure understanding that the nature of our per-  A 175
ceptions allows of such a mode of experience on, that we are
not justified in assuming the real in appearances to be uniform
in degree, differing only in aggregation and extensive magni-
tude, and that we are especially in error when we claim that
such interpretation can be based on an <1a priori>1 principle of
the understanding.
  This anticipation of perception must always, however  B 217
appear somewhat strange to anyone trained in transcend-
ental reflection,1 and to any student of nature who by such
teaching has been trained to circumspection. The assertion
that the understanding anticipates such a synthetic principle,
ascribing a degree to all that is real in the appearances, and
so asserting the possibility of an internal distinction in sensa-
tion itself (abstraction being made of its empirical quality),
awakens doubts and difficulties. It is therefore a question
not unworthy of solution, how the understanding can thus in
<1a priori>1 fashion pronounce synthetically upon appearances,
and can indeed anticipate in that which in itself is merely
empirical and concerns only sensation.
  The <1quality>1 of sensation, as for instance in colours, taste,
etc., is always merely empirical, and cannot be represented
00094
<1a priori.>1 But the real, which corresponds to sensations in
general, as opposed to negation = o, represents only that
something the very concept of which includes being,  and
A 176  signifies nothing but the synthesis in an empirical conscious-
  ness in general. Empirical consciousness can in inner sense
  be raised from 0 to any higher degree, so that a certain ex-
  tensive magnitude of intuition, as for instance of illuminated
  surface, may excite as great a sensation as the combined
  extensive magnitude of the appearance thus varies independ-
B 218  ently], we can completely abstract from it, and still represent
  in the mere sensation in any one of its moments a synthesis
  that advances uniformly from 0 to the given empirical con-
  sciousness. Consequently, though all sensations as such are
  given only <1a posteriori,a>1 their property of possessing a degree
  can be known <1a priori.>1 It is remarkable that of magnitudes
  in general we can know <1apriori>1 only a single <1quality,>1 namely,
  that of continuity, and that in all quality (the real in appear-
  ances) we can know <1a priori>1 nothing save [in regard to]
  their intensive <1quantity,>1 namely that they have degree.
  Everything else has to be left to experience.
  3
  ANALOGIES OF EXPERIENCE *
  The principle of the analogies is: Experience is possible
  only through the representation of a necessary connection
  of perceptions.
  <1Proof 3>1
  Experience is an empirical knowledge, that is, a know-
  ledge which determines an object through perceptions. It
  <1The Analogies of experience>1
  The general principle of the analogies is:  All appearances
A 177  are, as regards their existence, subject <1a priori>1 to rules deter-
  mining their relation to one another in one time.
00095
is a synthesis of perceptions, not contained in perception but
itself containing in one consciousness the synthetic unity of
the manifold of perceptions. This synthetic unity constitutes
the essential in any knowledge of <1objects>1 of the senses, that is,
in experience as distinguished from mere intuition or sensa-  B 219
tion of the senses. In experience, however, perceptions come
together only in accidental order, so that no necessity deter-
mining their connection is or can be revealed in the perceptions
themselves. For apprehension is only a placing together of the
manifold of empirical intuition; and we can find in it no re-
presentation of any necessity which determines the appearances
thus combined to have connected existence in space and time.
But since experience is a knowledge of objects through percep-
tions, the relation [involved] in the existence of the manifold has
to be represented in experience, not as it comes to be constructed1
in time but as itexists objectively in time. Since time, however,
cannot itself be perceived, the determination of the existence
of objects in time can take place only through their relation in  -
time in general, and therefore only through concepts that con-
nect them <1a priori.>1 Since these always carry necessity with
them, it follows that experience is only possible through a re-
presentation of necessary connection of perceptions.
  The three modes of time are <1duration, succession,>1 and <1co->1
<1existence.>1 There will, therefore, be three rules of all relations
of appearances in time, and these rules will be prior to all ex-
perience, and indeed make it possible. By means of these rules
the existence of every appearance can be determined in respect
of the unity of all time.
  The general principle of the three analogies rests on the  B 220
necessary <1unity>1 of apperception, in respect of all possible em-
pirical consciousness, that is, of all perception, <1at every [instant>1
<1of] time.>1 And since this unity lies <1a priori>1 at the foundation
of empirical consciousness, it follows that the above principle
rests on the synthetic unity of all appearances as regards their
relation in time. For the original apperception stands in rela-
tion to inner sense (the sum of all representations), and indeed
<1apriori>1 to its form, that is, to the time-order of the manifold
empirical consciousness. All this manifold must, as regards
its time-relations, be united in the original apperception. This
00096
is demanded by the <1a priori>1 transcendental unity of appercep-
tion, to which everything that is to belong to my knowledge
(that is, to my unified knowledge), and so can be an object for
me, has to conform. This <1synthetic unity>1 in the time-relations
of all perceptions, as thus determined <1a priori,>1 is the law, that
A 175  all empirical time-determinations must stand under rules of
  universaltime-determination. The analogies of experience, with
  which we are now to deal, must be rules of this description.
  These principles have this peculiarity, that they are not
  concerned with appearances and the synthesis of their em-
  pirical intuition, but only with the <1existence>1 of such appearances
  and their <1relation>1 to one another in respect of their existence.
  B 221 The manner in which something is apprehended in appear-
  ance can be so determined <1a priori>1 that the rule of its synthesis
  can at once give, that is to say, can bring into being, this
  [element of] <1a priori>1 intuition in every example that comes
  before us empirically. The <1existence>1 of appearances cannot,
  however, be thus known <1a priori;>1 and even granting that we
-  could in any such manner contrive to infer that something
  exists, we could not know it determinately, could not, that is,
  anticipate the features through which its empirical intuition is
  distinguished from other intuitions.
  The two previous principles, which, as justifying the ap-
  plication of mathematics to appearances, I entitled the mathe-
  matical, referred to the possibility of appearances, and taught
  how, alike as regards their intuition and the real in their per-
  ception, they can be generated according to rules of a mathe-
  matical synthesis. Both principles justify us in employing
  A 179  ance as magnitude. For instance, I can determine <1a priori,>1 that
 is, can construct, the degree of sensations of sunlight by com-
  bining some 200,000 illuminations of the moon. These first
  principles may therefore be called constitutive.
  It stands quite otherwise with those principles which seek
  B 222 to bring the <1existence>1 of appearances under rules <1a priori.>1
  For since existence cannot be constructed, the principles can
  apply only to the relations of existence, and can yield only <1re->1
  <1gulative>1 principles. We cannot,therefore, expect either axioms
00097
or anticipations. If, however, a perception is given in a time-
relation to some other perception, then even although this
latter is indeterminate, and we consequently cannot decide
<1what>1 it is, or what its <1magnitude>1 may be, we may none the
less assert that in its existence it is necessarily connected
with the former in this mode of time. In philosophy analogies
00098
or anticipations. If, however, a perception is given in a time-
relation to some other perception, then even although this
latter is indeterminate, and we consequently cannot decide
<1what>1 it is, or what its <1magnitude>1 may be, we may none the
less assert that in its existence it is necessarily connected
with the former in this mode of time. In philosophy analogies
signify something very different from what they represent in
mathematics. In the latter they are formulas which express
the equality of two quantitative relations, and are always <1con->1
<1stitutive;>1 so that if three 1 members of the proportion are given,
the fourth is likewise given, that is, can be constructed. But
in philosophy the analogy is not the equality of two <1quantitative>1
but of two <1qualitative>1 relations; and from three given mem-
bers we can obtain <1apriori>1 knowledge only of the relation to a  A 180
fourth, not of the fourth member itself. The relation yields, how
ever, a rule for seeking the fourth member in experience, and
a mark whereby it can be detected. An analogy of experience
is, therefore, only a rule according to which a unity of experi-
ence may arise from perception. It does not tell us how mere
perception or empirical intuition in general itself comes about.
It is not a principle <1constitutive>1 of the objects, that is, of the
appearances, but only <1regulative.>1 The same can be asserted of  B 223
the postulates of empirical thought in general, which concern
the synthesis of mere intuition (that is, of the form of appear-
ance), of perception (that is, of the matter of perception), and
of experience (that is, of the relation of these perceptions).
They are merely regulative principles, and are distinguished
from the mathematical, which are constitutive, not indeed in
certainty---both have certainty <1a priori>1 --but in the nature of
their evidence, that is, as regards the character of the intuitive
(and consequently of the demonstrative) factors peculiar to
the latter.
  In this connection what has been said of all principles that
are synthetic  must be specially emphasised, namely, that these
analogies have significance and validity only as principles of
the empirical, not of the transcendental, employment of under-
standing; that only as such can they be established; and that  A 181
appearances have therefore to be subsumed, not simply under
00099
the categories, but under their schemata. For if the objects
to which these principles are to be related were things in them-
selves, it would be altogether impossible to know anything of
them synthetically <1a priori.>1 They are, however, nothing but
appearances; and complete knowledge of them, in the further-
ultimately consist, is simply our possible experience of them.
The principles can therefore have no other purpose save that
B 224  of being the conditions of the unity of <1empirical>1 knowledge in
  the synthesis of <1appearances.>1 But such unity can be thought
  only in the <1schema>1 of the pure concept of understanding. The
  category expresses a function which is restricted by no sensible
  condition, and contains the unity of this schema,1 (in so far
  only] as [it is the schema] of a synthesis in general. By these
  principles, then, we are justified in combining appearances
  only according to what is no more than an analogy with the
  logical and universal unity of concepts. In the principle itself
  we do indeed make use of the category, but in applying it to
  appearances we substitute for it its schema as the key to its
  stricting condition, and as being what may be called its formula.
A182  A
  FIRST ANALOGY
  <1PrinciPle of Permanence of Substancea>1
  In all change of appearances substance is permanent; its
  quantum in nature is neither increased nor diminished.*
  ----------------------------------------------------
  All appearances contain the permanent (substance) as the
  object itself, and the transitory as its mere determination
  that is, as a way in which the object exists.
00100
  <1Proof *>1
All appearances are in time; and in it alone, as substratum
(as permanent form of inner intuition), can either coexistence
or succession be represented. Thus the time in which all
change of appearances has to be thought, remains and does B 225
not change. For it is that in which, and as determinations of
which, succession or coexistence can alone be represented.
Now time cannot by itself be perceived. Consequently there
must be found in the objects of perception, that is, in the
appearances, the substratum which represents time in general;
and all change or coexistence must, in being apprehended,
be perceived in this substratum, and through relation of the
appearances to it. But the substratum of all that is real, that is,
of all that belongs to the existence of things, is <1substance;>1
and all that belongs to existence can be thought only as a
determination of substance. Consequently the permanent, in
relation to which alone all time-relations of appearances can
be determined, is substance in the [field of] appearance, that
is, the real in appearance, and as the substrate of all change
remains ever the same. And as it is thus unchangeable in
its existence, its quantity in nature can be neither increased nor
diminished.
  Our <1apprehension>1 of the manifold of appearance is always
successive, and is therefore always changing. Through it alone
we can never determine whether this manifold, as object of
experience, is coexistent or successive. For such determination
we require an underlying ground which exists <1at all times,>1 that
is, something <1abiding>1 and <1permanent,>1 of which all change  B 226
and coexistence are only so many ways (modes of time) in
which the permanent exists. And simultaneity and succes-
  * [This heading and the first paragraph substituted in B for:]
  <1Proof of this first Analogy>1
  All appearances are in time. Time can determine them as
existing in a twofold manner, either as in succession to one
another or as coexisting. Time, in respect of the former, is
viewed as time-series, in respect of the latter as time-volume
00101
sion being the only relations in time, it follows that only in
A 183  the permanent are relations of time possible. In other words,
  the permanent is the <1substratum>1 of the empirical representa-
  tion of time itself; in it alone is any determination of time
  possible. Permanence, as the abiding correlate of all existence
  of appearances, of all change and of all concomitance, ex-
  presses time in general. For change does not affect time itself,
  but only appearances in time. (Coexistence is not a mode of
  time itself; for none of the parts of time coexist; they are all
  in succession to one another.) If we ascribe succession to time
  itself, we must think yet another time, in which the sequence
  would be possible. Only through the permanent does existence
  in different parts of the time-series acquire a magnitude which
  can be entitled duration. For in bare succession existence is
  always vanishing and recommencing, and never has the least
  magnitude. Without the permanent there is therefore no time-
  relation. Now time cannot be perceived in itself; the permanent
  in the appearances is therefore the substratum of all deter-
  mination of time, and, as likewise follows, is also the condition
  of the possibility of all synthetic unity of perceptions, that is,
B 227  of experience. All existence and all change in time have thus
  to be viewed as simply a mode of the existence of that which
  remains and persists. In all appearances the permanent is the
  object itself, that is, substance as phenomenon; everything, on
A 184  the other hand, which changes or can change belongs only to
  the way in which substance or substances exist, and therefore
  to their determinations.
  I find that in all ages, not only philosophers, but even
  the common understanding, has recognised this permanence
  as a substratum of all change of appearances, and always
  assume it to be indubitable. The only difference in this matter
  between the common understanding and the philosopher is
  that the latter expresses himself somewhat more definitely,
-==  asserting that throughout all changes in the world <1substance>1
  remains, and that only the <1accidents>1 change. But I nowhere
  find even the attempt at a proof of this obviously synthetic
  proposition. Indeed, it is very seldom placed, where it truly
  belongs, at the head of those laws of nature which are pure
  and completely <1a priori.>1 Certainly the proposition, that sub-
  stance is permanent, is tautological. For this permanence is
00102
our sole ground for applying the category of substance to
appearance; and we ought first to have proved that in all
appearances there is something permanent, and that the tran-
sitory is nothing but determination of its existence. But such
a proof cannot be developed dogmatically, that is, from con-  B 228
cepts, since it concerns a synthetic <1a priori>1 proposition. Yet
as it never occurred to anyone that such propositions are
valid only in relation to possible experience, and can therefore
be proved only through a deduction of the possibility of ex-  A 185
perience, we need not be surprised that though the above
principle is always postulated as lying at the basis of ex-
perience (for in empirical knowledge the need of it is <1felt),>1 it
has never itself been proved.
  A philosopher, on being asked how much smoke weighs,
made reply: ""Subtract from the weight of the wood burnt
the weight of the ashes which are left over, and you have the
weight of the smoke''. He thus presupposed as undeniable
that even in fire the matter (substance) does not vanish, but
only suffers an alteration of form. The proposition, that noth-
ing arises out of nothing, is still another consequence of the
principle of permanence, or rather of the ever-abiding exist-
ence, in the appearances, of the subject proper. For if that in
the (field of] appearance which we name substance is to be
the substratum proper of all time-determination, it must
follow that all existence, whether in past or in future time,
can be determined solely in and by it. We can therefore give
an appearance the title "substance' just for the reason that we
presuppose its existence through out all time, and that this is not
adequately expressed by the word permanence, a term which  B 229
applies chiefly to future time. But since the inner necessity of
persisting is inseparably bound up with the necessity of always
having existed, the expression [principle of permanence] may
be allowed to stand. <1Gigni de nihilo nihil, in nihilum nil>1 A 186
<1posse reverti,>1 were two propositions which the ancients al-
ways connected together, but which are now sometimes mis-
takenly separated owing to the belief that they apply to things
in themselves, and that the first would run counter to the
dependence of the world---even in respect of its substance---
upon a supreme cause. But such apprehension is unneces-
sary. For we have here to deal only with appearances in the
00103
field of experience;1 and the unity of experience would never
be possible if we were willing to allow that new things, that is,
new <1substances,>1 could come into existence. For we should then
lose that which alone can represent the unity of time, namely,
the identity of the substratum, wherein alone all change has
thoroughgoing unity. This permanence is, however, simply
the mode in which we represent to ourselves the existence of
things in the [field of] appearance.
  The determinations of a substance, which are nothing but
'  special ways in which it exists, are called <1accidents.>1 They are
  always real, because they concern the existence of substance.
  (Negations are only determinations which assert the non-
  existence of something in substance.) If we ascribe a special
  B 230  [kind of] existence to this real in substance (for instance, to
  motion, as an accident of matter), this existence is entitled
  inherence, in distinction from the existence of substance which
  A 187 is entitled subsistence. But this occasions many misunder-
standings; it is more exact and more correct to describe an
accident as being simply the way in which the existence of
  a substance is positively determined. But since it is unavoid-
  able, owing to the conditions of the logical employment of our
  understanding, to separate off, as it were, that which in the
'  existence of a substance can change while the substance still
  remains, and to view this variable element in relation to the
  truly permanent and radical, this category has to be assigned
  a place among the categories of relation, but rather as the
  condition of relations than as itself containing a relation.
  The correct understanding of the concept of <1alteration>1 is
"  also grounded upon [recognition of] this permanence. Coming
  to be and ceasing to be are not alterations of that which comes
  to be or ceases to be. Alteration is a way of existing which
  follows upon another way of existing of the same object. All
  that alters <1persists,>1 and only its <1state changes.>1 Since this
  change thus concerns only the determinations, which can
  cease to be or begin to be, we can say, using what may seem
  a somewhat paradoxical expression, that only the permanent
00104
(substance) is altered, and that the transitory suffers no B 231
alteration but only a <1change,>1 inasmuch as certain determina-
tions cease to be and others begin to be.
  Alteration can therefore be perceived onlyin substances. A  A 188
comingto be or ceasing to be that is not simply a determination
of the permanent but is absolute, can never be a possible per-
ception. For this permanent is what alone makes possible the
representation of the transition from one state to another, and
from not-being to being. These transitions can be empirically
known only as changing determinations of that which is per-
manent. If we assume that something absolutely begins to be,
we must have a point of time in which it was not. But to what
are we to attach this point, if not to that which already exists ?
For a preceding empty time is not an object of perception.
But if we connect the coming to be with things which pre-
viously existed, and which persist in existence up to the
moment of this coming to be, this latter must be simply a de-
termination of what is permanent in that which precedes it.1
Similarly also with ceasing to be; it presupposes the empirical
representation of a time in which an appearance no longer
exists.
  Substances, in the [field of] appearance, are the substrata
of all determinations of time. If some of these substances could
come into being and others cease to be, the one condition of
the empirical unity of time would be removed. The appear-
ances would then relate to two different times, and existence  B 232
would flow in two parallel streams---which is absurd. There
is only one time in which all different times must be located  A 189
not as coexistent but as in succession to one another.
  Permanence is thus a necessary condition under which
alone appearances are determinable as things or objects in a
possible experience. We shall have occasion in what follows
to make such observations as may seem necessary in regard
to the empirical criterion of this necessary permanence---the
criterion, consequently, of the substantiality of appearances.
00105
  B
  SECOND ANALOGY
  <1Principle of Succession in Time, in accordance with the>1
  <1Law of Causality *>1
All alterations take place in conformity with the law of the
  connection of cause and effect.
  <1Proof>1
(The preceeding principle has shown that all appearances
of succession in time are one and all only <1alterations,>1 that is
a successive being and not-being of the determinations of
substance which abides; and therefore that the being of
substance as following on its not-being, or its not-being as
B 233  following upon its being cannot be admitted---in other words,
  that there is no coming into being or passing away of sub-
  stance itself. Still otherwise expressed the principle is, that
  <1all change (succession) of appearances is merely alteration.>1
  Coming into being and passing away of substance are not
  alterations of it, since the concept of alteration presupposes
  one and the same subject as existing with two opposite deter-
  minations, and therefore as abiding. With this preliminary
  reminder, we pass to the proof.)
  I perceive that appearances follow one another, that is, that
  there is a state of things at one time the opposite of which was
  in the preceding time. Thus I am really connecting two percep-
  tions in time. Now connection is not the work of mere sense
  and intuition, but is here the product of a synthetic faculty
  of imagination, which determines inner sense in respect of the
  time-relation. But imagination can connect these two states
  <1Principle of Production>1
  Everything that happens, that is, begins to be, presupposes
  something upon which it follows according to a rule.
00106
in two ways, so that either the one or the other precedes in
time. For time cannot be perceived in itself, and what precedes
and what follows cannot, therefore, by relation to it, be em-
pirically determined in the object. I am conscious only that
my imagination sets the one state before and the other after,
not that the one state precedes the other in the object. In other
words, the <1objective relation>1 of appearances that follow upon  B 234
one another is not to be determined through mere perception.
In order that this relation be known as determined, the rela-
tion between the two states must be so thought that it is there-
by determined as necessary which of them must be placed
before, and which of them after, and that they cannot be
placed in the reverse relation. But the concept which carries
with it a necessity of synthetic unity can only be a pure
concept that lies in the understanding, not in perception;
and in this case it is the concept of the <1relation of cause>1
<1and effect,>1 the former of which determines the latter in time,
as its consequence---not as in a sequence that may occur
solely in the imagination (or that may not be perceived at
all). Experience itself---in other words, empirical knowledge
of appearances---is thus possible only in so far as we subject
the succession of appearances, and therefore all alteration,
to the law of causality; and, as likewise follows, the appear-
ances, as objects of experience, are themselves possible only
in conformity with the law.
  The apprehension of the manifold of appearance is always
successive. The representations of the parts follow upon one
another. Whether they also follow one another in the object
is a point which calls for further reflection, and which is not
decided by the above statement. Everything, every repre-
sentation even, in so far as we are conscious of it, may be
entitled object. But it is a question for deeper enquiry what  B 235
the word " object' ought to signify in respect of appearances  A 190
when these are viewed not in so far as they are (as representa-
tions) objects, but only in so far as they stand for an object. The
appearances, in so far as they are objects of consciousness
simply in virtue of being representations, are not in any way
distinct from their apprehension, that is, from their recep-  :
tion in the synthesis of imagination; and we must therefore
00107
agree that the manifold of appearances is always generated in
the mind successively.  Now if appearances were things in them-
selves, then since we have to deal solely with our representations,
we could never determine from the succession of the representa-
tions how their manifold may be connected in the object. How
things may be in themselves, apart from the representations
through which they affect us, is entirely outside our sphere of
knowledge. In spite, however, of the fact that the appearances
are not things in themselves, and yet are what alone can be
given to us to know, in spite also of the fact that their repre-
sentation in apprehension is always successive, I have to show
what sort of a connection in time belongs to the manifold
in the appearances themselves. For instance, the apprehen-
sion of the manifold in the appearance of a house which
stands before me is successive. The question then arises,
whether the manifold of the house is also in itself suc-
cessive. This, however, is what no one will grant. Now im-
B 236  mediately I unfold the transcendental meaning of my concepts
  of an object, I realise that the house is not a thing in itself,
A 191  but only an appearance, that is, a representation, the tran-
  scendental object of which is unknown. What, then, am I to
  understand by the question: how the manifold may be con-
  nected in the appearance itself, which yet is nothing in itself?
  That which lies in the successive apprehension is here viewed
  as representation, while the appearance which is given to
  me, notwithstanding that it is nothing but the sum of these
  representations, is viewed as their object; and my concept,
  which I derive from the representations of apprehension, has
  to agree with it. Since truth consists in the agreement of
  knowledge with the object, it will at once be seen that we can
  here enquire only regarding the formal conditions of empirical
  truth, and that appearance, in contradistinction to the repre-
  sentations of apprehension, can be represented as an object
  distinct from them only if it stands under a rule which dis-
  tinguishes it from every other apprehension and necessitates
  some one particular mode of connection of the manifold. The
  object is <1that>1 in the appearance which contains the condition
  of this necessary rule of apprehension.
  Let us now proceed to our problem. That something
  happens, <1i.e.>1 that something, or some state which did not pre-
00108
viously exist, comes to be, cannot be perceived1 unless it is  B 237
preceded by an appearance which does not contain in itself this
state. For an event which should follow upon an empty time,  A 192
that is, a coming to be preceded by no state of things, is as
little capable of being apprehended as empty time itself. Every
apprehension of an event is therefore a perception that fol-
lows upon another perception. But since, as I have above
illustrated by reference to the appearance of a house, this like-
wise happens in all synthesis of apprehension, the apprehen-
sion of an event is not yet thereby distinguished from other
apprehensions. But, as I also note, in an appearance which
contains a happening (the preceding state of the percep-
tion we may entitle A, and the succeeding B) B can be
apprehended only as following upon A; the perception A
cannot follow upon B but only precede it. For instance, I
see a ship move down stream. My perception of its lower
position follows upon the perception of its position higher
up in the stream, and it is impossible that in the appre-
hension of this appearance the ship should first be per-
ceived lower down in the stream and afterwards higher up.
The order in which the perceptions succeed one another in
apprehension is in this instance determined, and to this order
apprehension is bound down. In the previous example of a
house my perceptions could begin with the apprehension of
the roof and end with the basement, or could begin from below  B 238
and end above; and I could similarly apprehend the manifold
of the empirical intuition either from right to left or from left
to right. In the series of these perceptions there was thus no  A 193
determinate order specifying at what point I must begin in
order to connect the manifold empirically. But in the percep-
tion of an event there is always a rule that makes the order in
which the perceptions (in the apprehension of this appearance)
follow upon one another a <1necessary>1 order.
  In this case, therefore, we must derive the <1subjective suc->1
<1cession>1 of apprehension from the <1objective succession>1 of ap-
pearances. Otherwise the order of apprehension is entirely
undetermined, and does not distinguish one appearance from
another. Since the subjective succession by itself is altogether
00109
arbitrary, it does not prove anything as to the manner in
which the manifold is connected in the object. The objective
succession will therefore consist in that order of the manifold
of appearance according to which, <1in conformity with a>1
<1rule,>1 the apprehension of that which happens follows upon
the apprehension of that which precedes. Thus only can I be
justified in asserting, not merely of my apprehension, but of
appearance itself, that a succession is to be met with in it.
This is only another way of saying that I cannot arrange the
apprehension otherwise than in this very succession.
  In conformity with such a rule there must lie in that which
B 239  precedes an event the condition of a rule according to which
  this event invariably and necessarily follows. I cannot reverse
A 194 this order, proceeding back from the event to determine
  through apprehension that which precedes. For appearance
  never goes back from the succeeding to the preceding point
  of time, though it does indeed stand in relation to <1some>1 pre-
  ceding point of time. The advance, on the other hand, from
  a given time to the determinate time that follows is a neces-
  sary advance. Therefore, since there certainly is something
  that follows [i.e.that is <1apprehended>1 as following], I must refer
  it necessarily to something else which precedes it and upon
  which it follows in conformity with a rule, that is, of necessity.
  The event, as the conditioned, thus affords reliable evidence of
  some condition, and this condition is what determinesthe event.
  Let us suppose that there is nothing antecedent to an event,
  upon which it must follow according to rule. All succession of
  perception would then be only in the apprehension, that is,
  would be merely subjective, and would never enable us to de-
  termine objectively which perceptions are those that really
  precede and which are those that follow. We should then
  have only a play of representations, relating to no object;
  that is to say, it would not be possible through our percep-
  tion to distinguish one appearance from another as regards
  relations of time. For the succession in our apprehension
  would always be one and the same, and there would be nothing
B 240 in the appearance which so determines it that a certain se-
  quence is rendered objectively necessary. I could  not then
A 195  assert that two states follow upon one another in the [field of]













00001
appearance, but only that one apprehension follows upon the
other. That is something merely subjective, determining no
object; and may not, therefore, be regarded as1 knowledge of
any object, not even of an object in the [field of] appearance.
  If, then, we experience that something happens, we in
so doing always presuppose that something precedes it, on
which it follows according to a rule. Otherwise I should not
say of the object that it follows. For mere succession in my
apprehension, if there be no rule determining the succession
in relation to something that precedes, does not justify me
in assuming any succession in the object. I render my sub-
jective synthesis of apprehension objective only by reference
to a rule in accordance with which the appearances in their
succession, that is, as they happen, are determined by the pre-
ceding state. The experience of an events <1[i.e.>1 of anything as
<1happening]>1 is itself possible only on this assumption.
  This may seem to contradict all that has hitherto been
taught in regard to the procedure of our understanding. The
accepted view is that only through the perception and compari-
son of events repeatedly following in a uniform manner upon
preceding appearances are we enabled to discover a rule
according to which certain events always follow upon certain  B 241
appearances, and that this is the way in which we are first led
to construct for ourselves the concept of cause. Now the con-  A 196
cept, if thus formed, would be merely empirical, and the rule
which it supplies, that everything which happens has a cause,
would be as contingent as the experience upon which it is
based. Since the universality and necessity of the rule would
not be grounded <1a priori,>1 but only on induction, they would
be merely fictitious and without genuinely universal validity.
It is with these, as with other pure <1a priori>1 representations---
for instance, space and time. We can extract clear concepts
of them from experience, only because we have put them into
experience, and because experience is thus itself brought
about only by their means. Certainly, the logical clearness of
this representation of a rule determining the series of events is
possible only after we have employed it in experience.  Never-
00002
theless, recognition of the rule, as a condition of the synthetic
unity of appearances in time, has been the ground of ex-
perience itself, and has therefore preceded it <1a priori.>1
  We have, then, to show, in the case under consideration,
that we never, even in experience, ascribe succession (that is,
the happening of some event which previously did not exist)
to the object, and so distinguish it from subjective sequence
B 242  in our apprehension, except when there is an underlying rule
  which compels us to observe this order of perceptions rather
A 197  than any other; nay, that this compulsion is really what first
  makes possible the representation of a succession in the object.
  We have representations in us, and can become conscious
  of them. But however far this consciousness may extend, and
  representations, that is, inner determinations of our mind in
  this or that relation of time. How, then, does it come about
  that we posit an object for these representations, and so, in
  addition to their subjective reality, as modifications, ascribe
  to them some mysterious kind of1 objective reality. Objective
  meaning cannot consist in the relation to another representa-
  tion (of that which we desire to entitle object), for in that case
  the question again arises, how this latter representation goes
  out beyond itself, acquiring objective meaning in addition to
  the subjective meaning which belongs to it as determination
  of the mental state. If we enquire what new character <1relation>1
  <1to an object>1 confers upon our representations, what dignity they
  thereby acquire, we find that it results only in subjecting the
  representations to a rule, and so in necessitating us to connect
  them in some one specific manner; and conversely, that only
B 243  in so far as our representations are necessitated in a certain
  order as regards their time-relations do they acquire objective
  meaning.
A 198  In the synthesis of appearances the manifold of representa-
  tions is always sucessive. Now no object is hereby represented,
  since through this sucession, which is common to all appre-
  hensions, nothing is distinguished from anything else. But
  immediately I perceive or assume that in this succession there
  is a relation to the preceding state, from which the representa-
00003
tion follows in conformity with a rule, I represent1 something
as an event, as something that happens; that is to say, I appre-
hend an object to which I must ascribe a certain determinate
position in time---a position which, in view of the preceding
state, cannot be otherwise assigned. When, therefore, I per-
ceive that something happens, this representation first of all
contains [the consciousness] that there is something preceding,
because only by reference to what precedes does the appear-
ance acquire its time-relation, namely, that of existing after a
preceding time in which it itself was not. But it can acquire
this determinate position in this relation of time only in so far
as something is presupposed in the preceding state upon which
it follows invariably, that is, in accordance with a rule. From
this there results a twofold consequence. In the first place, I
cannot reverse the series, placing that which happens prior to
that upon which it follows. And secondly, if the state which
precedes is posited, this determinate event follows inevitably  B 244
and necessarily. The situation, then, is this: there is an order
in our representations in which the present, so far as it has
come to be, refers us to some preceding state as a correlate of  A 199
the event which is given; and though this correlate is, indeed,
indeterminate, it none the less stands in a determining relation
to the event as its consequence, connecting the event in neces-
sary relation with itself in the time-series.
  If, then, it is a necessary law of our sensibility, and there-
fore a <1formal condition>1 of all perceptions, that the preceding
time necessarily determines the succeeding (since I cannot ad-
vance to the succeeding time save through the preceding), it is
also an indispensable law of <1empirical representation>1 of the
time-series that the appearances of past time determine all
existences in the succeeding time, and that these latter, as
events, can take place only in so far as the appearances of past
time determine their existence in time, that is, determine them
according to a rule. <1For only in appearances can we empirically>1
<1apprehend this continuity in the connection of times.>1
  Understanding is required for all experience and for its
possibility. Its primary contribution does not consist in making
the representation of objects distinct, but in making the repre-
00004
sentation of an object possible at all. This it does by carrying
B 245  the time-order over into the appearances and their existence.
  For to each of them, [viewed] as [a] consequent, it assigns,
  through relation to the preceding appearances, a position de-
  termined <1a priori>1 in time. Otherwise, they would not accord
A 200  with time itself, which [in] <1a priori>1 [fashion] determines the
  position of all its parts. Now since absolute time is not an ob-
  ject of perception, this determination of position cannot be de-
  the appearances must determine for one another their position
  in time, and make their1 time-order a necessary order. In other
  words, that which follows or happens must follow in con-
  formity with a universal rule upon that which was contained in
  the preceding state. A series of appearances thus arises which,
  with the aid of the understanding, produces and makes neces-
  sary the same order and continuous connection in the series
  of possible perceptions as is met with <1a priori>1 in time---the
  form of inner intuition wherein all perceptions must have a
  position.
  That something happens is, therefore, a perception which
  belongs to a possible experience. This experience becomes
  actual when I regard the appearance as determined in its posi-
  tion in time, and therefore as an object that can always be
  found in the connection of perceptions in accordance with a
  rule.This rule, by which we determine something according to
  succession of time, is, that the condition under which an event
  invariably and necessarily follows is to be found in what pre-
  A 201  cedes the event. The principle of sufficient reason is thus the
  ground of possible experience, that is, of objective knowledge
  of appearances in respect of their relation in the succession of
  time.
  The proof of this principle rests on the following considera-
  tions. All empirical knowledge involves the synthesis of the
  manifold by the imagination. This synthesis is always succes-
  sive, that is, the representations in it are always sequent upon
  one another. In the imagination this sequence is not in any
  way determined in its order, as to what must precede and
00005
can indifferently be taken either in backward or in forward
order. But if this synthesis is a synthesis of apprehension1 of
the manifold of a given appearance, the order is determined
in the object, or, to speak more correctly, is an order of suc-
cessive synthesis that determines an object. In accordance
with this order something must necessarily precede, and when
this antecedent is posited, something else must necessarily
follow. If, then, my perception is to contain knowledge of an
event, of something as actually happening, it must be an
empirical judgment in which we think the sequence as deter-
mined; that is, it presupposes another appearance in time,  B 247
upon which it follows necessarily, according to a rule. Were
it not so, were I to posit the antecedent and the event were
not to follow necessarily thereupon, I should have to regard
the succession as a merely subjective play of my fancy; and if
I still represented it to myself as something objective, I should  A 202
have to call it a mere dream. Thus the relation of appearances
(as possible perceptions) according to which the subsequent
event, that which happens, is, as to its existence, necessarily
determined in time by something preceding in conformity
with a rule---in other words, the relation of cause to effect---is
the condition of the objective validity of our empirical judg-
ments, in respect of the series of perceptions, and so of their
empirical truth; that is to say, it is the condition of experience.
The principle of the causal relation in the sequence of appear-
ances is therefore also valid of all objects of experience ([in
so far as they are] under the conditions of succession), as
being itself the ground of the possibility of such experience.
  At this point a difficulty arises with which we must at
once deal. The principle of the causal connection among ap-
pearances is limited in our formula to their serial succession,
whereas it applies also to their coexistence, when cause and
effect are simultaneous. For instance, a room is warm while
the outer air is cool. I looa around for the cause, and find a  B 248
heated stove. Now the stove, as cause, is simultaneous with its
effect, the heat of the room. Here there is no serial succession
in time between cause and effect. They are simultaneous, and
00006
itself a matter for enquiry. The transition from the not-being
of a state to this state, even supposing that this state [as it
occurs] in the [field of] appearance exhibited no quality, of
itself demands investigation. This coming to be, as was shown
above in the <1First Analogy,>1 does not concern substance, which
does not come to be out of nothing. For if coming to be out
nothing is regarded as effect of a foreign cause, it has to be
among appearances  since its mere possibility would destroy
things not as phenomena but as things in themselves, and
B 252 as objects of the mere understanding, then despite their
  being substances they can be regarded, in respect of their
  existence, as depending upon a foreign cause. But our
  terms would then carry with them quite other meanings,
  and would not apply to appearances as possible objects of
  experience.
  How anything can be altered, and how it should be possible
A 207  that upon one state in a given moment an opposite state may
  follow in the next moment---of this we have not, <1apriori,>1 the
  least conception. For that we require knowledge of actual
  forces, which can only be given empirically, as, for instance,
  of the moving forces, or what amounts to the same thing, of
  certain successive appearances, as motions, which indicate [the
  presence of] such forces. But apart from all question of what
  the content of the alteration, that is, what the state which
  is altered, may be, the form of every alteration, the condition
  under which, as a coming to be of another state, it can alone
  take place, and so the succession of the states themselves (the
  happening), can still be considered <1a priori>1 according to the
  law of causality and the conditions of time a
B 253  If a substance passes from one state, <1a,>1 to another, <1b,>1 the
  point of time of the second is distinct from that of the first, and
   It should be carefully noted that I speak not of the alteration
  of certain relations in general, but of alteration of state. Thus, when
  a body moves uniformly, it does not in any way alter its state (of
  motion); that occurs only when its motion increases or diminishes.
00007
follows upon it. Similarly, the second state as reality in the
[field of] appearance differs from the first wherein it did not
exist, as <1b>1 from zero. That is to say, even if the state <1b>1
differed from the state <1a>1 only in magnitude, the alteration
would be a coming to be of <1b-a,>1 which did not exist in the A208
previous state, and in respect of which it=0.
  The question therefore arises how a thing passes from one
state=a to another=b.  Between two instants there is al-
ways a time, and between any two states in the two instants
there is always a difference which has magnitude. For all parts
of appearances are always themselves magnitudes. All transi-
tion from one state to another therefore occurs in a time which
is contained between two instants, of which the first deter-
mines the state from which the thing arises, and the second
that into which it passes. Both instants, then, are limits of the
time of a change, and so of the intermediate state between the
two states, and therefore as such form part of the total alteration.
Now every alteration has a cause which evinces its causality in
the whole time in which the alteration takes place. This cause,
therefore, does not engender the alteration suddenly, that is, at
once or in one instant, but in a time ;  so that, as the time in-  B 254
creases from the initial instant <1a>1 to its completion in <1b,>1 the
magnitude of the reality (b-a) is in like manner generated
through all smaller degrees which are contained between the
first and the last. All alteration is thus only possible through a
continuous action of the causality which, so far as it is uniform,
is entitled a moment. The alteration does not consist of these
moments, but is generated by them as their effect.  A 209
  That is the law of the continuity of all alteration. Its ground
is this: that neither time nor appearance in time consists of parts
which are the smallest [possible], and that, nevertheless, the
state of a thing passes in its alteration through all these parts,
as elements, to its second state. In the [field of] appearance
there is no difference of the real that is the smallest, just as in
the magnitude of times there is no time that is the smallest;
and the new state of reality accordingly proceeds from the
first wherein this reality was not, through all the infinite de-
grees, the differences of which from one another are all smaller
than that between 0 and <1a.>1
00008
  While we are not concerned to enquire what utility this
principle may have in the investigation of nature, what does
imperatively call for investigation is the question how such a
principle, which seems to extend our knowledge of nature, can
be possible completely <1a priori.>1 Such an enquiry cannot be dis-
pensed with, even though direct inspection may show the prin-
B 255  ciple to be true and [empirically] real, and though the question,
how it should be possible, may therefore be considered super-
flous. For there are so many ungrounded claims to the
  extension of our knowledge through pure reason, that we must
  take it as a universal principle that any such pretension is of
  itself a ground for being always mistrustful, and that, in the
  A 210 absence of evidence afforded by a thoroughgoing deduction,
  we may not believe and assume the justice of such claims, no
  matter how clear the <1dogmatic>1 proof of them may appear to be.
  All increase in empirical knowledge, and every advance of
  perception, no matter what the objects may be, whether ap-
  pearances or pure intuitions, is nothing but an extension of the
  determination of inner sense, that is, an advance in time. This
  advance in time determines everything, and is not in itself deter-
  mined through anything further. That is to say, its parts are
  given only in time, and only through the synthesis of time; they
  are not given antecedently to the synthesis. For this reason
  every transition in perception to something which follows in
  time is a determination of time through the generation of this
  perception, and since time is always and in all its parts a mag-
  nitude, is likewise the generation of a perception as a magnitude
  through all degrees of which no one is the smallest, from zero
 up to its determine degree. This reveals the possibility of
 knowing <1a priori>1 a law of alterations, in respect of their form.
  B 256  We are merely anticipating our own apprehension, the formal
  condition of which, since it dwells in us prior to all appearance
  that is given, must certainly be capable of being known <1a priori.>1
  In the same manner, therefore, in which time contains the
  sensible <1a priori>1 condition of the possibility of a continuous
  advance of the existing to what follows, the understanding,
  A 211 by virtue ofz the unity of apperception, is the <1a priori>1 condi-
  tion of the possibility of a continuous determination of all posi-
  tions for the appearances in this time, through the series of
00009
causes and effects, the former of which inevitably lead to the
existence of the latter, and so render the empirical knowledge
of the time-relations valid universally for all time, and there-
fore objectively valid.
  THIRD ANALOGY
  <1Principle of Coexistence, in accordance with the Law of>1
  <1Reciprocity or Community>1
All substances, in so far as they can be perceived to coexist in
  space, are in thoroughgoing reciprocity *
  <1Proof>1
   Things are coexistent when in empirical intuition the
perceptions of them can follow upon one another recipro-  B 257
cally, which, as has been shown in the proof of the second
principle, cannot occur in the succession of appearances.
Thus I can direct my perception first to the moon and then
to the earth, or, conversely, first to the earth and then to the
moon; and because the perceptions of these objects can follow
each other reciprocally, I say that they are coexistent. Now
coexistence is the existence of the manifold in one and the
same time. But time itself cannot be perceived, and we are
not, therefore, in a position to gather, simply from things
being set in the same time, that their perceptions can follow
each other reciprocally. The synthesis of imagination in
apprehension would only reveal that the one perception is
in the suject when the other is not there, and <1vice versa,>1
  at the objects are coexistent, that is, that if the one
exists the other exists at the same time, and that it is only
because they thus coexist that the perceptions are able to
  * [In A:]
  <1Principle of Community>1
  All substances, so far as they coexist, stand in thorough-
going community, that is, in mutual interaction.
00010
follow one another reciprocally. Consiquently, in the case of
things which coexist externally to one another, a pure concept
of the reciprocal sequence of their determinations is required,
if we are to be able to say that the reciprocal sequence of the
perceptions is grounded in the object, and so to represent the
coexistence as objective. But the relation of substances in
B 258  which the one contains determinations the ground of which
  is contained in the other is the relation of influence; and
  when each substance reciprocally contains the ground of the
  determinations in the other, the relation is that of community
  or reciprocity. Thus the coexistence of substances in space
  cannot be known in experience save on the assumption of
  their reciprocal interaction. This is therefore the condition
  of the possibility of the things themselves as objects of
  experience.
  Things are coexistent so far as they exist in one and the
  same time. But how do we know that they are in one and the
  same time? We do so when the order in the synthesis of ap-
  prehension of the manifold is a matter of indifference, that is,
  whether it be from A through B, C, D to E, or reversewise
  from E to A. For if they were in succession to one another
  in time, in the order, say, which begins with A and ends in
  E, it is impossible that we should begin the apprehension in
  the perception of E and proceed backwards to A, since A
  belongs to past time and can no longer be an object of appre-
  hension.
A 212  Now assuming that in a manifold of substances as appear-
  ances each of them is completely isolated, that is, that no one
  acts on any other and receives reciprocal influences in return,
  I maintain that their coexistence would not be an object of a
B 259  possible perception and that the existence of one could not
  lead by any path of empirical synthesis to the existence of
  another. For if we bear in mind that they would be separated
  by a completely empty space, the perception which advances
  from one to another in time would indeed, by means of a
  succeeding perception, determine the existence of the latter,
  but would not be able to distinguish whether it follows object-
00011
  ively upon the first or whether it is not rather coexistent
  with it.
  There must, therefore, besides the mere existence of A and
  B, be something through which A determines for B its position
in time, and also reversewise B for A, because only on this
condition can these substances be empirically represented as
<1coexisting.>1 Now only that which is the cause of another, or
of its determinations, determines the position of the other
in time. Each substance (inasmuch as only in respect of
its determinations can it be an effect) must therefore contain
in itself the causality of certain determinations in the other
substance, and at the same time the effects of the causality of
that other; that is, the substances must stand, immediately or
mediately, in dynamical community, if their coexistence is to  A 213
be known in any possible experience. Now, in respect to the
objects of experience, everything without which the experi-
ence of these objects would not itself be possible is necessary.  B 260
It is therefore necessary that all substances in the [field of]
appearance, so far as they coexist, should stand in thorough-
going community of mutual interaction.
  The word community is in the German language ambigu-
ous. It may mean either <1communio>1 or <1commercium.>1 We here
employ it in the latter sense, as signifying a dynamical com-
munity, without which even local community <1(communio spatii)>1
could never be empirically known. We may easily recognise
from our experiences that only the continuous influences in all
parts of space can lead our senses from one object to another.
The light, which plays between our eye and the celestial bodies,
produces a mediate community between us and them, and
thereby shows us that they coexist. We cannot empirically
change our position, and perceive the change, unless matter
in all parts of space makes perception of our position possible
to us. For only thus by means of their reciprocal influence can
the parts of matter establish their simultaneous existence, and
thereby, though only mediately, their coexistence, even to
the most remote objects. Without community each percep-
tion of an appearance in space is broken off from every other,  A 214
and the chain of empirical representations, that is, experience,
00012
  would have to begin entirely anew with each new object,
  B 261  without the least connection with the preceding representation,
  and without standing to it in any relation of time. I do not by
  this argument at all profess to disprove void space, for it may
  exist where perceptions cannot reach, and where there is,
  therefore, no empirical knowledge of coexistence. But such a
  space is not for us an object of any possible experience.
  The following remarks may be helpful in [further] elucida-
  tion [of my argument]. In our mind, all appearances, since
  they are contained in a possible experience, must stand in
  community <1(communio)>1 of apperception, and in so far as the
  objects are to be represented as coexisting in connection with
  each other, they must mutually determine their position in
  <1one>1 time, and thereby constitute a whole. If this subjective
  community is to rest on an objective ground, or is to hold of
  appearances as substances, the perception of the one must
  as ground make possible the perception of the other, and
  reversewise---in order that the succession which is always
  found in the perceptions, as apprehensions, may not be as-
  cribed to the objects, and in order that, on the contrary, these
  objects may be represented as coexisting. But this is a re-
  ciprocal influence, that is, a real community <1(commercium)>1 of
  A 215 substances; without it the empirical relation of coexistence
  could not be met with in experience.  Through this <1com->1
  <1mercium>1 the appearances, so far as they stand outside one
  B 262  another and yet in connection, constitute a composite <1(com->1
  <1positum reale),>1 and such composites are possible in many
  different ways. The three dynamical relations, from which
  all others spring, are therefore inherence, consequence, and
  composition.
                         *  *  *
  These, then, are the three analogies of experience. They are
  simply principles of the determination of the existence of ap-
  pearances in time, according to all its three modes, viz. the rela-
  tion to time itself as a magnitude (the magnitude of existence,
  that is, <1duration),>1 the relation in time as a <1successive>1 series, and
  finally the relation in time as a sum of all <1simultaneous>1 exist-
  ence. This unity of time-determination is altogether dynamical.
00013
For time is not viewed as that wherein experience immedi-
ately determines position for every existence. Such deter-
mination is impossible, inasmuch as absolute time is not an
object of perception with which appearances could be con-
fronted. What determines for each appearance its position in
time is the rule of the understanding through which alone the
existence of appearances can acquire synthetic unity as regards
relations of time; and that rule consequently determines the
position [in a manner that is] <1a priori>1 and valid for each and
every time.
  By nature, in the empirical sense, we understand the con- B 216
nection of appearances as regards their existence according
to necessary rules, that is, according to laws. There are certain
laws which first make a nature possible, and these laws are
<1a priori.>1 Empirical laws can exist and be discovered only
through experience, and indeed in consequence of those original
laws through which experience itself first becomes possible.
Our analogies therefore really portray the unity of nature in
the connection of all appearances under certain exponents
which express nothing save the relation of time (in so far as
time comprehends all existence) to the unity of apperception
---such unity being possible only in synthesis according to
rules. Taken together, the analogies thus declare that all
appearances lie, and must lie, in <1one>1 nature, because without
this <1a priori>1 unity no unity of experience, and therefore no
determination of objects in it, would be possible.
  As to the mode of proof of which we have made use in
these transcendental laws of nature, and as to their peculiar
character, an observation has to be made which must likewise
be of very great importance as supplying a rule to be followed
in every other attempt to prove <1a priori>1 propositions that are
intellectual and at the same time synthetic. Had we attempted
to prove these analogies dogmatically; had we, that is to say,
attempted to show from concepts that everything which exists
is to be met with only in that which is permanent, that every  B 264
event presupposes something in the preceding state upon A 217
which it follows in conformity with a rule; and finally, that
in the manifold which is coexistent the states coexist in rela-
tion to one another in conformity with a rule and so stand in
00014
  community,all our labour would have been wasted.  For through
  mere concepts of these things, analyse them as we may, we can
  never advance from one object and its existence to the exist-
  ence of another or to its mode of existence. But there is an
  alternative method, namely, to investigate the possibility of
  experience as a knowledge wherein all objects---if their repre-
  sentation is to have objective reality for us---must finally be
  capable of being given to us. In this third [medium],1 the
  essential form of which consists in the synthetic unity of the
  apperception of all appearances, we have found <1a priori>1 con-
  ditions of complete and necessary determination of time for
  all existence in the [field of] appearance, without which even
  empirical determination of time would be impossible. In it we
  have also found rules of synthetic unity <1a priori,>1 by means of
  which we can anticipate experience. For lack of this method,
  and owing to the erroneous assumption that synthetic proposi-
  recommends as being its principles, may be proved dogmatic-
  ally, the attempt has, time and again, been made, though
  B 265  always vainly, to obtain a proof of the principle of sufficient
  A 218  reason. And since the guiding-thread of the categories, which
  alone can reveal and make noticeable every gap in the under-
  standing, alike in regard to concepts and to principles, has
  hitherto been lacking, no one has so much as thought of the
  other two analogies, although use has always tacitly been
  made of them.a
  a The unity of the world-whole, in which all appearances have
  to be connected, is evidently a mere consequence of the tacitly
  assumed principle of the community of all substances which are
  coexistent. For if they were isolated, they would not as parts con-
  stitute a whole. And if their connection (the reciprocal action of the
  manifold) were not already necessary because of their coexistence,
  we could not argue from this latter, which is a merely ideal relation
  to the former, which is a real relation. We have, however, in the
  proper context, shown that community is really the ground of the
  possibility of an empirical knowledge of coexistence, and that the
  inference, rightly regarded, is simply from this empirical knowledge
  to community as its condition.
00015
POSTULATES OF EMPIRICAL THOUGHT
  4
THE POSTULATES OF EMPIRICAL THOUGHT IN GBNERAL
  1. That which agrees with the formal conditions of ex-
perience, that is, with the conditions of intuition and of con-
cepts, is <1possible.>1
  2. That which is bound up with the material conditions B 266
of experience, that is, with sensation, is <1actual.>1
  3. That which in its connection with the actual is deter-
mined in accordance with universal conditions of experience,
is (that is, exists as) <1necessary.>1
  <1Explanation>1
  The categories of modality have the peculiarity that, in A 219
determining an object, they do not in the least enlarge the
concept to which they are attached as predicates. They only
express the relation of the concept to the faculty of knowledge.
Even when the concept of a thing is quite complete, I can still
enquire whether this object is merely possible or is also actual,
or if actual, whether it is not also necessary. No additional
determinations are thereby thought in the object itself; the
question is only how the object, together with all its deter-
minations, is related to understanding and its empirical em-
ployment, to empirical judgment, and to reason in its appli-
cation to experience.
  Just on this account also the principles of modality are
nothing but explanations of the concepts of possibility, actual-
ity, and necessity, in their empirical employment; at the same
time they restrict all categories to their merely empirical em-
ployment, and do not approve or allow their transcendental  B 267
employment. For if they are not to have a purely logical sig-
nificance, analytically expressing the form of <1thought,>1 but are
to refer to the possibility, actuality, or necessity of <1things,>1 they
must concern possible experience and its synthetic unity, in
which alone objects of knowledge can be given.
  The postulate of the <1Possibility>1 of things requires that  A 220
the concept of the things should agree with the formal con-
ditions of an experience in general. But this, the objective
form of experience in general, contains all synthesis that is
00016
required for knowledge of objects. A concept which contains
a synthesis is to be regarded as empty and as not related to
any object, if this synthesis does not belong to experience
either as being derived from it, in which case it is an <1empiricat>1
<1concept>1, or as being an <1a priori>1 condition upon which experi-
ence in general in its formal aspect rests, in which case it is
a <1pure concept.>1 In the latter case it still belongs to experience,
  inasmuch as its object is to be met with only in experience:
  For whence shall we derive the character of the possibility of
  an object which is thought through a synthetic <1apriori>1 con-
  cept, if not from the synthesis which constitutes the form of
  B 268  the empirical knowledge of objects? It is, indeed, a necessary
  tain any contradiction; but this is not by any means sufficient
  to determine the objective reality of the concept, that is, the pos-
  sibility of such an object as is thought through the concept.
  Thus there is no contradiction in the concept of a figure which
  is enclosed within two straight lines, since the concepts of two
  straight lines and of their coming together contain no negation
  A 221 of a figure. The impossibility arises not from the concept in
  itself, but in connection with its construction in space, that is,
  from the conditions of space and of its construction in space, that is
  these have an objective reality of their own, that is, they apply
  to possible things, since they contain <1a priori>1 in themselves
  the form of experience in general.
  We shall now proceed to show the far-reaching utility and
  influence of this postulate of possibility. If I represent to my-
  self a thing which is permanent, so that everything in it which
  changes belongs only to its state, I can never know from such
  a concept that a thing of this kind is possible. Or if I represent
  to myself something which is so constituted that if it is posited
  something else invariably and inevitably follows from it, this
  may certainly be so thought without contradiction; but this
  thought affords no means of judging whether this property
  (causality) is to be met with in any possible thing.  Lastly,
  B 269  I can represent to myself diverse things (substances), which
  are so constituted that the state of the one carries with it some
  consequence in the state of the other, and this reciprocally;
  but I can never determine from these concepts, which contain
  a merely arbitrary synthesis, whether a relation of this kind
00017
can belong to any [possible] things. Only through the fact that
these concepts express <1a priori>1 the relations of perceptions in
every experience, do we know their objective reality, that is  A 222
their transcendental truth, and this, indeed, independently of
experience, though not independently of all relation to the
form of an experience in general, and to the synthetic unity
in which alone objects can be empirically known.
  But if we should seek to frame quite new concepts of sub-
stances, forces, reciprocal actions, from the material which
perception presents to us, without experience itself yielding
the example of their connection, we should be occupying our-
selves with mere fancies, of whose possibility there is absolutely
no criterion since we have neither borrowed these concepts
[directly] from experience, nor have taken experience as our
instructress in their formation. Such fictitious concepts, un-
like the categories, can acquire the character of possibility not
in <1a priori>1 fashion, as conditions upon which all experience
depends, but only <1a posteriori>1 as being concepts which are
given through experience itself. And, consequently, their pos-
sibility must either be known <1a posteriori>1 and empirically, or  B 270
it cannot be known at all. A substance which would be per-
manently present in space, but without filling it (like that
mode of existence intermediate between matter and thinking
being which some would seek to introduce), or a special ulti-
mate mental power of <1intuitively>1 anticipating the future (and
not merely inferring it), or lastly a power of standing in com-
munity of thought with other men, however distant they may
be---are concepts the possibility of which is altogether ground-  A 223
less, as they cannot be based on experience and its known laws;
and without such confirmation they are arbitrary combinations
of thoughts, which, although indeed free from contradiction,
can make no claim to objective reality, and none, therefore, as
to the possibility of an object such as we here profess to think.
As regards reality, we obviously cannot think it <1in concreto,>1
without calling experience to our aid. For reality is bound up
with sensation, the matter of experience, not with that form
of relation in regard to which we can, if we so choose, resort
to a playful inventiveness.
  But I leave aside everything the possibility of which can
00018
  be derived only from its actuality in experience, and have here
  in view only the possibility of things through <1apriori>1 concepts;
  B 271  and I maintain the thesis that their possibility can never be
  established from such concepts taken in and by themselves,
  but only when the concepts are viewed as formal and objective
  conditions of experience in general.
  It does, indeed, seem as if the possibility of a triangle could
  be known from its concept in and by itself (the concept is cer-
  tainly independent of experience), for we can, as a matter of
  fact, give it an object completely <1apriori,>1 that is, can construct
  it. But since this is only the form of an object, it would remain
A 224  a mere product of imagination, and the possibility of its object
  would still be doubtful. To determine its possibility, something
  more is required, namely, that such a figure be thought under
  no conditions save those upon which all objects of experience
  rest. That space is a formal <1a priori>1 condition of outer experi-
  ences, that the formative synthesis through which we con-
  struct a triangle in imagination is precisely the same as that
  which we exercise in the apprehension of an appearance, in
  making for ourselves an empirical concept of it---these are the
  considerations that alone enable us to connect the representa-
  tion of the possibility of such a thing with the concept of it.
  Similarly, since the concepts of continuous magnitudes, indeed
  of magnitudes in general, are one and all synthetic, the possi-
  bility of such magnitudes is never clear from the concepts them-
B 272  selves, but only when they are viewed as formal conditions
  of the determination of objects in experience in general. And
  where, indeed, should we seek for objects corresponding to
  these concepts if not in experience, through which alone ob-
  jects are given to us? We can, indeed, prior to experience
  itself, know and characterise the possibility of things, merely
  by reference to the formal conditions under which in experi-
  therefore can do so completely <1a priori.>1 But, even so, this is
  possible only in relation to experience and within its limits.
A 225  The postulate bearing on the knowledge of things as
  <1actual>1 does not, indeed, demand immediate <1perception>1 (and,
  therefore, sensation of which we are conscious) of the object
  whose existence is to be known. What we do, however,
00019
require is the connection of the object with some actual
perception, in accordance with the analogies of experi-
ence, which define all real connection in an experience in
general.
  In the <1mere concept>1 of a thing no mark of its existence is
to be found. For though it may be so complete that nothing
which is required for thinking the thing with all its inner deter-
minations is lacking to it, yet existence has nothing to do with
all this, but only with the question whether such a thing be so
given us that the perception of it can, if need be, precede the
concept. For that the concept precedes the perception signi-  B 273
fies the concept's mere possibility; the perception which sup-
plies the content to the concept is the sole mara of actuality.
We can also, however, know the existence of the thing prior to
its perception and, consequently, comparatively speaking, in
an <1a priori>1 manner, if only it be bound up with certain percep-
tions, in accordance with the principles of their empirical con-
nection (the analogies). For the existence of the thing being
thus bound up with our perceptions in a possible experience,
we are able in the series of possible perceptions and under the  A 226
guidance of the analogies to make the transition from our
actual perception to the thing in question. Thus from the per-
ception of the attracted iron filings we know of the existence
of a magnetic matter pervading all bodies, although the con-
stitution of our organs cuts us off from all immediate percep-
tion of this medium. For in accordance with the laws of sensi-
bility and the context of our perceptions, we should, were our
Senses more refined, come also in an experience upon the im-
mediate empirical intuition of it. The grossness of our senses
does not in any way decide the form of possible experience
general. Our knowledge of the existence of things reaches,
then, only so far as perception and its advance according
to empirical laws can extend. If we do not start from ex-
perience, or do not proceed accordance with laws of the em-  B 274
00020
pirical connection of appearances, our guessing or enquiring
into the existence of anything will only be an idle pretence.
 Idealism raises, however, what is a serious objection to these
rules for proving existence mediately; and this is the proper
place for its refutation.
                         * * *
                <1Refutation of Idealism>1
  Idealism---meaning thereby <1material>1 idealism---is the
  theory which declares the existence of objects in space out-
  side us either to be merely doubtful and indemonstrable or to
  be false and impossible. The former is the <1problematic>1 ideal-
  ism of Descartes, which holds that there is only one empirical
  assertion that is indubitably certain, namely, that "I am'. The
  latter is the <1dogmatic>1 idealism of Berkeley. He maintains that
  space, with all the things of- which it is the inseparable condi-
  tion, is something which is in itself impossible; and he there-
  fore regards the things in space as merely imaginary entities.
  Dogmatic idealism is unavoidable, if space be interpreted as a
  property that must belong to things in themselves. For in that
  case space, and everything to which it serves as condition, is a
  non-entity. The ground on which this idealism rests has al-
  ready been undermined by us in the Transcendental Aesthetic.
  Problematic idealism, which makes no such assertion, but
  B 275 merely pleads incapacity to prove, through immediate experi-
  ence, any existence except our own, is, in so far as it allows
  of no decisive judgment until sufficient proof has been found,
  reasonable and in accordance with a thorough and philo-
  sophical mode of thought. The required proof must, therefore,
  show that we have <1experience,>1 and not merely imagination of
  outer things; and this, it would seem, cannot be achieved save
  by proof that even our inner experience, which for Descartes
  is indubitable, is possible only on the assumption of outer ex-
  perience.
00021
<1The mere, but empirically determined, consciousness of my>1
  <1own existence proves the existence of objects in space>1
  <1outside me.>1
  <1Proof>1
  I am conscious of my own existence as determined in
time. All determination of time presupposes something <1per->1
<1manent>1 in perception. This permanent cannot, however,
be something in me, since it is only through this per-
manent that my existence in time can itself be deter-
mined. Thus perception of this permanent is possible only
through a <1thing>1 outside me and not through the mere <1re->1
<1Presentation>1 of a thing outside me; and consequently the
determination of my existence in time is possible only through
the existence of actual things which I perceive outside me-  B 276
Now consciousness [of my existence] in time is necessarily
bound up with consciousness of the [condition of the] possi-
bility of this time-determination;  and it is therefore necessarily
bound up with the existence of things outside me, as the
condition of the time-determination. In other words, the con-
sciousness of my existence is at the same time an immediate
consciousness of the existence of other things outside me.
  <1Note>1 I. It will be observed that in the foregoing proof
the game played by idealism has been turned against itself,
and with greater justice. Idealism assumed that the only
immediate experience is inner experience, and that from it
we can only <1infer>1 outer things---and this, moreover, only in an
untrustworthy manner, as in all cases where we are inferring
from given effects to determinate causes.  In this particular case,
the cause of the representations, which we ascribe, perhaps
falsely, to outer things, may lie in ourselves. But in the above
proof it has been shown that outer experience is really
00022
B 277  immediate,a and that only by means of it is inner experience
  ---not indeed the consciousness of my own existence, but the
  determination of it in time---possible. Certainly, the repre-
  sentation "I am', which expresses the consciousness that can
  accompany all thought, immediately includes in itself the
  existence of a subject; but it does not so include any <1knowledge>1
  of that subject, and therefore also no empirical knowledge,
  that is, no experience of it. For this we require, in addition to
  the thought of something existing, also intuition, and in this
  case inner intuition, in respect of which, that is, of time, the
  subject must be determined. But in order so to determine it,
  outer objects are quite indispensable; and it therefore follows
  that inner experience is itself possible only mediately, and
  only through outer experience.
  <1Note>1 2. With this thesis all employment of our cognitive
  faculty in experience, in the determination of time, entirely
  agrees. Not only are we unable to perceive1 any deter-
  mination of time save  through change  in  outer  relations
  (motion) relatively to the permanent in space (for instance,
  the motion of the sun relatively to objects on the earth), we
B 278  have nothing permanent on which, as intuition, we can base
  the concept of a substance, save only <1matter;>1 and even this
  permanence is not obtained from outer experience, but is
  presupposed <1a priori>1 as a necessary condition of determina-
  tion of time, and therefore also as a determination of inner
  sense in respect of [the determination of] our own existence
  through the existence of outer things. The consciousness of
  myself in  the  representation  "I'  is  not  an  intuition,  but  a
  a The <1immediate>1 consciousness of the existence of outer things
  is, in the preceding thesis, not presupposed, but proved, be the
  possibility of this consciousness understood by us or not. The ques-
  tion as to its possibility would be this: whether we have an inner
  sense only, and no outer sense, but merely an outer imagination. It
  is clear, however, that in order even only to imagine something as
B 277  outer, that is, to present it to sense in intuition, we must already
  have an outer sense, and must thereby immediately distinguish the
  mere receptivity of an outer intuition from the spontaneity which
  characterises every act of imagination. For should we merely be
  imagining an outer sense, the faculty of intuition, which is to be
  determined by the faculty of imagination, would itself be annulled.
00023
merely <1intellectual>1 representation of the spontaneity of a
thinking subject. This "I' has not, therefore, the least pre-
dicate of intuition, which, as permanent, might serve as cor-
relate for the determination of time in inner sense---in the
manner in which, for instance, <1impenetrability>1 serves in our
<1empirical>1 intuition of matter.
  <1Note>1 3. From the fact that the existence of outer things
is required for the possibility of a determinate consciousness
of the self, it does not follow that every intuitive representa-
tion of outer things involves the existence of these things,
for their representation can very well be the product merely
of the imagination (as in dreams and delusions). Such re-
presentation is merely the reproduction of previous outer
perceptions, which, as has been shown, are possible only
through the reality of outer objects. All that we have here
sought to prove is that inner experience in general is possible
only through outer experience in general. Whether this or that  B 279
supposed experience be not purely imaginary, must be ascer-
tained from its special determinations, and through its con-
gruence with the criteria of all real experience.
                          *  *
  Lastly, as regards the third postulate, it concerns material
necessity in existence, and not merely formal and logical
necessity in the connection of concepts. Since the existence of
any object of the senses cannot be known completely <1a priori,>1
but only comparatively <1a priori,>1 relatively to some other pre-
viously given existence;  and since, even so, we can then  A 227
arrive only at such an existence as must somewhere be
contained in the context of the experience, of which the
given perception is a part, the necessity of existence can
never be known from concepts, but always only from con-
nection with that which is perceived, in accordance with
universal laws of experience. Now there is no existence that
can be known as necessary under the condition of other given
appearances, save the existence of effects from given causes,
00024
  in accordance with laws of causality. It is not, therefore, the
  existence of things (substances) that we can know to be neces-
  sary, but only the existence of their state; and this necessity
B 280  of the existence of their state we can know only from other
  states, which are given in perception, in accordance with
  empirical laws of causality. It therefore follows that the cri-
  terion of necessity lies solely in the law of possible experience,
  the law that everything which happens is determined <1apriori>1
  through its cause in the [field of] appearance. We thus know
  the necessity only of those <1effects>1 in nature the causes of which
  extends no further than the field of possible experience, and
  even in this field is not applicable to the existence of things as
  substances, since substances can never be viewed as empirical
  effects---that is, as happening and coming to be. Necessity con-
A 228  cerns only the relations of appearances in conformity with the
  dynamical law of causality and the possibility grounded upon
  it of inferring <1a priori>1 from a given existence (a cause) to
  another existence (the effect). That everything which happens
  is hypothetically necessary is a principle which subordinates
  alteration in the world to a law, that is, to a rule of necessary
  existence, without which there would be nothing that could be
  entitled nature. The proposition that nothing happens through
  blind chance <1(in mundo non datur casus)>1 is therefore an <1a>1
  <1priori>1 law of nature. So also is the proposition that no neces-
  sity in nature is blind, but always a conditioned and therefore
  intelligible necessity <1(non daturfatum).>1 Both are laws through
B 281  which the play of alterations is rendered subject to a <1nature of>1
  <1things>1 (that is, of things as appearances), or what amounts to
  the same thing, to the unity of understanding, in which
  alone they can belong to <1one>1 experience, that is, to the syn-
  thetic unity of appearances. Both belong to the class of
  dynamical principles. The first is really a consequence of the
  principle of causality, and so belongs to the analogies of
  experience. The second is a principle of modality; but this
  modality, while adding the concept of necessity to causal
  determination, itself stands under a rule of understanding.
  The principle of continuity forbids any leap in the series of
  appearances, that is, of alterations <1(in mundo non datur saltus);>1
00025
it also forbids, in respect of the sum of all empirical intuitions  A 229
in space, any gaps or cleft between two appearances <1(non>1
<1datur hiatus);>1 for so we may express the proposition, that
nothing which proves a vacuum, or which even admits it as a
part of empirical synthesis, can enter into experience. As regards
a void which may be conceived to lie beyond the field of possible
experience, that is, outside the world, such a question does not
come within the jurisdiction of the mere understanding---which
decides only upon questions that concern the use to be made
of given appearances for the obtaining of empirical know-
ledge. It is a problem for that ideal reason1 which goes out
beyond the sphere of a possible experience and seeks to judge  B 282
of that which surrounds and limits it; and is a problem which
will therefore have to be considered in the Transcendental
Dialectic. These four propositions <1(in mundo non datur>1
<1hiatus, non datur saltus, non datur casus, non datur fatum),>1
like all principles of transcendental origin, we can easily ex-
hibit in their order, that is, in accordance with the order of
the categories, and so assign to each its proper place. But the
reader has now had sufficient practice to allow of his doing
this for himself, or of easily discovering the guiding principle
for so doing. They are all entirely at one in this, that they
allow of nothing in the empirical synthesis which may do
violence or detriment to the understanding and to the con-
tinuous connection of all appearances---that is, to the unity of  A 230
the concepts of the understanding. For in the understanding
alone is possible the unity of experience, in which all percep-
tions must have their place.
  To enquire whether the field of possibility is larger than the
field which contains all actuality, and this latter, again, larger
than the sum of that which is necessary, is to raise somewhat
subtle questions which demand a synthetic solution and yet
come under the jurisdiction of reason alone. For they are
tantamount to the enquiry whether things as appearances one
and all belong to the sum  nd context of a single experience,
of which every given perception is a part, a part which there-
fore cannot be connected with any other [series of] appearances,
or whether my perceptions can belong, in their general con-  B 283
nection, to more than one possible experience. The under-
00026
standing, in accordance with the subjective and formal con-
ditions of sensibility as well as of apperception, prescribes
<1a priori>1 to experience in general the rules which alone make
experience possible. Other forms of intuition than space and
time, other forms of understanding than the discursive forms
of thought, or of knowledge through concepts, even if they
should be possible, we cannot render in any way conceivable
and comprehensible to ourselves; and even assuming that we
could do so, they still would not belong to experience--the
only kind of knowledge in which objects are given to us.
A 231  Whether other perceptions than those belonging to our whole
  possible experience, and therefore a quite different field of
  matter, may exist, the understanding is not in a position to
  decide. It can deal only with the synthesis of that which is
  given. Moreover, the poverty of the customary inferences
  through which we throw open a great realm of possibility, of
  which all that is actual (the objects of experience) is only a small
  part, is patently obvious. Everything actual is possible; from
  this proposition there naturally follows, in accordance with the
  logical rules of conversion, the merely particular proposition,
  B 284 that some possible is actual; and this would seem to mean
  that much is possible which is not actual. It does indeed
  seem as if we were justified in extending the number of
  possible things beyond that of the actual, on the ground
  that something must be added to the possible to constitute
  the actual. But this [alleged] process of adding to the pos-
  sible I refuse to allow. For that which would have to be
  added to the possible, over and above the possible, would
  be impossible What can be added is only a relation to my
  understanding, namely that in addition to agreement with
  the formal conditions of experience there should be conect-
  tion with some perception. But whatever is connected with
  perception in accordance with empirical laws is actual, even
  although it is not immediately perceived. That yet another
  series of appearances in thoroughgoing connection with that
  which is given in perception, and consequently that more
A 232 than one all-embracing experience is possible, cannot be in-
  ferred from what is given; and still less can any such infer-
  ence be drawn independently of anything being given---since
00027
without material nothing whatsoever can be thought. What
is possible only under conditions which themselves are merely
possible is not <1in all respects>1 possible. But such [absolute]
possibility is in question when it is asked whether the possi-
bility of things extends further than experience can reach.
  I have made mention of these questions only in order to
omit nothing which is ordinarily reckoned among the concepts  B 285
of understanding. But as a matter of fact absolute possibility,
that which is in all respects valid, is no mere concept of
understanding, and can never be employed empirically. It
belongs exclusively to reason, which transcends all possible
empirical employment of the understanding. We have there-
fore had to content ourselves with some merely critical re-
marks; the matter must otherwise be left in obscurity until we
come to the proper occasion for its further treatment.
  Before concluding this fourth section, and therewith the
system of all principles of pure understanding, I must explain
why I have entitled the principles of modality postulates. I
interpret this expression not in the sense which some recent
philosophical writers, wresting it from its proper mathematical  A 233
significance, have given to it, namely, that to postulate should
mean to treat a proposition as immediately certain, with-
out justification or proof. For if, in dealing with synthetic
propositions, we are to recognise them as possessing un-
conditioned validity, independently of deduction, on the evi-
dence [merely] of their own claims, then no matter how evident
they may be, all critique of understanding is given up. And
since there is no lack of audacious pretensions, and these are
supported by common belief (though that is no credential of
their truth), the understanding lies open to every fancy, and is  B 286
in no position to withhold approval of those assertions which,
though illegitimate, yet press upon us, in the same confident
tone, their claims to be accepted as actual axioms. Whenever,
therefore, an <1a priori>1 determination is synthetically added to
the concept of a thing, it is indispensable that, if not a proof,
at least a deduction of the legitimacy of such an assertion
should be supplied.
  The principles of modality are not, however, objectively
synthetic. For the predicates of possibility, actuality, and
00028
  necessity do not in the least enlarge the concept of which they
  are affirmed, adding something to the representation of the
  object. But since they are none the less synthetic, they are so
A 234  subjectively only, that is, they add to the concept of a thing (of-
  something real), of which otherwise they say nothing, the cog-
  nitive faculty from which it springs and in which it has its seat.
  Thus if it is in connection only with the formal conditions of
  experience, and so merely in the understanding, its object is
  called possible. If it stands in connection with perception, thatis,
  with sensation as material supplied bythe senses, and through
  perception is determined by means of the understanding, the
  object is actual. If it is determined through the connection of per-
B 257  ceptions according to concepts, the object is entitled necessary.
  The principles of modality thus predicate of a concept nothing
  but the action of the faculty of knowledge through which it
  is generated. Now in mathematics a postulate means the prac-
  tical proposition which contains nothing save the synthesis
  through which we first give ourselves an object and generate
  its concept---for instance, with a given line, to describe a circle
  on a plane from a given point. Such a proposition cannot be
  proved, since the procedure which it demands is exactly that
  through which we first generate the concept of such a figure.
  With exactly the same right we may postulate the principles of
  modality, since they do not increase ours concept of things,a
A 235  but only show the manner in which it is connected with the
  faculty of knowledge.
B 258  <1General Note on the System of the Principles>1
  That the possibility of a thing cannot be determined from
  the category alone, and that in order to exhibit the objective
  reality of the pure concept of understanding we must always

  a Through the actuality of a thing I certainly posit more than
  the possibility of it, but not <1in the thing.>1 For it can never contain
  more in its actuality than is contained in its complete possibility.
  But while possibility is merely a positing of the thing in relation to
  the understanding (in its empirical employment), actuality is at the
  same time a connection of it with perception.
00029
have an intuition, is a very noteworthy fact. Take, for instance,
the categories of relation. We cannot determine from mere
concepts how (I) something can exist as subject only, and not
as a mere determination of other things, that is, how a thing
can be substance, or (2) how, because something is, something
else must be, and how, therefore, a thing can be a cause, or (3)
when several things exist, how because one of them is there,
something follows in regard to the others and <1vice versa,>1 and
how in this way there can be a community of substances.
This likewise applies to the other categories; for example,
how a thing can be equal to a number of things taken together,
that is, can be a quantity. So long as intuition is lacking, we do
not know whether through the categories we are thinking an
object, and whether indeed there can anywhere be an object
suited to them. In all these ways, then, we obtain confirmation
that the categories are not in themselves knowledge, but are
merely <1forms of thought>1 for the making of knowledge from
given intuitions.
  For the same reason it follows that no synthetic proposi-  B 289
tion can be made from mere categories. For instance, we are
not in a position to say that in all existence there is substance,
that is, something which can exist only as subject and not as
mere predicate; or that everything is a quantum, etc. For if
intuition be lacking, there is nothing which can enable us to
go out beyond a given concept, and to connect another with it.
No one, therefore, has ever yet succeeded in proving a syn-
thetic proposition merely from pure concepts of the under-
standing---as, for instance, that everything which exists con-
tingently has a cause. We can never get further than proving,
that without this relation we are unable to comprehend the
existence of the contingent, that is, are unable <1a priori>1 through
the understanding to know the existence of such a thing---
from which it does not, however, follow that this is also a con-
dition of the possibility of the things themselves. If the reader
will go back to our proof of the principle of causality---that
everything which happens, that is, every event, presupposes a
cause---he will observe that we were able to prove it only of
objects of possible experience; and even so, not from pure con-
cepts, but only as a principle of the possibility of experience,
and therefore of the knowledge of an object given in <1empirical>1
00030
  <1intuition.>1 We cannot, indeed, deny that the proposition, that
B 290  everything contingent must have a cause, is patent to every-
  one from mere concepts. But the concept of the contingent
  is then being apprehended as containing, not the category
  of modality (as something the not-being of which can be
  <1thought),>1 but that of relation (as something which can exist
  only as consequence of something else); and it is then, of
  course, an identical proposition---that which can exist only
  as consequence has a cause. As a matter of fact, when we are
  required to cite examples of contingent existence, we invari-
  ably have recourse to <1alterations,>1 and not merely to the possi-
  bility of <1entertaining the opposite in thought.a>1 Now alteration
B 291  is an event which, as such, is possible onlythrough a cause, and
  the not-being of which is therefore in itself possible. In other
  words, we recognise contingency in and through the fact that
  something can exist only as the effect of a cause; and if, there-
  fore, a thing is assumed to be contingent, it is an analytic pro-
  position to say that it has a cause.
  But it is an even more noteworthy fact, that in order to
  understand the possibility of things in conformity with the
  categories, and so to demonstrate the <1objective reality>1 of the
  latter, we need, not merely intuitions, but intuitions that are in
  all cases <1outer intuitions.>1 When, for instance, we take the pure
  concepts of <1relation,>1 we find, firstly, that in order to obtain
  something <1permanent>1 in intuition corresponding to the con-
  cept of <1substance,>1 and so to demonstrate the objective reality
  of this concept, we require an intuition in space (of matter).
  a We can easily think the non-existence of matter. From this
  the ancients did not, however, infer its contingency. Even the
  change from being to not-being of a given state of a thing, in which
  all alteration consists, does not prove the contingency of this
  state, on the ground of the reality of its opposite. For instance, that
  a body should come to rest after having been in motion does not
  prove the contingency of the motion as being the opposite of the
  state of rest. For this opposite is <1opposed>1 to the other only logically,
  not <1realiter.>1 To prove the contingency of its motion, we should have
  to prove that <1instead of>1 the motion at the preceding moment, it was
  possible for the body to have been <1then>1 at rest, not that it is <1after->1
  <1wards>1 at rest; for in the latter case the opposites are quite consistent
  with each other.
00031
For space alone is determined as permanent, while time, and
therefore everything that is in inner sense, is in constant flux.
Secondly, in order to exhibit <1alteration>1 as the intuition corre-
sponding to the concept of <1causality,>1 we must take as our
example motion, that is, alteration in space. Only in this way
can we obtain the intuition of alterations, the possibility of
which can never be comprehended through any pure under-
standing. For alteration is combination of contradictorily
opposed determinations in the existence of one and the same
thing. Now how it is possible thatfrom a given state of a thing  B 292
an opposite state should follow, not only cannot be conceived
by reason without an example, but is actually incomprehensible
to reason without intuition. The intuition required is the in-
tuition of the movement of a point in space. The presence of
the point in different locations (as a sequence of opposite de-
terminations) is what alone first yields to us an intuition of
alteration. For in order that we may afterwards make inner
alterations likewise thinkable, we must represent time (the
form of inner sense) figuratively as a line, and the inner
alteration through the drawing of this line (motion), and so
in this manner by means of outer intuition make compre-
hensible the successive existence of ourselves in different
states. The reason of this is that all alteration, if it is to be
perceived as alteration, presupposes something permanent in
intuition, and that in inner sense no permanent intuition is
to be met with. Lastly, the possibility of the category of
<1community>1 cannot be comprehended through mere reason
alone; and consequently its objective reality is only to be de-
termined through intuition, and indeed through outer intuition
in space. For how are we to think it to be possible, when several
substances exist, that, from the existence of one, something (as
effect) can follow in regard to the existence of the others, and
<1vice versa;>1 in other words, that because there is something
in the one there must also in the others be something which  B 293
is not to be understood solely from the existence of these
others? For this is what is required in order that there be com-
munity; community is not conceivable as holding between
things each of which, through its subsistence, stands in com-
plete isolation. Leibniz, in attributing to the substances of the
00032
world, as thought through the understanding alone, a com-
munity, had therefore to resort to the mediating intervention
of a Deity. For, as he justly recognised, a community of sub-
stances is utterly inconceivable as arising simply from their
existence. We can, however, render the possibility of com-
munity---of substances as appearances---perfectly compre-
hensible, if we represent them to ourselves in space, that is,
in outer intuition. For this already contains in itself <1a priori>1
formal outer relations as conditions of the possibility of the
real relations of action and reaction, and therefore of the
possibility of community.
  Similarly, it can easily be shown that the possibility of
things as <1quantities,>1 and therefore the objective reality of
quantity, can be exhibited only in outer intuition, and that
only through the mediation of outer intuition can it be applied
also to inner sense. But, to avoid prolixity, I must leave the
reader to supply his own examples of this.
  These remarks are of great importance, not only in con-
firmation of our previous refutation of idealism, but even
more, when we come to treat of <1self-knowledge>1 by mere inner
B 294  consciousness, that is, by determination of our nature without
  the aid of outer empirical intuitions---as showing us the limits
  of the possibility of this kind of knowledge.
  The final outcome of this whole section is therefore this:
  all principles of the pure understanding are nothing more than
  principles <1a priori>1 of the possibility of experience, and to
  experience alone do all <1a priori>1 synthetic propositions relate---
  indeed, their possibility itself rests entirely on this relation.
00033
              TRANSCENDENTAL DOCTRINE OF JUDGMENT
                   (ANALYTIC OF PRINCIPLES)
                         CHAPTER III
          THE GROUND OF THE DISTINCTION OF ALL OBJECTS
             IN GENERAL INTO PHENOMENA AND NOUMENA


WE have now not merely explored the territory of pure under-
standing, and carefully surveyed every part of it, but have
also measured its extent, and assigned to everything in it its
rightful place. This domain is an island, enclosed by nature
itself within unalterable limits. It is the land of truth---en-
chanting name!---surrounded by a wide and stormy ocean,  B 295
the native home of illusion, where many a fog bank and many
a swiftly melting iceberg give the deceptive appearance of
farther shores, deluding the adventurous seafarer ever anew A 236
with empty hopes, and engaging him in enterprises which
he can never abandon and yet is unable to carry to com-
pletion. Before we venture on this sea, to explore it in
all directions and to obtain assurance whether there be any
ground for such hopes, it will be well to begin by casting
a glance upon the map of the land which we are about
to leave, and to enquire, first, whether we cannot in any
case be satisfied with what it contains --- are not, indeed,
under compulsion to be satisfied, inasmuch as there may be
no other territory upon which we can settle; and, secondly,
by what title we possess even this domain, and can consider
ourselves as secured against all opposing claims. Although
we have already given a sufficient answer to these questions
in the course of the Analytic, a summary statement of its
solutions may nevertheless help to strengthen our conviction,
by focussing the various considerations in their bearing on
the questions now before us.
00034
  We have seen that everything which the understanding
  derives from itself is, though not borrowed from experience,
  at the disposal of the understanding solely for use in experi-
B 296 ence. The principles of pure understanding, whether con-
  stitutive <1a priori,>1 like the mathematical principles, or merely
  regulative, like the dynamical, contain nothing but what
A 237  may be called the pure schema of possible experience. For
  experience obtains its unity only from the synthetic unity
  which the understanding originally and of itself confers
  upon the synthesis of imagination in its relation to apper-
  ception; and the appearances, as data for a possible know-
  ledge, must already stand <1a priori>1 in relation to, and in agree-
  ment with, that synthetic unity. But although these rules of
  understanding are not only true <1a priori,>1 but are indeed
  the source of all truth (that is, of the agreement of our know-
  ledge with objects), inasmuch as they contain in themselves
  the ground of the possibility of experience viewed as the sum
  of all knowledge wherein objects can be given to us, we are
  not satisfied with the exposition merely of that which is true,
  but likewise demand that account be taken of that which we
  desire to know. If, therefore, from this critical enquiry we
  learn nothing more than what, in the merely empirical em-
  ployment of understanding, we should in any case have
  practised without any such subtle enquiry, it would seem
  as if the advantage derived from it by no means repays
  the labour expended. The reply may certainly be made that
  in the endeavour to extend our knowledge a meddlesome
  curiosity is far less injurious than the habit of always insisting,
B 297  before entering on any enquiries, upon antecedent proof of
  the utility of the enquiries---an absurd demand, since prior
  to completion of the enquiries we are not in a position to form
  the least conception of this utility, even if it were placed before
  our eyes. There is, however, one advantage which may be
  made comprehensible and of interest even to the most re-
A 238  fractory and reluctant learner, the advantage, that while the
  understanding, occupied merely with its empirical employ-
  ment, and not reflecting upon the sources of its own know-
  ledge, may indeed get along quite satisfactorily, there is yet
  one task to which it is not equal, that, namely, of determining
  the limits of its employment, and of knowing what it is that
00035
may lie within and what it is that lies without its own proper
sphere. This demands just those deep enquiries which we have
instituted. If the understanding in its empirical employment
cannot distinguish whether certain questions lie within its
horizon or not, it can never be assured of its claims or of its
possessions, but must be prepared for many a humiliating
disillusionment, whenever, as must unavoidably and con-
stantly happen, it oversteps the limits of its own domain,
and loses itself in opinions that are baseless and mis-
leading.
  If the assertion, that the understanding can employ its
various principles and its various concepts solely in an em-
pirical and never in a transcendental manner, is a proposition
which can be known with certainty, it will yield important  B 298
consequences. The transcendental employment of a concept
in any principle is its application to things <1in general and in>1
<1themselves;>1 the empirical employment is its application <1merely>1
<1to appearances;>1 that is, to objects of a possible experience. That  A 239
the latter application of concepts is alone feasible is evident
from the following considerations. We demand in every con-
cept, first, the logical form of a concept (of thought) in general,
and secondly, the possibility of giving it an object to which
it may be applied. In the absence of such object, it has no
meaning and is completely lacking in content, though it may
still contain the logical function which is required for making
a concept out of any data that may be presented. Now the
object cannot be given to a concept otherwise than in intui-
tion; for though a pure intuition can indeed precede the object
<1a priori,>1 even this intuition can acquire its object, and there-
fore objective validity, only through the empirical intuition
of which it is the mere form. Therefore all concepts, and
with them all principles, even such as are possible <1a priori,>1
relate to empirical intuitions, that is, to the data for a
possible experience. Apart from this relation they have no
objective validity, and in respect of their representations are
a mere play of imagination or of understanding. Take, for
instance, the concepts of mathematics, considering them first  B 299
of all in their pure intuitions. Space has three dimensions;
between two points there can be only one straight line, etc.
Although all these principles, and the representation of the
00036
  object with which this science occupies itself, are generated
A 240 in the mind completely <1a priori,>1 they would mean nothing,
  were we not always able to present their meaning in appear-
  ances, that is, in empirical objects. We therefore demand
  that a bare concept be <1made sensible,>1 that is, that an object
  corresponding to it be presented in intuition. Otherwise the
  concept would, as we say, be without <1sense,>1 that is, without
  meaning. The mathematician meets this demand by the con-
  struction of a figure, which, although produced <1a priori,>1 is an
  appearance present to the senses. In the same science the
  concept of magnitude seeks its support and sensible meaning
  in number, and this in turn in the fingers, in the beads of the
  abacus, or in strokes and points which can be placed before
  the eyes. The concept itself is always <1a priori>1 in origin, and
  so likewise are the synthetic principles or formulas derived
  from such concepts; but their employment and their relation
  to their professed objects can in the end be sought nowhere
  but in experience, of whose possibility they contain the formal
  conditions.
B 300  That this is also the case with all categories and the prin-
  ciples derived from them, appears from the following con-
  sideration. We cannot define any one of them in any real
  fashion, that is, make the possibility of their object under-
  standable, without at once descending to the conditions of
  sensibility, and so to the form of appearances---to which, as
A 241  their sole objects, they must consequently be limited. For if
  this condition be removed, all meaning, that is, relation to the
  object, falls away; and we cannot through any example make
  comprehensible to ourselves what sort of a thing is to be meant
  by such a concept.*
  ---------------------------------------------------------------------------

  * [In A follows the passage, omitted in B:]
  In the above statement of the table of categories, we relieved
  ourselves of the task of defining each of them, as our purpose,
  which concerned only their synthetic employment, did not
  require such definition, and we are not called upon to incur
  any responsibility through unnecessary undertakings from
00037
The concept of magnitude in general can never be explained
except by saying that it is that determination of a thing
whereby we are enabled to think how manytimes a unit is posited
in it. But this how-many-times is based on successive repetition,
and therefore on time and the synthesis of the homogeneous
in time. Reality, in contradistinction to negation, can be ex-
plained only ifwe think time (as containing all being) as either
filled with being or as empty. If I leave out permanence (which
is existence in all time), nothing remains in the concept of sub-
stance save only the logical representation of a subject---a re-
presentation which I endeavour to realise by representing to
myself something which can exist only as subject and never as  B
which we can be relieved. It was no evasion but an important
prudential maxim, not to embark upon the task of definition,
attempting or professing to attain completeness and precision
in the determination of a concept, so long as we can achieve our
end with one or other of its properties, without requiring a
complete enumeration of all those that constitute the com-
plete concept. But we now perceive that the ground of this
precaution lies still deeper. We realise that we are unable to
define them even if we wished.a For if we remove all those
conditions of sensibility which mark them out as concepts of  A 242
possible empirical employment, and view them as concepts of
things in general and therefore of transcendental employment,
all that we can then do with them is to regard the logical
function in judgments [to which they give expression] as the
condition of the possibility of the things themselves, without
in the least being able to show how they can have application
to an object, that is, how in pure understanding, apart from
sensibility, they can have meaning and objective validity.

  a I here mean real definition--which does not merely substitute
for the name of a thing other more intelligible words, but contains
a clear property by which the defined <1object>1 can always be known
with certainty, and which makes the explained concept serviceable
in application. Real explanation would be that which makes clear  A 242
not only the concept but also its <1objective reality.>1 Mathematical
explanations which present the object in intuition, in conformity
with the concept, are of this latter kind.
00038
predicate. But not only am I ignorant of any conditions under
which this logical pre-eminence may belong to anything; I
can neither put such a concept to any use, nor draw the least
inference from it. For no object is thereby determined for
its employment, and consequently we do not know whether
it signifies anything whatsoever. If I omit from the concept
of cause the time in which something follows upon some-
thing else in conformity with a rule, I should find in the pure
category nothing further than that there is something from
which we can conclude to the existence of something else. In
that case not only would we be unable to distinguish cause and
effect from one another, but since the power to draw such in-
ferences requires conditions of which I know nothing, the con-
cept would yield no indication how it applies to any object.
The so-called principle, that everything accidental has a cause,
presents itself indeed somewhat pompously, as self-sufficing
in its own high dignity. But if I ask what is understood by
accidental, and you reply, ""That the not-being of which is
possible,'' I would gladly know how you can determine this
possibility of its not-being, if you do not represent a succession
in the series of appearances and in it a being which follows
upon not-being (or reversewise), that is, a change. For to say
A 244  that the not-being of a thing does not contradict itself, is a lame
B 302  appeal to a logical condition, which, though necessary to the
  concept, is very far from being sufficient for real possibility.
  I can remove in thought every existing substance without
  contradicting myself, but I cannot infer from this their objec-
  tive contingency in existence, that is, that their non-existence
  is possible. As regards the concept of community, it is easily
  seen that inasmuch as the pure categories of substance
  and causality admit of no explanation determinant of the
  object, neither is any such explanation possible of reciprocal
  causality in the relation of substances to one another <1(com->1
  <1mercium).>1 So long as the definition of possibility, existence,
  and necessity is sought solely in pure understanding, they can-
  not be explained save through an obvious tautology. For to
  substitute the logical possibility of the <1concept>1 (namely, that
  the concept does not contradict itself) for the transcendental
  possibility of <1things>1 (namely, that an object corresponds to
00039
the concept) can deceive and leave satisfied only the simple-
minded *a
  * [In A follows the passage, omitted in B:]
  There is something strange and even absurd in the asser-
tion that there should be a concept which possesses a meaning
and yet is not capable of any explanation. But the categories
have this peculiar feature, that only in virtue of the general
condition of sensibility can they possess a determinate mean-
ing and relation to any object. Now when this condition has  A 245
been omitted from the pure category, it can contain nothing but
the logical function for bringing the manifold under a concept.
By means of this function or form of the concept, thus taken
by itself, we cannot in any way know and distinguish what
object comes under it, since we have abstracted from the sens-
ible condition through which alone objects can come under it.
Consequently, the categories require, in addition to the pure
concept of understanding, determinations of their application to
sensibility in general (schemata 1). Apart from such application
they are not concepts through which an object is known and
distinguished from others, but only so many modes of think-
ing an object for possible intuitions, and of giving it meaning,
under the requisite further conditions, in conformity with some
function of the understanding, that is, <1of defining it.>1  But they
cannot themselves be defined. The logical functions of judg-
ments in general, unity and plurality, assertion and denial,
subject and predicate, cannot be defined without perpetrat-
ing a circle, since the definition must itself be a judgment, and
so must already contain these functions. The pure categories
are nothing but representations of things in general, so far as
the manifold of their intuition must be thought through one or
other of these logical functions. Magnitude is the determina-

  a In a word, if all sensible intuition, the only kind of intuition
which we possess, is removed, not one of these concepts can in any
fashion <1verify>1 itself, so as to show its <1real>1 possibility. Only <1logical>1
possibility then remains, that is, that the concept or thought is pos-  B 303
sible. That, however, is not what we are discussing, but whether
the concept relates to an object and so signifies something.
00040
B 203  From all this it undeniably follows that the pure concepts of
  understanding can <1never>1 admit of <1transcendental>1 but <1always>1
  only of <1empirical>1 employment, and that the principles of pure
  understanding can apply only to objects of the senses under
  the universal conditions of a possible experience, never to
  things in general without regard to the mode in which we are
  able to intuit them.
  Accordingly the Transcendental Analytic leads to this
  important conclusion, that the most the understanding can
  achieve <1a priori>1 is to anticipate the form of a possible experi-
  ence in general. And since that which is not appearance can-
  not be an object of experience, the understanding can never
  transcend those limits of sensibility within which alone objects
A 247  can be given to us. Its principles are merely rules for the ex-
  position of appearances; and the proud name of an Ontology
  that presumptuously claims to supply, in systematic doctrinal
  form, synthetic <1a priori>1 knowledge of things in general (for
  instance, the principle of causality) must, therefore, give place
  to the modest title of a mere Analytic of pure understanding.
B 304  Thought is the act which relates given intuition to an
  object. If the mode of this intuition is not in any way
  given, the object is merely transcendental, and the concept of
  understanding has only transcendental employment, namely,
  as the unity of the thought of a manifold in general. Thus no
  object is determined through a pure category in which ab-
  straction is made of every condition of sensible intuition---the
  only kind of intuition possible to us.  It then expresses only the
  tion which can be thought only through a judgment which has
A 246 quantity <1(judicium commune);>1 reality is that determination
  which can be thought only through an affirmative judgment;
  substance is that which, in relation to intuition, must be the
  last subject of all other determinations. But what sort of a
  thing it is that demands one of these functions rather than
  another, remains altogether undetermined. Thus the cate-
  gories, apart from the condition of sensible intuition, of
  which they contain the synthesis, have no relation to any
  determinate object, cannot therefore define any object, and
  so do not in themselves have the validity of objective concepts.
00041
thought of an object in general, according to different modes.
Now the employment of a concept involves a function of judg-
ment1 whereby an object is subsumed under the concept, and
so involves at least the formal condition under which some-
thing can be given in intuition. If this condition of judgment
(the schema) is lacking, all subsumption becomes impossible.
For in that case nothing is given that could be subsumed under
the concept. The merely transcendental employment of the cate-
gories is, therefore, really no employment at all, and has no
determinate object, not even one that is determinable in its  A 248
mere form. It therefore follows that the pure category does not
suffice for a synthetic <1a priori>1 principle, that the principles
of pure understanding are only of empirical, never of tran-
scendental employment, and that outside the field of possible
experience there can be no synthetic <1a priori>1 principles.  B 305
  It may be advisable, therefore, to express the situation as
follows. The pure categories, apart from formal conditions of
sensibility, have only transcendental meaning ; nevertheless
they may not be employed transcendentally, such employment
being in itself impossible, inasmuch as all conditions of any
employment in judgments are lacking to them, namely, the
formal conditions of the subsumption of any ostensible object
under these concepts. Since, then, as pure categories merely,
they are not to be employed empirically, and cannot be em-
ployed transcendentally, they cannot, when separated from all
sensibility, be employed in any manner whatsoever, that is,
they cannot be applied to any ostensible object. They are the
pure form of the employment of understanding in respect of
objects in general, that is, of thought; but since they are
merely its form, through them alone no object can be thought
or determined.*
  * [In A follows the passage, omitted in B:]
  Appearances, so far as they are thought as objects accord-
ing to the unity of the categories, are called <1phaenomena.>1 But  A 249
if I postulate things which are mere objects of understanding,
and which, nevertheless, can be given as such to an intuition,
00042
  But we are here subject to an illusion from which it is
difficult to escape. The categories are not, as regards their
origin, grounded in sensibility, like the <1forms of intuition,>1
space and time; and they seem, therefore, to allow of an
application extending beyond all objects of the senses. As a
matter of fact they are nothing but <1forms of thought,>1 which
contain the merely logical faculty of uniting <1a priori>1 in one con-
B 306  sciousness the manifold given in intuition; and apart, therefore,
  from the only intuition that is possible to us, they have even
  less meaning than the pure sensible forms. Through these
  forms an object is at least given, whereas a mode of com-
  bining the manifold---a mode peculiar to our understanding---
  by itself, in the absence of that intuition wherein the mani-
  fold can alone be given, signifies nothing at all. At the
  same time, if we entitle certain objects, as appearances,
  sensible entities (phenomena), then since we thus distin-
  guish the mode in which we intuit them from the nature that
  -------------------------------------------------------------------------
  although not to one that is sensible---given therefore <1coram>1
  <1intuitu intellectuali->1--such things would be entitled <1noumena>1
  <1(intelligibilia).>1
  Now we must bear in mind that the concept of appear-
  ances, as limited by the Transcendental Aesthetic, already of
  itself establishes the objective reality of <1noumena>1 and justifies
  the division of objects into <1phaenomena>1 and <1noumena,>1 and so
  of the world into a world of the senses and a world of the under-
  standing <1(mundus sensibilis et intelligibilis),>1 and indeed in
  such manner that the distinction does not refer merely to the
  logical form of our knowledge of one and the same thing, ac-
  cording as it is indistinct or distinct, but to the difference in
  the manner in which the two worlds can be first given to our
  knowledge, and in conformity with this difference, to the
  manner in which they are in themselves generically distinct
  from one another. For if the senses represent to us something
  merely <1as it appears,>1 this something must also in itself be a
00043
belongs to them in themselves, it is implied in this distinction
that we place the latter, considered in their own nature,
although we do not so intuit them, or that we place other
possible things, which are not objects of our senses but are
thought as objects merely through the understanding, in
opposition to the former, and that in so doing we entitle them
intelligible entities1 (noumena).  The question then arises,
whether our pure concepts of understanding have meaning
in respect of these latter, and so can be a way of knowing
them.
  At the very outset, however, we come upon an ambiguity
which may occasion serious misapprehension. The under-
standing, when it entitles an object in a [certain] relation
mere phenomenon, at the same time forms, apart from
that relation, a representation of an <1object in itself,>1 and so
comes to represent itself as also being able to form <1con->1 B 3o7
<1cepts>1 of such objects. And since the understanding yields no
concepts additional to the categories, it also supposes that
the object in itself must at least be <1thought>1 through these
thing, and an object of a non-sensible intuition, that is, of the
understanding. In other words, a [kind of] knowledge must be
possible, in which there is no sensibility, and which alone has
reality that is absolutely objective. Through it objects will be
represented <1as they are,>1 whereas in the empirical employment
of our understanding things will be known only <1as they appear.>1  A 250
If this be so, it would seem to follow that we cannot assert,
what we have hitherto maintained, that the pure modes of
knowledge yielded by our understanding are never anything
more than principles of the exposition of appearance, and that
even in their <1a priori>1 application they relate only to the formal
possibility of experience. On the contrary, we should have to
recognise that in addition to the empirical employment of the
categories, which is limited to sensible conditions, there is like-
wise a pure and yet objectively valid employment. For a field
quite different from that of the senses would here lie open to
us, a world which is thought as it were in the spirits (or even
perhaps intuited), and which would therefore be for the under-
standing a far nobler, not a less noble, object of contemplation.
00044
pure concepts, and so is misled into treating the entirely
<1indeterminate>1 concept of an intelligible entity, namely, of a
something in general outside our sensibility, as being a <1de->1
<1terminate>1 concept of an entity that allows of being known in
a certain [purely intelligible] manner by means of the under-
standing.
  If by "noumenon' we mean a thing so far as it is <1not an>1
<1object of our sensible intuition,>1 and so abstract from our mode
of intuiting it, this is a noumenon in the <1negative>1 sense of the
term. But if we understand by it an <1object>1 of a <1non-sensible>1
<1intuition,>1 we thereby presuppose a special mode of intuition,
namely, the intellectual, which is not that which we possess,
and of which we cannot comprehend even the possibility.
This would be "noumenon' in the <1Positive>1 sense of the term.
  The doctrine of sensibility is likewise the doctrine of the
noumenon in the negative sense, that is, of things which the
understanding must think without this reference to our mode
of intuition, therefore not merely as appearances but as
  things in themselves. At the same time the understanding is
  All our representations are, it is true, referred by the under-
  standing to some object; and since appearances are nothing
  but representations, the understanding refers them to a <1some->1
  <1thing,>1 as the object of sensible intuition. But this something,
  thus conceived,1 is only the transcendental object; and by that
  is meant a something= X, of which we know, and with the
  present constitution of our understanding can know, nothing
  whatsoever, but which, as a correlate of the unity of apper-
  ception, can serve only for the unity of the manifold in sensible
  intuition. By means of this unity the understanding combines
  the manifold into the concept of an object. This transcendental
  object cannot be separated from the sense data, for nothing is
  A 251  then left through which it might be thought. Consequently it
  is not in itself an object of knowledge, but only the representa-
  tion of appearances under the concept of an object in general
  ---a concept which is determinable through the manifold of
  these appearances.
  Just for this reason the categories represent no special ob-
  ject, given to the understanding alone, but only serve to deter-
00045
well aware that in viewing things in this manner, as thus
apart from our mode of intuition, it cannot make any use of  B 308
the categories. For the categories have meaning only in rela-
tion to the unity of intuition in space and time; and even this
unity they can determine, by means of general <1a priori>1 con-
necting concepts, only because of the mere ideality of space
and time. In cases where this unity of time is not to be found,
and therefore in the oase of the noumenon, all employment,
and indeed the whole meaning of the categories, entirely
vanishes; for we have then no means of determining whether
things in harmony with the categories are even possible. On
this point I need only refer the reader to what I have said in
the opening sentences of the <1General Note>1 appended to the
preceding chapter.1 The possibility of a thing can never be
proved merely from the fact that its concept is not self-con-
tradictory, but only through its being supported by some
corresponding intuition. If, therefore, we should attempt to
apply the categories to objects which are not viewed as being
appearances, we should have to postulate an intuition other
mine the transcendental object, which is the concept of some-
thing in general, through that which is given in sensibility, in
order thereby to know appearances empirically under concepts
of objects.
  The cause of our not being satisfied with the substrate of
sensibility, and of our therefore adding to the phenomena nou-
mena which only the pure understanding can think, is simply
as follows. The sensibility (and its field, that of the appear-
ances) is itself limited by the understanding in such fashion that
it does not have to do with things in themselves but only with
the mode in which, owing to our subjective constitution, they
appear. The Transcendental Aesthetic, in all its teaching, has
led to this conclusion; and the same conclusion also, of course,
follows from the concept of an appearance in general; namely,
that something which is not in itself appearance must cor-
respond to it. For appearance can be nothing by itself, outside
our mode of representation. Unless, therefore, we are to move  A252
constantly in a circle, the word appearance must be recognised
as already indicating a relation to something, the immediate
  1  [Above, p. 252.]
00046
than the sensible, and the object would thus be a noumenon
in the <1positive sense.>1  Since, however, such a type of intuition,
intellectual intuition, forms no part whatsoever of our
faculty of knowledge, it follows that the employment of
the categories can never extend further than to the objects
of experience. Doubtless, indeed, there are intelligible entities
B 309  corresponding to the sensible entities; there may also be in-
  telligible entities to which our sensible faculty of intuition
  has no relation whatsoever; but our concepts of understand-
  ing, being mere forms of thought for our sensible intuition,
  could not in the least apply to them. That, therefore, which
  we entitle "noumenon' must be understood as being such
  only in a <1negative>1 sense.
  If I remove from empirical knowledge all thought (through
  categories), no knowledge of any object remains. For through
  mere intuition nothing at all is thought, and the fact that this
  affection of sensibility is in me does not [by itself] amount to
  a relation of such representation to any object. But if, on the
A 254 other hand, I leave aside all intuition, the form of thought
  representation of which is, indeed, sensible, but which, even
  apart from the constitution of our sensibility (upon which the
  form of our intuition is grounded), must be something in itself,
  that is, an object independent of sensibility.
  There thus results the concept of a <1noumenon.>1 It is not
  of anything, but signifies only the thought of something in
  general, in which I abstract from everything that belongs to
  the form of sensible intuition. But in order that a noumenon
  may signify a true object, distinguishable from all phenomena,
  it is not enough that I <1free>1 my thought from all conditions of
  sensible intuition; I must likewise have ground for <1assuming>1
  another kind of intuition, different from the sensible, in which
  such an object may be given. For otherwise my thought, while
  indeed without contradictions, is none the less empty. We have
  not, indeed, been able to prove that sensible intuition is the only
  possible intuition, but only that it is so for us. But neither have
  we been able to prove that another kind of intuition is possible.
  Consequently, although our thought can abstract from all
00047
00048
still remains---that is, the mode of determining an object for
the manifold of a possible intuition. The categories accord-
ingly extend further than sensible intuition, since they think
objects in general, without regard to the special mode (the
sensibility) in which they may be given. But they do not
thereby determine a greater sphere of objects. For we cannot
assume that such objects can be given, without presupposing
the possibility of another kind of intuition than the sensible;
and we are by no means justified in so doing.
  If the objective reality of a concept cannot be in any way  B 310
known, while yetthe concept contains no contradiction and also
at the same time is connected with other modes of knowledge
that involve given concepts which it serves to limit, I entitle
that concept problematic. The concept of a <1noumenon->1--that is,
of a thing which is not to be thought as object of the senses
but as a thing in itself, solely through a pure understanding---
is not in any way contradictory. For we cannot assert of sensi-
bility that it is the sole possible kind of intuition. Further, the
sensibility, it is still an open question whether the notion of
a noumenon be not a mere form of a concept, and whether,  A 253
when this separation has been made, any object whatsoever
is left.
  The object to which I relate appearance in general is
the transcendental object, that is, the completely indeter-
minate thought of <1something>1 in general. This cannot be
entitled the <1noumenon;>1 for I know nothing of what it is in
itself, and have no concept of it save as merely the object of
a sensible intuition in general, and so as being one and the
same for all appearances. I cannot think it through any cate-
gory; for a category is valid [only] for empirical intuition, as
bringing it under a concept of object in general. A pure use of
the category is indeed possible [logically], that is, without con-
tradiction; but it has no objective validity, since the category
is notthen being applied to any intuition so as to impartto it
the unity of an object. For the category is a mere function
of thought, through which no object is given to me, and by
which I merely think that which may be given in intuition.
00049
concept of a noumenon is necessary, to prevent sensible intuition
from being extended to things in themselves, and thus to limit
the objective validity of sensible knowledge. The remaining
A 255  things, to which it does not apply, are entitled noumena, in
  order to show that this knowledge cannot extend its domain
  over everything which the understanding thinks. But none the
  less we are unable to comprehend how such noumena can be
  possible, and the domain that lies out beyond the sphere of
  appearances is for us empty. That is to say, we have an
  understanding which <1problematically>1 extends further, but
  we have no intuition, indeed not even the concept of a
  possible intuition, through which objects outside the field
  of sensibility can be given, and through which the under-
  standing can be employed <1assertorically>1 beyond that
  field. The concept of a noumenon is thus a merely <1limiting>1
B 311  <1concept,>1 the function of which is to curb the pretensions of
  sensibility; and it is therefore only of negative employment.
  At the same time it is no arbitrary invention; it is bound up
  with the limitation of sensibility, though it cannot affirm any-
  thing positive beyond the field of sensibility.
  The division of objects into phenomena and noumena, and
  the world into a world of the senses and a world of the under-
  standing, is therefore quite inadmissible in the positive sense
  although the distinction of concepts as sensible and intellectual
  is certainly legitimate.  For no object can be determined for the
  latter concepts, and consequently they cannot be asserted to be
  objectively valid. If we abandon the senses, how shall we make
A 256  it conceivable that our categories, which would be the sole re-
  maining concepts for noumena, should still continue to signify
  something, since for their relation to any object more must be
  given than merely the unity of thought---namely, in addition,
  a possible intuition, to which they may be applied. None the
  less, if the concept of a noumenon be taken in a merely prob-
  lematic sense, it is not only admissible, but as setting limits
  to sensibility is likewise indispensable. But in that case a nou-
  menon is not for our understanding a special [kind of] object,
  namely, an <1intelligible object;>1 the [sort of] understanding to
  which it might belong is itself a problem. For we cannot in
00050
the least represent to ourselves the possibility of an under-
standing which should know its object, not discursively
through categories, but intuitively in a non-sensible intuition.  B 312
What our understanding acquires through this concept of a
noumenon, is a negative extension; that is to say, under-
standing is not limited through sensibility; on the contrary,
it itself limits sensibility by applying the term noumena to
things in themselves (things not regarded as appearances).
But in so doing it at the same time sets limits to itself, recog-
nising that it cannot anow these noumena through any of the
categories, and that it must therefore think them only under
the title of an unknown something.
  In the writings of modern philosophers I find the expres-
sions <1mundus sensibilis>1 and <1intelligibilisa>1 used with a mean-
ing altogether different from that of the ancients---a meaning  A 257
which is easily understood, but which results merely in an
empty play upon words. According to this usage, some have
thought good to entitle the sum of appearances, in so far as
they are intuited, the world of the senses, and in so far as their
connection is thought in conformity with laws of understand-
ing, the world of the understanding. Observational astronomy,  B 313
which teaches merely the observation of the starry heavens,
would give an account of the former; theoretical astronomy,
on the other hand, as taught according to the Copernican
system, or according to Newton's laws of gravitation, would
give an account of the second, namely, of an intelligible
world. But such a twisting of words is a merely sophistica
subterfuge; it seeks to avoid a troublesome question by
changing its meaning to suit our own convenience. Under-
standing and reason are, indeed, employed in dealing with
appearances; but the question to be answered is whether they
have also yet another employment, when the object is not a
  a  We must not, in place of the expression <1mundus intelligibilis,>1
use the expression " an <1intellectual>1 world', as is commonly done
in German exposition.  For only modes of knowledge are either
intellectual or sensuous.  What can only be an <1object>1 of the one
or the other kind of intuition must be entitled (however harsh-
sounding) intelligible or sensible.
00051
phenomenon (that is, is a noumenon); and it is in this latter
  sense that the object is taaen, when it is thought as merely
  intelligible, that is to say, as being given to the understanding
  alone, and notto the senses. The question, therefore, is whether
  in addition to the empirical employment of the understanding
  ---to its employment even in the Newtonian account of the
  structure of the universe---there is likewise possible a tran-
  scendental employment, which has to do with the noumenon
  as an object. This question we have answered in the negative.
  A 258  When, therefore, we say that the senses represent objects
  <1as they appear,>1 and the understanding objects <1as they are,>1 the
  latter statement is to be taken, not in the transcendental, but
  in the merely empirical meaning of the terms, namely as
  meaning that the objects must be represented as objects of
  experience, that is, as appearances in thoroughgoing inter-
  B 314 connection with one another, and not as they may be apart
  from their relation to possible experience (and consequently
  to any senses), as objects of the pure understanding. Such
  objects of pure understanding will always remain unknown
  to us; we can never even know whether such a transcen-
  dental or exceptional knowledge is possible under any con-
  ditions---at least not if it is to be the same kind of know-
  ledge as that which stands under our ordinary categories.
  <1Understanding>1 and <1sensibility,>1 with us, can determine objects
  <1only when they are employed in conjunction.>1 When we separ-
  ate them, we have intuitions without concepts, or concepts
  without intuitions---in both cases, representations which we
  are not in a position to apply to any determinate object.
  If, after all these explanations, any one still hesitates to
  abandon the merely transcendental employment of the cate-
  gories, let him attempt to obtain from them a synthetic pro-
  position. An analytic proposition carries the understanding no
  further; for since it is concerned only with what is already
  thought in the concept, it leaves undecided whether this con-
  cept has in itself any relation to objects, or merely signifies
  A 259  the unity of thought in general---complete abstraction being
  made from the mode in which an object may be given. The
  understanding [in its analytic employment] is concerned only
  to know what lies in the concept; it is indifferent as to the
00052
object to which the concept may apply. The attempt must
therefore be made with a synthetic and professedly tran- B 315
scendental principle, as, for instance, "Everything that exists,
exists as substance, or as a determination inherent in it', or
"Everything contingent exists as an effect of some other thing,
namely, of its cause'. Now whence, I ask, can the understand-
ing obtain these synthetic propositions, when the concepts are
to be applied, not in their relation to possible experience, but
to things in themselves (noumena)? Where is here that third
something, which is always required for a synthetic proposi-
tion, in order that, by its mediation, the concepts which have
no logical (analytic) affinity may be brought into connection
with one another? The proposition can never be established,
nay, more, even the possibility of any such pure assertion can-
not be shown, without appealing to the empirical employment
of the understanding, and thereby departing completely from
the pure and non-sensible judgment. Thus the concept of pure
and merely intelligible objects is completely lacking in all
principles that might make possible its application. For we
cannot think of any way in which such intelligible objects
might be given.  The problematic thought which leaves open
a place for them serves only, like an empty space, for the
limitation of empirical principles, without itself containing or  A 260
revealing any other object of knowledge beyond the sphere of
those principles.
00053
  ARISING FROM THE CONFUSION OF THE EMPIRICAL WITH THE
  TRANSCENDENTAL EMPLOYMENT OF UNDERSTANDING
  <1Reflection (reflexio)>1 does not concern itself with objects them-
  selves with a view to deriving concepts from them directly,
  but is that state of mind in which we first set ourselves
  to discover the subjective conditions under which [alone] we
  are able to arrive at concepts. It is the consciousness of the re-
  lation of given representations to our different sources of know-
  ledge;  and only by way of such consciousness can the relation
  of the sources of knowledge to one another be rightly deter-
  mined. Prior to all further treatment of our representations,
  this question Must first be asked: In which of our cognitive
  faculties are our representations connected together? Is it the
  understanding, or is it the senses, by which they are combined
  or compared? Many a judgment is accepted owing to custom
  or is grounded in inclination; but since no reflection precedes
A 261  it, or at least none follows critically upon it, it is taken as
  having o iginated in the understanding. An <1examination>1
  <1(i.e.>1 the direction of our attention to the grounds of the truth
  of a judgment) is notindeed required in every case; for if the
B 317  judgment is immediately certain (for instance, the judgment
  that between two points there can only be one straight line),
  there can be no better evidence of its truth than the judgment
  itself. All judgments, however, and indeed all comparisons,
  require <1reflection, i.e.>1 distinction of the cognitive faculty to
  which the given concepts belong. The act by which I confront
00054
the comparison of representations with the cognitive faculty
to which it belongs, and by means of which I distinguish
whether it is as belonging to the pure understanding or to
sensible intuition that they are to be compared with each
other, I call <1transcendental reflection.>1 Now the relations1 in
which concepts in a state of mind can stand to one another are
those of <1identity>1 and <1difference,>1 of <1agreement>1 and <1opposition,>1
of the <1inner>1 and the <1outer,>1 and finally of the <1determinable>1 and
the <1determination>1 (matter and form). The right determining
of the relation depends on the answer to the question, in which
faculty of knowledge they belong together <1subjectively>1---in the
sensibility or in the understanding. For the difference between
the faculties makes a great difference to the mode in which we
have to think the relations.
  Before constructing any objective judgment we compare A 262
the concepts to find in them <1identity>1 (of many representa-
tions under one concept) with a view to <1universal>1 judgments,
<1difference>1 with a view to <1Particular>1 judgments, <1agreement>1 B 318
with a view to <1affirmative>1 judgments, <1opposition>1 with a view
to <1negative>1 judgments, etc. For this reason we ought, it seems,
to call the above-mentioned concepts, concepts of comparison
<1(conceptus comparationis).>1 If, however, the question is not
about the logical form, but about the content of the concepts,
<1i.e.>1 whether things are themselves identical or different, in
agreement or in opposition, etc.,then since the things can have
a twofold relation to our faculty of knowledge, namely, to sensi-
bility and to understanding, it is the place to which they belong
in this regard that determines the mode in which they belong
to one another. For this reason the interrelations of given re-
presentations can be determined only through transcendental
reflection, that is, through [consciousness of] their relation to
one or other of the two kinds of knowledge. Whether things are
identical or different, in agreement or in opposition, etc., can-
not be established at once from the concepts themselves by
mere comparison <1(comparatio),>1 but solely by means of tran-
scendental consideration <1(reflexio),>1 through distinction of the
cognitive faculty to which they belong. We may therefore say
00055
that <1logical reflection>1 is a mere act of comparison; for since
we take no account whatsoever of the faculty of knowledge to
which the given representations belong, the representations
B 319 must be treated as being, so far as their place in the mind is
concerned, all of the same order. <1Transcendental reflection>1, on
the other hand, since it bears on the objects themselves, con-
tains the ground of the possibility of the objective comparison
  of representations with each other, and is therefore altogether
  A 263  different from the former type of reflection.1 Indeed they do
  not even belong to the same faculty of knowledge. This trans-
  cendental consideration is a duty from which nobody who
  wishes to make any <1apriori>1 judgments about things can claim
  exemption. We shall now take it in hand, and in so doing shall
  obtain no little light for the determining of the real business
  of the understanding.
  I. <1Identity>1 and <1Difference.>1---If an object is presented to us
  on several occasions but always with the same inner determina-
  tions <1(qualitas et quantitas),>1 then if it be taken as object of
  pure understanding, it is always one and the same, only one
  thing <1(numerica identitas),>1 not many. But if it is appearance,
  we are not concerned to compare concepts; even if there is
  no difference whatever as regards the concepts, difference of
  spatial position at one and the same time is still an adequate
  ground for the <1numerical difference>1 of the object, that is, of the
  we can abstract altogether from all internal difference (of
  A 264  quality and quantity), and the mere fact that they have been
  intuited simultaneously in different spatial positions is suffi-
  B 320  cientjustification for holding them to be numerically different.
  Leibniz took the appearances for things-in-themselves, and so
  for intelligibilia, <1i.e.>1 objects of the pure understanding (al-
  though, on account of the confused character of our represen-
  tations of them, he still gave them the name of phenomena),
  and on that assumption his principle of the identity of indis-
  cernibles <1(principium identitatis indiscernibilium)>1 certainly
  could not be disputed. But since they are objects of sensibility,
  in relation to which the employment of the understanding is
  not pure but only empirical, plurality and numerical difference
  are already given us by space itself, the condition of outer
00056
appearances. For one part of space, although completely simi-
lar and equal to another part, is still outside the other, and for
this very reason is a different part, which when added to it
constitutes with it a greater space. The same must be true of
all things which exist simultaneously in the different spatial
positions, however similar and equal they may otherwise be.
  2. <1Agreement>1 and <1Opposition.>1---If reality is represented
only by the pure understanding <1(realitas noumenon),>1 no oppo-
sition can be conceived between the realities, <1i.e.>1 no relation
of such a kind that, when combined in the same subject, they  A 265
cancel each other's consequences and take a form like 3 - 3 = 0.
On the other hand, the real in appearance <1(realitas phaeno->1
<1menon)>1 may certainly allow of opposition. When such realities  B 321
are combined in the same subject, one may wholly or partially
destroy the consequences of another, as in the case of two
moving forces in the same straight line, in so far as they either
attract or impel a point in opposite directions, or again in the
case of a pleasure counterbalancing pain.
  3. The <1Inner>1 and the <1Outer.>1---In an object of the pure
understanding that only is inward which has no relation what-
soever (so far as its existence is concerned) to anything different
from itself. It is quite otherwise with a <1substantia phaenomenon>1
in space; its inner determinations are nothing but relations, and
it itself is entirely made up of mere relations.We are acquainted
with substance in space only through forces which are active
in this and that space, either bringing other objects to it (at-
traction), or preventing them penetrating into it (repulsion
and impenetrability). We are not acquainted with any other  =
properties constituting the concept of the substance which
appears in space and which we call matter. As object of pure
understanding, on the other hand, every substance must have
inner determinations and powers which pertain to its inner
reality. But what inner accidents can I entertain in thought,
save only those which my inner sense presents to me? They  A 266
must be something which is either itself a <1thinking>1 or ana-
logous to thinking.  For this reason Leibniz, regarding sub-
stances as noumena, took away from them, by the manner in  B 322
which he conceived them, whatever might signify outer re-
lation, including also, therefore, <1composition,>1 and so made
00057
them all, even the constituents of matter, simple subjects with
powers of representation---in a word, MONADS.
  4. <1Matter>1 and <1Form.>1---These two concepts underlie all
other reflection, so inseparably are they bound up with all
employment of the understanding. The one [matter] signifies
the determinable in general, the other [form] its determina-
tion---both in the transcendental sense, abstraction being
made from all differences in that which is given and from the
mode in which it is determined  Logicians formerly gave the
name "matter' to the universal, and the name "form' to the
specific difference. In any judgment we can call the given
concepts logical matter <1(i.e.>1 matter for the judgment), and
their relation (by means of the copula) the form of the judg-
  ment. In every being the constituent elements of it <1(essentialia)>1
  are the matter, the mode in which they are combined in one
  thing the essential form. Also as regards things in general
  unlimited reality was viewed as the matter of all possibility,
  A 267  and its limitation (negation) as being the form by which one
  thing is distinguished from others according to transcendental
  B 323  concepts. The understanding, in order that it may be in a posi-
  tion to determine anything in definite fashion, demands that
  something be first given, at least in concept. Consequently in
  the concept of the pure understanding matter is prior to form;
  and for this reason Leibniz first assumed things (monads),
  and within them a power of representation, in order after-
  wards to found on this their outer relation and the community
  of their states <1(i.e.>1 of the representations). Space and time
  ---the former through the relation of substances, the latter
  through the connection of their determinations among them-
  selves---were thus, on this view, possible as grounds and con-
  sequents. This, in fact, is how it would necessarily be, if the
  pure understanding could be directed immediately to objects,
  and if space and time were determinations of things-in-them-
  selves. But if they are only sensible intuitions, in which we
  determine all objects merely as appearances, then the form of
  intuition (as a subjective property of sensibility) is prior to all
  matter (sensations); space and time come before all appear-
  ances and before all data of experience, and are indeed what
  make the latter at all possible. The intellectualist philo-
  sopher could not endure to think of the form as preceding
00058
the things themselves and determining their possibility---a
perfectly just criticism on the assumption that we intuit things
as they really are, although in confused representation. But  A 268
since sensible intuition is a quite specific subjective condition,
which lies <1a priori>1 at the foundation of all perception, as its  B 324
original form, it follows that the form is given by itself, and that
so far is the matter (or the things themselves which appear)
from serving as the foundation (as we should have to judge
if we followed were concepts) that on the contrary its own
possibility presupposes a formal intuition (time and space)
as antecedently given.
NOTE TO THE AMPHIBOLY 0F CONCEPTS OF REFLECTION
  Let me call the place which we assign to a concept, either
in sensibility or in pure understanding, its <1transcendental>1
<1location.>1 Thus the decision as to the place which belongs to
every concept according to difference in the use to which it
is put, and the directions for determining this place for all
concepts according to rules, is a <1transcendental topic.>1 This
doctrine, in distinguishing the cognitive faculty to which in
each case the concepts properly belong, will provide a sure
safeguard against the surreptitious employment of pure under-
standing and the delusions which arise therefrom. We may
call every concept, every heading, under which many items of
knowledge fall, a <1logical location.>1 On this is based the <1logical>1
<1topic>1 of Aristotle, of which teachers and orators could make
use in order under given headings of thought to find what A 269
would best suit the matter in hand, and then, with some.
appearance of thoroughness, to argue or be eloquent about it.
  The transcendental topic, on the other hand, contains no
more than the above-mentioned four headings of all com-
parison and distinction. They are distinguished from cate-
gories by the fact that they do not present the object accord-
ing to what constitutes its concept (quantity, reality), but
only serve to describe in all its manifoldness the comparison
of the representations which is prior to the concept of things.
But this comparison requires in the first place a reflection,
that is, a determination of the location to which the repre-
00059
namely, whether they are thought by the pure understanding
or given in appearance by sensibility.
Concepts can be compared logically without our troubling
to which faculty their objects belong, that is, as to whether
their objects are noumena for the understanding, or arc
phenomena for the sensibility. But if we wish to advance
to the objects with these concepts, we must first resort to tran-
scendental reflection, in order to determine for which cognitive
faculty they are to be objects, whether for pure understanding
or for sensibility. In the absence of such reflection, the use of
270 these concepts is very unsafe, giving birth to alleged synthetic
  principles, which the critical reason cannot recognise, and
  which are based on nothing better than a transcendental
  amphiboly, that is, a confounding of an object of pure under-
  standing with appearance.
  Having no such transcendental topic, and being therefore
  deceived by the amphiboly of the concepts of reflection, the
  celebrated Leibniz erected an <1intellectual system of the world,>1
  or rather believed that he could obtain knowledge of the
  inner nature of things by comparing all objects merely with
  the understanding and with the separated,1 formal concepts
  of its thought. Our table of concepts of reflection gives us the
  unexpected advantage of putting before our eyes the distinct-
  ive features of his system in all its parts, and at the same time
  the chief ground of this peculiar way of thinking, which indeed
  rested on nothing but a misunderstanding. He compared all
  things with each other by means of concepts alone, and natur-
  the understanding distinguishes its pure concepts from one
  another. The conditions of sensible intuition, which carry
  with them their own differences, he did not regard as original,
  sensibility being for him only a confused mode of representa-
  tion, and not a separate source of representations. Appear-
  ance was, on his view, the representation of the <1thing in>1
  <1itself.>1 Such representation is indeed, as he recognised,
271) different in logical form from knowledge through the under-
  standing, since, owing to its usual lack of analysis, it intro-
  duces a certain admixture of accompanying representations
00060
into the concept of the thing, an admixture which the under-
standing knows how to separate from it. In a word, Leibniz
<1intellectualised>1 appearances, just as Locke, according to his
system of <1noogony>1 (if I may be allowed the use of such ex-
pressions), <1sensualised>1 all concepts of the understanding, <1i.e.>1
interpreted them as nothing more than empirical or abstracted
concepts of reflection. Instead of seeking in understanding
and sensibility two sources of representations which, while
quite different, can supply objectively valid judgments of
things only in <1conjunction>1 with each other, each of these great
men holds to one only of the two, viewing it as in immediate
relation to things in themselves. The other faculty is then
regarded as serving only to confuse or to order the represen-
tations which this selected faculty yields.
  Leibniz therefore compared the objects of the senses
with each other merely in regard to understanding, taking
them as things in general. <1First,>1 he compared them in so far
as they are to be judged by understanding to be identical or
to be different. And since he had before him only their con-
cepts and not their position in intuition (wherein alone the
objects can be given), and left entirely out of account the
transcendental place of these concepts (whether the object is
to be reckoned among appearances or things in themselves),
it inevitably followed that he should extend his principle of A 272
the identity of indiscernibles, which is valid only of concepts
of things in general, to cover also the objects of the senses
<1(mundus phaenomenon),>1 and that he should believe that in
so doing he had advanced our knowledge of nature in no
small degree. Certainly, if I know a drop of water in all its
internal determinations as a thing in itself, and if the whole
concept of any one drop is identical with that of every other,
I cannot allow that any drop is different from any ot
if the drop is an appearance in space, it has its loca ion not
only in understanding (under concepts) but in sensible outer
intuition (in space), and the physical locations are there quite
indifferent to the inner determinations of the things. A loca-
tion <1b>1 can contain a thing which is completely similar and
equal to another in a location <1a,>1 just as easily as if the things
were inwardly ever so different. Difference of locations, with-
out any further conditions, makes the plurality and distinction
00061
of objects, as appearances, not only possible but also neces-
sary.  Consequently, the above so-called law is no law of
nature. It is only an analytic rule for1 the comparison of
things through mere concepts.
  <1Secondly,>1 the principle that realities (as pure assertions)
A 273) never logically conflict with each other is an entirely true
  proposition as regards the relation of concepts, but has not
  the least meaning in regard either to nature or to anything
  in itself. For real conflict certainly does take place; there are
  cases where A - B =0, that is, where two realities combined
  in one subject cancel one another's effects. This is brought
  before our eyes incessantly by all the hindering and counter-
  acting processes in nature, which, as depending on forces,
  must be called <1realitates phaenomena.>1 General mechanics can
  indeed give the empirical condition of this conflict in an <1a>1
  <1priori>1 rule, since it takes account of the opposition in the
  direction of forces, a condition totally ignored by the tran-
  scendental concept of reality. Although Herr von Leibniz did
  not indeed announce the above proposition with all the pomp
  of a new principle, he yet made use of it for new assertions,
  and his successors expressly incorporated it into their Leib-
  nizian-Wolffian system. Thus, according to this principle all
  evils are merely consequences of the limitations of created
  beings, that is, negations, since negations alone conflict
  with reality. (This is indeed the case as regards the mere
  concept of a thing in general, but not as regards things as
  appearances.) Similarly his disciples consider it not only pos-
  330) sible, but even natural, to combine all reality in one being,
  without fear of any conflict. For the only conflict which they
  recognise is that of contradiction, whereby the concept of a
  thing is itself removed. They do not admit the conflict of re-
  ciprocal injury, in which each of two real grounds destroys the
  effect of the other---a conflict which we can represent to our-
  selves only in terms of conditions presented to us in sensibility.
  <1Thirdly,>1 Leibniz's monadology has no basis whatsoever
  save his mode of representing the distinction of inner and
  outer merely in relation to the understanding. Substances in
  general must have some <1internal>1 nature, which is therefore
  free from all outer relations, and consequently also from com-
00062
position. The simple is therefore the basis of that which is
inner in things-in-themselves. But that which is inner in the
state of a substance cannot consist in place, shape, contact,
or motion (these determinations being all outer relations), and
we can therefore assign to substances no inner state save that
through which we ourselves inwardly determine our sense,
namely, the <1state of the representations.>1 This, therefore, com-
pleted the conception of the monads, which, though they have
to serve as the basic material of the whole universe, have no
other active power save only that which consists in representa-
tions, the efficacy of which is confined, strictly speaking, to
themselves.
  For this very reason his principle of the possible reciprocal
<1community of substances>1 had to be a <1pre-established harmony>1,  B 331
and could not be a physical influence. For since everything in A275
merely inward, <1i.e.>1 concerned with its own representations  the
state of the representations of one substance could not stand
in any effective connection whatever with that of another.
There had to be some third cause, determining all substances
whatsoever, and so making their states correspond to each
other, not indeed by an occasional special intervention in each
particular case <1(systema assestentiae),>1 but by the unity of the
idea of a cause valid for all substances, and in which they
must one and all obtain their existence and permanence, and
consequently also their reciprocal correspondence, according
to universal laws.
  <1Fourthly,>1 Leibniz's famous <1doctrine of time and space,>1 in
which he intellectualised these forms of sensibility, owed its
origin entirely to this same fallacy of transcendental reflec-
tion. If I attempt, by the mere understanding, to represent to
myself outer relations of things, this can only be done by means
of a concept of their reciprocal action; and if I seek to connect
two states of one and the same thing, this can only be in the
order of grounds and consequences. Accordingly, Leibniz
conceived space as a certain order in the community of sub-
stances, and time as the dynamical sequence of their states.
That which space and time seem to possess as proper to them-
selves, in independence of things, he ascribed to the <1confusion>1 B 332
in their concepts, which has led us to regard what is a mere
00063
form of dynamical relations as being a special intuition, self-
subsistent an  antecedent to the things themselves. Thus space
and time were for him the intelligible form of the connection
of things (substances and their states) in themselves; and the
things were intelligible substances <1(substantiae noumena).>1
And since he allowed sensibility no mode of intuition peculiar
to itself but sought for all representation of objects, even the
empirical, in the understanding, and left to the senses nothing
but the despicable task of confusing and distorting the repre-
sentations of the former, he had no option save to treat the
[intellectualised] concepts as being likewise valid of appear-
ances.
  But even if we could by pure understanding say anything
synthetically in regard to <1things-in-themselves>1 (which, how-
ever, is impossible), it still could not be applied to appear-
ances, which do not represent things-in-themselves. In dealing
with appearances I shall always be obliged to compare my
concepts, in transcendental reflection, solely under the con-
ditions of sensibility; and accordingly space and time will not
be determinations of things-in-themselves but of appearances.
A 277) What the things-in-themselves may be I do not know, nor do
333  I need to know, since a thing can never come before me except
  in appearance.
  The remaining concepts of reflection have to be dealt with
  in the same manner. Matter is <1substantia phaenomenon.>1 That
  which inwardly belongs to it I seek in all parts of the space
  which it occupies, and in all effects which it exercises, though
  admittedly these can only be appearances of outer sense. I
  have therefore nothing that is absolutely, but only what is
  comparatively inward and is itself again composed of outer
  relations. The absolutely inward [nature] of matter, as it would
  have to be conceived by pure understanding, is nothing but
  a phantom; for matter is not among the objects of pure
  understanding, and the transcendental object which may be
  the ground of this appearance that we call matter is a mere
  something of which we should not understand what it is, even
  if someone were in a position to tell us. For we can understand
  only that which brings with it, in intuition, something corre-
  sponding to our words. If by the complaints---<1that we have no>1
00064
<1insight whatsoever into the inner [nature] of things>1---it be
meant that we cannot conceive by pure understanding what
the things which appear to us may be in themselves, they are
entirely illegitimate and unreasonable. For what is demanded
is that we should be able to know things, and therefore to
intuit them, without senses, and therefore that we should have
a faculty of knowledge altogether different from the human, A278
and this not only in degree but as regards intuition likewise  33
in kind---in other words, that we should be not men but
beings1 of whom we are unable to say whether they are even
possible, much less how they are constituted. Through ob-
servation and analysis of appearances we penetrate to nature's
inner recesses, and no one can say how far this knowledge
may in time extend. But with all this knowledge, and even if
the whole of nature were revealed to us, we should still never
be able to answer those transcendental questions which go
beyond nature. The reason of this is that it is not given to us
to observe our own mind with any other intuition than that
of inner sense; and that it is yet precisely in the mind that
the secret of the source of our sensibility is located. The rela-
tion of sensibility to an object and what the transcendental
ground of this [objective] unity may be, are matters undoubtedly
so deeply concealed that we, who after all know even ourselves
only through inner sense and therefore as appearance, can
never be justified in treating sensibility as being a suitable
instrument of investigation for discovering anything save
always still other appearances---eager as we yet are to explore
their non-sensible cause.
  What makes this critique of conclusions based merely on
acts of reflection so exceedingly useful is that it renders mani-
fest the nullity of all conclusions about objects which are
compared with each other solely in the understanding, and at
the same time confirms our principal contention, namely, that A 279
although appearances are not included as things-in-them-  335  =
selves among the objects of pure understanding, they are yet
the only objects in regard to which our knowledge can possess
objective reality, that is, in respect of which there is an in-
tuition corresponding to the concepts.
  If we reflect in a merely logical fashion, we are only com-
00065
  paring our concepts with each other in the understanding, to
  find whether both have the same content, whether they are
  contradictory or not, whether something is contained within
  the concept or is an addition from outside, which of the two
  is given and which should serve only as a mode of thinking
  what is given. But if I apply these concepts to an objext in
  general (in the transcendental sense), without determining
  whether it be an object of sensible or of intellectual intuition,
  limitations are at once revealed in the very notion of this
  object which forbid any non-empirical employment of the
  concepts, and by this very fact prove that the representation
  of an object as a thing in general is not only <1insufficient,>1 but,
  when taken without sensible determination, and independ-
  ently of any empirical condition, <1self-contradictory.>1 The con-
  clusion is that we must either abstract from any and every
  object (as in logic), or, if we admit an object, must think it
  under the conditions of sensible intuition. For the intelligible
  would require a quite peculiar intuition which we do not
  B 336 possess, and in the absence of this would <1before us>1 nothing at
  A 280  all; and, on the other hand, it is also evident that appearances
  could not be objects in themselves. If I think to myself merely
  things in general, the difference in their outer relations cannot
  constitute a difference in the things themselves; on the con-
  trary, it presupposes this difference. And if there is no inward
  difference between the concept of the one and the concept of the
  other, I am only positing one and the same thing in different
  relations. Further, the addition of one sheer affirmation
  (reality) to another increases the positive in them; nothing is
  withdrawn or inhibited; accordingly the real in things cannot
  be in conflict with itself---and so on.
  As we have shown, the concepts of reflection, owing to a
  certain misinterpretation, have exercised so great an influence
  upon the employment of the understanding that they have
  misled even one of the most acute of all philosophers into a
  supposititious system of intellectual knowledge, which under-
00066
takes to determine its objects without any assistance from the
senses. For this reason the exposition of the cause of what is
deceptive---occasioning these false principles---in the amphi-
boly of these concepts, is of great utility as a reliable method of
determining and securing the limits of the understanding.
  It is indeed true that whatever universally agrees with or  B 337
contradicts a concept also agrees with or contradicts every A 281
particular which is contained under it <1(dictum de omni et>1
<1nullo);>1 but it would be absurd to alter this logical principle so
as to read:---what is notcontained in a universal concept is also
not included in the particular concepts which stand under it.
For these are particular concepts just because they include in
themselves more than is thought in the universal. Nevertheless
it is upon this latter principle that the whole intellectual sys-
tem of Leibniz is based; and with this principle it therefore
falls, together with all the ambiguities (in the employment of
the understanding) that have thence arisen.
  The principle of the identity of indiscernibles is really based
on the presupposition, that if a certain distinction is not found
in the concept of a thing in general, it is also not to be found
in the things themselves, and consequently that all things
which are not distinguishable from one another in their con-
cepts (in quality or quantity) are completely identical <1(numero>1
<1eadem).>1 Because in the mere concept of a thing in general we
abstract from the many necessary conditions of its 1 intuition,
the conditions from which we have abstracted are, with strange
presumption, treated as not being there at all, and nothing is  B 338
allowed to the thing beyond what is contained in its concept.
  The concept of a cubic foot of space, wherever and how-  A 282
ever often I think it, is in itself throughout one and the same.
But two cubic feet are nevertheless distinguished in space by
the mere difference of their locations <1(numero diversa);>1 these
locations are conditions of the intuition wherein the object of
this concept is given; they do not, however, belong to the con-
cept but entirely to sensibility. Similarly there is no conflict
in the concept of a thing unless a negative statement is com-
bined with an affirmative; merely affirmative concepts cannot,
when combined, produce any cancellation. But in the sensible
00067
intuition, wherein reality <1(e.g.>1 motion) is given, there are
conditions (opposite directions), which have been omitted in
the concept of motion in general, that make possible a conflict
(though not indeed a logical one), namely, as producing from
what is entirely positive a zero (=0). We are not, therefore, in
a position to say that since conflict is not to be met with in
the concepts of reality, all reality is in agreement with itself.a
A328393)  According to mere concepts the inner is the substratum of
  all relational or outer determinations. If, therefore, I abstract
  from all conditions of intuition and confine myself to the con-
  cept of a thing in general, I can abstract from all outer rela-
  tion, and there must still be left a concept of something which
  signifies no relation, but inner determinations only. From this
  it seems to follow that in whatever is a thing (substance) there
  is something which is absolutely inward and precedes all outer
  determinations, inasmuch as it is what first makes them
  possible; and consequently, that this substratum, as no longer
  containing in itself any outer relations, is <1simple.>1 (Corporeal
  things are never anything save relations only, at least of
  their parts external to each other.) And since we know of no
  determinations which are absolutely inner except those [given]
  through our inner sense, this substratum is not only simple;
  it is likewise (in analogy with our inner sense) determined
  through <1representations;>1 in other words, all things are really
B 340  <1monads,>1 simple beings endowed with representations. These
  contentions would be entirely justified, if beyond the con-
A284  cept of a thing in general there were no further conditions
  under which alone objects of outer intuition can be given us
  ---those from which the pure concept has [as a matter of fact]
  a  If we here wished to resort to the usual subterfuge, maintaining
  as regards <1realitates noumena>1 that they at least do not act in opposi-
  tion to each other, it would be incumbent on us to produce an ex-
B 339  ample of such pure and non-sensuous reality, that it may be dis-
  cerned whether such a concept represents something or nothing.
  But no example can be obtained otherwise than from experience,
  which never yields more than phenomena. This proposition has
  therefore no further meaning than that a concept which only in-
  cludes affirmation includes no negation---a proposition which we
  have never doubted.
00068
made abstraction. For under these further conditions, as we
find, an abiding appearance in space (impenetrable extension)
can contain only relations and nothing at all that is absolutely
inward, and yet be the primary substratum of all outer per-
ception. Through mere concepts I cannot, indeed, think what
is outer without thinking something that is inner;1 and this
for the sufficient reason that concepts of relation presuppose
things which are absolutely <1[i.e.>1 independently] given, and
without these are impossible. But something is contained in
intuition which is not to be met with in the mere concept of a
thing; and this yields the substratum, which could never be
known through mere concepts, namely, a space which with all
that it contains consists solely of relations, formal or, it may be,
also real. Because, without an absolutely inner element, a thing
can never be represented <1by mere concepts,>1 I may not therefore
claim that there is <1not>1 also in the things themselves which are
subsumed under these concepts, and <1in their intuition,>1 some-
thing external that has no basis in anything wholly inward.
Once we have abstracted from all conditions of intuition, there
is, I admit, nothing left in the mere concept but the inner in  B 341
general and its interrelations, through which alone the ex-
ternal is possible. But this necessity, which is founded solely
on abstraction, does not arise in the case of things as given in
intuition with determinations that express mere relations, with-  A 285
out having anything inward as their basis; for such are not
things in themselves but merely appearances. All that we
know in matter is merely relations (what we call the inner
determinations of it are inward only in a comparative sense),
but among these relations some are self-subsistent and per-
manent, and through these we are given a determinate object.
The fact that, if I abstract from these relations, there is no-
thing more left for me to think does not rule out the concept
of a thing as appearance, nor indeed the concept of an object
<1in abstracto.>1 What it does remove is all possibility of an object
determinable through mere concepts, that is, of a noumenon.
It is certainly startling to hear that a thing is to be taken as
consisting wholly of relations. Such a thing is, however, mere
appearance, and cannot be thought through pure categories;
00069
what it itself consists in is the mere relation of something in
general to the senses. Similarly, if we begin with mere con-
cepts, we cannot think the relations of things <1in abstracto>1 in
B 342  any other manner than by regarding one thing as the cause of
  determinations in another, for that is how our understanding
  conceives of relations. But since we are in that case disregard-
  ing all intuition, we have ruled ourselves out from any kind of
  recognition of the special mode in which the different elements
  of the manifold determine each other's positions, that is, of
A286  the form of sensibility (space), which yet is presupposed in all
  empirical causality.
  If by merely intelligible objects we mean those things which
  are thought through pure categories, without any schema
  of sensibility, such objects are impossible. For the condition of
  the objective employment of all our concepts of understanding
  is merely the mode of our sensible intuition, by which objects
  are given us; if we abstract from these objects, the con-
  cepts have no relation to any object. Even if we were willing
  to assume a kind of intuition other than this our sensible
  kind, the functions of our thought would still be without
  meaning in respect to it. If, however, we have in mind only
  objects of a non-sensible intuition, in respect of which our
  categories are admittedly not valid, and of which therefore
  we can never have any knowledge whatsoever (neither in-
  tuition nor concept), noumena in this purely negative sense
  must indeed be admitted. For this is no more than saying
  that our kind of intuition does not extend to all things, but
B 343  only to objects of our senses, that consequently its objective
  validity is limited, and that a place therefore remains open
  for some other kind of intuition, and so for things as its
-  objects. But in that case the concept of a noumenon is problem-
  atic, that is, it is the representation of a thing of which we
  A287  can neither say that it is possible nor that it is impossible; for
  we are acquainted with no kind of intuition but our own
  sensible kind and no kind of concepts but the categories, and
  neither of these is appropriate to a non-sensible object. We
  cannot, therefore, positively extend the sphere of the objects
  of our thought beyond the conditions of our sensibility, and
  assume besides appearances objects of pure thought, that is,
00070
<1noumena,>1 since such objects have no assignable positive
meaning. For in regard to the categories we must admit that
they are not of themselves adequate to the knowledge of
things in themselves, and that without the data of sensibility
they would be merely subjective forms of the unity of under-
standing, having no object. Thought is in itself, indeed, no
product of the senses, and in so far is also not limited by
them; but it does not therefore at once follow that it has a
pure employment of its own, un ided by sensibility, since it is
then without an object. We cannot call the noumenon such
an <1object;>1 signifying, as it does, the problematic concept of
an object for a quite different intuition and a quite different  B 344
understanding from ours, it is itself a problem. The concept
of the noumenon is, therefore, not the concept of an object,
but is a problem unavoidably bound up with the limitation
of our sensibility---the problem, namely, as to whether there
may not be objects entirely disengaged from any such kind
of intuition. This is a question which can only be answered  A288
in an indeterminate manner, by saying that as sensible in-
tuition does not extend to all things without distinction, a
place remains open for other and different objects; and con-
sequently that these latter must not be absolutely denied,
though---since we are without a determinate concept of them
(inasmuch as no category can serve that purpose)---neither
can they be asserted as objects for our understanding.
Understanding accordingly limits sensibility, but does
not thereby extend its own sphere. In the process of warning
the latter that it must not presume to claim applicability to
things-in-themselves but only to appearances, it does indeed
think for itself an object in itself, but only as transcendental
object, which is the cause of appearance and therefore not
itself appearance, and which can be thought neither as quan-
tity nor as reality nor as substance etc. (because these concepts
always require sensible forms in which they determine an
object). We are completely ignorant whether it is to be met
with in us or outside us, whether it would be at once removed
with the cessation of sensibility, or whether in the absence of  B 345
sensibility it would still remain. If we are pleased to name
this object noumenon for the reason that its representation
is not sensible, we are free to do so. But since we can apply
00071
to it none of the concepts of our understanding, the repre-
sentation remains for us empty, and is of no service except
A289 to mark the limits of our sensible knowledge and to leave
  open a space which we can fill neither through possible ex-
  perience nor through pure understanding.
  The critique of this pure understanding, accordingly,
  does not permit us to create a new field of objects beyond those
  which may be presented to it as appearances, and so to stray
  into intelligible worlds; nay, it does not allow of our entertain-
  ing even the concept of them. The error, which quite obvi-
  ously is the cause of this mistaken venture, and which indeed
  excuses though it does not justify it, lies in employing the
  understanding, contrary to its vocation, transcendentally, and
  in making objects, that is, possible intuitions, conform to con-
  cepts, not concepts to possible intuitions, on which alone their
  objective validity rests. This error, in turn, is due to the fact
  that apperception, and with it thought, precedes all possible
  determinate ordering of representations. Consequently what
  we do is to think something in general; and while on the one
B 346  hand we determine it in sensible fashion, on the other hand we
  distinguish from this mode of intuiting it the universal object
  represented <1in abstracto.>1 What we are then left with is a mode
  of determining the object by thought alone---a merely logical
  form without content, but which yet seems to us to be a
  mode in which the object exists in itself <1(noumenon)>1 without
  regard to intuition, which is limited to our senses.
A 290  Before we leave the Transcendental Analytic we must
  add some remarks which, although in themselves not of
  special importance, might nevertheless be regarded as re-
  quisite for the completeness of the system. The supreme
  concept with which it is customary to begin a transcendental
  philosophy is the division into the possible and the impossible.
  But since all division presupposes a concept to be divided, a
  still higher one is required, and this is the concept of an object
  in general, taken problematically, without its having been
  decided whether it is something or nothing. As the categories
  are the only concepts which refer to objects in general, the
00072
distinguishing of an object, whether it is something or
nothing, will proceed according to the order and under the
guidance of the categories.
  I. To the concepts of all, many, and one there is opposed  B 347
the concept which cancels everything, that is, <1none.>1 Thus the
object of a concept to which no assignable intuition whatso-
ever corresponds is = nothing. That is, it is a concept without
an object <1(ens rationis),>1 like noumena, which cannot be
reckoned among the possibilities, although they must not for
that reason be declared to be also impossible; or like certain
new fundamental forces, which though entertained in thought  A 291
without self-contradiction are yet also in our thinking un-
supported by any example from experience, and are therefore
not to be counted as possible.
  2. Reality is <1something;>1 negation is <1nothi>1, namely, a
concept of the absence of an object, such as shadow, cold
<1(nihil privativum).>1
  3. The mere form of intuition, without substance, is in
itself no object, but the merely formal condition of an object
(as appearance), as pure space and pure time <1(ens imagina->1
<1rium).>1 These are indeed something, as forms of intuition,
but are not themselves objects which are intuited.
  4. The object of a concept which contradicts itself is B 348
nothing, because the concept is nothing, is the impossible,
<1e.g.>1 a two-sided rectilinear figure <1(nihil negativum).>1
  The table of this division of the concept of <1nothing>1 would
therefore have to be drawn up as follows. (The corresponding
division of <1something>1 follows directly from it):
  Nothing,  A 292
  as
  I
  Empty concept without object,
  <1ens rationis.>1
  2  3
Empty object of a concept,  Empty intuition without object,
  <1nihil privativum.  ens imaginarium.>1
  4
  Empty object without concept,
  <1nihil negativum.>1
00073
  We see that the <1ens rationis1>1 (1) is distinguished from the
<1nihil negativum>1 (4), in that the former is not to be counted
among possibilities because it is mere fiction (although not
self-contradictory), whereas the latter is opposed to possi-
B 349  bility in that the concept cancels itself.  Both, however, are
  empty concepts. On the other hand, the <1nihil privativum>1 (2)
  and the <1ens imaginarium>1 (3) are empty <1data>1 for concepts. If
  light were not given to the senses we could not represent dark-
  ness, and if extended beings were not perceived we could not
  represent space. Negation and the mere form of intuition, in
  the absence of a something real, are not objects.
00074
TRANSCENDENTAL LOGIC  A293  =
  SECOND DIVISION
TRANSCENDENTAL DIALECTIC
  INTRODUCTION
  TRANSCENDENTAL ILLUSION
WE have already entitled dialectic in general a <1logic of illu->1
<1sion.>1 This does not mean a doctrine of <1probability;>1 for prob-
ability is truth, known however on insufficient grounds, and
the knowledge of which, though thus imperfect, is not on that
account deceptive; and such doctrine, accordingly, is not to be
separated from the analytic part of logic. Still less justification
have we for regarding <1appearance>1 and <1illusion>1 as being identi-  B 350
cal. For truth or illusion is not in the object, in so far as it is
intuited, but in the judgment about it, in so far as it is thought.
It is therefore correct to say that the senses do not err---not
because they always judge rightly but because they do not
judge at all. Truth and error, therefore, and consequently also
illusion as leading to error, are only to be found in the judg-
ment, <1i.e.>1 only in the relation of the object to our understand-
ing. In any knowledge which completely accords with the laws
of understanding there is no error. In a representation of the  A294
senses---as containing no judgment whatsoever---there is also
no error. No natural force can of itself deviate from its own
laws. Thus neither the understanding by itself (uninfluenced
by another cause), nor the senses by themselves, would fall
into error. The former would not, since, if it acts only accord-
ing to its own laws, the effect (the judgment) must necessarily
be in conformity with these laws; conformity with the laws
00075
of the understanding is the formal element in all truth. In
the senses there is no judgment whatsoever, neither a true
nor a false judgment. Now since we have no source of know-
ledge besides these two, it follows that error is brought about
solely by the unobserved influence of sensibility on the under-
standing, through which it happens that the subjective grounds
B 351  of the judgment enter into union with the objective grounds
  and make these latter deviate from their true function a-- just
  as a body in motion would always of itself continue in a
  straight line in the same direction, but if influenced by another
  force acting in another direction starts off into curvilinear
A295  motion. In order to distinguish the specific action of under-
  standing from the force which is intermixed with it, it is neces-
  sary to regard the erroneous judgment as the diagonal between
  two forces---forces which determine the judgment in different
  directions that enclose, as it were, an angle---and to resolve
  this composite action into the simple actions of the under-
  standing and of the sensibility. In the case of pure <1a priori>1
  judgments this is a task which falls to be discharged by tran-
  scendental reflection, through which, as we have already shown,
  every representation is assigned its place in the corresponding
  faculty of knowledge, and by which the influence of the one
  upon the other is therefore likewise distinguished.
  We are not here concerned with empirical <1(e.g.>1 optical)
B 352  illusion, which occurs in the empirical employment of rules of
  understanding that are otherwise correct, and through which
  the faculty of judgment is misled by the influence of imagina-
  tion; we are concerned only with <1transcendental illusion,>1 which
  exerts its influence on principles that are in no wise intended for
  use in experience, in which case we should at least have had a
  criterion of their correctness. In defiance of all the warnings of
  criticism, it carries us altogether beyond the empirical employ-
  ment of categories and puts us off with a merely deceptive exten-
  sion <1of pure understanding.>1 We shall entitle the principles whose
  application is confined entirely within the limits of possible
B 351  a Sensibility, when subordinated to understanding, as the object
  upon which the latter exercises its function, is the source of real
  modes of knowledge. But the same sensibility, in so far as it in-
  fluences the operation of understanding, and determines it to make
  judgments, is the ground of error.
00076
experience, <1immanent;>1 and those, on the other hand, which  A296
profess to pass beyond these limits, <1transcendent.>1 In the case of
these latter, I am not referring to the <1transcendental>1 employ-
ment or misemployment of the categories, which is merely an
error of the faculty of judgment when it is not duly curbed by
criticism, and therefore does not pay sufficient attention to the
bounds of the territory within which alone free play is allowed
to pure understanding. I mean actual principles which incite
us to tear down all those boundary-fences and to seize posses-
sion of an entirely new domain which recognises no limits of
demarcation. Thus <1transcendental>1 and <1transcendent>1 are not
interchangeable terms. The principles of pure understanding,
which we have set out above, allow only of empirical and not
of transcendental employment, that is, employment extend-  B 353
ing beyond the limits of experience. A principle, on the other
hand, which takes away these limits, or even commands us
actually to transgress them, is called <1transcendent.>1 If our
criticism can succeed in disclosing the illusion in these alleged
principles, then those principles which are of merely empirical
employment may be called, in opposition to the others, <1im->1
<1manent>1 principles of pure understanding.
  Logical illusion, which consists in the mere imitation
of the form of reason (the illusion of formal fallacies), arises
entirely from lack of attention to the logical rule. As soon
as attention is brought to bear on the case that is before us,  A297
the illusion completely disappears. Transcendental illusion,
on the other hand, does not cease even after it has been de-
tected and its invalidity clearly revealed by transcendental
criticism <1(e.g.>1 the illusion in the proposition: the world must
have a beginning in time). The cause of this is that there are
fundamental rules and maxims for the employment of our
reason (subjectively regarded as a faculty of human know-
ledge), and that these have all the appearance of being ob-
jective principles. We therefore take the subjective necessity
of a connection of our concepts, which is to the advantage of
the understanding, for an objective necessity in the deter-
mination of things in themselves. This is an <1illusion>1 which
can no more be prevented than we can prevent the sea B 354
appearing higher at the horizon than at the shore, since we see
it through higher light rays; or to cite a still better example,
00077
than the astronomer can prevent the moon from appearing
larger at its rising, although he is not deceived by this illusion.
  The transcendental dialectic will therefore content itself
with exposing the illusion of transcendent judgments, and at
the same time taking precautions that we be not deceived by
it. That the illusion should, like logical illusion, actually dis-
appear and cease to be an illusion, is something which tran-
A298  scendental dialectic can never be in a position to achieve. For
  here we have to do with a <1natural>1 and inevitable <1illusion,>1
  which rests on subjective principles, and foists them upon us
  as objective; whereas logical dialectic in its exposure of de-
  ceptive inferences has to do merely with an error in the fol-
  lowing out of principles, or with an illusion artificially created
  in imitation of such inferences. There exists, then, a natural
  and unavoidable dialectic of pure reason---not one in which a
  bungler might entangle himself through lack of knowledge,
  or one which some sophist has artificially invented to confuse
  thinking people, but one inseparable from human reason, and
  which, even after its deceptiveness has been exposed, will not
B 355  cease to play tricks with reason and continually entrap it into
  momentary aberrations ever and again calling for correction.
  II
  PURE REASON AS THE SEAT OF TRANSCENDENTAL
  ILLUSION
  <1Reason in general>1
  All our knowledge starts with the senses, proceeds from
  thence to understanding, and ends with reason, beyond which
  there is no higher faculty to be found in us for elaborating the
  matter of intuition and bringing it under the highest unity of
A 299  thought. Now that I have to give an explanation of this highest
  faculty of knowledge, I find myself in some difficulty. Reason,
  like understanding, can be employed in a merely formal, that
  is, logical manner, wherein it abstracts from all content of
  knowledge. But it is also capable of a real use, since it contains
  within itself the source of certain concepts and principles,
00078
which it does not borrow either from the senses or from the
understanding. The former faculty has long since been defined
by logicians as the faculty of making mediate inferences (in dis-
tinction from immediate inferences, <1consequentiis immediatis);>1
but the nature of the other faculty, which itself gives birth to con-
cepts, is not to be understood from this definition. Now since
we are here presented with a division of reason into a logical
and a transcendental faculty, we are constrained to seek for a  B 356
higher concept of this source of knowledge which includes
both concepts as subordinate to itself. Following the analogy
of concepts of understanding, we may expect that the logical
concept will provide the key to the transcendental, and that
the table of the functions of the former will at once give us the
genealogical tree of the concepts of reason.
  In the first part of our transcendental logic we treated the
understanding as being the faculty of rules; reason we shall
here distinguish from understanding by entitling it <1the faculty>1
<1of principles.>1
  The term "principle' is ambiguous, and commonly sig-  A 300
nifies any knowledge which can be used as a principle,
although in itself, and as regards its proper origin, it is no
principle. Every universal proposition, even one derived from
experience, through induction, can serve as major premiss in
a syllogism; but it is not therefore itself a principle. The
mathematical axioms <1(e.g.>1 that there can only be one straight
line between two points) are instances of universal <1a priori>1
knowledge, and are therefore rightly called principles, rela-
tively to the cases which can be subsumed under them. But I
cannot therefore say that I apprehend this property of straight
lines in general and in itself, from principles; I apprehend it  B 357
only in pure intuition.
  Knowledge from principles is, therefore, that anowledge
alone in which I apprehend the particular in the universal
through concepts. Thus every syllogism is a mode of deducing
knowledge from a principle. For the major premiss always
gives a concept through which everything that is subsumed
under the concept as under a condition is known from the con-
cept according to a principle. Now since any universal know-
ledge can serve as major premiss in a syllogism, and since the
understanding presents us with universal <1a priori>1 propositions
00079
of this kind, they can also be called principles in respect of
their possible employment.
A301  But if we consider them in themselves in relation to their
  origin, these fundamental propositions of pure understanding
  are anything rather than knowledge based on concepts. For
  they would not even be possible <1a priori,>1 if we were not sup-
  ported by pure intuition (in mathematics), or by conditions of
  a possible experience in general. That everything that happens
  has a cause cannot be inferred merely from the concept of
  happening in general; on the contrary, it is this fundamental
  proposition which shows how in regard to that which happens
  we are in a position to obtain in experience any concept what-
  soever that is really determinate.
  The understanding can, then, never supply any synthetic
  modes of knowledge derived from concepts; and it is such
B 358  modes of knowledge that are properly, without qualification,
  to be entitled "principles'. All universal propositions, however,
  may be spoken of as "principles' in a comparative sense.
  It has long been wished---and sometime perhaps (who
  knows when!) may be fulfilled---that instead of the endless
  multiplicity of civil laws we should be able to fall back on their
  general principles. For it is in these alone that we can hope to
  find the secret of what we are wontto call the simplifying of
  legislation. In this domain, however, the laws are only limita-
  tions imposed upon our freedom in order that such freedom
  may completely harmonise with itself; hence they are directed
  to something which is entirely our own work, and of which we
  ourselves, through these concepts, can be the cause. But that
A302  objects in themselves, the very nature of things, should stand
  under principles, and should be determined according to mere
  concepts, is a demand which, if not impossible, is at least quite
  contrary to common sense. But however that may be (it is
  a question which we still have to discuss), it is now at least
  evident that knowledge derived from principles which are
  genuinely such is something quite different from knowledge
  obtained merely through the understanding. The latter may,
  indeed, also take the form of a principle and thus be prior to
  some other knowledge, but in itself, in so far as it is syn-
00080
thetic, it does not depend on thought alone, nor contain in
itself a universal obtained from concepts.
  Understanding may be regarded as a faculty which secures  B 359
the unity of appearances by means of rules, and reason as
being the faculty which secures the unity of the rules of under-
standing under principles. Accordingly, reason never applies
itself directly to experience or to any object, but to understand-
ing, in order to give to the manifold knowledge of the latter
an <1a priori>1 unity by means of concepts, a unity which may be
called the unity of reason, and which is quite different in kind
from any unity that can be accomplished by the understanding.
  This is the universal concept of the faculty of reason in so
far as it has been possible to make it clear in the total absence
of examples. These will be given in the course of our argu-
ment.
  B  A303
  <1The Logical Employment of Reason>1
  A distinction is commonly made between what is immediately
known and what is merely inferred. That in a figure which is
bounded by three straight lines there are three angles, is known
immediately; but that the sum of these angles is equal to two right
angles, is merely inferred. Since we have constantly to make
use of inference, and so end by becoming completely accus-
tomed to it, we no longer take notice of this distinction, and
frequently, as in the so-called deceptions of the senses, treat as
being immediately perceived what has really only been inferred.
In every process of reasoning there is a fundamental proposi-  B 360
tion, and another, namely the conclusion, which is drawn
from it, and finally, the inference (logical sequence) by which
the truth of the latter is inseparably connected with the truth
of the former. If the inferred judgment is already so contained
in the earlier judgment that it may be derived from it without
the mediation of a third representation, the inference is called
immediate <1(consequentia immediata)>1---I should prefer to entitle
it inference of the understanding. But if besides the know-
ledge contained in the primary proposition still another judg-
00081
ment is needed to yield the conclusion, itis to be entitled an
inference of the reason. In the proposition :  ""All men are
mortal'', there are already contained the propositions : ""some
men are mortal'', ""some mortal beings are men'', ""nothing
A 304  that is not mortal is a man''; and these are therefore immediate
  conclusions from it. On the other hand, the proposition: ""All
  learned beings are mortal'', is not contained in the funda-
  mental judgment (for the concept of learned beings does not
  occur in it at all), and it can only be inferred from it by means
  of a mediating judgment.
  In every syllogism I first think a <1rule>1 (the major premiss)
  through the <1understanding.>1 Secondly, I <1subsume>1 something
  known under the condition of the rule by means <1of judgment>1
  (the minor premiss). Finally, what is thereby known I <1deter->1
B 361  <1mine>1 through the predicate of the rule, and so <1a priori>1 through
  <1reason>1 (the conclusion).  The relation, therefore, which the
  major premiss, as the rule, represents between what is known
  and its condition is the ground of the different kinds of syllo-
  gism. Consequently, syllogisms, like judgments, are of three
  kinds, according to the different ways in which, in the under-
  standing, they express the relation of what is known; they
  are either <1categorical, hypothetical,>1 or <1disjunctive.>1
  If, as generally happens, the judgment that forms the con-
  clusion is set as a problem---to see whether it does not follow
  from judgments already given, and through which a quite
  different object is thought---I look in the understanding for the
  assertion of this conclusion, to discover whether it is not there
  found to stand under certain conditions according to a uni-
  A305 versal rule. If I find such a condition, and if the object of the
  conclusion can be subsumed under the given condition, then
  the conclusion is deduced from the rule, <1which is also valid for>1
  other objects of knowledge.>1 From this we see that in inference
  reason endeavours to reduce the varied and manifold know-
  ledge obtained through the understanding to the smallest
  number of principles (universal conditions) and thereby to
  achieve in it the highest possible unity.
00082
  C  B362
  <1The Pure Employment of Reason>1
Can we isolate reason, and is it, so regarded, an independ-
ent source of concepts and judgments which spring from it
alone, and by means of which it relates to objects; or is it a
merely subordinate faculty, for imposing ongiven modes of
knowledge a certain form, called logical---a faculty through
which what is known by means of the understanding is deter-
mined in its interrelations, lower rules being brought under
higher (namely, those the condition of which includes in its
own sphere the condition of the lower), as far as this can be
done through [processes of] comparison? This is the question
with which we are now provisionally occupying ourselves. As
a matter of fact, multiplicity of rules and unity of principles is a
demand of reason, for the purpose of bringing the understand-
ing into thoroughgoing accordance with itself, just as the
understanding brings the manifold of intuition under concepts  A 306
and thereby connects the manifold. But such a principle does
not prescribe any law for objects, and does not contain any
general ground of the possibility of knowing or of determining
objects as such; it is merely a subjective law for the orderly
management of the possessions of our understanding, that by
comparison of its concepts it may reduce them to the smallest
possible number; it does not justify us in demanding from the
objects such uniformity as will minister to the convenience  B 363
and extension of our understanding; and we may not, there-
fore, ascribe to the maxim any objective validity. In a word,
the question is, does reason in itself, that is, does pure reason,
contain <1a Priori>1 synthetic principles and rules, and in what
may these principles consist?
  The formal and logical procedure of reason in syllogisms
gives us sufficient guidance as to the ground on which the
transcendental princi  le of pure reason in its synthetic know-
ledge will rest.
  In the first place, reason in the syllogism does not concern
itself with intuitions, with a view to bringing them under rules
(as the understanding does with its categories), but with con-
00083
cepts and judgments. Accordingly, even if pure reason does
concern itself with objects, it has no immediate relation to
A307  these and the intuition of them, but only to the understand-
  ing and its judgments---which deal at first hand withthe senses
  and their intuition for the purpose of determining their object.
  The unity of reason is therefore not the unity of a possible
  experience, but is essentially different from such unity, which
  is that of understanding. That everything which happens has
  a cause, is not a principle known and prescribed by reason.
  That principle makes the unity of experience possible, and
B 364  borrows nothing from reason, which, apart from this relation
  to possible experience, could never, from mere concepts, have
  imposed any such synthetic unity.
  Secondly, reason, in its logical employment, seeks to dis-
  cover the universal condition of its judgment (the conclusion),
  and the syllogism is itself nothing but a judgment made by
  means of the subsumption of its condition under a universal
  rule (the major premiss). Now since this rule is itself subject
  to the same requirement of reason, and the condition of the con-
  dition must therefore be sought (by means of a prosyllogism)
  whenever practicable, obviously the principle peculiar to reason
  in general, in its logical employment, is:---to find for the con-
  ditioned knowledge obtained through the understanding the
  unconditioned whereby its unity is brought to completion.
  But this logical maxim can only become a principle of
  <1pure reason>1 through our assuming that if the conditioned is
  A 308 given, the whole series of conditions, subordinated to one
  another---a series which is therefore itself unconditioned---
  is likewise given, that is, is contained in the object and its
  connection.
  Such a principle of pure reason is obviously <1synthetic;>1
  the conditioned is analytically related to some condition but
  not to the unconditioned. From the principle there must also
  follow various synthetic propositions, of which pure under-
  B365  standing---inasmuch as it has to deal only with objects of a
  possible experience, the knowledge and synthesis of which is
  always conditioned---knows nothing. The unconditioned, if its
  actuality be granted, is especially to be considered in respect
  of all the determinations which distinguish it from whatever
00084
is conditioned, and thereby must yield material for many
synthetic <1a priori>1 propositions.
  The principles1 arising from this supreme principle of
pure reason will, however, be <1transcendent>1 in relation to all
appearances, <1i.e.>1 there can never be any adequate empirical
employment of the principle. It will therefore be entirely
different from all principles of understanding, the employment
of which is wholly <1immanent,>1 inasmuch as they have as their
theme only the possibility of experience. Take the principle,
that the series of conditions (whether in the synthesis of
appearances, or even in the thinking of things in general)
extends to the unconditioned. Does it, or does it not, have
objective applicability? What are its implications as regards
the empirical employment of understanding?  Or is there A 309
no such objectively valid principle of reason, but only
a logical precept, to advance towards completeness by an
ascent to ever higher conditions and so to give to our know-
ledge the greatest possible unity of reason? Can it be that
this requirement of reason has been wrongly treated in being
viewed as a transcendental principle of pure reason, and that  B 366
we have been overhasty in postulating such an unbounded
completeness of the series of conditions in the objects them-
selves? In that case, what other misunderstandings and de-
lusions may have crept into the syllogisms, whose major pre-
miss (perhaps rather an assumption than a postulate) is
derived from pure reason, and which proceed from experience
upwards to its conditions? To answer these questions will be
our task in the Transcendental Dialectic, which we shall now
endeavour to develop from its deeply concealed sources in
human reason. We shall divide the Dialectic into two chapters,
the first on the <1transcendent concepts>1 of pure reason, the
second on its transcendent and <1dialectical syllogisms.>1
00085
A310  THE TRANSCENDENTAL DIALECTIC
  BOOK I
  THE CONCEPTS OF PURE REASON
  WHATEVER we may have to decide as to the possibility of
  the concepts derived from pure reason, it is at least true that
  they are not to be obtained by mere reflection but only by
  inference. Concepts of understanding are also thought <1a>1
B 367 <1priori>1 antecedently to experience and for the sake of experi-
  ence, but they contain nothing more than the unity of reflec-
  tion upon appearances, in so far as these appearances must
  necessarily belong to a possible empirical consciousness.
  Through them alone is knowledge and the determination of
  an object possible. They first provide the material required
  for making inferences, and they are not preceded by any
  <1a priori>1 concepts of objects from which they could be inferred.
  On the other hand, their objective reality is founded solely
  on the fact that, since they constitute the intellectual form of
  all experience, it must always be possible to show their appli-
  cation in experience.
  The title "concept of reason' already gives a preliminary
  indication that we are dealing with something which does
  cerns a knowledge of which any empirical knowledge (perhaps
A311  even the whole of possible experience or of its empirical syn-
  thesis) is only a part. No actual experience has ever been com-
  pletely adequate to it, yet to it every actual experience belongs.
  Concepts of reason enable us to <1conceive,>1 concepts of under-
  standing to <1understand>1---([as employed in reference to] percep-
  tions). If the concepts of reason contain the unconditioned, they
  are concerned with something to which all experience is subor-
00086
dinate, but which is never itself an object of experience---
something to which reason leads in its inferences from experi-
ence, and in accordance with which it estimates and gauges
the degree of its empirical employment, but which is never
itself a member of the empirical synthesis. If, none the less,  B368
these concepts possess objective validity, they may be called
<1conceptus ratiocinati>1 (rightly inferred concepts); if, however,
they have no such validity, they have surreptitiously obtained
recognition through having at least an illusory appearance
of being inferences, and may be called <1conceptus ratiocinantes>1
(pseudo-rational concepts). But since this can be established
only in the chapter on the dialectical inferences of pure reason,
we are not yet in a position to deal with it. Meantime, just as
we have entitled the pure concepts of understanding cate-
gories, so we shall give a new name to the concepts of pure
reason, calling them transcendental ideas. This title we shall
now explain and justify.
  FIRST BOOK OF THE TRANSCENDENTAL  A312
  DIALECTIC
  Section I
  THE IDEAS IN GENERAL
  Despite the great wealth of our languages, the thinker often
finds himself at a loss for the expression which exactly fits his
concept, and for want of which he is unable to be really intel-
ligible to others or even to himself. To coin new words is to ad-  B 369
vance a claim to legislation in language that seldom succeeds;
and before we have recourse to this desperate expedient it is
advisable to look about in a dead and learned language, to see
whether the concept and its appropriate expression are not
already there provided. Even if the old-time usage of a term
should have become somewhat uncertain through the careless-
ness of those who introduced it, it is always better to hold fast
to the meaning which distinctively belongs to it (even though
it remain doubtful whether it was originally used in precisely
this sense) than to defeat our purpose by maaing ourselves
unintelligible.
00087
  For this reason, if there be only a single word the estab-
lished meaning of which exactly agrees with a certain concept,
A313  then, since it is of great importance that this concept be dis-
  tinguished from related concepts, it is advisable to economise
  in the use of the word and not to employ it, merely for the sake of
  variety, as a synonym for some other expression, but carefully
  to keep to its own proper meaning. Otherwise it may easily
  happen that the expression ceasing to engage the attention in
  one specific sense, and being lost in the multitude of other
  words of very different meaning, the thought also is lost which
  it alone could have preserved.
B 370  plato made use of the expression <1"idea'>1 in such a way as
  quite evidently to have meant by it  something which not only can
  never be borrowed from the senses but far surpasses even the
  concepts of understanding (with which Aristotle occupied him-
  self), inasmuch as in experience nothing is ever to be met with
  that is coincident with it. For Plato ideas are archetypes
  of the things themselves, and not, in the manner of the cate-
  gories, merely keys to possible experiences. In his view they
  have issued from highest reason, and from that source have
  come to be shared in by human reason, which, however, is now
  no longer in its original state, but is constrained laboriously to
  recall, by a process of reminiscence (which is named philo-
  sophy), the old ideas, now very much obscured. I shall not
  engage here in any literary enquiry into the meaning which
A 314  this illustrious philosopher attached to the expression. I need
  only remark that it is by no means unusual, upon comparing
  the thoughts which an author has expressed in regard to his
  subject, whether in ordinary conversation or in writing, to find
  that we understand him better than he has understood himself.
  As he has not sufficiently determined his concept, he has some-
  times spoken, or even thought, in opposition to his own in-
  tention.
  Plato very well realised that our faculty of knowledge feels
  a much higher need than merely to spell out appearances ac-
B371  cording to a synthetic unity, in order to be able to read them
  as experience.  He knew that our reason naturally exalts itself
  to forms of knowledge which so far transcend the bounds of
  experience that no given empirical object can ever coincide
00088
with them, but which must none the less be recognised as
having their own reality, and which are by no means mere
fictions of the brain.
  Plato found the chief instances of his ideas in the field of
the practical,a that is, in what rests upon freedom, which in its
turn rests upon modes of knowledge that are a peculiar product  A 315
of reason. Whoever would derive the concepts of virtue from
experience and make (as many have actually done) what at best
can only serve as an example in an imperfect kind of exposi-
tion, into a pattern from which to derive knowledge, would
make of virtue something which changes according to time
and circumstance, an ambiguous monstrosity not admitting of
the formation of any rule. On the contrary, as we are well
aware, if anyone is held up as a pattern of virtue, the true  B 372
original with which we compare the alleged pattern and by
which alone we judge of its value is to be found only in our
minds. This original is the idea of virtue, in respect of which
the possible objects of experience may serve as examples
(proofs that what the concept of reason commands is in a cer-
tain degree practicable), but not as archetype. That no one
of us will ever act in a way which is adequate to what is con-
tained in the pure idea of virtue is far from proving this thought
to be in any respect chimerical. For it is only by means of this
idea that any judgment as to moral worth or its opposite is
possible; and it therefore serves as an indispensable founda-
tion for every approach to moral perfection---however the
obstacles in human nature, to the degree of which there are no
assignable limits, may keep us far removed from its complete
achievement.
  The <1Republic>1 of Plato has become proverbial as a striking  A316
example of a supposedly visionary perfection, such as can exist
  a He also, indeed, extended his concept so as to cover specu-
lative knowledge, provided only the latter was pure and given com-
pletely <1a priori.>1 He even extended it to mathematics, although the
object of that science is to be found nowhere except in <1possible>1 ex-
perience. In this I cannot follow him, any more than in his mystical
deduction of these ideas, or in the extravagances whereby he, so to
speak, hypostatised them--although, as must be allowed, the exalted
language, which he employed in this sphere, is quite capable of a
milder interpretation that accords with the nature of things.
00089
only in the brain of the idle thinker; and Brucker has ridiculed
the philosopher for asserting that a prince can rule well only
in so far as he participates in the ideas. We should, however,
be better advised to follow up this thought, and, where the
great philosopher leaves us without help, to place it, through
fresh efforts, in a proper light, rather than to set it aside as use-
B 373  less on the very sorry and harmful pretext of impracticability.
  A constitution allowing <1the greatestpossible human freedom>1 in
  accordance with laws by which <1the freedom of each is made to>1
  <1be consistent with that of all others>1---I do not speak of the
  greatest happiness, for this will follow of itself---is at any rate
  a necessary idea, which must be taken as fundamental not only
  in first projecting a constitution but in all its laws. For at the
  start we are required to abstract from the actually existing
  hindrances, which, it may be, do not arise unavoidably out
  of human nature, but rather are due to a quite remediable
  cause, the neglect of the pure ideas in the making of the laws.
  Nothing, indeed, can be more injurious, or more unworthy of
  a philosopher, than the vulgar appeal to so-called adverse ex-
  perience. Such experience would never have existed at all, if
  A 317 at the proper time those institutions had been established in
  accordance with ideas, and if ideas had not been displaced by
  crude conceptions which, just because they have been derived
  from experience, have nullified all good intentions. The more
  legislation and government are brought into harmony with the
  above idea, the rarer would punishments become, and it is there-
  fore quite rational to maintain, as Plato does, that in a perfect
  state no punishments whatsoever would be required. This per-
  fect state may never, indeed; come into being; none the less
  B 374  this does not affect the rightfulness of the idea, which, in order
  to bring the legal organisation of mankind ever nearer to its
  greatest possible perfection, advances this maximum as an
  archetype. For what the highest degree may be at which
  mankind may have to come to a stand, and how great a gulf
  may still have to be left between the idea and its realisation,
  are questions which no one can, or ought to, answer. For the
  issue depends on freedom; and it is in the power of freedom
  to pass beyond any and every specified limit.
































00001
But it is not only where human reason exhibits genuine
causality, and where ideas are operative causes (of actions and
their objects), namely, in the moral sphere, but also in regard
to nature itself, that Plato rightly discerns clear proofs of an
origin from ideas. A plant, an animal, the orderly arrangement
of the cosmos---presumably therefore the entire natural world
---clearly show that they are possible only according to ideas,  A 318
and that though no single creature in the conditions of its
individual existence coincides with the idea of what is most
perfect in its kind---just as little as does any human being
with the idea of humanity, which he yet carries in his soul
as the archetype of his actions---these ideas are none the
less completely determined in the Supreme Understanding,
each as an individual and each as unchangeable, and are
the original causes of things. But only the totality of things,
in their interconnection as constituting the universe, is com-  B 375
pletely adequate to the idea. If we set aside the exaggera-
tions in Plato's methods of expression, the philosopher's
spiritual flight from the ectypal mode of reflecting upon the
physical world-order to the architectonic ordering of it ac-
cording to ends, that is, according to ideas, is an enterprise
which calls for respect and imitation. It is, however, in regard
to the principles of morality, legislation, and religion, where
the experience, in this case of the good, is itself made possible
only by the ideas---incomplete as their empirical expression
must always remain---that Plato's teaching exhibits its quite
peculiar merits. When it fails to obtain recognition, this is due
to its having been judged in accordance with precisely those
empirical rules, the invalidity of which, regarded as principles,
it has itself demonstrated. For whereas, so far as nature is con-
cerned, experience supplies the rules and is the source of
truth, in respect of the moral laws it is, alas, the mother of
illusion! Nothing is more reprehensible than to derive the laws  A 319
prescribing what <1ought to be done>1 from what <1is done,>1 or to
impose upon them the limits by which the latter is circum-
scribed.
  But though the following out of these considerations is
what gives to philosophy its peculiar dignity, we must mean-
time occupy ourselves with a less resplendent, but still meri-
00002
torious task, namely, to level the ground, and to render it
B 376  sufficiently secure for moral edifices of these majestic dimen-
  sions. For this ground has been honeycombed by subterranean
  workings which reason, in its confident but fruitless search
  for hidden treasures, has carried out in all directions, and
  which threaten the security of the superstructures. Our present
  duty is to obtain insight into the transcendental employment
  of pure reason, its principles and ideas, that we may be in a
  position to determine and estimate its influence and true value.
  Yet, before closing these introductory remarks, I beseech
  those who have the interests of philosophy at heart (which is
  more than is the case with most people) that, if they find
  themselves convinced by these and the following considera-
  tions, they be careful to preserve the expression "idea' in
  its original meaning, that it may not become one of those
  expressions which are commonly used to indicate any and
  every species of representation, in a happy-go-lucky confu-
  sion, to the consequent detriment of science. There is no lack
  of terms suitable for each kind of representation, that we
A 320  should thus needlessly encroach upon the province of any one
  of them. Their serial arrangement is as follows. The genus
  is <1representation>1 in general <1(repraesentatio).>1 Subordinate to
  it stands representation with consciousness <1(perceptio).>1 A
  <1perception>1 which relates solely to the subject as the modifica-
  tion of its state is <1sensation (sensatio),>1 an objective perception
B 377  is <1knowledge (cognitio).>1 This is either <1intuitions>1 or <1concept>1
  <1(intuitus vel conceptus).>1 The former relates immediately to the
  object and is single, the latter refers to it immediately by means
  of a feature which several things may have in common. The
  concept is either an <1empirical>1 or a <1pure concept.>1 The pure con-
  cept, in so far as it has its origin in the understanding alone
  (not in the pure image of sensibility), is called a <1notion.>1 A
  concept formed from notions and transcending the possibility
  of experience is an <1ideas>1 or concept of reason. Anyone who
  has familiarised himself with these distinctions must find it
  intolerable to hear the representation of the colour, red, called
  an idea. It ought not even to be called a concept of under-
  standing, a notion.
00003
  THE TRANSCENDENTAL IDEAS  315
FIRST  BOOK OF THE TRANSCENDENTAL  A 321
  DIALECTIC
  Section 2
  THB TRANSCENDENTAL IDEAS
The Transcendental Analytic has shown us how the mere
logical form of our knowledge may in itself contain original
pure <1a priori>1 concepts, which represent objects prior to all
experience, or, speaking mo e correctly, indicate the synthetic
unity which alone makes p ssible an empirical knowledge of  B 378
objects. The form of judgments (converted into a concept of
the synthesis of intuitions) yielded categories which direct all
employment of understanding in experience. Similarly, we
may presume that the form of syllogisms, when applied to
the synthetic unity of intuitions under the direction of the
categories, will contain the origin of special <1a priori>1 concepts,
which we may call pure concepts of reason, or <1transcendental>1
<1ideas,>1 and which will determine according to principles how
understanding is to be employed in dealing with experience
in its totality.
  The function of reason in its inferences consists in the
universality of knowledge [which it yields] according to con-
cepts, the syllogism being itself a judgment which is deter-
mined <1a priori>1 in the whole extent of its conditions. The pro-  A 322
position, "Caius is mortal', I could indeed derive from experi-
ence by means of the understanding alone. But I am in pursuit
of a concept (in this case, the concept `man') that contains the
condition under which the predicate (general term for what
is asserted) of this judgment is given; and after I have sub-
sumed the predicate under this condition taken in its whole
extension ("All men are mortal'), I proceed, in accordance
therewith, to determine the knowledge of my object ("Caius
is mortal').
  Accordingly, in the conclusion of a syllogism we restrict a
00004
B 379 predicate to a certain object, after having first thought it in
  the major premiss in its whole extension under a given con-
  dition. This complete quantity of the extension in relation to
  such a condition is called <1universality (universalitas).>1 In the
  synthesis of intuitions we have corresponding to this the <1allness>1
  <1(universitas)>1 or <1totality>1 of the conditions. The transcendental
  concept of reason is, therefore, none other than the concept of
  the <1totality>1 of the <1conditions>1 for any given conditioned. Now
  since it is the <1unconditioned>1 alone which makes possible the
  totality of conditions, and, conversely, the totality of conditions
  is always itself unconditioned, a pure concept of reason can
  in general be explained by the concept of the unconditioned,
  conceived as containing a ground of the synthesis of the
  conditioned.
A 323  The number of pure concepts of reason will be equal to the
  number of kinds of relation which the understanding repre-
  sents to itself by means of the categories. We have therefore
  to seek for an <1unconditioned,>1 first, of the <1categorical>1 synthesis
  in a <1subject;>1 secondly, of the <1hypothetical>1 synthesis of the
  members of a <1series;>1 thir  ly, of the <1disjunctive>1 synthesis of     the
  parts in a <1system.>1
  There is thus precisely the same number of kinds of syl-
  logism, each of which advances through prosyllogisms to the
  unconditioned: first, to the subject which is never itself a pre-
B 380 dicate; secondly, to the presupposition which itself presup-
  poses nothing further; thirdly, to such an aggregate of the
  members of the division of a concept as requires nothing
  further to complete the division. The pure concepts of reason
  ---of totality in the synthesis of conditions---are thus at least
  necessary as setting us the task of extending the unity of
  understanding, where possible, up to the unconditioned, and
  are grounded in the nature of human reason. These tran-
  scendental concepts may, however, be without any suitable
  corresponding employment <1in concreto,>1 and may therefore
  have no other utility than that of so directing the understand-
  ing that, while it is extended to the uttermost, it is also atthe
  same time brought into complete consistency with itself.
A 324  But while we are here speaking of the totality of con-
  ditions and of the unconditioned, as being  quivalent titles
  for all concepts of reason, we again come upon an expression
00005
with which we cannot dispense, and which yet, owing to an
ambiguity that attaches to it through long-standing misuse,
we also cannot with safety employ. The word <1"absolute'>1 is
one of the few words which in their original meaning were
adapted to a concept that no other word in the same language
exactly suits. Consequently its loss, or what amounts to the
same thing, looseness in its employment, must carry with it B 381
the loss of the concept itself. And since, in this case, the con-
cept is one to which reason devotes much of its attention,
it cannot be relinquished without greatly harming all tran-
scendental philosophy. The word <1"absolute'>1 is now often used
merely to indicate that something is true of a thing considered
<1in itself,>1 and therefore of its <1inward>1 nature. In this sense the
<1absolutely possible>1 would mean that which in itself <1(interne)>1
is possible---which is, in fact, the <1least>1 that can be said of an
object. On the other hand, the word is also sometimes used to
indicate that something is valid in all respects, without limita-
tion, <1e.g.>1 absolute despotism, and in this sense the <1absolutely>1
<1possible>1 would mean what is <1in every relation>1 (in all respects)1
<1possible->1--which is the <1most>1 that can be said of the possibility  A 325
of a thing. Now frequently we find these two meanings com-
bined. For example, what is internally impossible is impossible
in any relation, and therefore absolutely impossible. But in
most cases the two meanings are infinitely far apart, and I can
in no wise concludethat because something is in itself possible,
it is therefore also possible in every relation, and so absolutely
possible. Indeed, as I shall subsequently show, <1absolute>1 neces-
sity is by no means always dependent on inner necessity, and
must not, therefore, be treated as synonymous with it. If the
opposite of something is internally impossible, this opposite B 382
is, of course, impossible in all respects, and the thing itself
is therefore absolutely necessary.  But I cannot reverse the
reasoning so as to conclude that if something is absolutely
necessary its opposite is <1internally>1 impossible, <1i.e.>1 that the
<1absolute>1 necessity of things is an <1inner>1 necessity. For this
inner necessity is in certain cases a quite empty expression
to which we cannot attach any concept whatsoever, whereas
the concept of the necessity of a thing in all relations (to every-
thing possible) involves certain quite special determinations.
00006
Since the loss of a concept that is of great importance for
speculative science can never be a matter of indifference to the
philosopher, I trust that the fixing and careful preservation
of the expression, on which the concept depends, will like-
wise be not indifferent to him.
A326  It is, then, in this wider sense that I shall use the word
  <1"absolute',>1 opposing it to what is valid only comparatively,
  that is, in some particular respect. For while the latter is re-
  stricted by conditions, the former is valid without restriction.
  Now the transcendental concept of reason is directed
  always solely towards absolute totality in the synthesis of con-
  ditions, and never terminates save in what is absolutely, that is,
  in all relations, unconditioned. For pure reason leaves every-
B 383  thing to the understanding---the understanding [alone] apply-
  ing immediately to the objects of intuition, or rather to their
  synthesis in the imagination. Reason concerns itself exclusively
  with absolute totality in the employment of the concepts of the
  understanding, and endeavours to carry the synthetic unity.
  which is thought in the category, up to the completely uncon-
  ditioned. We may call this unity of appearances the <1unity of>1
  <1reason,>1 and that expressed by the category the <1unity of under->1
  <1standing.>1 Reason accordingly occupies itself solely with the
  employment of understanding, not indeed in so far as the latter
  contains the ground of possible experience (for the concept of
  the absolute totality of conditions is not applicable in any
  experience, since no experience is unconditioned), but solely
  in order to prescribe to the understanding its direction to-
  wards a certain unity of which it has itself no concept, and
  in such manner as to unite all the acts of the understanding,
A 327  in respect of every object, into an <1absolute>1 whole. The object-
  ive employment of the pure concepts of reason is, therefore,
  always <1transcendent,>1 while that of the pure concepts of under-
  standing must, in accordance with their nature, and inasmuch
  as their application is solely to possible experience, be always
  <1immanent.>1
  l understand by idea a necessary concept of reason to
  which no corresponding object can be given in sense-ex-
  perience. Thus the pure concepts of reason, now under con-
B 384  sideration, are <1transcendental ideas.>1 They are concepts of pure
00007
reason, in that they view all knowledge gained in experience as
being determined through an absolute totality of conditions.
They are not arbitrarily invented; they are imposed by the
very nature of reason itself, and therefore stand in necessary
relation to the whole employment of understanding. Finally,
they are transcendent and overstep the limits of all experi-
ence; no object adequate tothe transcendental idea can ever be
found within experience. If I speak of an idea, then as regards
its object, viewed as an object of pure understanding, I am
saying a <1great deal,>1 but as regards its relation to the subject,
that is, in respect of its actuality under empirical conditions,
I am for the same reason saying <1very little,>1 in that, as being
the concept of a maximum, it can never be correspondingly
given <1in concreto.>1 Since in the merely speculative employment
of reason the latter [namely, to determine the actuality of the  A 328
idea under empirical conditions] is indeed our whole purpose,
and since the approximation to a concept, which yet is never
actually reached, puts us in no better position than if the con-
cept were entirely abortive, we say of such a concept---it is <1only>1
an idea. The absolute whole of all appearances---we mightthus
say---<1is only an idea;>1 since we can never represent it in image,
it remains a <1problem>1 to which there is no solution. But since,
on the other hand, in the practical employment of understand-
ing, our sole concern is with the carrying out of rules, the idea  B 385
of practical reason can always be given actually <1in concreto,>1
although only in part; it is, indeed, the indispensable condition
of all practical employment of reason. The practice of it is al-
ways limited and defective, but is not confined within determin-
able boundaries, and is therefore always under the influence
of the concept of an absolute completeness. The practical idea
is, therefore, always in the highest degree fruitful, and in its
relation to our actual activities is indispensably necessary.
Reason is here, indeed, exercising causality, as actually
bringing about that which its concept contains; and of such
wisdom we cannot, therefore, say disparagingly <1it is only an>1
<1idea.>1 On the contrary, just because it is the idea of the neces-
sary unity of all possible ends, it must as an original, and at
least restrictive condition, serve as standard in all that bears
on the practical.
  Although we must say of the transcendental concepts of A 329
00008
reason that <1they are only ideas,>1 this is not by any means to be
taken as signifying that they are superfluous and void. For
even if they cannot determine any object, they may yet, in a
fundamental and unobserved fashion, be of service to the
understanding as a canon for its extended and consistent em-
ployment. The understanding does not thereby obtain more
knowledge of any object than it would have by means of its
own concepts, but for the acquiring of such knowledge it
receives better and more extensive guidance. Further---what
B 386  we need here no more than mention---concepts of reason may
  perhaps make possible a transition from the concepts of
  nature to the practical concepts, and in that way may give
  support to the moral ideas themselves, bringing them into
  connection with the speculative knowledge of reason. As to
  all this, we must await explanation in the sequel.
  In accordance with our plan we leave aside the practical
  ideas, and consider reason only in its speculative, or rather,
  restricting ourselves still further, only in its transcendental
  employment. Here we must follow the path that we have
  taken in the deduction of the categories; we must consider
  the logical form of knowledge through reason, to see whether
  perhaps reason may not thereby be likewise a source of con-
  cepts which enable us to regard objects in themselves as deter-
  mined synthetically <1a priori,>1 in relation to one or other of the
  functions of reason.
A 330o  Reason, considered as the faculty of a certain logical form
  of knowledge, is the faculty of inferring, <1i.e.>1 judging medi-
  ately (by the subsumption of the condition of a possible judg-
  ment under the condition of a given judgment). The given
  judgment is the universal rule (major premiss). The subsump-
  tion of the condition of another possible judgment under the
  condition of the rule is the minor premiss. The actual judg-
  ment which applies the assertion of the rule to the <1subsumed>1
B 387  <1case>1 is the conclusion. The rule states something universally,
  subject to a certain condition. The condition of the rule is
  found to be fulfilled in an actual case. What has been asserted
  to be universally v lid under that condition is therefore to be
  regarded as valid also in the actual case, which involves that
  condition. It is very evident, therefore, that reason arrives at
00009
knowledge by means of acts of the understanding which con-
stitute a series of conditions. Thus if I arrive at the proposi-
tion that all bodies are alterable, only by beginning with
the more remote knowledge (in which the concept of body
does not occur, but which nevertheless contains the condi-
tion of that concept), namely, that everything composite is
alterable; if I then proceed from this to a proposition which
is less remote and stands under the condition of the last-
named proposition, namely, that bodies are composite; and if
from this I finally pass to a third proposition, which connects
the more remote knowledge (alterable) with the knowledge
actually before me, and so conclude that bodies are alter- A 331
able---by this procedure I have arrived at anowledge (a con-
clusion) by means of a series of conditions (the premisses).
Now every series the exponent of which is given (in categori-
cal or hypothetical judgment) can be continued; consequently
this same activity of reason leads to <1ratiocinatio polysyllo->1
<1gistica,>1 which1 is a series of inferences that can be prolonged
indefinitely on the side either of the conditions <1(perprosyllo->1  B 388
<1gismos)>1 or of the conditioned <1(per episyllogismos).>1
  But we soon become aware that the chain or series of pro-
syllogisms, that is, of inferred knowledge on the side of the
grounds or conditions of a given knowledge, in other words, of
the <1ascending>1 series of syllogisms, must stand in a different
relation to the faculty of reason from that of the <1descending>1
series, that is, of the advance of reason in the direction of the
conditioned, by means of episyllogisms. For since in the former
case the knowledge <1(conclusio)>1 is given only as conditioned, we
cannot arrive at it by means of reason otherwise than on the
assumption that all the members of the series on the side of the
conditions are given (totality in the series of the premisses);
only on this assumption is the judgment before us possible
<1a priori:>1 whereas on the side of the conditioned, in respect of
consequences, we only think a series <1in process of becoming,>1  A 332
not one already presupposed or given <1in its completeness,>1 and
therefore an advance that is merely potential. If, therefore,
knowledge be viewed as conditioned, reason is constrained to
regard the series of conditions in the ascending line as com-
pleted and as given in their totality. But if the same knowledge
00010
is viewed as a condition of yet other knowledge, and this know-
B 389 ledge as constituting a series of consequences in a descend-
  ing line, reason can be quite indifferent as to how far this
  advance extends <1a parte posteriori,>1 and whether a totality of
  the series is possible at all. For it does not need such a series
  in order to be able to draw its conclusion, this being already
  sufficiently determined and secured by its grounds <1a parte>1
  <1priori.>1 The series of premisses on the side of the conditions
  may have a <1first>1 member, as its highest condition, or it may
  have no such member, in which case it is without limits <1a parte>1
  <1priori.>1 But however this may be, and even admitting that we
  can never succeed in comprehending a totality of conditions,1
  the series must none the less contain such a totality; and the
  entire series must be unconditionally true if the conditioned,
  which is regarded as a consequence resulting from it, is to be
  counted as true. This is a requirement of reason, which an-
  nounces its knowledge as being determined <1a priori>1 and as
  necessary, either in itself, in which case it needs no grounds,
  or, if it be derivative, as a member of a series of grounds,
  which itself, as a series, is unconditionally true.
A 333  FIRST BOOK OF THE TRANSCENDENTAL
  DIALECTIC
  Section 3
  SYSTEM OF THE TRANSCENDENTAL IDEAS
  We are not at present concerned with logical dialectic,
  which abstracts from all the content of knowledge and con-
  fines itself to exposing the fallacies concealed in the form of
  syllogisms, but with a transcendental dialectic which has to
  contain, completely <1a priori,>1 the origin of certain modes of
  knowledge derived from pure reason as well as of certain
  inferred concepts, the object of which can never be given em-
  pirically and which therefore lie entirely outside [the sphere
  of ] the faculty of pure understanding. From the natural rela-
  tion which the transcendental employment of our knowledge,
  alike in inferences and in judgments, must bear to its logical
00011
employment, we have gathered that there can be only three
ainds of dialectical inference, corresponding to the three
kinds of inference through which reason can arrive at know-
ledge by means of principles, and that in all of these its busi-
ness is to ascend from the conditioned synthesis, to which
understanding always remains restricted, to the unconditioned,
which understanding can never reach.
  The relations which are to be universally found in all our
representations are (1) relation to the subject; (2) relation to B 391
objects, either as appearances or as objects of thought in
general. If we combine the subdivision with the main division,
all relation of representations, of which we can form either a
concept or an idea, is then threefold: (1) the relation to the
subject; (2) the relation to the manifold of the object in the
[field of] appearance; (3) the relation to all things in general.
  Now all pure concepts in general are concerned with the
synthetic unity of representations, but [those of them which
are] concepts of pure reason (transcendental ideas) are con-
cerned with the unconditioned synthetic unity of all conditions
in general. All transcendental ideas can therefore be arranged in
three classes, the <1first>1 containing the absolute (unconditioned)
<1unity>1 of the <1thinking subject,>1 the <1second>1 the absolute <1unity of>1
<1the series of conditions of appearance,>1 the <1third>1 the absolute
<1unity of the condition of all objects of thought in general.>1
  The thinking subject is the object of <1psychology,>1 the sum-
total of all appearances (the world) is the object of <1cosmology,>1
and the things which contains the highest condition of the
possibility of all that can be thought (the being of all beings)
the object of <1theology.>1 Pure reason thus furnishes the idea
for a transcendental doctrine of the soul <1(psychologia ratio->1
<1nalis),>1 for a transcendental science of the world <1(cosmologia>1 B 392
<1rationalis),>1 and, finally, for a transcendental knowledge of A 335
God <1(theologia transyendentalis).>1 The understanding is not in
a position to yield even the mere project of any one of these
sciences, not even though it be supported by the highest
logical employment of reason, that is, by all the conceiv-
able inferences through which we seek to advance from one
of its objects (appearance) to all others, up to the most remote
00012
A 338 in the course of these enquiries. Indeed, we have already,
  in a preliminary manner, obtained an answer to the question,
B 396 since in treating of the transcendental concepts of reason
  which, in philosophical theory, are commonly confused with
  others, and not properly distinguished even from concepts of
  understanding, we have been able to rescue them from their
  ambiguous position, to determine their origin, and at the
  same time, in so doing, to fix their precise number (to which
  we can never add), presenting them in a systematic connec-
  tion, and so marking out and enclosing a special field for pure
  reason.
00013
THE TRANSCENDENTAL DIALECTIC
  BOOK II
THE DIALECTICAL INFERENCES OF PURE REASON
ALTHOUGH a purely transcendental idea is, in accordance
with the original laws of reason, a quite necessary product of
reason, its object, it may yet be said, is something of which
we have no concept. For in respect of an object which is
adequate to the demands of reason, it is not, in fact, possible
that we should ever be able to form a concept of the under-  A 339
standing, that is, a concept that allows of being exhibited and
intuited in a possible experience. But we should be better
advised and less likely to be misunderstood if we said that  B 397
although we cannot have any knowledge of the object which
corresponds to an idea, we yet have a problematic concept
of it.
  The transcendental (subjective) reality of the pure concepts
of reason depends on our having been led to such ideas by a
necessary syllogism.1 There will therefore be syllogisms which
contain no empirical premisses, and by means of which we
conclude from something which we know to something else of
which we have no concept, and to which, owing to an inevitable
illusion, we yet ascribe objective reality. These conclusions
are, then, rather to be called <1pseudo-rational>1 than rational,
although in view of their origin they may well lay claim to
the latter title, since they are not fictitious and have not arisen
fortuitously, but have sprung from the very nature of reason.
They are sophistications not of men but of pure reason itself.
Even the wisest of men cannot free himself from them. After
long effort he perhaps succeeds in guarding himself against
00014
actual error; but he will never be able to free himself from the
illusion, which unceasingly mocks and torments him.
  There are, then, only three kinds of dialectical syllogisms
A340  -- just so many as there are ideas in which their conclusions
  result. In the <1first>1 kind of syllogism I conclude from the
B 398  transcendental concept of the subject, which contains nothing
  manifold, the absolute unity of this subject itself, of which,
  however, even in so doing, I possess no concept whatsoever.
  This dialectical inference I shall entitle the transcendental
  <1paralogism.>1 The <1second>1 kind of pseudo-rational inference is
  directed to the transcendental concept of the absolute totality
  of the series of conditions for any given appearance. From the
  fact that my concept of the unconditioned synthetic unity of the
  series, as thought in a certain way, is always self-contradictory,
  I conclude that there is really a unity of the opposite kind,
  although of it also I have no concept. The position of reason in
  these dialectical inferences I shall entitle the <1antinomy>1 of pure
  reason. Finally, in the <1third>1 kind of pseudo-rational inference,
  from the totality of the conditions under which objects in
  general, in so far as they can be given me, have to be thought,
  I conclude to the absolute synthetic unity of all conditions of
  the possibility of things in general, <1i.e.>1 from things which I do
  not anow through the merely transcendental concept of them
  I infer an <1ens entium,>1 which I know even less through any
  transcendental concept, and of the unconditioned necessity
  of which I can form no concept whatsoever. This dialectical
  syllogism I shall entitle the <1ideal>1 of pure reason.
A341)  SECOND BOOK OF THE TRANSCENDENTAL
  DIALECTIC
  CHAPTER I
  THE PARALOGISMS OF PURE REASON
  A logical paralogism is a syllogism which is fallacious in
  form, be its content what it may. A transcendental paralogism
  is one in which there is a transcendental ground, constraining
  us to draw a formally invalid conclusion. Such a fallacy is
00015
therefore grounded in the nature of human reason, and gives
rise to an illusion which cannot be avoided, although it may,
indeed, be rendered harmless.
  We now come to a concept which was not included in the
general list of transcendental concepts but which must yet be
counted as belonging to that list, without, however, in the least
altering it or declaring it defective. This is the concept or, if the
term be preferred, the judgment, "I think'. As is easily seen,
this is the vehicle of all concepts, and therefore also of tran-
scendental concepts, and so is always included in the conceiv-
ing of these latter, and is itself transcendental. But it can have
no special designation, because it serves only to introduce all our  B 400
thought, as belonging to consciousness. Meanwhile, however
free it be of empirical admixture (impressions of the senses),  A 342
it yet enables us to distinguish, through the nature of our
faculty of representation, two kinds of objects. "I', as think-
ing, am an object of inner sense, and am called "soul'. That
which is an object of the outer senses is called "body'. Accord-
ingly the expression "I', as a thinking being, signifies the
object of that psychology which may be entitled the "rational
doctrine of the soul', inasmuch as I am not here seeking to
learn in regard to the soul anything more than can be in-
ferred, independently of all experience (which determines me
more specifically and <1in concreto),>1 from this concept "I', so
far as it is present in all thought.
  The <1rational>1 doctrine of the soul is really an undertaking
of this kind; for if in this science the least empirical element
of my thought, or any special perception of my inner state,
were intermingled with the grounds of knowledge, it would
no longer be a rational but an <1empirical>1 doctrine of the soul.
Thus we have here what professes to be a science built upon
the single proposition "I <1think'.>1 Whether this claim be well or
ill grounded, we may, very fittingly, in accordance with the
nature of a transcendental philosophy, proceed to investi-
gate. The reader must not object that this proposition, which
expresses the perception of the self, contains an inner experi-  B 401
ence, and that the rational doctrine of the soul founded upon
it is never pure and is therefore to that extent based upon an  A343
empirical principle. For this inner perception is nothing more
than the mere apperception "I <1think',>1 by which even tran-
00016
scendental concepts are made possible; what we assert in them
is "I think substance, cause, etc. For inner experience in
general and its possibility, or perception in general and its
  relation to other perception, in which no special distinction
  or empirical determination is given, is not to be regarded as
  empirical knowledge but as knowledge of the empirical in
  general, and has to be reckoned with the investigation of the
  possibility of any and every experience, which is certainly a
  transcendental enquiry. The least object of perception (for ex-
  ample, even pleasure or displeasure), if added to the universal
  representation of self-consciousness, would at once transform
  rational psychology into empirical psychology.
  "I <1think'>1 is, therefore, the sole text of rational psychology,
  and from it the whole of its teaching has to be developed.
  Obviously, if this thought is to be related to an object (myself),
  it can contain none but transcendental predicates of that ob-
  ject, since the least empirical predicate would destroy the
  rational purity of the science and its independence of all
  A  ) experience.
  B402  All that is here required is that we follow the guidance of
  the categories, with this difference only, that since our starting-
  point is a given thing, "I' as thinking being, we begin with the
  category of substance, whereby a thing in itself is represented,
  and so proceed backwards through the series, without, how-
  ever, otherwise changing the order adopted in the table of the
  categories. The topic of the rational doctrine of the soul, from
  which everything else that it contains must be derived, is
  The soul is <1substance.>1
  2  3
  As regards its quality it is  As  regards  the  different
  <1simple.>1  times in which it exists, it is
  numerically identical, that
  is, <1unity>1 (not plurality).
00017
  4
It is in relation to <1possible>1 objects in space.
All the concepts of pure psychology arise from these ele  A 345
ments, simply by way of combination, without admission of
any other principle. This substance, merely as object of in  er
sense, gives the concept of <1immateriality;>1 as simple substance,
that of <1incorruptibility;>1 its identity, as intellectual substance,
<1personality;>1 all these three together, <1spirituality;>1 while the
relation to objects in space gives <1commercium>1 with bodies,
and so leads us to represent the thinking substance as the
principle of life in matter, that is, as soul <1(anima),>1 and as the
ground of <1animality.>1 This last, in turn, as limited by spiritu-
ality, gives the concept of <1immortality.>1
  In connection with these concepts we have four paralogisms
of a transcendental psychology---which is wrongly regarded as
a science of pure reason---concerning the nature of our thinking
being. We can assign no other basis for this teaching than the  B 404
simple, and in itself completely empty, representation "I'; and we  A 346
cannot even say that this is a concept, but only that it is a bare
consciousness which accompanies all concepts. Through this
I or he or it (the thing) which thinks, nothing further is repre-
sented than a transcendental subject of the thoughts =X. It
is known only through the thoughts which are its predicates,
and of it, apart from them, we cannot have any concept what-
soever, but can only revolve in a perpetual circle, since any
judgment upon it has always already made use of its repre-
sentation. And the reason why this inconvenience is insepar-
ably bound up with it, is that consciousness in itself is not a
representation distinguishing a particular object, but a form
  a The reader who has difficulty in guessing the psychological
meaning of these expressions taken in their transcendental abstract-
ness, and in discovering why the last-mentioned attribute of the soul
belongs to the category of <1existence,>1 will find the terms sufficiently  B 403
explained and justified in the sequel. Further, I have to apologise
for the Latin expressions which, contrary to good taste, have usurped
the place of their German equivalents, both in this section and in the
work as a whole. My excuse is that I have preferred to lose somewhat
in elegance of language rather than to increase, in however minor
a degree, the reader's difficulties.
00018
  of representation in general, that is, of representation in so far
  as it is to be entitled knowledge; for it is only of knowledge
  that I can say that I am thereby thinking something.
  It must, on first thoughts, seem strange that the condition
  under which alone I think, and which is therefore merely a pro-
  perty of myself as subject, should likewise be valid for every-
  thing that thinks, and that on a seemingly empirical proposition
  we can presume to base an apodeictic and universal judgment,
  namely, that that which thinks must, in all cases, be constituted
  B 405  as the voice of self-consciousness declares it to be constituted
  in my own self. The reason is this: we must assign to things,
  A 347  necessarily and <1a priori,>1 all the properties that constitute the
  conditions under which alone we think them. Now I cannot
  have any representation whatsoever of a thinking being,
  through any outer experience, but only through self-conscious-
  ness. Objects of this kind are, therefore, nothing more than
  the transference of this consciousness of mine to other things,
  which in this way alone can be represented as thinking beings.
  The proposition, "I think', is, however, here taken only prob-
  lematically, not in so far as it may contain perception of an
  existent (the Cartesian <1cogito, ergo sum),>1 but in respect of its
  mere possibility, in order to see what properties applicable to
  its subject (be that subject actually existent or not) may follow
  from so simple a proposition.
  If our knowledge of thinking beings in general, by means
  of pure reason, were based on more than the <1cogito,>1 if we
  thoughts and the natural laws of the thinking self to be de-
  rived from these thoughts, there would arise an empirical psy-
  chology, which would be a kind of <1physiology>1 of inner sense,
  capable perhaps of explaining the appearances of inner sense,
  but never of revealing such properties as do not in any way
  B 406 belong to possible experience <1(e.g.>1 the properties of the simple),
  nor of yielding any <1apodeictic>1 knowledge regarding the nature
.  of thinking beings in general. It would not, therefore, be a
  <1rational>1 psychology.
  A 348  Since the proposition "I think' (taken problematically) con-
  tains the form of each and every judgment of the understand-
  ing and accompanies all categories as their vehicle, it is evi-
  dent that the inferences from it admit only of a transcendental
00019
employment of the understanding. And since this employment
excludes any admixture of experience, we cannot, after what
has been shown above, entertain any favourable anticipations
in regard to its methods of procedure. We therefore propose to
follow it, with a critical eye, through all the predicaments of
pure psychology.
  <1[The Paralogisms of Pure Reason.- as in Ist edition->111
  FIRST PARALOGISM: OF SUBSTANTIALITY
  That, the representation of which is the <1absolute subject>1 of
our judgments and cannot therefore be employed as deter-
mination of another thing, is <1substance.>1
  I, as a thinking being, am the <1absolute subject>1 of all my
possible judgments, and this representation of myself cannot
be employed as predicate of any other thing.
  Therefore I, as thinking being (soul), am <1substance.>1
  <1Criticism of the First Paralogism of Pure Psychology>1
  In the analytical part of the Transcendental Logic we have
s own that pure categories, and among them that of sub-
stance, have in themselves no objective meaning, save in so far
as they rest upon an intuition, and are applied to the manifold  A 349
of this intuition, as functions of synthetic unity. In the ab-
sence of this manifold, they are merely functions of a judg-
ment, without content. I can say of any and every thing that
it is substance, in the sense that I distinguish it from mere
predicates and determinations of things. Now in all our
thought the "I' is the subject, in which thoughts in here only
as determinations;  and this "I' cannot be employed  as the
determination of another thing. Everyone must, therefore,
necessarily regard himself as substance, and thought as [con-
sisting] only [in] accidents of his being, determinations of his
state.
  But what use am I to make of this concept of a substance?
That I, as a thinking being, <1persist>1 for myself, and do not in
any natural manner either <1arise>1 or <1perish,>1 can by no means be
00020
00021
deduced from it. Yet there is no other use to which I can put
the concept of the substantiality of my thinking subject, and
==  apart from such use I could very well dispense with it.
  So far from being able to deduce these properties merely
  from the pure category of substance, we must, on the contrary,
  take our start from the permanence of an object given in ex-
  perience as permanent. For only to such an object can the
  concept of <1substance>1 be applied in a manner that is empiric-
  ally serviceable. In the above proposition, however, we have
  not taken as our basis any experience; the inference is merely
  A 350 from the concept of the relation which all thought has to the
  "I' as the common subject in which it inheres. Nor should we, in
  resting it upon experience, be able, by any sure observation, to
  demonstrate such permanence. The "I' is indeed in all thoughts,
  but there is not in this representation the least trace of intui-
  tion,  distinguishing the  "I'  from other objects of intuition.
  Thus we can indeed perceive that this representation is invari-
  ably present in all thought, but not that it is an abiding and
  continuing intuition, wherein the thoughts, as being transitory,
  give place to one another.
  It follows, therefore, that the first syllogism of tran-
  scendental psychology, when it puts forward the constant logi-
  cal subject of thought as being knowledge of the real subject
  in which the thought inheres, is palming off upon us what is
  a mere pretence of new insight. We do not have, and cannot
  have, any knowledge whatsoever of any such subject. Con-
  tions to be thoughts, and in it, therefore, as the transcendental
  subject, all our perceptions must be found; but beyond this
  logical meaning of the "I', we have no knowledge of the sub-
  ject in itself, which as substraum underlies this "I', as it does
  all thoughts. The proposition, " <1The soul is substance',>1 may,
  however, quite well be allowed to stand, if only it be recog-
  nised that this concept [of the soul as substance] does not
  carry us1 a single step further, and so cannot yield us any of the
  A 351  usual deductions of the pseudo-rational doctrine of the soul,
  as, for instance, the everlasting duration of the human soul in
  all changes and even in death---if, that is to say, we recognise
  that this concept signifies a substance only in idea, not in reality.
00022
That, the action of which can never be regarded as the
concurrence of several things acting, is <1simple.>1
  Now the soul, or the thinking "I', is such a being. There-
fore,  etc.
  <1Critique of the Second Paralogism of Transcendental>1
00023
  SECOND PARALOGISM: OF SIMPLICITY
That, the action of which can never be regarded as the
concurrence of several things acting, is <1simple.>1
  Now the soul, or the thinking "I', is such a being. There-
fore,  etc.
  <1Critique of the Second Paralogism of Transcendental>1
  <1Psychology>1
  This is the Achilles of all dialectical inferences in the pure
doctrine of the soul. It is no mere sophistical play, contrived
by a dogmatist in order to impart to his assertions a super-
ficial plausibility, but an inference which appears to with-
stand even the keenest scrutiny and the most scrupulously
exact investigation. It is as follows.
  Every <1composite>1 substance is an aggregate of several sub-
stances, and the action of a composite, or whatever inheres in
it as thus composite, is an aggregate of several actions or acci-
dents, distributed among the plurality of the substances. Now
an effect which arises from the concurrence of many acting  A 352
substances is indeed possible, namely, when this effect is
external only (as, for instance, the motion of a body is the
combined motion of all its parts). But with thoughts, as in-
ternal accidents belonging to a thinking being, it is different.
For suppose it be the composite that thinks: then every part of
it would be a part of the thought, and only all of them taken
together would contain the whole thought. Butthis cannot con-
sistently be maintained. For representations (for instance, the
single words of a verse), distributed among different beings,
never make up a whole thought (a verse), and it is therefore
impossible that a thought should inhere in what is essentially
composite. It is therefore possible only in a <1single>1 substance,
which, not being an aggregate of many, is absolutely simple a
  The so-called <1nervus probandi>1 of this argument lies in the
proposition, that in order to constitute a thought many repre-
sentations must be contained in the absolute unity of the
  a This proof can very easily be given the customary syllogistic
correctness of form. But for my purpose it is sufficient to have made
clear, though in popular fashion, the bare ground of proof.
00024
entertain the thought of an absolute, but logical, unity of the
subject (simplicity). It does not, however, follow that I thereby
know the actual simplicity of my subject. The proposition, "I
am substance', signifies, as we have found, nothing but the
pure category, of which I can make no use (empirically) <1in>1
<1concreto;>1 and I may therefore legitimately say: "I am a simple
substance', that is, a substance the representation of which never
contains a synthesis of the manifold. But this concept, as also
the proposition, tells us nothing whatsoever in regard to my-
self as an object of experience, since the concept of substance
is itself used only as a function of synthesis, without any under-
lying intuition, and therefore without an object. It concerns
only the condition of our knowledge; it does not apply to any
assignable object. We will test the supposed usefulness of the
proposition by an experiment.
  Everyone must admit that the assertion of the simple nature
  of the soul is of value only in so far as I can thereby dis-
  tinguish this subject from all matter, and so can exempt it
  from the dissolution to which matter is always liable. This is
  indeed, strictly speaking, the only use for which the above
  proposition is intended, and is therefore generally expressed
  A 357 as "The soul is not corporeal'. If, then, I can show that,
  although we allow full objective validity---the validity ap-
  propriate to a judgment of pure reason derived solely from
  pure categories---to this cardinal proposition of the rational
  doctrine of the soul (that is, that everything which thinks is a
  simple substance), we still cannot make the least use of this
  proposition in regard to the question of its dissimilarity from
  or relation to matter, this will be the same as if I had relegated
  this supposed psychological insight to the field of mere ideas,
  without any real objective use.
  In the Transcendental Aesthetic we have proved, beyond
  all question, that bodies are mere appearances of our outer
  sense and not things in themselves. We are therefore justified
  in saying that our thinking subject is not corporeal; in other
  words, that, inasmuch as it is represented by us as object of
  inner sense, it cannot, in so far as it thinks, be an object of
  outer sense, that is, an appearance in space. This is equivalent
  to saying that thinking beings, <1as such,>1 can never be found by
  us among outer appearances, and that their thoughts, con-
00025
sciousness desires etc. cannot be outwardlyintuited. All these
belong to inner sense. This argument does, in fact, seem to
be so natural and so popular that even the commonest under-
standing appears to have always relied upon it, and thus al-  A 358
ready, from the earliest times, to have regarded souls as quite
different entities from their bodies.
  But although extension, impenetrability, cohesion, and
motion---in short, everything which outer senses can give us
---neither are1 nor contain thoughts, feeling, desire, or resolu-
tion, these never being objects of outer intuition, nevertheless
the something which underlies the outer appearances and
which so affects our sense that it obtains the representations
of space, matter, shape, etc., may yet, when viewed as nou-
menon (or better, as transcendental object), be at the same
time the subject of our thoughts. That the mode in which
our outer sense is thereby affected gives us no intuition of re-
presentations, will, etc., but only of space and its determina-
tions, proves nothing to the contrary. For this something is
not extended, nor is it impenetrable or composite, since all
these predicates concern only sensibility and its intuition, in
so far as we are affected by certain (to us otherwise unknown)
objects. By such statements we are not, however, enabled
to know what kind of an object it is, but only to recognise
that if it be considered in itself, and therefore apart from any
relation to the outer senses, these predicates of outer appear-  A 359
ances cannot be assigned to it. On the other hand, the predi-
cates of inner sense, representations and thought, are not
inconsistent with its nature. Accordingly, even granting the
human soul to be simple in nature, such simplicity by no
means suffices to distinguish it from matter, in respect of
the substratum of the latter---if, that is to say, we consider
matter, as indeed we ought to, as mere appearance.
  If matter were a thing in itself, it would, as a composite
being, be entirely different from the soul, as a simple being. But
matter is mere outer appearance, the substratum of which can-
not be known through any predicate that we can assign to it.
I can therefore very well admit the possibility that it is in itself
simple, although owing to the manner in which it affects our
senses it produces in us the intuition of the extended and so of
00026
the composite. I may further assume that the substance which
in relation to our outer sense possesses extension is in itself the
possessor of thoughts, and that these thoughts can by means of
its own inner sense be consciously represented. In this way,
what in one relation is entitled corporeal would in another
relation be at the same time a thinking being, whose thoughts
we cannot intuit, though we can indeed intuit their signs in
the [field of] appearance. Accordingly, the thesis that only
souls (as particular kinds of substances) think, would have
to be given up; and we should have to fall back on the
A 360 common expression that men think, that is, that the very
  same being which, as outer appearance, is extended, is (in
  itself) internally a subject, and is not composite, but is simple
  and thinks.
  But, without committing ourselves in regard to such hypo-
  theses, we can make this general remark. If I understand by
  soul a thinking being in itself, the question whether or not it is
  the same in kind as matter---matter not being a thing in itself,
  but merely a species of representations in us---is by its very
  terms illegitimate. For it is obvious that a thing in itself is of a
  different nature from the determinations which constitute only
  its state.
  If, on the other hand, we compare the thinking "I' not with
  matter but with the intelligible that lies at the basis of the
  outer appearance which we call matter, we have no knowledge
  whatsoever of the intelligible, and therefore are in no position
  to say that the soul is in any inward respect different from it.
  The simple consciousness is not, therefore, knowledge of
  the simple nature of the self as subject, such as might enable us
  to distinguish it from matter, as from a composite being.
  If, therefore, in the only case in which this concept can be
  of service, namely, in the comparison of myself with objects of
  outer experience, it does not suffice for determining what is
  A 361  we may still profess to know that the thinking "I', the soul (a
  name for the transcendental object of inner sense), is simple,
  such a way of speaaing has no sort of application to real ob-
  jects, and therefore cannot in the least extend our knowledge.
00027
Thus the whole of rational psychology is involved in the
collapse of its main support. Here as little as elsewhere can we
hope to extend our knowledge through mere concepts---still
less by means of the merely subjective form of all our concepts,
consciousness---in the absence of any relation to possible ex-
perience. For [as we have thus found], even the fundamental
concept of a <1simple nature>1 is such that it can never be met
with in any experience, and such, therefore, that there is no
way of attaining to it, as an objectively valid concept.
  THIRD PARALOGISM: OF PERSONALITY
  That which is conscious of the numerical identity of itself
at different times is in so far a <1person>1
  Now the soul is conscious, etc.
  Therefore it is a person.
  <1Critique of the Third Paralogism of Transcendental>1
  <1Psychology>1
  If I want to know through experience, the numerical iden-
tity of an external object, I shall pay heed to that permanent  A 362
element in the appearance to which as subject everything else
is related as determination, and note its identity throughoutthe
time in which the determinations change. Now I am an object
of inner sense, and all time is merely the form of inner sense.
Consequently, I refer each and all of my successive determina-
tions to the numerically identical self, and do so throughout
time, that is, in the form of the inner intuition of myself. This
being so, the personality of the soul has to be regarded not as
inferred but as a completely identical proposition of self-con-
sciousness intime; and this, indeed, is why1 it is valid <1a priori.>1
For it really says nothing more than that in the whole time in
which I am conscious of myself, I am conscious of this time as
belonging to the unity of myself; and it comes to the same
whether I say that this whole time is in me, as individual unity,
or that I am to be found as numericallyidentical in all this time.
  In my own consciousness, therefore, identity of person is
unfailingly met with. But if I view myself from the standpoint
of another person (as object of his outer intuition), it is this
00028
outer observer who first represents <1me in time,>1 for in the apper-
ception <1time>1 is represented, strictly speaking, only <1in me.>1 Al-
though he admits, therefore, the "I', which accompanies, and
A 363  indeed with complete identity, all representations at all times
  in <1my>1 consciousness, he will draw no inference from this to the
  objective permanence of myself. For just as the time in which
  the observer sets me is not the time of my own but of his sensi-
  bility, so the identity which is necessarily bound up with my
  consciousness is not therefore bound up with his, that is, with
  the consciousness which contains the outer intuition of my
  subject.
  The identity of the consciousness of myself at different
  times is therefore only a formal condition of my thoughts and
  their coherence, and in no way proves the numerical identity of
  my subject. Despite the logical identity of the "I', such a change
  may have occurred in it as does not allow of the retention of
  its identity, and yet we may ascribe to if the same-sounding
  "I', which in every different state, even in one involving change
:  of the [thinking] subject, might still retain the thought of the
  preceding subject and so hand it over to the subsequent
  subject a
  A 364  Although the dictum of certain ancient schools, that every-
  thing in the world is <1in aflux>1 and nothing is <1permanent>1 and
  abiding, cannot be reconciled with the admission of sub-
  stances, it is not refuted by the unity of self-consciousness.
  a An elastic ball which impinges on another similar ball in a
  straight line communicates to the latter its whole motion, and there-
  fore its whole state (that is, if we take account only of the positions
  in space). If, then, in analogy with such bodies, we postulate sub-
  stances such that the one communicates to the other representations
  A 364  together with the consciousness of them, we can conceive a whole
  series of substances of which the first transmits its state together
  with its consciousness to the second, the second its own state with
  that of the preceding substance to the third, and this in turn the
  states of all the preceding substances together with its own conscious-
  ness and with their consciousness to another. The last substance
  would then be conscious of all the states of the previously changed
  substances, as being its own states, because they would have been
  transferred to it together with the consciousness of them. And yet it
  would not have been one and the same person in all these states.
00029
For we are unable from our own consciousness to determine
whether, as souls, we are permanent or not. Since we reckon
as belonging to our identical self only that of which we are
conscious, we must necessarily judge that we are one and the
same throughout the whole time of which we are conscious.
We cannot, however, claim that this judgment would be valid
from the standpoint of an outside observer. For since the only
permanent appearance which we encounter in the soul is the
representation "I' that accompanies and connects them all, we
are unable to prove that this "I', a mere thought, may not be
in the same state of flux as the other thoughts which, by
means of it, are linked up with one another.
  It is indeed strange that personality, and its presupposi- A 365
tion, permanence, and therefore the substantiality of the soul,
should have to be proved <1at this stage and not earlier.>1 For
could we have presupposed these latter [permanence and sub-
stantiality], there would follow, not indeed the continuance of
consciousness, yet at least the possibility of a continuing con-
sciousness in an abiding subject, and that is already sufficient
for personality. For personality does not itself at once cease
because its activity is for a time interrupted. This permanence,
however, is in no way given prior to that numerical identity
of our self which we infer from identical apperception, but
on the contrary is inferred first from the numerical identity.
(If the argument proceeded aright, the concept of substance,
which is applicable only empirically, would first be brought
in after such proof of numerical identity.) Now, since this
identity of person [presupposing, as it does, numerical iden-
tity] in nowise follows from the identity of the "I' in the con-
sciousness of all the time in which I know myself, we could
not, earlier in the argument, have founded upon it the sub-
stantiality of the soul.
  Meanwhile we may still retain the concept of personality
just as we have retained the concept of substance and of the
simple---in so far as it is merely transcendental, that is, con-
cerns the unity of the subject, otherwise unknown to us,
in the determinations of which there is a thoroughgoing
connection through apperception. Taken in this way, the con-
cept is necessary for practical employment and is sufficient for
00030
A 366  such use; but we can never parade it as an extension of our
  self-knowledge through pure reason, and as exhibiting to us
  from the mere concept of the identical self an unbroken con-
  tinuance of the subject. For this concept revolves perpetually
  in a circle, and does not help us in respect to any question
  which aims at synthetic knowledge. What matter may be as a
  thing in itself (transcendental object) is completely unknown
  to us, though, owing to its being represented as something ex-
  ternal, its permanence as appearance can indeed be observed.
  But if I want to observe the mere "I' in the change of all repre-
  sentations, I have no other <1correlatiim>1 to use in my comparisons
  except again myself, with the universal conditions of my con-
  sciousness. Consequently, I can give none but tautological
  answers to all questions, in that I substitute my concept and
  its unity for the properties which belong to myself as object,
  and so take for granted that which the questioner has desired
  to know.
  THE FOURTH PARALOGISM: OF IDEALITY
  (IN REGARD TO OUTER RELATION)
  That, the existence of which can only be inferred as a cause
  of given perceptions, has a merely doubtful existence.
  A 367  Now all outer appearances are of such a nature that their
  existence is not immediately perceived, and that we can only
  infer them as the cause of given perceptions.
  Therefore the existence of all objects of the outer senses is
  doubtful. This uncertainty I entitle the ideality of outer appear-
  ances, and the doctrine of this ideality is called <1idealisin,>1 as
  distinguished from the counter-assertion of a possible certainty
  in regard to objects of outer sense, which is called <1dualism.>1
  <1Critique of the Fourth Paralogi-sm of Transcendental>1
  -  <1Psychology>1
  Let us first examine the premisses. We are justified, [it is
  argued], in maintaining that only what is in ourselves can be
  perceived immediately, and that my own existence is the sole
  object of a mere perception. The existence, therefore, of an
  actual object outside me (if this word "me' be taken in the
00031
intellectual [not in the empirical] sense) is never given directly
in perception. Perception is a modification of inner sense, and
the existence of the outer object can be added to it only in
thought, as being its outer cause, and accordingly as being
inferred. For the same reason, Descartes was justified in
limiting all perception, in the narrowest sense of that term,to
the proposition, "I, as a thinking being, exist.' Obviously, since  A 368
what is without is not in me, I cannot encounter it in my
apperception, nor therefore in any perception, which, properly
regarded, is merely the determination of apperception.
  I am not, therefore, in a position to <1perceive>1 external things,
but can only infer their existence from my inner perception,
taking the inner perception as the effect of which something
external is the proximate cause. Now the inference from a
given effect to a determinate cause is always uncertain, since
the effect may be due to more than one cause. Accordingly, as
regards the relation of the perception to its cause, it always
remains doubtful whether the cause be internal or external;
whether, that is to say, all the so-called outer perceptions are
not a mere play of our inner sense, or whether they stand in
relation to actual external objects as their cause. At all events,
the existence of the latter is only inferred, and is open to all
the dangers of inference, whereas the object of inner sense (I
myself with all my representations) is immediately perceived,
and its existence does not allow of being doubted.
  The term <1"idealist'>1 is not, therefore, to be understood as
applying to those who deny the existence of external objects
of the senses, but only to those who do not admit that their
existence is known through immediate perception, and who
therefore conclude that we can never, by way of any possible  A 369
experience, be completely certain as to their reality.
  Before exhibiting our paralogism in all its deceptive
illusoriness, I have first to remark that we must necessarily
distinguish two types of idealism, the transcendental and the
empirical. By <1transcendental idealism>1 I mean the doctrine
that appearances are to be regarded as being, one and all,
representations only, not things in themselves, and that time
and space are therefore only sensible forms of our intuition,
not determinations given as existing by themselves, nor con-
ditions of objects viewed as things in themselves. To this ideal-
00032
ism there is opposed a <1transcendental realism>1 which regards
time and space as something given in themselves, independ-
ently of our sensibility. The transcendental realist thus inter-
prets outer appearances (their reality being taken as granted)
as things-in-themselves, which exist independently of us and of
our sensibility, and which are therefore outside us---the phrase
"outside us' being interpreted in conformity with pure con-
cepts of understanding. It is, in fact, this transcendental realist
who afterwards plays the part of empirical idealist. After
wrongly supposing that objects of the senses, if they are to be
external, must have an existence by themselves, and inde-
pendently of the senses, he finds that, judged from this point
of view, all our sensuous representations are inadequate to
establish their reality.
A 370  The transcendental idealist, on the other hand, may be an
  empirical realist or, as he is called, a <1dualist;>1 that is, he may
  admit the existence of matter without going outside his mere
  self-consciousness, or assuming anything more than the cer-
  tainty of his representations, that is, the <1cogito, ergo sum.>1 For
  he considers this matter and even its inner possibility to be
  appearance merely; and appearance, if separated from our
  sensibility, is nothing. Matter is with him, therefore, only a
  species of representations (intuition), which are called external,
  not as standing in relation to objects <1in themselves external,>1
  but because they relate perceptions to the space in which all
  things are external to one another, while yet the space itself is
  1n us.
  From the start, we have declared ourselves in favour of
  this transcendental idealism; and our doctrine thus removes
  all difficulty in the way of accepting the existence of matter
  on the unaided testimony of our mere self-consciousness, or of
  declaring it to be thereby proved in the same manner as the
  existence of myself as a thinking being is proved. There can
  be no question that I am conscious of my representations;
  these representations and I myself, who have the representa-
  tions, therefore exist. External objects (bodies), however, are
  mere appearances, and are therefore nothing but a species of
  my representations, the objects of which are something only
  through these representations. Apart from them they are
A 371  nothing. Thus external things exist as well as I myself, and
00033
both  indeed, upon the immediate witness of my self-conscious-
ness. The only difference is that the representation of myself,
as the thinking subject, belongs to inner sense only, while
the representations which mark extended beings belong also
to outer sense. In order to arrive at the reality of outer objects
I have just as little need to resort to inference as I have in re-
gard to the reality of the object of my inner sense, that is, in
regard to the reality of my thoughts. For in both cases alike the
objects are nothing but representations, the immediate per-
ception (consciousness) of which is at the same time a suffi-
cient proof of their reality.
  The transcendental idealist is, therefore, an empirical real-
ist, and allows to matter, as appearance, a reality which does
not permit of being inferred, but is immediately perceived.
Transcendental realism, on the other hand, inevitably falls
into difficulties, and finds itself obliged to give way to em-
pirical idealism, in that it regards the objects of outer sense as
something distinct from the senses themselves, treating mere
appearances as self-subsistent beings, existing outside us. On
such a view as this, however clearly we may be conscious of
our representation of these things, it is still far from certain
that, if the representation exists, there exists also the object
corresponding to it. In our system, on the other hand, these
external things, namely matter, are in all their configurations
and alterations nothing but mere appearances, that is, repre-  A 372
sentations in us, of the reality of which we are immediately
conscious.
  Since, so far as I know, all psychologists who adopt em-
pirical idealism are transcendental realists, they have cer-
tainly proceeded quite consistently in ascribing great import-
ance to empirical idealism, as one of the problems in regard to
which the human mind is quite at a loss how to proceed. For
if we regard outer appearances as representations produced in
us by their objects, and if these objects be things existing in
themselves outside us, it is indeed impossible to see how we can
come to know the existence of the objects otherwise than by in-
ference from the effect to the cause; and this being so, it must
always remain doubtful whether the cause in question be in
us or outside us. We can indeed admit that something, which
00034
may be (in the transcendental sense) outside us, is the cause of
our outer intuitions, but this is not the object of which we are
thinking in the representations of matter and of corporeal
things; for these are merely appearances, that is, mere kinds of
representation, which are never to be met with save in us, and
the reality of which depends on immediate consciousness, just
as does the consciousness of my own thoughts. The transcend-
ental object is equally unknown in respect to inner and to
A 373  outer intuition. But it is not of this that we are here speaking,
  but of the empirical object, which is called an <1external>1 object
  if it is represented <1in space,>1 and an <1inner>1 object if it is repre-
  sented only <1in its time-relations.>1 Neither space nor time, how-
  ever, is to be found save <1in us.>1
  The expression <1"outside us'>1 is thus unavoidably ambiguous
  in meaning, sometimes signifying what <1as thing in itself>1 exists
  apart from us, and sometimes what belongs solely to outer
  <1appearance.>1 In order, therefore, to make this concept, in the
  latter sense---the sense in which the psychological question as
  to the reality of our outer intuition has to be understood---
  quite unambiguous, we shall distinguish <1empirically external>1
  objects from those which may be said to be external in the
  transcendental sense, by explicitly entitling the former <1"things>1
  <1which are to befound in space'.>1
  Space and time are indeed <1a priori>1 representations, which
  dwell in us as forms of our sensible intuition, before any real
  object, determining our sense through sensation, has enabled
  us to represent the object under those sensible relations. But
  the material or real element, the something which is to be
  intuited in space, necessarily presupposes perception. Per-
  ception exhibits the reality of something in space; and in the
  absence of perception no power of imagination can invent and
A 374  produce that something. It is sensation, therefore, that indicates
  a realityin space or in time, according as it is related to the one
  or to the other mode of sensible intuition. (Once sensation is
  given---if referred to an object in general, though not as deter-
  mining that object, it is entitled perception---thanks to its mani-
  foldness we can picture in imagination many objects which have
  no empirical place in space or time outside the imagination.)
00035
This admits of no doubt; whether we take pleasure and pain,
or the sensations of the outer senses, colours, heat, etc., per-
ception is that whereby the material required to enable us to
think objects of sensible intuition must first be given. This
perception, therefore (to consider, for the moment, only outer
intuitions), represents something real in space. For, in the first
place, while space is the representation of a mere possibility
of coexistence, perception is the representation of a reality.
Secondly, this reality is represented in outer sense, that is, in
space. Thirdly, space is itself nothing but mere representation,
and therefore nothing in it can count as real save only what
is represented in it; and conversely, what is given in it, that
is, represented through perception, is also real in it. For if it  A 375
were not real, that is, immediately given through empirical
intuition, it could not be pictured in imagination, since what
is real in intuitions cannot be invented <1a priori.>1
  All outer perception, therefore, yields immediate proof of
something real in space, or rather is the real itself. In this
sense empirical realism is beyond question; that is, there
corresponds to our outer intuitions something real in space.
Space itself, with all its appearances, as representations, is,
indeed, only in me, but nevertheless the real, that is, the
material of all objects of outer intuition, is actually given in this
space, independently of all imaginative invention. Also, it is
impossible that in <1this space>1 anything <1outside us>1 (in the tran-
scendental sense) should be given, space itself being nothing
outside our sensibility. Even the most rigid idealist cannot,
therefore, require a proof that the object outside us (taking
"outside' in the strict [transcendental] sense) corresponds to  A 376
our perception. For if there be any such object, it could not be
  a  We must give full credence to this paradoxical but correct pro-
position, that there is nothing in space save what is represented in it.
For space is itself nothing but representation, and whatever is in it
must therefore be contained in the representation. Nothing whatso-  A 375
ever is in space, save in so far as it is actually represented in it. It is
a proposition which must indeed sound strange, that a thing can exist
only in the representation of it, but in this case the objection falls,
inasmuch as the things with which we are here concemed are not
things in themselves, but appearances only, that is, representations.
00036
represented and intuited as outside us, because such repre-
sentation and intuition presuppose space, and reality in space,
being the reality of a mere representation, is nothing other
than perception itself. The real of outer appearances is there-
fore real in perception only, and can be real in no other way.
  From perceptions knowledge of objects can be generated,
either by mere play of imagination or by way of experience;
and in the process there may, no doubt, arise illusory repre-
sentations to which the objects do not correspond, the decep-
tion being attributable sometimes to a delusion of imagination
(in dreams) and sometimes to an error ofjudgment  in so-called
sense-deception).  To avoid such deceptive illusion, we have
to proceed according to the rule: <1Whatever is connected with a>1
<1perception according to empirical laws, is actual.>1 But such
deception, as well as the provision against it, affects idealism
quite as much as dualism, inasmuch as we are concerned only
with the form of experience. Empirical idealism, and its mis-
taken questionings as to the objective reality of our outer
perceptions, is already sufficiently refuted, when it has been
shown that outer perception yields immediate proof of some-
A 377  thing actual in space, and that this space, although in itself
  only a mere form of representations, has objective reality in
  relation to all outer appearances, which also are nothing else
  than mere representations; and when it has likewise been
  shown that in the absence of perception even imagining and
  dreaming are not possible, and that our outer senses, as regards
  the data from which experience can arise, have therefore their
  actual corresponding objects in space.
  The <1dogmatic idealist>1 would be one who <1denies>1 the exist-
  ence of matter, the <1sceptical idealist>1 one who <1doubts>1 its exist-
  ence, because holding it to be incapable of proof. The former
  must base his view on supposed contradictions in the pos-
  sibility of there being such a thing as matter at all a view
  with which we have not yet been called upon to deal. The
  following section on dialectical inferences, which represents
  reason as in strife with itself in regard to the concepts which
  it makes for itself of the possibility of what belongs to the
00037
connection of experience, will remove this difficulty. The
sceptical idealist, however, who merely challenges the ground
of our assertion and denounces as insufficiently justified our
conviction of the existence of matter, which we thought to
base on immediate perception, is a benefactor of human
reason in so far as he compels us, even in the smallest ad-
vances of ordinary experience, to keep on the watch, lest we  A 378
consider as a well-earned possession what we perhaps obtain
only illegitimately. We are now in a position to appreciate
the value of these idealist objections. Unless we mean to
contradict ourselves in our commonest assertions, they drive
us by main force to view all our perceptions, whether we
call them inner or outer, as a consciousness only of what is
dependent on our sensibility. They also compel us to view the
outer objects of these perceptions not as things in themselves,
but only as representations, of which, as of every other repre-
sentation, we can become immediately conscious, and which
are entitled outer because they depend on what we call "outer
sense', whose intuition is space. Space itself, however, is noth-
ing but an inner mode of representation in which certain
perceptions are connected with one another.
  If we treat outer objects as things in themselves, it is quite
impossible to understand how we could arrive at a knowledge
of their reality outside us, since we have to rely merely on
the representation which is in us. For we cannot be sentient
(of what is] outside ourselves, but only [of what is] in us, and
the whole of our self-consciousness therefore yields nothing
save merely our own determinations. Sceptical idealism thus
constrains us to have recourse to the only refuge still open,
namely, the ideality of all appearances, a doctrine which
has already been established in the Transcendental Aesthetic
independently of these consequences, which we could not at  A 379
that stage fore  ee. If then we ask, whether it follows that in the
doctrine of the soul dualism alone is tenable, we must answer:
"Yes, certainly; but dualism only in the empirical sense'. That
is to say, in the connection of experience matter, as substance
in the [field of] appearance,is really given to outer sense,just as
the thinking "I', also as substance in the [field of] appearance,
is given to inner sense. Further, appearances in both fields1
00038
must be connected with each other according to the rules which
this category introduces into that connection of our outer as
well as of our inner perceptions whereby they constitute one ex-
perience. If, however, as commonly happens, we seek to extend
the concept of dualism, and take it in the transcendental sense,
neither it nor the two counter-alternatives---<1pneumatism>1 on
the one hand, <1materialism>1 on the other---would have any sort
of basis, since we should then have misapplied our concepts,
taking the difference in the mode of representing objects, which,
as regards what they are in themselves, still remain unknown
to us, as a difference in the things themselves. Though the "I',
as represented through inner sense in time, and objects in space
outside me, are specifically quite distinct appearances, they
are not for that reason thought as being different things.
Neither the <1transcendental object>1 which underlies outer ap-
A 380  pearances nor that which underlies inner intuition, is in itself
  either matter or a thinking being, but a ground (to us un-
  known) of the appearances which supply to us the empirical
  concept of the former as well as of the latter mode of exist-
  ence.
  If then, as this critical argument obviously compels us to
  do, we hold fast to the rule above established, and do not push
  our questions beyond the limits within which possible experi-
  ence can present us with its object, we shall never dream of
  seeking to inform ourselves about the objects of our senses as
  they are in themselves, that is, out of all relation to the senses.
  But if the psychologist takes appearances for things in them-
  selves, and as existing in and by themselves, then whether he
  be a materialist who admits into his system nothing but matter
  alone, or a spiritualist who admits only thinking beings (that
  is, beings with the form of our inner sense), or a dualist who
  accepts both, he will always, owing to this misunderstanding,
  be entangled in pseudo-rational speculations as to how that
  which is not a thing in itself, but only the appearance of a
  thing in general, can exist by itself.
  A 381  <1Consideration of Pure Psychology as a whole,>1
  <1in view of these paralogisms>1
  If we compare the <1doctrine of the soul>1 as the physiology of
  inner sense, with the <1doctrine of the body>1 as a physiology of
00039
the object of the outer senses, we find that while in both much
can be learnt empirically, there is yet this notable difference
In the latter science much that is <1a priori>1 can be synthetically
known from the mere concept of an extended impenetrable
being, but in the former nothing whatsoever that is <1a priori>1
can be known synthetically from the concept of a thinking
being. The cause is this. Although both are appearances,
the appearance to outer sense has something fixed or abiding
which supplies a substratum as the basis of its transitory
determinations and therefore a synthetic concept, namely,
that of space and of an appearance in space; whereas time,
which is the sole form of our inner intuition, has nothing
abiding, and therefore yields knowledge only of the change
of determinations, not of any object that can be thereby deter-
mined. For in what we entitle "soul', everything is in con-
tinual flux and there is nothing abiding except (if we must so
express ourselves) the "I', which is simple solely because its
representation has no content, and therefore no manifold, and
for this reason seems to represent, or (to use a more correct A 382
term) denote, a simple object. In order that it should be possible,
by pure reason, to obtain knowledge of the nature of a thinking
being in general, this "I' would have to be an intuition which,
in being presupposed in all thought (prior to all experience),
might as intuition yield <1a priori>1 synthetic propositions. This
"I' is, however, as little an intuition as it is a concept of any
object; it is the mere form of consciousness, which can accom-
pany the two kinds of representation and which is in a position
to elevate them to the rank of knowledge onlyin so far as some-
thing else is given in intuition which provides material for a
representation of an object. Thus the whole of rational psy-
chology, as a science surpassing all powers of human reason,
proves abortive, and nothing is left for us but to study our soul
under the guidance of experience, and to confine ourselves
to those questions which do not go beyond the limits within
which a content can be provided for them by possible inner
experience.
  But although rational psychology cannot be used to extend
knowledge, and when so employed is entirely made up of
value, if it is taken as nothing more than a critical treatment
00040
of our dialectical inferences, those that arise from the common
and natural reason of men.
A383  Why do we have resort to a doctrine of the soul founded
  exclusively on pure principles of reason? Beyond all doubt,
  chiefly in order to secure our thinking self against the danger
  of materialism. This is achieved by means of the pure con-
  cept1 of our thinking self which we have just given. For by
  this teaching so completely are we freed from the fear that on
  the removal of matter all thought, and even the very existence
  of thinking beings, would be destroyed, that on the contrary
  it is clearly shown, that if I remove the thinking subject the
  whole corporeal world must at once vanish: it is nothing save
  an appearance in the sensibility of our subject and a mode
  of its representations
  I admit that this does not give me any further knowledge
  of the properties of this thinking self, nor does it enable me to
  determine its permanence or even that it exists independently
  of what we may conjecture to be the transcendental sub-
  stratum of outer appearances; for the latter is just as un-
  known to me as is the thinking self. But it is nevertheless
  possible that I may find cause, on other than merely specu-
  lative grounds, to hope for an independent and continuing
  existence of my thinking nature, throughout all possible change
  of my state. In that case much will already have been gained
  if, while freely confessing my own ignorance, I am yet in a
  position to repel the dogmatic assaults of a speculative op-
A 384  ponent, and to show him that he can never know more of the
  nature of the self in denying the possibility of my expectations
  than I can know in clinging to them.
  Three other dialectical questions, constituting the real
  goal of rational psychology, are grounded on this transcend-
  ental illusion in our psychological concepts, and cannot be
  decided except by means of the above enquiries: namely (1) of
  the possibility of the communiona of the soul with an organised
  body, <1i.e.>1 concerning animality and the state of the soul in the
  life of man; (2) of the beginning of this communion, that is, of
  the soul in and before birth; (3) of the end of this communion,
  that is, of the soul in and after death (the question of im-
  mortality).
00041
Now I maintain that all the difficulties commonly found in
these questions, and by means of which, as dogmatic objections,
men seek to gain credit for a deeper insight into the nature of
things than any to which the ordinary understanding can
properly lay claim, rest on a mere delusion by which they
hypostatise what exists merely in thought, and take it as a real
object existing, in the same character, outside the thinking sub-
ject. In other words, they regard extension, which is nothing
but appearance, as a property of outer things that subsists  A 385
even apart from our sensibility, and hold that motion is
due to these things and really occurs in and by itself, apart
from our senses. For matter, the communion of which with
the soul arouses so much questioning, is nothing but a mere
form, or a particular way of representing an unknown object
by means of that intuition which is called outer sense. There
may well be something outside us to which this appearance,
which we call matter, corresponds; in its character of appear-
ance it is not, however, outside us, but is only a thought in us,
although this thought, owing to the above-mentioned outer
sense, represents it as existing outside us. Matter, therefore,
does not mean a kind of substance quite distinct and hetero-
geneous from the object of inner sense (the soul), but only the
distinctive nature of those appearances of objects---in them-
selves unknown to us---the representations of which we call
outer as compared with those which we count as belonging to
inner sense, although like all other thoughts these outer repre-
sentations belong only to the thinking subject. They have,
indeed, this deceptive property that, representing objects in
space, they detach themselves as it were from the soul and
appear to hover outside it. Yet the very space in which they
are intuited is nothing but a representation, and no counter-
part of the same quality is to be found outside the soul. Con-
sequently, the question is no longer of the communion of the  A 386
soul with other known substances of a different kind outside us,
but only of the connection of the representations of inner sense
with the modifications of our outer sensibility---as to howthese
can be so connected with each other according to settled laws
that they exhibit the unity of a coherent experience.
  As long as we take inner and outer appearances together
as mere representations in experience, we find nothing absurd
00042
and strange in the association of the two kinds of senses. But
as soon as we hypostatise outer appearances and come to re-
gard them not as representations but <1as things existing by them->1
<1selves outside us, with the same quality as that with which they>1
<1exist in us,>1 and as bringing to bear on our thinking subject the
activities which they exhibit as appearances in relation to each
other, then the efficient causes outside us assume a character
which is irreconcilable with their effects in us. Forthe cause re-
lates only to outer sense, the effect to inner sensesenses which,
although combined in one subject, are extremely unlike each
other. In outer sense we find no other outer effects save changes
of place, and no forces except mere tendencies which issue in
spatial relations as their effects. Within us, on the other hand,
A387  the effects are thoughts, among which is not to be found any
  relation of place, motion, shape, or other spatial determina-
  tion, and we altogether lose the thread of the causes in the
  effects to which they are supposed to have given rise in inner
  sense. We ought, however, to bear in mind that bodies are
  not objects in themselves which are present to us, but a mere
  appearance of we know not what unknown object; that motion
  is not the effect of this unknown cause, but only the appearance
  of its influence on our senses  Neither bodies nor motions are
  anything outside us; both alike are mere representations in us;
  and it is not, therefore, the motion of matter that produces re-
  presentations in us; the motion itself is representation only, as
  also is the matter which makes itself known in this way. Thus
  in the end the whole difficulty which we have made for our-
  selves comes to this, how and why the representations of our
  sensibility are so interconnected that those which we entitle
  outer intuitions can be represented according to empirical
  laws as objects outside us---a question which is not in any
  way bound up with the supposed difficulty of explaining
  the origin of our representations from quite heterogeneous
  efficient causes outside us. That difficulty has arisen from
  our taking the appearances of an unknown cause as being
  the cause itself outside us, a view which can result in no-
  thing but confusion. In the case of judgments in which a
  misapprehension has taken deep root through long custom,
A 388  it is impossible at once to give to their correction that clarity
00043
which can be achieved in other cases where no such inevitable
illusion confuses the concept. Our freeing of reason from
sophistical theories can hardly, therefore, at this stage have
the clearness which is necessary for its complete success.
  The following comments will, I think, be helpful as contri-
buting towards this ultimate clarity.
  All <1objections>1 can be divided into <1dogmatic, critical,>1 and
<1sceptical.>1 A dogmatic objection is directed against a <1proposi->1
<1ti-on,>1 a critical objection against the <1proof>1 of a proposition.
The former requires an insight into the nature of the object
such that we can maintain the opposite of what the proposi-
tion has alleged in regard to this object. It is therefore itself
dogmatic, claiming acquaintance with the constitution of the
object fuller than that of the counter-assertion. A critical objec-
tion, since it leaves the validity or invalidity of the proposition
unchallenged, and assails only the proof, does not presuppose
fuller acquaintance with the object or oblige us to claim
superior knowledge of its nature; it shows only that the asser-
tion is unsupported, not that it is wrong. A sceptical objec-
tion sets assertion and counter-assertion in mutual opposition
to each other as having equal weight, treating each in turn as
dogma and the other as the objection thereto. And the con-
flict, as the being thus seemingly dogmatic on both the oppos-  A 389
ing sides, is taken as showing that all judgment in regard
to the object is completely null and void. Thus dogmatic
and sceptical objections alike lay claim to such insight into
their object as is required to assert or to deny something in
regard to it. A critical objection, on the other hand, confines
itself to pointing out that in the making of the assertion some-
thing has been presupposed that is void and merely fictitious;
and it thus overthrows the theory by removing its alleged
foundation without claiming to establish anything that
bears directly upon the constitution of the object.
  So long as we hold to the ordinary concepts of our
reason with regard to the communion in which our thinking
subject stands with the things outside us, we are dogmatic,
looking upon them as real objects existing independently of
us, in accordance with a certain transcendental dualism which
does not assign these outer appearances to the subject as
representations, but sets them, just as they are given us in
00044
sensible intuition, as objects outside us, completely separ-
ating them from the thinking subject. This subreption is
the basis of all theories in regard to the communion between
soul and body. The objective reality thus assigned to ap-
pearances is never brought into question. On the contrary,
it is taken for granted; the theorising is merely as to the
mode in which it has to be explained and understood. There
A 390 are three usual systems devised on these lines, and they are
  indeed the only possible systems: that of <1physical influence,>1
  that of predetermined <1harmony,>1 and that of <1supernatural>1
  <1intervention.>1
  The two last methods of explaining the communion be-
  tween the soul and matter are based on objections to the first
  view, which is that of common sense. It is argued, namely, that
  what appears as matter cannot by its immediate influence be
  the cause of representations, these being effects which are
  quite different in kind from matter. Now those who take this
  line cannot attach to what they understand by "object of outer
  senses' the concept of a matter which is nothing but ap-
  pearance, and so itself a mere representation produced by
  some sort of outer objects. For in that case they would be say-
  ing that the representations of outer objects (appearances) can-
  not be outer causes of the representations in our mind; and
  this would be a quite meaningless objection, since no one could
  dream of holding that what he has once come to recognise as
  mere representation, is an outer cause. On our principles they
  can establish their theory only by showing that that which is
  the true (transcendental) object of our outer senses cannot be
  the cause of those representations (appearances) which we
A 391  comprehend under the title "matter'. No one, however, can
  have the right to claim that he knows anything in regard to the
  transcendental cause of our representations of the outer senses;
  and their assertion is therefore entirely groundless. If, on the
  other hand, those who profess to improve upon the doctrine of
  physical influence keep to the ordinary outlook of transcend-
  ental dualism, and suppose matter, as such, to be a thing-in-
  itself (not the mere appearance of an unknown thing), they will
  direct their objection to showing that such an outer object,
  which in itself exhibits no causality save that of movements,
  can never be the efficient cause of representations, but that a
00045
third entity must intervene to establish, if not reciprocal inter-
action, at least correspondence and harmony between the two.
But in arguing in this way, they begin their refutation by ad-
mitting into their dualism the  of [a doctrine of]
physical influence, and consequently their objection is not so
much a disproof of natural influence as of their own dualistic
presupposition. For the difficulties in regard to the connection
of our thinking nature with matter have their origin, one and
all, in the illicitly assumed dualistic view, that matter as such
is not appearance, that is, a mere representation of the mind
to which an unknown object corresponds, but is the object in
itself as it exists outside us independently of all sensibility.
  As against the commonly accepted doctrine of physical in-  A 392
fluence, an objection of the dogmatic type is not, therefore,
practicable. For if the opponent of the doctrine accepts the
view that matter and its motion are mere appearances and so
themselves mere representations, his difficulty is then simply
this, that it is impossible that the unknown object of our sensi-
bility should be the cause of the representations in us. He can-
not, however, have the least justification for any such conten-
tion, since no one is in a position to decide what an unknown
object may or may not be able to do. And this transcendental
idealism, as we have just proved, he cannot but concede. His
only way of escape would be frankly to hypostatise representa-
tions, and to set them outside himself as real things .
  The doctrine of physical influence, in its ordinary form,
is, however, subject to a well-founded <1critical>1 objection. The
alleged communion between two kinds of substances, the
thinking and the extended, rests on a crude dualism, and
treats the extended substances, which are really nothing
but mere representations of the thinking subject, as existing
by themselves. This mistaken interpretation of physical in-
fluence can thus be effectively disposed of: we have shown
that the proof of it is void and illicit.
  The much-discussed question of the communion between
the thinking and the extended, if we leave aside allthatis merely  A 393
fictitious, comes then simply to this:  <1how in a thinking sub->1
<1ject outer intuition,>1 namely, that of space, with its filling-in of
figure and motion, <1ispossible.>1 And this is a question which no
human being can possibly answer. This gap in our knowledge
00046
can never be filled; all that can be done is to indicate it through
the ascription of outer appearances to that transcendental ob-
ject which is the cause of this species of representations, but of
which we can have no knowledge whatsoever and of which we
shall never acquire any concept. In all problems which may
arise in the field of experience we treat these appearances as
objects in themselves, without troubling ourselves about the
primary ground of their possibility (as appearances). But to
advance beyond these limits the concept of a transcendental
object would be indispensably required.
  The settlement of all disputes or objections which concern
the state of the thinking nature prior to this conmunion (prior
to life), or after the cessation of such communion (in death),
rests upon these considerations regarding the communion
between thinking beings and extended beings. The opinion
that the thinking subject has been capable of thought prior to
any communion with bodies would now appear as an assertion
that, prior to the beginning of the species of sensibility in
A 394  virtue of which something appears to us in space, those tran-
  scendental objects, which in our present state appear as bodies,
  could have been intuited in an entirely different manner. The
  opinion that the soul after the cessation of all communion with
  the corporeal world could still continue to think, would be
  formulated as the view that, if that species of sensibility, in
  virtue of which transcendental objects, at present quite un-
  known to us, appear as a material world, should cease, all in-
  tuition of the transcendental objects would not for that reason
  be removed, and itwould still be quite possible that those same
  unknown objects should continue to be known by the thinking
  subject, though no longer, indeed, in the quality of bodies
  Now on speculative principles no one can give the least
  ground for any such assertion. Even the possibility of what is
  asserted cannot be established; it can only be assumed. But it
  is equally impossible for anyone to bring any valid dogmatic
  objection against it. For whoever he may be, he knows just as
  little of the absolute, inner cause of outer corporeal appear-
  ances as I or anybody else. Since he cannot, therefore, offer
  any justification for claiming to know on what the outer ap-
  pearances in our present state (that of life) really rest,
  neither can he know that the condition of all outer intui-
00047
tion or the thinking  ubject itself, will cease with this state A 395
(in death).
  Thus all controversy in regard to the nature of the thinking
being and its connection withthe corporeal world is merely a re-
sult of filling the gap where knowledge is wholly lacking to us
with paralogisms of reason, treating our thoughts as things and
hypostatising them. Hence originates an imaginary science,
imaginary both in the case of him who affirms and of him
who denies, since all parties either suppose some knowledge
of objects of which no human being has any concept, or treat
their own representations as objects, and so revolve in a per-
petual circle of ambiguities and contradictions. Nothing but
the sobriety of a critique, atonce strict and just, can free us from
this dogmatic delusion, which through the lure of an imagined
felicity keeps so many in bondage to theories and systems.
Such a critique confines all our speculative claims rigidly to
the field of possible experience; and it does this not by shallow
scoffing at ever-repeated failures or pious sighs over the limits
of our reason, but by an effective determining of these limits
in accordance with established principles, inscribing its <1nihil>1
<1ulterius>1 on those Pillars of Hercules which nature herself has
erected in order that the voyage of our reason may be ex-
tended no further than the continuous coastline of experience  A 396
itself reaches---a coast we cannot leave without venturing
upon a shoreless ocean which, after alluring us with ever-
deceptive prospects, compels us in the end to abandon as
hopeless all this vexatious and tedious endeavour.
  *  *  *
  We still owe the reader a clear general exposition of the
transcendental and yet natural illusion in the paralogisms of
pure reason, and also a justification of the systematic ordering
of them which runs parallel with the table of the categories.
We could not have attempted to do so at the beginning of this
section without running the risk of becoming obscure or of
clumsily anticipating the course of our argument. We shall
now try to fulfil this obligation.
  All <1illusion>1 may be said to consist in treating the <1subjective>1
condition of thinking as being knowledge of the <1object.>1 Further
in the Introduction to the Transcendental Dialectic we have
00048
shown that pure reason concerns itself solely with the totality
of the synthesis of the conditions, for a given conditioned. Now
since the dialectical illusion of pure reason cannot be an em-
pirical illusion, such as occurs in certain specific instances of
empirical knowledge, it will relate to what is universal in the
conditions of thinking, and there will therefore be only three
A 397  cases of the dialectical employment of pure reason.
  1.  The synthesis of the conditions of a thought in general.
  2. The synthesis of the conditions of empirical thinking.
  3. The synthesis of the conditions of pure thinking.
  In all these three cases pure reason occupies itself only
  with the absolute totality of this synthesis, that is, with that
  condition which is itself unconditioned. On this division is
  founded the threefold transcendental illusion which gives
  occasion for the three main sections of the Dialectic, and for
  the three pretended sciences of pure reason---transcendental
  psychology, cosmology, and theology. Here we are concerned
  only with the first.
  Since, in thinking in general, we abstract from all relation
  of the thought to any object (whether of the senses or of the
  pure understanding), the synthesis of the conditions of a
  thought in general (No. I) is not objective at all, but merely a
  synthesis of the thought with the subject, which is mistaken
  for a synthetic representation of an object.
  It follows from this that the dialectical inference to the
  condition of all thought in general, which is itself uncon-
  ditioned, does not commit a material error (for it abstracts
A 398  from all content or objects), but is defective in form alone, and
  must therefore be called a paralogism.
  Further, since the one condition which accompanies all
  thought is the "I' in the universal proposition "I think',
  reason has to deal with this condition in so far as it is itself
  unconditioned. It is only the formal condition, namely, the
  logical unity of every thought, in which I abstract from all
  objects; but nevertheless it is represented as an object which I
  think, namely, I myself and its unconditioned unity.
  If anyone propounds to me the question, "What is the con-
00049
stitution1 of a thing which thinks?', I have no <1apriori>1 know-
ledge wherewith to reply. For the answer has to be synthetic---
an analytic answer will perhaps explain what is meant by
thought, but beyond this cannot yield any knowledge of that
upon which this thought depends for its possibility. For a
synthetic solution, however, intuition is always required; and
owing to the highly general character of the problem, intuition
has been left entirely outof account.  Similarly no one can answer
in all its generality the question, "What must a thing be, to be
movable?' For the question contains no trace of the answer,
viz. impenetrable extension (matter). But although I have no
general answer to the former question, it still seems as if I
could reply in the special case of the proposition which ex-
presses self-consciousness---"I think'. For this "I' is the primary  A 399
subject, that is, substance; it is simple, etc. But these would
then have to be propositions derived from experience, and in
the absence of a universal rule which expresses the conditions
of the possibility of thought in general and <1a priori,>1 they could
not contain any such non-empirical predicates. Suspicion is
thus thrown on the view, which at first seemed to me so
plausible, that we can form judgments about the nature of a
thinking being, and can do so from concepts alone. But the
error in this way of thinking has not yet been detected.
  Further investigation into the origin of the attributes which
I ascribe to myself as a thinking being in general can, however,
show in what the error consists. These attributes are nothing
but pure categories, by which I do not think a determinate ob-
ject but only the unity of the representations---in order to deter-
mine an object for them. In the absence of an underlying intui-
tion the category cannot byitself yield a concept of an object; for
by intuition alone is the object given, which thereupon is thought
in accordance with the category. If I am to declare a thing to
be a substance in the [field of] appearance, predicates of its in-
tuition must first be given me, and I must be able to distinguish
in these the permanent from the transitory and the substratum
(the thing itself) from what is merely inherent in it. If I call a  A 400
thing in the [field of] appearance <1simple,>1 I mean by this that
the intuition of it, although a part of the appearance, is not
00050
itself capable of being divided into parts, etc. But if I know
something as simple in concept only and not in the [field of]
appearance, I have really no knowledge whatsoever of the
object, but only of the concept which I make for myself of a
something in general that does not allow of being intuited. I
say that I think something as completely simple, only because
I have really nothing more to say of it than merely that it is
something.
  Now the bare apperception, "I', is in concept substance, in
concept simple, etc.; and in this sense all those psychological
doctrines are unquestionably true. Yet this does not give us
that knowledge of the soul for which we are seeking. For since
none of these predicates are valid of intuition, they cannot
have any consequences which are applicable to objects of
experience, and are therefore entirely void. The concept of
substance does not teach me that the soul endures by itself,
nor that it is a part of outer intuitions which cannot itself be
divided into parts, and cannot therefore arise or perish by any
natural alterations. These are properties which would make
the soul known to me in the context of experience and might
A 401  reveal something concerning its origin and future state. But
  if I say, in terms of the1 mere category, "The soul is a simple
  substance', it is obvious that since the bare concept of sub-
  stance (supplied by the understanding) contains nothing be-
  yond the requirement that a thing be represented as being
  subject in itself, and not in turn predicate of anything else,
  nothing follows from this as regards the permanence of the
  "I', and the attribute "simple' certainly does not aid in adding
  this permanence. Thus, from this source, we learn nothing
  whatsoever as to what may happen to the soul in the changes
  of the natural world. If we could be assured that the soul is a
  <1simple part of matter,>1 we could use this knowledge, with the
  further assistance of what experience teaches in this regard, to
  deduce the permanence, and, as involved in its simple nature,
  the indestructibility of the soul. But of all this, the concept
  of the "I', in the psychological principle "I think', tells us
  nothing.
  That the being which thinks in us is under the impression
  that it knows itself through pure categories, and precisely
00051
through those categories which in  each type of category
express absolute unity, is due to the following reason. Apper-
ception is itself the ground of the possibility of the categories,
which on their part represent nothing but the synthesis of the
manifold of intuition, in so far as the manifold has unity in
apperception. Self-consciousness in general is therefore the
representation of that which is the condition of all unity, and
itself is unconditioned. We can thus say of the thinking "I'
(the soul) which regards itself as substance, as simple, as  A 402
numerically identical at all times, and as the correlate of all
existence, from which all other existence must be inferred,
that it does <1not>1 know <1itself through the categories,>1 but knows
the categories, and through them all objects, in the absolute
unity of apperception, and so <1through itself.>1 Now it is, in-
deed, very evident that I cannot know as an object that which
I must presuppose in order to know any object, and that the
determining self (the thought) is distinguished from the self
that is to be determined (the thinking subject) in the same
way as knowledge is distinguished from its object. Neverthe-
less there is nothing more natural and more misleading than
the illusion which leads us to regard the unity in the synthesis
of thoughts as a perceived unity in the subject of these thoughts.
We might call it the subreption of the hypostatised conscious-
ness <1(apperception is substantiatae).>1
  If we desire to give a logical title to the paralogism con-
tained in the dialectical syllogisms of the rational doctrine of
the soul, then in view of the fact that their premisses are cor-
rect, we may call it a <1sophi-smafigurae dictionis.>1 Whereas the
major premiss, in dealing with the condition, makes a merely
transcendental use of the category, the minor premiss and the
conclusion, in dealing with the soul which has been subsumed
under this condition, use the same category empirically. Thus,
for instance, in the paralogism of substantiality, the con-  A 403
cept of substance is a pure intellectual concept, which in the
absence of the conditions of sensible intuition admits only of
transcendental use, that is, admits of no use whatsoever. But in
the minor premiss the very same concept is applied to the object
00052
of all inner experience without our having first ascertained
and established the condition of such employment <1in concreto,>1
namely, the permanence of this object. We are thus making an
empirical, but in this case inadmissible, employment of the
category.1
  Finally, in order to show the systematic interconnection of
all these dialectical assertions of a pseudo-rational doctrine of
the soul in an order determined by pure reason, and so to show
that we have them in their completeness, we may note that
apperception has been carried through all the classes of the
categories but only in reference to those concepts of under-
standing which in each class form the basis of the unity of the
others in a possible perception, namely, subsistence, reality,
unity (not plurality), and existence. Reason here represents all
of these as conditions, which are themselves unconditioned, of
the possibility of a thinking being. Thus the soul knows in
itself---
A 404  (1) <1the unconditioned unity of relati-on, i.e.>1 that it itself is not
  inherent [in something else] but <1self-subsistent.>1
  (2) <1the unconditioned unity of quality,>1 that is, that it is not a
  real whole but <1simple.>1
  (3) <1the unconditioned unity in the plurality in time, i.e.>1 that
  it is not numerically different at different times but <1one>1
  and <1the very same subject.>1
  (4) <1the unconditioned unity of existence in space, i.e.>1 that it
  is not the consciousness of many things outside it, but
  the consciousness <1of the existence of itself>1 only, and of
  other things merely as its <1representations.>1
A 405  Reason is the faculty of principles. The assertions of pure
  psychology do not contain empirical predicates of the soul but
  those predicates, if there be any such, which are meant to de-
  termine the object in itself independently of experience, and
  so by mere reason. They ought, therefore, to be founded on
  principles and universal concepts bearing on the nature of
  a How the simple here again corresponds to the category of
  reality I am not yet in a position to explain. This will be shown in
  the next chapter on the occasion of this same concept being put by
  reason to yet another use.
00053
thinking beings in general. But instead we find that the single
representation, "I am', governs them all. This representation
just because it expresses the pure formula of all my experience
in general announces itself as a universal proposition valid
for all thinking beings; and since it is at the same time in all
respects unitary, it carries with it the illusion of an absolute
unity of the conditions of thought in general, and so extends
itself further than possible experience can reach.
00054
-THE PARALOGISMS OF PURE REASON
  [AS RESTATED IN SECOND EDITION]
SINCE the proposition "I think' (taken problematically) con-
tains the form of each and every judgment of understanding
and accompanies all categories as their vehicle, it is evident
that the inferences from it admit only of a transcendental em-
ployment of the understanding. And since this employment
excludes any admixture of experience, we cannot, after what
has been shown above, entertain any favourable anticipations
in regard to its methods of procedure. We therefore propose to
follow it, with a critical eye, through all the predicaments of
pure psychology. But for the sake of brevity the examination
had best proceed in an unbroken continuity.
  The following general remark may, at the outset, aid us in
our scrutiny of this kind of argument. I do not know an object
merely in that I think, but only in so far as I determine a given
intuition with respect to the unity of consciousness in which all
thought consists. Consequently, I do not know myself through
being conscious of myself as thinking, but only when I am con-
scious of the intuition of myself as determined with respect
to the function of thought. <1Modi>1 of self-consciousness in
B 407  thought are not by themselves concepts of objects (categories),
  but are mere functions which do not give thought an object
  to be known, and accordingly do not give even myself as
  object. The object is not the consciousness of the <1determining>1
  self, but only that of the <1determinable>1 self, that is, of my
  inner intuition (in so far as its manifold can be combined in
  accordance with the universal condition of the unity of apper-
  ception in thought).
00055
(1) In all judgments I am the <1determining>1 subject of that
relation which constitutes the judgment. That the "I', the "I'
that thinks, can be regarded always as <1subject,>1 and as something
which does not belong to thought as a mere predicate, must be
granted. It is an apodeictic and indeed <1identical>1 proposition;
but it does not mean that I, as <1object,>1 am for myself a <1self->1
<1subsistent>1 being or <1substance.>1 The latter statement goes very far
beyond the former, and demands for its proof data which are
not to be met with in thought, and perhaps (in so far as I have
regard to the thinking self merely as such) are more than I
shall ever find in it.
  (2) That the "I' of apperception, and therefore the "I' in
every act of thought, is <1one,>1 and cannot be resolved into a
plurality of subjects, and consequently signifies a logically
simple subject, is something already contained in the very
concept of thought, and is therefore an analytic proposition.
But this does not mean that the thinking "I' is a simple <1sub->1  B 408
<1stance.>1 That proposition would be synthetic. The concept of
substance always relates to intuitions which cannot in me be
other than sensible, and which therefore lie entirely outside
the field of the understanding and its thought. But it is of
this thought that we are speaking when we say that the "I' in
thought is simple. It would, indeed, be surprising if what in
other cases requires so much labour to determine---namely,
what, of all that is presented in intuition, is substance, and
further, whether this substance can be simple <1(e.g.>1 in the
parts of matter)---should be thus given me directly, as if by
revelation, in the poorest of all representations.
  (3)  The proposition, that in all the manifold of which I am
conscious I am identical with myself, is likewise implied in the
concepts themselves, and is therefore an analytic proposition.
But this identity of the subject, of which I can be conscious in
all my representations, does not concern any intuition of the
subject, whereby it is given as object, and cannot therefore
signify the identity of the person, if by that is understood the
consciousness of the identity of one's own substance, as a
thinking being, in all change of its states. No mere analysis of
the proposition "I think' will suffice to prove such a proposi-
00056
B 409  tion; for that we should require various synthetic judgments,
  based upon given intuition.
  (4) That I distinguish my own existence as that of a
  thinking being, from other things outside me--among them
  my body---is likewise an analytic proposition; for <1other>1 things
  are such as I think to be <1distinct>1 from myself. But I do not
  thereby learn whether this consciousness of myself would be
  even possible apart from things outside me through which
  representations are given to me, and whether, therefore, I
  could exist merely as thinking being <1(i.e.>1 without existing in
  human form).
  The analysis, then, of the consciousness of myself in
  thought in general, yields nothing whatsoever towards the
  knowledge of myself as object. The logical exposition of
  thought in general has been mistaken for a metaphysical
  determination of the object.
  Indeed, it would be a great stumbling-block, or rather
  would be the one unanswerable objection, to our whole cri-
  tique, if there were a possibility of proving <1a priori>1 that all
  thinking beings are in themselves simple substances, and that
  consequently (as follows from this same mode of proof) per-
  sonality is inseparable from them, and that they are conscious
  of their existence as separate and distinct from all matter.
  For by such procedure we should have taken a step beyond
  the world of sense, and have entered into the field of noumena;
  B 410 and no one could then deny our right of advancing yet further
  in this domain, indeed of settling in it, and, should our star
  prove auspicious, of establishing claims to permanent posses-
  sion. The proposition, "Every thinking being is, as such, a
  simple substance', is a synthetic <1a priori>1 proposition; it is syn-
  thetic in that it goes beyond the concept from which it starts,
  and adds to the thought in general <1[i.e.>1 to the concept of
  a thinking being] the mode of [its] existence: it is <1a priori,>1
  in that it adds to the concept a predicate (that of simplicity)
  which cannot be given in any experience. It would then follow
  that <1a priori>1 synthetic propositions are possible and admis-
  sible, not only, as we have asserted, in relation to objects of
  possible experience, and indeed as principles of the possibility
  of this experience, but that they are applicable to things in
  general and to things in themselves---a result that would make
00057
an end of our whole critique, and would constrain us to ac-
quiesce in the old-time procedure. Upon closer consideration
we find, however, that there is no such serious danger.
  The whole procedure of rational psychology is determined
by a paralogism, which is exhibited in the following syllogism:
  <1That which cannot be thought otherwise than as subject>1
  <1does not exist otherwise than as subject, and is therefore>1
  <1substance.>1
  A  <1thinking being, considered merely  as such,  cannot be  B>1 411
  <1thought otherwise than as subject.>1
  <1Therefore it exists also only as subject, that is, as substance.>1
  In the major premiss we speak of a being that can be
thought in general, in every relation, and therefore also as it
may be given in intuition. But in the minor premiss we speak
of it only in so far as it regards itself, as subject, simply in
relation to thought and the unity of consciousness, and not as
likewise in relation to the intuition through which it1 is given
as object to thought. Thus the conclusion is arrived at fallaci-
ously, <1per sophisma figurae dictionis a>1
  That we are entirely right in resolving this famous argu-  B 412
ment into a paralogism will be clearly seen, if we call to mind
what has been said in the General Note to the Systematic
Representation of the Principles and in the Section on Nou-
mena. For it has there been proved that the concept of a thing
  a "Thought' is taken in the two premisses in totally different
senses: in the major premiss, as relating to an object in general and
therefore to an object as it may be given in intuition; in the minor
premiss, only as it consists in relation to self-consciousness. In
this latter sense, no object whatsoever is being thought; all that is
being represented is simply the relation to self as subject (as the
form of thought). In the fonner premiss we are speaking of <1things>1
which cannot be thought otherwise than as subjects; but in the latter
premiss we speak not of <1things>1 but of <1thought>1 (abstraction being  B 412
made from all objects) in which the "I' always serves as the subject
of consciousness. The conclusion cannot, therefore, be, "I cannot
exist otherwise than as subject', but merely, "In thinking my exist-
ence, I cannot employ myself, save as subject of the judgment
(therein involved]'. This is an identical proposition, and casts no
light whatsoever upon the mode of my existence.
00058
which can exist by itself as subject and never as mere predi-
cate, carries with it no objective reality; in other words, that we
cannot know whether there is any object to which the concept
is applicable---as to the possibility of such a mode of existence
  we have no means of deciding---and that the concept1 therefore
  yields no knowledge whatsoever. If by the term "substance' be
  meant an object which can be given, and if it is to yield know-
  ledge, it must be made to rest on a permanent intuition, as
  being that through which alone the object of our concept can
  be given, and as being, therefore, the indispensable condition
  B 413  of the objective reality of the concept. Now in inner intuition
  there is nothing permanent, for the "I' is merely the conscious-
  ness of my thought. So long, therefore, as we do not go beyond
  mere thinking, we are without the necessary condition for
  applying the concept of substance, that is, of a self-subsistent
  subject, to the self as a thinking being. And with the objective
  reality of the concept of substance, the allied concept of
  simplicity likewise vanishes; it is transformed into a merely
  logical qualitative unity of self-consciousness in thought in
  general, which has to be present whether the subject be com-
  posite or not.
  REFUTATION OF MENDELSSOHN'S PROOF OF THE
  PERMANENCE OF THE SOUL
  This acute philosopher soon noticed that the usual argu-
  ment by which it is sought to prove that the soul---if it be
  admitted to be a simple being---cannot cease to be through
  <1dissolution,>1 is insufficient for its purpose, that of proving the
  necessary continuance of the soul, since it may be supposed
  to pass out of existence through simply <1vanishing.>1 In his
  <1Phaedo>1 he endeavoured to prove that the soul cannot be
  subject to such a process of vanishing, which would be a
  true annihilation, by showing that a simple being cannot
  cease to exist. His argument is that since the soul cannot
  be diminished, and so gradually lose something of its exist-
  B 414 ence, being by degrees changed into nothing (for since it
  has no parts, it has no multiplicity in itself), there would be
00059
no time between a moment in which it is and another in which
it is not---which is impossible. He failed, however, to observe
that even if we admit the simple nature of the soul, namely,
that it contains no manifold of constituents external to one
another, and therefore no extensive quantity, we yet cannot
deny to it, any more than to any other existence, intensive
quantity, that is, a degree of reality in respect of all its facul-
ties, nay, in respect of all that constitutes its existence, and
that this degree of reality may diminish through all the in-
finitely many smaller degrees. In this manner the supposed
substance---the thing, the permanence of which has not yet
been proved---may be changed into nothing, not indeed by
dissolution, but by gradual loss <1(reniissio)>1 of its powers, and
so, if I may be permitted the use of the term, by elanguescence.
For consciousness itself has always a degree, which always
allows of diminution,a and the same must also hold of the
faculty of being conscious of the self, and likewise of all the  B415
other faculties. Thus the permanence of the soul, regarded
merely as object of inner sense, remains undemonstrated, and
indeed indemonstrable. Its permanence during life is, of course,
evident <1per se,1>1 since the thinking being (as man) is itself liae-
wise an object of the outer senses. But this is very far from
satisfying the rational psychologist who undertakes to prove
from mere concepts its absolute permanence beyond this life.b
  a Clearness is not, as the logicians assert, the consciousness of
a representation. A certain degree of consciousness, though it be
insufficient for recollection, must be met with even in many obscure
representations, since in the absence of all consciousness we should
make no distinction between different combinations of obscure repre-  B 415
sentations, which yet we are able to do in respect of the characters
of many concepts, such as those of right or equity, or as when the
musician in improvising strikes several keys at once. But a repre-
sentation is clear, when the consciousness suffices for the <1conscious->1
<1ness of the distinction>1 of this representation from others. If it suffices
for distinguishing, but not for consciousness of the distinction, the
representation must still be entitled obscure. There are therefore
infinitely many degrees of consciousness, down to its complete
vanishing.
  b  Some philosophers, in making out a case for a new possibility,
consider that they have done enough if they can defy others to show
00060
B 416  If we take the above propositions in <1synthetic>1 connec-
  tion, as valid for all thinking beings, as indeed they must
  be taken in the system of rational psychology, and proceed
  from the category of relation, with the proposition, "All think-
B 417  ing beings are, as such, substances', backwards through the
  series of the propositions, until the circle is completed, we
B 416 those who profess to comprehend the possibility of thought--of
  which they have an example only in the empirical intuitions of our
  human life---even after this life has ceased. But those who resort to
  such a method of argument can be quite nonplussed by the citation
  of other possibilities which are not a whit more adventurous. Such
  is the possibility of the division of a <1simple substance>1 into severaI
  substances, and conversely the fusing together (coalition) of several
  into one simple substance. For although divisibility presupposes a
  composite, it does not necessarily require a composite of substances,
  but only of degrees (of the manifold powers) of one and the same sub-
  stance. Now just as we can think all powers and faculties of the soul,
  even that of consciousness, as diminished by one half, but in such a
  way that the substance still remains, so also, without contradiction,
  we can represent this extinguished half as being preserved, not in
  the soul, but outside it; and we can likewise hold that since every-
  thing which is real in it, and which therefore has a degree---in other
  words, its entire existence, from which nothing is lacking-= has been
  halved, another separate substance would then come into existence
  outside it. For the multiplicity which has been divided existed
  before, not indeed as a multiplicity of substances, but as the multi-
  plicity of every reality proper to the substance, that is, of the quan-
  tum of existence in it; and the unity of substance was therefore only
  a mode of existence, which in virtue of this division has been trans-
B 417  formed into a plurality of subsistence. Similarly, several simple sub-
  stances might be fused into one, without anything being lost except
  only the plurality of subsistence, inasmuch as the one substance
  would contain the degree of reality of all the former substances to-
  gether. We might perhaps also represent the simple substances which
  yield us the appearance [which we entitle] matter as producing--not
  indeed by a mechanical or chemical influence upon one another, but
  by an influence unknown to us, of which the former influence would
  be merely the appearance--the souls of children, that is, as pro-
  ducing them through such <1dynami-cal>1 division of the parent souls,
  considered as <1intensive quantities,>1 and those parent souls as making
  good their loss through coalition with new material of the same kind.
00061
come at last to the <1existence>1 of these thinaing beings. Now in
this system of rational psychology these beings are taken not
only as being conscious of their existence independently of
outer things, but as also being able, in and by themselves, to
determine that existence in respect of the permanence which  B 418
is a necessary characteristic of substance. This rationalist sys-
tem is thus unavoidably committed to <1idealism,>1 or at least to
problematic idealism. For if the existence of outer things is
not in any way required for determination of one's own
existence in time, the assumption of their existence is a
quite gratuitous assumption, of which no proof can ever be
given.
  If, on the other hand, we should proceed <1analytically,>1
starting from the proposition "I think', as a proposition that
already in itself includes an existence as given, and therefore
modality, and analysing it in order to ascertain its content,
and so to discover whether and how this "I' determines its
existence in space or time solely through that content, then
the propositions of the rational doctrine of the soul would not
begin with the concept of a thinking being in general, but with
a reality, and we should infer from the manner in which this
reality is thought, after everything empirical in it has been
removed, what it is that belongs to a thinking being in general.  B 419
This is shown in the following table:
I am far from allowing any serviceableness or validity to such fancies;
and as the principles of our Analytic have sufficiently demonstrated,
no other than an empirical employ1nent of the categories (including
that of substance) is possible. But if the rationalist is bold enough,
out of the mere faculty of thought, without any permanent intuition  -
whereby an object might be given, to construct a self-subsistent being,
and this merely on the ground that the unity of apperception in thought
does not allow of its being explained [as arising] out of the composite,
instead of admitting, as he ought to do, that he is unable to explain  B 418
the possibility of a thinking nature, why should not the <1materiali-st,>1
though he can as little appeal to experience in support of his [con-
jectured] possibilities, be justified in being equally daring, and in
using his principle to establish the opposite conclusion, while still
preserving the formal unity upon which his opponent has relied.
00062
  1.  I <1think,>1
  2. <1as subject,>1  3. <1as simple subject,>1
  4. <1as identical subject>1
  <1in every state of my thought.>1
  In the second proposition it has not been determined
whether I can exist and be thought as subject only, and not
also as a predicate of another being, and accordingly the con-
cept of a subject is here taken in a merely logical sense, and it
remains undetermined whether or not we are to understand
by it a substance. Similarly, the third proposition establishes
nothing in regard to the constitution or subsistence of the sub-
ject; none the less in this proposition the absolute unity of apper-
ception, the simple "I' in the representation to which all com-
bination or separation that constitutes thought relates, has its
own importance. For apperception is something real, and its
simplicity is already given in the mere fact of its possibility.
Now in space there is nothing real which can be simple; points,
which are the only simple things in space, are merely limits
not themselves anything that can as parts serve to constitute
B 420 space. From this follows the impossibility of any explana-
  tion in <1materialist>1 terms of the constitution of the self as a
  merely thinking subject. But since my existence is taken in
  the first proposition as given---for it does not say that every
  thinking being exists, which would be to assert its absolute
  necessity and therefore to say too much, but only, "I <1exist>1
  thinking'---the proposition is empirical, and can determine
  my existence only in relation to my representations in time.
  But since for this purpose I again require something perma-
  nent, which, so far as I think myself, is in no way given to me
  in inner intuition, it is quite impossible, by means of this simple
  self-consciousness, to determine the manner in which I exist,
  whether it be as substance or as accident. Thus, if materialism
  is disqualified from explaining my existence, spiritualism is
  equally incapable of doing so; and the conclusion is that in no
  way whatsoever can we know anything of the constitution of
  the soul, so far as the possibility of its separate existence is
  concerned.
  How, indeed, should it be possible, by means of the unity
00063
00064
of consciousness---which we only know because we cannot
but make use of it, as indispensable for the possibility of
experience---to pass out beyond experience (our existence in
this life), and even to extend our knowledge to the nature of
all thinking beings in general, through the empirical, but in  B 421
respect of every sort of intuition the quite indeterminate pro-
position,  "I  think'?
  Rational psychology exists not as <1doctrine,>1 furnishing an
addition to our knowledge of the self, but only as <1discipline.>1
It sets impassable limits to speculative reason in this field, and
thus keeps us, on the one hand, from throwing ourselves into
the arms of a soulless materialism, or, on the other hand, from
losing ourselves in a spiritualism which must be quite un-
founded so long as we remain in this present life. But though
it furnishes no positive doctrine, it reminds us that we should
regard this refusal of reason to give satisfying response to our
inquisitive probings into what is beyond the limits of this
present life as reason's hint to divert our self-knowledge from
fruitless and extravagant speculation to fruitful practical em-
ployment. Though in such practical employment it is directed
always to objects of experience only, it derives its principles
from a higher source, and determines us to regulate our actions
as if our destiny reached infinitely far beyond experience, and
therefore far beyond this present life.
  From all this it is evident that rational psychology owes
its origin simply to misunderstanding.  The unity of conscious-
ness, which underlies the categories, is here mistaken for an
intuition of the subject as object, and the category of sub-
stance is then applied to it. But this unity is only unity in  B 422
<1thought,>1 by which alone no object is given, and to which,
therefore, the category of substance, which always presup-
poses a given <1intuition,>1 cannot be applied. Consequently, this
subject cannot be known. The subject of the categories cannot
by thinking the categories acquire a concept of itself as an
object of the categories. For in order to think them, its pure
self-consciousness, which is what was to be explained, must
itself be presupposed. Similarly, the subject, in which the re-
presentation of time has its original ground, cannot thereby
determine its own existence in time. And if this latter is im-
possible, the former, as a determination of the self (as a
00065
thinking being in general) by means of the categories is
equally so a
B 423  Thus the expectation of obtaining knowledge which while
  extending beyond the limits of possible experience is like-
  wise to further the highest interests of humanity, is found,
  so far as speculative philosophy professes to satisfy it, to
B 424  be grounded in deception, and to destroy itself in the attempt
  at fulfilment. Yet the severity of our criticism has rendered
  reason a not unimportant service in proving the impossibility
  of dogmatically determining, in regard to an object of experi-
  ence, anything that lies beyond the limits of expe ience. For in
  so doing it has secured reason against all possible assertions of
  the opposite. That cannot be achieved save in one or other
  a The "I think' is, as already stated, an empirical proposition,
  and contains within itself the proposition "I exist'. But I cannot say
  "Everything which thinks, exists'. For in that case the property of
  thought would render all beings which possess it necessary beings.
  My existence cannot, therefore, be regarded as an inference from
  the proposition "I think', as Descartes sought to contend---for it
  would then have to be preceded by the major premiss "Everything
  which thinks, exists'---but is identical with it. The "I think' ex-
  presses an indeterminate empirical intuition, <1i.e.>1 perception (and
  B 423  thus shows that sensation, which as such belongs to sensibility, lies
  at the basis of this existential  proposition)  But  the  "I  think'
  precedes the experience which is required to determine the object
  of perception through the category in respect of time; and the
  existence here [referred to] is not a category. The category as
  such does not apply to an indeterminately given object but only to
  one of which we have a concept and about which we seek to know
  whether it does or does not exist outside the concept. An indetermin-
  ate perception here signifies only something real that is given, given
  indeed to thought in general, and so not as appearance, nor as thing
  in itself <1(noumenon),>1 but as something which actually 1 exists, and
  which in the proposition, "I think', is denoted as such. For it must
  be observed, that when I have called the proposition, "I think', an
  empirical proposition, I do not mean to say thereby, that the "I' in
  this proposition is an enpirical representation. On the contrary,
  it is purely intellectual, because belonging to thought in general.
  Without some empirical representation to supply the material for
  thought, the <1actus,>1 "I think', would not, indeed, take place; but the
  empirical is only the condition of the application, or of the employ-
  ment, of the pure intellectual faculty.
00066
of two ways. Either we have to prove our proposition apo-
deictically; or, if we do not succeed in this, we have to seek out
the sources of this inability, which, if they are traceable to the
necessary limits of our reason, must constrain all opponents
to submit to this same law of renunciation in respect of all
claims to dogmatic assertion.
  Yet nothing is thereby lost as regards the right, nay, the
necessity, of postulating a future life in accordance with the
principles of the practical employment of reason, which is
closely bound up with its speculative employment. For the
merely speculative proof has never been able to exercise any
influence upon the common reason of men. It so stands upon
the point of a hair, that even the schools preserve it from fall-
ing only so long as they keep it unceasingly spinning round
like a top; even in their own eyes it yields no abiding founda-
tion upon which anything could be built. The proofs which are
serviceable for the world at large all preserve their entire value  B 425
undiminished, and indeed, upon the surrender of these dog-
matic pretensions, gain in clearness and in natural force. For
reason is then located in its own peculiar sphere, namely, the
order of ends, which is also atthe same time an orderof nature;
and since it is in itself not only a theoretical but also a practical
faculty, and as such is not bound down to natural conditions,
it is justified in extending the order of ends, and therewith our
own existence, beyond the limits of experience and of life. If
we judged according to <1analogy with the nature>1 of living
beings in this world, in dealing with which reason must
necessarily accept the principle that no organ, no faculty, no
impulse, indeed nothing whatsoever is either superfluous or
disproportioned to its use, and that therefore nothing is pur-
poseless, but everything exactly conformed to its destiny in
life---if we judged by such an analogy we should have to re-
gard man, who alone can contain in himself the final end of
all this order, as the only creature that is excepted from it.
Man's natural endowments---not merely his talents and the
impulses to enjoy them, but above all else the moral law within
him---go so far beyond all the utility and advantage which he
may derive from them in this present life, that he learns there-
by to prize the mere consciousness of a righteous will as being,
apart from all advantageous consequences, apart even from the  B 426
00067
shadowy reward of posthumous fame, supreme over all other
values; and so feels an inner call to fit himself, by his conduct
in this world, and by the sacrifice of many of its advantages,
for citizenship in a better world upon which he lays hold in
idea. This powerful and incontrovertible proof is reinforced
by our ever-increasing knowledge of purposiveness in all that
we see around us, and by contemplation of the immensity of
creation, and therefore also by the consciousness of a certain
illimitableness in the possible extension of our knowledge, and
of a striving commensurate therewith. All this still remains to
us, but we must renounce the hope of comprehending, from
the merely theoretical knowledge of ourselves, the necessary
continuance of our existence.
  CONCLUSION, IN REGARD TO THE SOLUTION OF THE
  PSYCHOLOGICAL PARALOGISM
  The dialectical illusion in rational psychology arises from
the confusion of an idea of reason---the idea of a pure intelli-
gence---with the completely undetermined concept of a think-
ing being in general. I think myself on behalf of a possible
experience, at the same time abstracting from all actual ex-
perience; and I conclude therefrom that I can be conscious of
B 427 my existence even apart from experience and its empirical
  conditions. In so doing I am confusing the possible <1abstrac->1
  <1tion>1 from my empirically determined existence with the sup-
  posed consciousness of a possible <1separate>1 existence of my
  thinking self, and I thus come to believe that I have <1knowledge>1
  that what is substantial in me is the transcendental subject.
  But all that I really have in thought is simply the unity of con-
  sciousness, on which, as the mere form of knowledge, all
  determination is based.
  The task of explaining the communion of the soul with
  the body does not properly belong to the psychology with
  prove the personality of the soul even apart from this com-
  munion (that is, after death), and is therefore <1transcendent>1 in
  the proper sense of that term. It does, indeed, occupy itself
  with an object of experience, but only in that aspect in which
00068
it ceases to be an object of experience. Our teaching, on the
other hand, does supply a sufficient answer to this question.
The difficulty peculiar to the problem consists, as is generally
recognised, in the assumed heterogeneity of the object of inner
sense (the soul) and the objects of the outer senses, the formal
condition of their intuition being, inthe case of the former, time
only, and in the case of the latter, also space. But if we consider
that the two kinds of objects thus differ from each other, not in-
wardly but only in so far as one <1appears>1 outwardlyto the other,
and that what, as thing in itself, underlies the appearance of  B 428
matter, perhaps after all may not be so heterogeneous in
character, this difficulty vanishes, the only question that re-
mains being how in general a communion of substances is
possible. This, however, is a question which lies outside the
field of psychology, and which the reader, after what has been
said in the Analytic regarding fundamental powers and facul-
ties, will not hesitate to regard as likewise lying outside the
field of all human knowledge
  GENERAL NOTE ON THE TRANSITION FROM RATIONAL
  PSYCHOLOGY TO COSMOLOGY
  The proposition, "I think' or "I exist thinking', is an em-
pirical proposition. Such a proposition, however, is conditioned
by empirical intuition, and is therefore also conditioned by the
object [that is, the self] which is thought [in its aspe~t] as
appearance. It would consequently seem that on our theory
the soul, even in thought, is completely transformed into
appearance, and that in this way our consciousness itself, as
being a mere illusion,1 must refer in fact to nothing.
  Thought, taken by itself, is merely the logical function,
and therefore the pure spontaneity of the combination of the
manifold of a merely possible intuition, and does not exhibit
the subject of consciousness as appearance; and this for the  B 429
sufficient reason that thought takes no account whatsoever of
the mode of intuition, whether it be sensible or intellectual. I
thereby represent myself to myself neither as I am nor as I
appear to myself. I think myself only as I do any object in
general from whose mode of intuition I abstract. If I here re-
00069
  present myself as <1subject>1 of thoughts or as <1ground>1 of thought,
  these modes of representation do not signify the categories of
  substance or of cause. For the categories are those functions
  of thought (of judgment) as already applied to our sensible in-
  tuition, such intuition being required if I seek to <1know>1 myself.
  If, on the other hand, I would be conscious of myself simply as
  thinking, then since I am not considering how my own self
  may be given in intuition, the self may be mere appearance to
  me, the "I' that thinks, but is no mere appearance in so far as
  I think; in the consciousness of myself in mere thought I am
  the <1being itself,>1 although nothing in myself is thereby given
  for thought.
  The proposition, "I think', in so far as it amounts to the
  assertion, "I <1exist thinking',>1 is no mere logical function, but
  determines the subject (which is then at the same time object)
  in respect of existence, and cannot taae place without inner
  sense, the intuition of which presents the object not as thing in
  B 430  itself but merely as appearance. There is here, therefore, not
  simply spontaneity of thought, but also receptivity of intui-
  tion, that is, the thought of myself applied to the empirical
  intuition of myself. Now it is to this intuition that the thinking
  self would have to look for the conditions of the employment
  of its logical functions as categories of substance, cause, etc.,
  if it is not merely to distinguish itself as object in itself, through
  the "I', but is also to determine the mode of its existence, that
  is, to know itself as noumenon. This, however, is impossible,
  since the inner empirical intuition is sensible and yields only
  data of appearance, which furnish nothing to the object of
  <1pure consciousness>1 for the knowledge of its separate existence,
  but can serve only for the obtaining of experience.
  Should it be granted that we may in due course discover,
  not in experience but in certain laws of the pure employment
  of reason---laws which are not merely logical rules, but which
  while holding <1a priori>1 also concern our existence--ground for
  regarding ourselves as <1legislating>1 completely <1a priori>1 in re-
  gard to our own <1existence,>1 and as determining this existence,
  there would thereby be revealed a spontaneity through which
  our reality would be determinable, independently of the con-
  ditions of empirical intuition. And we should also become
00070
aware that in the consciousness of our existence there is con-
tained a something <1a priori,>1 which can serve to determine our
existence---the complete determination of which is possible  B 431
only in sensible terms---as being related, in respect of a certain
inner faculty, to a non-sensible intelligible world.
  But this would not be of the least service in furthering
the attempts of rational psychology. In this marvellous faculty,
which the consciousness of the moral law first reveals to me, I
should indeed have, for the determination of my existence, a
principle which is purely intellectual. But through what predi-
cates would that determination have to be made? They could
be no other than those which must be given to me in sensible
intuition; and thus I should find myself, as regards rational
psychology, in precisely the same position as before, namely,
still in need of sensible intuitions to confer meaning on my
concepts of understanding (substance, cause, etc.), through
which alone I can have knowledge of myself; and these in-
tuitions can never aid me in advancing beyond the field of
experience. Nevertheless, in respect of the practical employ-
ment, which is always directed to objects of experience, I
should be justified in applying these concepts, in conformity
with their analogical meaning when employed theoretically,
to freedom and the subject that is possessed of freedom. In so
doing, however, I should understand by these concepts the
merely logical functions of subject and predicate, of ground
and consequence, in accordance with which the acts or effects
are so determined conformably to those [moral] laws, that  B 432
they always allow of being explained, together with the laws
of nature, in accordance with the categories of substance and
cause, although they have their source in an entirely different
principle. These observations are designed merely to prevent
a misunderstanding to which the doctrine of our self-intuition,
as appearance, is particularly liable. We shall have occasion
to make further application of them in the sequel.
00071
THE TRANSCENDENTAL DIALECTIC
  BOOK II
  CHAPTER II
  THE ANTINOMY OF PURE REASON
WE have shown in the introduction to this part of our work
that all transcendental illusion of pure reason rests on dia-
lectical inferences whose schema is supplied by logic in the
A 406  three formal species of syllogisms-- just as the categories find
  their logical schema in the four functions of all judgments. The
  first type of these pseudo-rational inferences deals with the
  unconditioned unity of the subjective conditions of all repre-
  sentations in general (of the subject or soul), in correspondence
  with the <1categorical>1 syllogisms, the major premiss of which is
  a principle asserting the relation of a predicate to a subject.
B 433  The second type of dialectical argument follows the analogy
  of the <1hypothetical>1 syllogisms. It has as its content the un-
  conditioned unity of the objective conditions in the [field of]
  appearance. In similar fashion, the third type, which will be
  dealt with in the next chapter, has as its theme the un-
  conditioned unity of the objective conditions of the possibility
  of objects in general.
  But there is one point that calls for special notice.
  Transcendental paralogism produced a purely one-sided
  illusion in regard to the idea of the subject of our thought.
  No illusion which will even in the slightest degree support the
  opposing assertion is caused by the concepts of reason. Con-
  sequently, although transcendental paralogism, in spite of a
  favouring illusion, cannot disclaim the radical defect through
  which in the fiery ordeal of critical investigation it dwindles
00072
into mere semblance, such advantage as it offers is altogether
on the side of pneumatism.
  A completely different situation arises when reason is ap-
plied to the <1objective>1 synthesis of appearances. For in this  A 407
domain, however it may endeavour to establish its principle
of unconditioned unity, and though it indeed does so with
great though illusory appearance of success, it soon falls into
such contradictions that it is constrained, in this cosmological
field, to desist from any such pretensions.
  We have here presented to us a new phenomenon of human
reason---an entirely natural antithetic, in which there is no
need of making subtle enquiries or of laying snares for the
unwary, but into which reason of itself quite unavoidably falls.  B 434
It certainly guards reason from the slumber <1offctitious>1 con-
viction such as is generated by a purely one-sided illusion, but
at the same time subjects it to the temptation either of aban-
doning itself to a sceptical despair, or of assuming an ob-
stinate attitude, dogmatically committing itself to certain
assertions, and refusing to grant a fair hearing to the argu-
ments for the counter-position. Either attitude is the death
of sound philosophy, although the former might perhaps be
entitled the <1euthanasia>1 of pure reason.
  Before considering the various forms of opposition and
dissension to which this conflict or antinomy of the laws of
pure reason gives rise, we may offer a few remarks in explana-
tion and justification of the method which we propose to
employ in the treatment of this subject. I entitle all tran-
scendental ideas, in so far as they refer to absolute totality in
the synthesis of appearances, <1cosmical concepts,>1 partly be- A 408
cause this unconditioned totality also underlies the concept
---itself only an idea---of the world-whole; partly because
they concern only the synthesis of appearances, therefore
only empirical synthesis When, on the contrary, the abso-
lute totality is that of the synthesis of the conditions of
all possible things in general, it gives  rise to an <1ideal>1 of B 435
pure reason which, though it may indeed stand in a certain
relation to the cosmical concept, is quite distinct from it.
Accordingly, just as the paralogisms of pure reason formed
the basis of a dialectical psychology, so the antinomy of
pure reason will exhibit to us the transcendental principles
00073
00074
of a pretended pure rational cosmology. But it will not do
so in order to show this science to be valid and to adopt it.
As the title, conflict of reason, suffices to show, this pretended
science can be exhibited only in its bedazzling but false
illusoriness, as an idea which can never be reconciled with
appearances.
  THE ANTINOMY OF PURE REASON
  Section I
  SYSTEM OF COSMOLOGICAL IDEAS
  In proceeding to enumerate these ideas with systematic
precision according to a principle, we must bear in mind two
points. In the first place we must recognise that pure and
transcendental concepts can issue only from the understand-
A 409 ing. Reason does not really generate any concept. The most
  it can do is to <1free>1 a concept of <1understanding>1 from the
  unavoidable limitations of possible experience, and so to en-
  deavour to extend it beyond the limits of the empirical, though
B436  still, indeed, in terms of its relation to the empirical. This is
  achieved in the following manner. For a given conditioned,
  reason demands on the side of the conditions---to which as
  the conditions of synthetic unity the understanding subjects
  all appearances---absolute totality, and in so doing converts
  the category into a transcendental idea. For only by carrying
  the empirical synthesis as far as the unconditioned is it en-
  abled to render it absolutely complete; and the unconditioned
  is never to be met with in experience, but only in the idea.
  Reason makes this demand in accordance with the principle
  that if <1the conditi-oned is given, the entire sum of conditions,>1
  <1and consequently the absolutely unconditioned>1 (through which
  alone the conditioned has been possible) <1is also given.>1 The
  transcendental ideas are thus, in the <1first>1 place, simply cate-
  gories extended to the unconditioned, and can be reduced to
  a table arranged according to the (fourfold] headings of the
  latter. In the <1second>1 place, not all categories are fitted for such
  employment, but only those in which the synthesis constitutes
  a <1series>1 of conditions subordinated to, not co-ordinated with,
00075
one another, and generative of a [given] conditioned. Ab-
solute totality is demanded by reason only in so far as the
ascending series of conditions relates to a given conditioned.  A 410
It is not demanded in regard to the descending line of con-
sequences, nor in reference to the aggregate of co-ordinated
conditions of these consequences. For in the case of the given  B 437
conditioned, conditions are presupposed, and are considered
as given together with it. On the other hand, since conse-
quences do not make their conditions possible, but rather
presuppose them, we are not called upon, when we advance
to consequences or descend from a given condition to the con-
ditioned, to consider whether the series does or does not cease;
the question as to the totality of the series is not in any way a
presupposition of reason.
  Thus we necessarily think time as having completely
elapsed up to the given moment, and as being itself given in
this completed form. This holds true, even though such com-
pletely elapsed time is not determinable by us. But since the
future is not the condition of our attaining to the present, it is
a matter of entire indifference, in our comprehension of the
latter, how we may think of future time, whether as coming
to an end or as flowing on to infinity. We have, as it were, the
series <1m, n, 0,>1 in which <1n>1 is given as conditioned by <1m,>1 and
at the same time as being the condition of <1o.>1 The series ascends
from the conditioned <1n>1 to <1m>1 (l, <1k, i,>1 etc.), and also descends
from the condition n to the conditioned 0 <1(p, q, r,>1 etc.). Now
I must presuppose the first series in order to be able to view
n as given. According to reason, with its demand for totality
of conditions, n is possible only by means of that series. Its  A411
possibility does not, however, rest upon the subsequent series,
<1o, p, q, r.>1 This latter series may not therefore be regarded as  B 438
given, but only as allowing of being given <1(dabilis).>1
  I propose to name the synthesis of a series which begins, on
the side of the conditions, from the condition which stands near-
est to the given appearance and so passes to the more remote
conditions, the <1regressive>1 synthesis; and that which advances,
on the side of the conditioned, from the first consequence to
the more distant, the <1Progressive.>1 The first proceeds <1in ante->1
<1cedentia,>1 the second <1in consequentia.>1 The cosmological ideas
deal, therefore, with the totality of the regressive synthesis
00076
proceeding <1in antecedentia,>1 not <1in consequentia.>1 The problem
of pure reason suggested by the progressive form of totality
is gratuitous and unnecessary, since the raising of it is not
required for the complete comprehension of what is given in
appearance. For that we require to consider only the grounds,
not the consequences.
  In arranging the table of ideas in accordance with the
table of categories, we first take the two original <1quanta>1 of
all our intuition, <1tinie>1 and <1space.>1 Time is in itself a series, and
indeed the formal condition of all series. In it, in regard to a
given present, the antecedents can be <1a priori>1 distinguished as
conditions (the past) from the consequents (the future). The
A 412  transcendental idea of the absolute totality of the series of con-
B 439 ditions of any given conditioned therefore refers only to all
  <1past>1 time; and in conformity with the idea of reason past time,
  as condition of the given moment, is necessarily thought as
  being given in its entirety. Now in space, taken in and by itself,
  there is no distinction between progress and regress. For as its
  parts are co-existent, it is an <1aggregate, not a series.>1 The present
  moment can be regarded only as conditioned by past time,
  never as conditioning it, because this moment comes into exist-
  ence only through past time, or rather through the passing of
  the preceding time. But as the parts of space are co-ordinated
  with, not subordinated to, one another, one part is not the con-
  dition of the possi  ility of another; and unlike time, space does
  not in itself constitute a series. Nevertheless the synthesis of  -
  the manifold parts of space, by means of which we apprehend
  space, is successive, taking place in time and containing a
  series. And since in this series of the aggregated spaces (as for
  instance of the feet in a rood) of the given space, those which
  are thought in extension of the given space are always <1the con->1
  <1dition of the limits>1 of the given space, the <1measuring>1 of a space
  is also to be regarded as a synthesis of a series of the conditions
  of a given conditioned, only with this difference that the side of
A413  the conditions is not in itself distinct from that of the condi-
B 440  tioned, and that in space <1regressus andprogressuswould>1 there-
  fore seem to be one and the same. Inasmuch as one part of
  space is not given through the others but only limited by them,
  we must consider each space, in so far as it is limited, as being
  also conditioned, in that it presupposes another space as the
00077
condition of its limits, and so on. In respect of limitation the
advance in space is thus also a regress, and the transcendental
idea of the absolute totality of the synthesis in the series of con-
ditions likewise applies to space. I can as legitimately enquire
regarding the absolute totality of appearance in space as of
that in past time. Whether an answer to this question is ever
possible, is a point which will be decided later.
  Secondly, reality in space, <1i.e. matter,>1 is a conditioned. Its
internal conditions are its parts, and the parts of these parts its
remote conditions. There thus occurs a regressive synthesis,
the absolute totality of which is demanded by reason. This can
be obtained only by a completed division in virtue of which the
reality of matter vanishes either into nothing or into what is
no longer matter---namely, the simple. Here also, then, we have
a series of conditions, and an advance to the unconditioned.
  Thirdly, as regards the categories of real relation between  B 441
appearances, that of substance with its accidents is not adapted  A 414
to being a transcendental idea. That is to say, in it reason
finds no ground for proceeding regressively to conditions. Acci-
dents, in so far as they inhere in one and the same substance,
are co-ordinated with each other, and do not constitute a series.
Even in their relation to substance they are not really subordi-
nated to it, but are the mode of existence of the substance
itself. What in this category may still, however, seem to be an
idea of transcendental reason, is the concept of the 1 <1substantial.>1
But since this means no more than the concept of object in
general, which subsists in so far as we think in it merely the
transcendental subject apart from all predicates, whereas
we are here dealing with the unconditioned only as it may
exist in the series of appearances, it is evident that the sub-
stantial cannot be a member of that series. This is also true
of substances in community. They are mere aggregates, and
contain nothing on which to base a series. For we cannot say
of them, as we can of spaces, whose limits are never deter-
mined in and by themselves but only through some other space,
that they are subordinated to each other as conditions of the
possibility of one another. There thus remains only the cate-
gory of <1causality.>1 It presents a series of causes of a given
00078
B 442 effect such that we can proceed to ascend from the latter as the
  conditioned to the former as conditions, and so to answer the
  question of reason.
A 415  Fourthly, the concepts of the possible, the actual, and the
  necessary do not lead to any series, save in so far as the <1acci->1
  <1dental>1 in existence must always be regarded as conditioned,
  and as pointing in conformity with the rule of the understand-
  ing to a condition under which it is necessary, and this latter in
  turn to a higher condition, until reason finally attains uncondi-
  tioned necessity in the totality of the series.
  When we thus select out those categories which necessarily
  lead to a series in the synthesis of the manifold, we find that
  there are but four cosmological ideas,  orresponding to the
  four titles of the categories:
B 443  I.  Absolute completeness
  of the <1Composition>1
  of the given whole of all appearances.
  2.  Absolute completeness
  in the <1Division>1
  of a given whole in the [field of] appearance.
  3.  Absolute completeness
  in the <1Origination>1
  of an appearance.
  4. -  Absolute completeness
  as regards <1Dependence>1 of <1Existence>1
  of the changeable in the [field of] appearance.
A 416  There are several points which here call for notice. In the
  first place, the idea of absolute totality concerns only the ex-
  position of <1appearances,>1 and does not therefore refer to the
  pure concept, such as the understanding may form, of a total-
  ity of <1things in general.>1 Appearances are here regarded as
  given; what reason demands is the absolute completeness of the
  conditions of their possibility, in so far as these conditions con-
  stitute a series. What reason prescribes is therefore an abso-
  lutely (that is to say, in every respect) complete synthesis,
  whereby the appearance may be exhibited in accordance with
  the laws of understanding.
00079
Secondly, what reason is really seeking in this serial, re-
gressively continued, synthesis of conditions, is solely the un-  B 444
conditioned. What it aims at is, as it were, such a completeness
in the series of premisses as will dispense with the need of pre-
supposing other premisses. This <1unconditioned>1 is always con-
tained in the <1absolute totality of the series>1 as represented in
imagination. But this absolutely complete synthesis is again
only an idea; for we cannot know, at least at the start of this
enquiry, whether such a synthesis is possible in the case of ap-
pearance. If we represent everything exclusively through pure
concepts of understanding, and apart from conditions of sen-
sible intuition, we can indeed atonce assert that for a given con-
ditioned, the whole series of conditions subordinated to each
other is likewise given. The former is given only through the
latter. When, however, it is with appearances that we are deal-
ing, we find a special limitation due to the manner in which
conditions are given, namely, through the successive synthesis  A 417
of the manifold of intuition---a synthesis which has to be
made complete through the regress. Whether this complete-
ness is sensibly possible is a further problem; the idea of it
lies in reason, independently alike of the possibility or of the
impossibility of our connecting with it any adequate empirical
concepts. Since, then, the <1unconditioned>1 is necessarily con-
tained in the absolute totality of the regressive synthesis of
the manifold in the [field of] appearance---the synthesis being
executed in accordance with those categories which represent
appearance as a series of conditions to a given conditioned---
reason here adopts the method of starting from the idea of B445
totality, though what it really has in view is the <1unconditioned,>1
whether of the entire series or of a part of it. Meantime, also,  =
it leaves undecided whether and how this totality is attain-
able.
  This unconditioned may be conceived in either of two
ways. It may be viewed as consisting of the entire series in
which all the members without exception are conditioned and
only the totality of them is absolutely unconditioned. This
regress is to be entitled infinite. Or alternatively, the absolutely
unconditioned is only a part of the series a part to which the
other members are subordinated, and which does not itself stand
00080
under any other condition. On the first view, the series <1a parte>1
A 418  <1priori>1 is without limits or beginning, <1i.e.>1 is infinite, and at the
  same time is given in its entirety. But the regress in it is never
  completed, and can only be called potentially infinite. On the
B 446  second view, there is a first member of the series which in
  respect of past time is entitled, <1the beginning of the world,>1 in
  respect of space, <1the limit of the world,>1 in respect of the parts
  of a given limited whole, the <1simple,>1 in respect of causes,
  absolute <1self-activity>1 (freedom), in respect of the existence of
  alterable things, absolute <1natural necessity.>1
  We have two expressions, <1world>1 and <1nature,>1 which some-
  times coincide. The former signifies the mathematical sum-
  total of all appearances and the totality of their synthesis, alike
  in the great and in the small, that is, in the advance alikethrough
  composition and through division. This same world is entitled
  A 419 nature when it is viewed as a dynamical whole. We are not
  then concerned with the aggregation in space and time, with
  B 447 a view to determining it as a magnitude, but with the unity in
  the <1existence>1 of appearances. In this case the condition of that
  which happens is entitled the cause. Its unconditioned caus-
  ality in the [field of] appearance is called <1freedom,>1 and its
  conditioned causality is called <1natural>1 cause1 in the narrower
  [adjectival] sense. The conditioned in existence in general is
  termed contingent and the unconditioned necessary. The un-
  a  The absolute totality of the series of conditions to a given con-
  ditioned is always unconditioned, since outside it there are no further
  conditions in respect of which it could be conditioned. But this
  absolute totality of such a series is only an idea, or rather a problem-
  atic concept, the possibility of which has to be investigated, especi-
  ally in regard to the manner in which the unconditioned (the tran-
  scendental idea really at issue) is involved therein.
  B 446  b Nature, taken adjectivally <1(formali-ter),>1 signifies the connec-
  tion of the determinations of a thing according to an inner principle
  of causality. By nature, on the other hand, taken substantivally
  <1(materiali-ter),>1 is meant the sum of appearances in so far as they
  stand, in virtue of an inner principle of causality, in thorough-
  going interconnection. In the first sense we speak of the nature of
  fluid matter, of fire, etc. The word is then employed in an adjectival
  manner. When, on the other hand, we speak of the things of nature,
  we have in mind a self-subsisting whole.
00081
conditioned necessity of <1appearances>1 may be entitled natural
necessity.
  The ideas with which we are now dealing I have above
entitled cosmological ideas, partly because by the term "world'
we mean the sum of all <1appearances,>1 and it is exclusively
to the unconditioned in the <1appearances>1 that our ideas are
directed, partly also because the term "world', in the tran-
scendental sense, signifies the absolute <1totality>1 of all existing
things, and we direct our attention solely to the <1completeness>1
of the synthesis, even though that is only attainable in the  A 420
regress to its conditions. Thus despite the objection that these
ideas are one and all transcendent, and that although they do
not in kind surpass the object, namely, appearances, but are
concerned exclusively with the world of sense, not with nou-
mena, they yet carry the synthesis to a degree which tran-
scends all possible experience, I none the less still hold that
they may quite appropriately be entitled <1cosmical concepts.1>1 In
respect of the distinction between the mathematically and the  B 448
dynamically unconditioned at which the regress aims, I might,
however, call the first two concepts cosmical in the narrower
  sense, as referring to the world of the great and the small, and
  the other two <1transcendent concepts of nature.2>1 This distinction
  has no special immediate value; its significance will appear
  later.
  THE ANTINOMY OF PURE REASON
  Section 2
  ANTITHETIC OF PURE REASON
  If thetic be the name for any body of dogmatic doctrines,
  antithetic may be taken as meaning, not dogmatic assertions of
  the opposite,but the conflict of the doctrines of seemingly dog-
  matic knowledge <1(thesis cum antithesi)>1 in which no one asser-
  tion can establish superiority over another. The antithetic  does
  not, therefore, deal with one-sided assertions. It treats only
  the conflict of the doctrines of reason with one another a
  causes of this conflict. The transcendental antithetic is an en-
  quiry into the antinomy of pure reason, its causes and out-
00082
come. If in employing the principles of understanding we do
B 449 not merely apply our reason to objects of experience, but
  venture to extend these principles beyond the limits of experi-
  ence, there arise <1pseudo-rational>1 doctrines which can neither
  hope for confirmation in experience nor fear refutation by it.
  Each of them is not only in itself free from contradiction, but
  finds conditions of its necessity in the very nature of reason---
  only that, unfortunately, the assertion of the opposite has, on
  its side, grounds that are just as valid and necessary.
  The questions which naturally arise in connection with
  such a dialectic of pure reason are the following: (1) In what
  propositions is pure reason unavoidably subject to an anti-
  nomy? (2) On what causes does this antinomy depend? (3)
  Whether and in what way, despite this contradiction, does
  there still remain open to reason a path to certainty?
  A dialectical doctrine of pure reason must therefore be
  distinguished from all sophistical propositions in two respects.
A 422  It must not refer to an arbitrary question such as may be raised
  for some special purpose, but to one which human reason
  must necessarily encounter in its progress. And secondly, both
  it and its opposite must involve no mere artificial illusion such
  as at once vanishes upon detection, but a natural and un-
B450  avoidable illusion, which even after it has ceased to beguile
  still continues to delude though not to deceive us, and which
  though thus capable of being rendered harmless can never be
  eradicated.
  Such dialectical doctrine relates not to the unity of under-
  standing in empirical concepts, but to the unity of reason in
  mere ideas. Since this unity of reason involves a synthesis ac-
  cording to rules, it must conform to the understanding; and
  yet as demanding absolute unity of synthesis it must at the
  same time harmonise with reason. But the conditions of this
  unity are such that when it is adequate to reason it is too great
  for the understanding; and when suited to the understanding,
  too small for reason. There thus arises a conflict which cannot
  be avoided, do what we will.
  These pseudo-r  tional assertions thus disclose a dialectical
  battlefield in which the side permitted to open the attack is
A 423  invariably victorious, and the side constrained to act on the
  defensive is always defeated. Accordingly, vigorous fighters, no
00083
matter whether they support a good or a bad cause, if only they
contrive to secure the right to make the last attack, and are  -
not required to withstand a new onslaught from their oppo-
nents, may always count upon carrying off the laurels. We can
easily understand that while this arena should time and again
be contested, and that numerous triumphs should be gained
by both sides, the last decisive victory always leaves the B 451
champion of the good cause master of the field, simply be-
cause his rival is forbidden to resume the combat. As im-
partial umpires, we must leave aside the question whether it
is for the good or the bad cause that the contestants are
fighting. They must be left to decide the issue for themselves.
After they have rather exhausted than injured one another,
they will perhaps themselves perceive the futility of their
quarrel, and part good friends.
  This method of watching, or rather provoking, a conflict
of assertions, not for the purpose of deciding in favour of one
or other side, but of investigating whether the object of con-
troversy is not perhaps a deceptive appearance which each
vainly strives to grasp, and in regard to which, even if there
were no opposition to be overcome, neither can arrive at any  A 424
result,---this procedure, I say, may be entitled the <1sceptical>1
<1method.>1 It is altogether different from <1scepticism->1--a principle
of technical and scientific ignorance, which undermines the
foundations of all knowledge, and strives in all possible ways
to destroy its reliability and steadfastness. For the sceptical
method aims at certainty. It seeks to discover the point of B 452
misunderstanding in the case of disputes which are sincerely
and competently conducted by both sides, just as from the
embarrassment of judges in cases of litigation wise legislators
contrive to obtain instruction regarding the defects and am-
biguities of their laws. The antinomy which discloses itself in
the application of laws is for our limited wisdom the best
criterion of the legislation that has given rise to them. Reason,
which does not in abstract speculation easily become aware
of its errors, is hereby awakened to consciousness of the
factors [that have to be reckoned with] in the determination
of its principles
00084
  But it is only for transcendental philosophy that this scep-
tical method is essential. Though in all other fields of enquiry
it can, perhaps, be dispensed with, it is not so in this field.
In mathematics its employment would, indeed, be absurd; for
in mathematics no false assertions can be concealed and ren-
A 425  dered invisible, inasmuch as the proofs must always proceed
  under the guidance of pure intuition and by means of a syn-
  thesis that is always evident. In experimental philosophy the
  delay caused by doubt may indeed be useful; no misunder-
  standing is, however, possible which cannot easily be re-
  moved; and the final means of deciding the dispute, whether
  found early or late, must in the end be supplied by experience.
B 453 Moral philosophy can also present its principles, together
  with their practical consequences, one and all <1in concreto,>1 in
  what are at least possible experiences; and the misunder-
  standing due to abstraction is thereby avoided. But it is quite
  otherwise with transcendental assertions which lay claim to
  insight into what is beyond the field of all possible experiences.
  Their abstract synthesis can never be given in any <1a priori>1
  intuition, and they are so constituted that what is erroneous
  in them can never be detected by means of any experience.
  Transcendental reason consequently admits of no other test
  than the endeavour to harmonise its various assertions. But
  for the successful application of this test the conflict into
  which they fall with one another must first be left to develop
  free and untrammelled. This we shall now set about arranging.
  426 )  THE ANTINOMY OF PURE REASON  ( B4 7
  FIRST CONFLICT OF THB TRANSCBNDENTAL IDEAS
  <1Thesis  Antithesis>1
  The world has a beginning  The world has no begin-
  in time, and is also limited as  ning, and no limits in space;
  regards space.  it is infinite as regards both
  time and space.
  a The antinomies follow one another in the order of the tran-
  scendental ideas above enumerated [p. 39o].
00085
<1Proof  Proof>1
If we assume that the world  For let us assume that it
has no beginning in time,  has a beginning. Since the
then up to every given mo-  beginning  is  an  existence
ment an eternity has elapsed,  which is preceded by a time
and there has passed away in  in which the thing is not,
the world an infinite series of  there  must  have  been  a
successive states of things.  preceding time in which the
Now the infinity of a series  world was not, <1i.e.>1 an empty
consists in the fact that it can  time. Now no coming to be
never be completed through  of a thing is possible in an
successive synthesis. It thus  empty time, because no part
follows that itisimpossible for  of such a time possesses, as
an infinite world-series to have  compared with any other, a
passed away, and that a be-  distinguishing  condition  of
ginning of the world is there-  existence rather than of non-
fore a necessary condition of  existence; and this applies
the world's existence. This was  whether the thing is sup-
the first point that called for  posed to arise of itself or
proof.  through some other cause. In
  Asregards thesecond point,  the world many series of
let us again assume the oppo-  things  can,  indeed,  begin;
site, namely, that the world is  but the world itself cannot
an infinite given whole of co-  have  a  beginning,  and  is
existing things. Now the mag-  therefore  infinite in  respect
nitude of a quantum which is  of past time.
not given in intuitiona as  As regards the second
6) within certain limits, can be  point, let us start by assum-
  thought  only  through  the  ing the opposite, namely, that
  synthesis of its parts, and the  the world in space is finite
  totality of such  a  quantum  and limited, and consequently
  only through a synthesis that  exists  in  an empty space
  is brought to completion which is unlimited. Things
  through repeated addition of  will therefore not only be
  a  an indeterminate quantum can be intuited as a whole when it
  is such that though enclosed within limits we do not require to con- B 654
  struct its totality through measurement, that is, through the success-
  ive synthesis of its parts. For the limits, in cutting off anything
  further, themselves determine its completeness.
00086
unit to unit.a In order, there-  related  <1in  space>1  but  also
fore, to think, as a whole, the  related <1to space.>1 Now since
world  which  fills  all  spaces,  the world is an absolute whole
the successive synthesis of  beyond which there is no B457
the parts of an infinite world  object of intuition, and there-
must be viewed as completed,  fore no correlate with which
that is, an infinite time must  the world stands in relation,
be viewed as having elapsed  the  relation  of  the  world
in the enumeration of all co-  to empty space would be a
existing things. This, how-  relation of it to no <1object.>1
ever, is impossible. An in-  But such a relation, and con-
finite aggregate of actual sequently the limitation of
things cannot therefore be  the world by empty space, is
viewed as a given whole, nor  nothing. The world cannot,
consequently  as  simultane-  therefore, be limited in space;
ously given.  The world  is,  that is, it is infinite in respect
-  therefore, as regards exten- of extension b
  sion in space, not infinite, but
-  is enclosed within limits. This
  was the second point in
  dispute.
  a The concept of totality is in this case simply the representa-
  tion of the completed synthesis of its parts; for, since we cannot
  obtain the concept from the intuition of the whole---that being in
  this case impossible---we can apprehend it only through the syn-
  thesis of the parts viewed as carried, at least in idea, to the comple-
  tion of the infinite.
  B 457  b Space is merely the form of outer intuition (formal intuition).
  It is not a real object which can be outwardly intuited. Space, as
  prior to all things which determine (occupy or limit) it, or rather
  which give an empirical intuition in accordance with its form, is,
  under the name of absolute space, nothing but the mere possibility
  of outer appearances in so far as they either exist in themselves or
  can be added to given appearances. Empirical intuition is not, there-
  fore, a composite of appearances and space (of perception and empty
  intuition). The one is not the correlate of the other in a synthesis;
  they are connected in one and the same empirical intuition as
  matter and form of the intuition. If we attempt to set one of these
  two factors outside the other, space outside all appearances, there
  arise all sorts of empty determinations of outer intuition, which yet
  are not possible perceptions. For example, a determination of the
  relation of the motion (or rest) of the world to infinite empty space
00087
A430   OBSERVATION ON THE FIRST ANTINOMY   A 431
  I. <1On the Thesis>1  II. <1On the Antithesis>1
  In stating these conflicting  The proof of the infinitude
arguments I have not sought  of the given world-series and
to  elaborate  sophisms.  That  of the world-whole, rests upon
is to say, I have not resorted  the factthat, on the contrary
to the method of the special  assumption,  an empty time
pleader who attempts to take  and an empty space, must
advantage of an opponent's  constitute the limit of the
carelessness---freely allowing world. I am aware that
the appealto a misunderstood  attempts have been made to
law, in order that he may be  evade this conclusion by argu-
in a position to establish his  ing that a limit of the world
own unrighteous claims by  in time and space is quite
the refutation of that law.  possible without our having
Each of the above proofs  to make the impossible as-
arises naturally out of the  sumption  of an absolute
matter in dispute, and no ad-  time prior to the beginning
vantage  has  been  taken  of  of the world, or of an absolute
the openings afforded by er-  space extending beyond the
roneous conclusions arrived  real world. With the latter
at by dogmatists in either  part of this doctrine, as held
party.  by the philosophers of the
  I might have made a Leibnizian school, I am en-
pretence  of  establishing  the  tirely satisfied. Spaceis merely
thesis in the usual manner of  the form of outer intuition;
the dogmatists, by starting  it is not a real object which
from a defective concept of  can be outwardly intuited; it
the infinitude of a given mag-  is not a correlate of the ap-
nitude. I might have argued  pearances, but the form of
that a magnitude is infinite  the appearances themselves.
if a greater than itself, as  And since space is thus no
determined by the multipli-  object but only the form of
city of given units which it  possible objects, it cannot be
is a determination which can never be perceived, and is therefore
the predicate of a mere thought-entity.
00088
contains, is not possible. Now  regarded as something abso-
no multiplicity is the great-  lute in itself that determines
=  est, since one or more units the existence of things. Things,
  can always be added to it.  as  appearances,  determine
  Consequently aninfinite given  space, that is, of all its pos-
  magnitude, and therefore an  sible predicates of magnitude
  infinite world infinite as re- and relation they determine
  gards the elapsed series or as  this or that particular one to
  regards extension) is impos-  belong to the real. Space, on
  sible; it must be limited in  the other hand, viewed as a
  both respects. Such is the self-subsistent something, is
  line that my proof might have  nothing real in itself; and can-
  followed. But the above con-  not, therefore, determine the
  cept is not adequate to what  magnitude or shape of real
  we mean by an infinite whole. things. Space, it further fol-
  It does not represent <1how>1  lows, whether full or empty,a
  <1great>1 it is, and consequently may be limited by appear-
  is not the concept of a <1maxi->1  ances, but appearances can- A
  B 462) <1nium.>1 Through it we think  not be limited <1by an empty>1
  only its relation to any assign-  <1space>1 outside them.  This is
  able unit in respect to which likewise true of time. But
  it  is  greater than all num-  while all this may be granted,
  ber. According as the unit  it yet cannot be denied that
  chosen is greater or smaller,  these two non-entities,1empty
  the infinite would be greater  space outside the world and
  or smaller. Infinitude, how-  empty time prior to it, have
  ever, as it consists solely to be assumed if we are to
  in the relationto the given  assume a limit to the world
  unit,  would always  remain  in space and in time.
  the same. The absolute mag-  The method of argument
  nitude of the whole would   which professes to enable us
  not, therefore, be known in  to avoid the above conse-
  this way; indeed, the above  quence (that of having to
  a  It will be evident that what we here desire to say is that <1empty>1
  B 461  <1space,>1 so far as it is <1limited by appearances,>1 that is, empty space
  <1within the world,>1 is at least not contradictory of transcendental
  principles and may therefore, so far as they are concerned, be
  admitted. This does not, however, amount to an assertion of its
  possibility.
00089
concept does not really deal  assume that if the world has
with it.  limits in time and space, the
  The true transcendental infinite void must determine
concept of infinitude is this,  the magnitude in which actual
that the successive synthesis  things are to exist) consists
of units required for the enu-  in surreptitiously substituting
meration of a quantum can  for the sensible world some
never be completed.a Hence  intelligible  world  of  which
it follows with complete cer-  we know nothing; for the
tainty that an eternity of first beginning (an exist-
actual successive states lead-  ence preceded by a time of
ing up to a given (the pre-  non-existence) an existence
sent)  moment cannot have  in general which presupposes
elapsed, and that the world  no other condition whatso-
must therefore have a begin-  ever; and for the limits of
ning.  extension boundaries of the
  In the second part of the  world-whole---thus  getting
thesis the difficulty involved  rid of time and space. But we
in a series that is infinite and  are here treating only of the
yet has elapsed does not arise,  <1mundus  phaenomenon>1  and
since the manifold of a world  its  magnitude,  and  cannot
which is infinite in respect of  therefore abstract from the
extension is given as <1co-exist->1  aforesaid conditions of sensi-
<1ing.>1 Butif we are to thinkthe  bility without destroying the
totality of such a multiplicity,  very being of that world. If
and yet cannot appeal to  the sensible world is limited,
limits that of themselves con-  it must necessarily lie in the
stitute it a totalityin intuition,  infinite void. If that void, and
we have to account for a con-  consequently space in general
cept which in this case cannot  as <1a priori>1 condition of the
proceed from the whole to  possibility of appearances, be
the determinate multiplicity  set aside, the entire sensible
of the parts, but which must  world vanishes. This world
demonstrate the possibility of  is all that is given us in
a whole by means of the  our problem. The <1mundus>1
successive synthesis of the <1intelligibilis>1 is nothing but
parts. Now since this syn-  the general concept of a
  a This quantum therefore contains a quantity (of given units)
which is greater than any number---which is the mathematical con-
cept of the infinite.
00090
thesis must constitute a never  world in general, in which
to be completed series, I can-  abstraction is made from all
not think a totality either  conditions of its intuition,
prior to the synthesis or by  and in reference to which,
means of the synthesis. For  therefore, no synthetic pro-
the concept of totality is in  position,  either  affirmative
this case itself the representa-  or negative, can possibly be
tion of a completed synthesis  asserted.
of the parts. And since this
completion is impossible, so
likewise is the concept of it.
  434)  THE ANTINOMY OF PURE REASON  ( A435
  SECOND CONFLICT OF THE TRANSCENDENTAL IDEAS
  <1Thesis  Antithesis>1
  Every composite substance  No composite thing in the
in the world is made up of  world is made up of simple
simple parts, and nothing any-  parts,  and  there  nowhere
where exists save the simple  exists in the world anything
or what is composed of the  simple.
simple.
  <1Proof  Proof>1
-  Let us assume that com-  Assume that a composite
  posite  substances  are  not  thing (as substance) is made
.a=  made up of simple parts. If up of simple parts. Since all
  all composition be then re-  external relation, and there-
  moved in thought, no con-  fore all composition of sub-
  posite part, and (since we  stances, is possible only in
  admit no simple parts) also  space, a space must be made
  no simple part, that is to say,  up of as many parts as are
  nothing at all, will remain,  contained in the composite
  and accordingly no substance  which  occupies  it.  Space,
  will be given. Either, there-  however, is not made up of
  I  fore, it is impossible to remove simple parts, but of spaces.
  in thought all composition,  Every part of the composite
  or  after  its  removal  there  musttherefore occupy a space.
  niust remain something which But the absolutely first parts
00091
exists  without  composition,  of every composite are simple.
that is, the simple. In the for-  The simple therefore occupies
mer case the-composite would  a space. Now since every-
not be made up of substances;  thing real, which occupies a
composition, as applied to space, contains in itself a
substances, is only an acci-  manifold of constituents ex-
dental relation in independ-  ternal to one another, and is
ence  of  which  they  must  therefore composite; and since
still persist as self-subsistent  a real composite is not made
 beings. Since this contradicts  up of accidents (for accidents
our supposition,there remains  could not exist outside one
only the original supposition,  another, in the absence of
that  a  composite of sub-  substance) but of substances,
stances in the world is made  it follows that the simple
up of simple parts.  would be a composite of
  It follows, as an immediate  substances --- which  is  self-
consequence, that the things  contradictory.
in the world are all, without  The second proposition of
exception, simple beings; that  the antithesis, that nowhere
composition  is  merely  an  in the world does there exist
external state of these beings;  anything simple, is intended A 437
and that although we can  to mean only this, that the
never so isolate these ele- existence of the absolutely
mentary substances  as to  simple cannot be established
take them out of this state  by any experience or percep-
of composition, reason must  tion,  either outer or inner;
think  them  as  the  primary  and that the absolutely simple
subjects of all composition,  is therefore a mere idea, the
  and therefore, as simple be-  objective reality of which can
ings, prior to all composition.  never be shown in any pos-
  sible experience, and which,
  as being without an object,
  has no application in the
  -  explanation of the appear-
  ances. For if we assumed
  that in experience an object
  might be found for this tran-
  scendental idea, the empiri-
  cal intuition of such an object
00092
  would have to be known as
  one that contains no manifold
  [factors] external to one an-
  other and combined into
  unity. But since from the
  non-consciousness of such a
  manifold we cannot conclude
  to its complete impossibility
  in every kind of intuition of
  an object; and since without
  such proof absolute simplicity
  can never be established, it
  follows that such simplicity
  cannot be inferred from any
  perception whatsoever. An
  absolutely simple object can
  never be given in any pos-
  sible experience. And since
  by the world of sense we
  must mean the sum of all
  possible experiences, it follows
  that nothing simple is to be.
  found anywhere in it.
  This second proposition of
  the antithesis has a much
  wider application than the
  first. Whereas the first pro-
  position banishes the simple
  only from the intuition of the
  composite, the second ex-
  cludes it from the whole of
  nature. Accordingly it has
  not been possible to prove
  this second proposition by
  reference to the concept of
  a given object of outer in-
  tuition (of the composite), but
  only by reference to its rela-
  tion to a possible experience
  in general.
00093
  I. <1On the Thesis>1  II. <1On the Antithesis>1
  When I speak of a whole  Against the doctrine of the
as necessarily made up of  infinite divisibility of matter,
simple parts  I am referring  the proof of which is purely
only to a substantial whole  mathematical, objections have
that is composite in the strict  been raised by the monadists.
sense of the term "composite',  These objections, however, at
that  is,  to  that  accidental  once laythe monadists open to
unity of the manifold which,  suspicion. For however evi-
given as <1separate>1 (at least in  dent mathematical proofs
thought),  is  brought into  a  may be, they decline to recog-
mutual connection, and there-  nise that the proofs are based
by constitutes a unity. Space  upon insight into the constitu-
should properly be called not  tion of space, in so far as space
<1compositum>1 but <1totum,>1 since  is in actual fact the formal
its parts are possible only in  condition of the possibility of
the whole,  not the whole  all matter. They regard them
through the parts. It might,  merely as inferences from ab=
indeed, be called a <1composi->1  stract but arbitrary concepts,
<1tum  ideale,>1  but  not  <1reale.>1  and so as not being applicable
This,  however,  is  a  mere  to real things. How can it be
subtlety. Since space is not  possible to invent a different
a composite made up of kind of intuition from that
substances  (nor  even  of  given in the original intuition
real accidents), if I remove  of space, and how can the a
all  compositeness  from  it,  <1priori>1 determinations of space
nothing remains, not even the  fail to be directly applicable
point. For a point is possible  to what is only possible in so
only as the limit of a space,  far as it fills this space! Were
and so of a composite. Space  we to give heed to them,
440) and time do  not,  therefore,  then beside the mathematical
  consist of simple parts. What  point, which, while simple,
  belongs only to the state of a  is not a part but only the
  substance, even though it has  limit of a space, we should
  a magnitude, <1e.g.>1 alteration,  have  to  conceive  physical
  does not consist of the simple;  points  as  being  likewise
00094
that is to say, a certain degree  simple, and yet as having the
of alteration does not come  distinguishing characteristic
about through the accretion  of being able, as parts of
of many simple alterations.  space, to fill space through
Our inference from the com-  their mereaggregation. With-
posite to the simple applies  out repeating the many fa-
only to self-subsisting things.  miliar and conclusive refuta-
Accidents of the state [of a  tions  of this  absurdity---it
thing] are not self-subsisting.  being quite futile to attempt
Thus the proof of the neces-  to reason away by sophistical
sity of the simple, as the con-  manipulation of purely dis-
stitutive parts of the sub- cursive concepts the evident
-  stantially composite, can easily demonstrated truth of mathe-
  be upset (and therewith the  matics---I make only one ob-
  thesis as a whole), if it be servation, that when philo-
  extended too far and in the  sophy here plays tricks with
  absence of a limiting qualifi-  mathematics, it does so be-
  cation be made to apply to  cause it forgets that in this
'  everything composite---as has discussion we are concerned
  frequently happened.  only with <1appearances>1 and
  Moreover I am here speak- their condition. Here it is
  ing only of the simple in so  not sufficient to find for the
  far as it is necessarily given pure concept of the com-
  in the composite---the latter  posite formed by the under-
  being resolvable into the standing the concept of the
  A4421 t Th  d  i th i  i t iti  f h i l
  strict sense in which it is em- for the intuition of the com-
  ployed by Leibniz, should refer  posite (matter).  But by the
  only to the simple which is  laws of sensibility, and there-
  <1immediately>1 given as simple  fore in objects of the senses,
  substance <1(e.g.>1 in self-con- this is quite impossible.
  sciousness), and not to an  Though it may be true that
  element of the composite. when a whole, made up of
  This latter is better entitled  substances, is thought by the
  <1atomus.1>1 As  I  am  seeking  pure understanding alone, we
  to prove the [existence of]  must, prior to all composi-
  simple substances only as tion of it, have the simple,
  elements in the composite, I  this  does  not  hold  of the
00095
might entitle the thesis 1 of  <1totum  substantiale  phaeno->1
the second antinomy, tran-  <1menon>1 which, as empirical
scendental <1atomistic.>1 But as intuition in space, carries
this word has long been ap-  with it the necessary char-
propriated to signify a parti-  acteristic that no part of it
cular  mode  of  explaining  is simple, because no part of
bodily appearances  <1(mole->1  space is simple. The monad-
<1culae),>1 and therefore pre-  ists have, indeed, been suffi-
supposes empirical concepts,  ciently acute to seek escape
the thesis may more suitably  from this difficulty by refusing
be entitled the dialectical  to treat space as a condition
principle of <1monadology.>1  of the possibility of the objects
  of outer intuition (bodies),
  and by taking instead these
  and the dynamical relation of
  substances as the condition of
  the possibility of space. But
  we have a concept of bodies
  only as appearances; and as
  such they necessarily pre-
  suppose space as the condi-
  tion of the possibility of all
  outer appearance. This eva-
  sion of the issue is therefore
  futile, and has already been
  sufficiently disposed of in
  the Transcendental Aesthetic.
  The argument of the monad-
  ists would indeed be valid if
  bodies were things in them-
  selves.
  The second dialectical as- (B 443
  sertion has this peculiarity,
  that over against it stands
  a dogmatic assertion which
  is the only one of all the
  pseudo-ration al assertions that
  undertakes to afford mani-
  fest evidence, in an empirical
00096
  which we have been ascrib-
  ing only to transcendental
  ideas, namely, the absolute
  simplicity of substance---I
  refer to the assertion that
  the object of inner sense,
  the " I ' which there thinks,
  is an absolutely simple sub-
  stance. Without entering upon
  this question (it has been
  fully considered above), I
  need only remark, that if (as
  happens in the quite bare
  representation,  "  I  ')  anything
  is thought as object only,
  without the addition of any
  synthetic determination of its
  intuition, nothing manifold
  and no compositeness can be
  perceived in such a representa-
  tion. Besides, since the predi-
  cates through which I think
  this object are merely intui-
  tions of inner sense, nothing
  can there be found which
  shows a manifold [of ele-
  ments] external to one an-
  other, and therefore real com-
  positeness.  Self-cons ciousness
  is of such a nature that since
  the subject which thinks is
  at the same time its own
  object, it cannot divide itself,
  though it can divide the de-
  terminations which inhere in
  it ; for in regard to itself
  every object is absolute unity.
  Nevertheless, when this sub-
  ject is viewed <1outwardly,>1 as
00097
  an object of intuition, it must
  exhibit [some sort of] com-
  positeness in its appearance;
  and it must always be viewed
  in this way if we wish to
  know whether or not there
  be in it a manifold [of ele-
  ments] <1external>1 to one an-
  other.
A444 )  THE ANTINOMY OF PURE REASON  ( A445
  THIRD CONFLICT OF THE TRANSCENDENTAL IDEAS
  <1Thesis  Antithesis>1
  Causality  in  accordance  There is no freedom; every-
with laws of nature is not the  thing in the world takes place
only causality from which the  solely  in  accordance  with
appearances of the world can  laws of nature.
one and all be derived. To
explain these appearances it
is necessary to assume that
there is also another causality,
that of freedom.
  <1Proof  Proof>1
  Let us assume that there  Assume that there is free-
is no other causality than that  dom  in  the  transcendental
in accordance with laws of  sense, as a special kind of
nature. This being so, every-  causality in accordance with
thing which <1takes place>1 pre-  which  the  events  in  the
supposes a preceding state  world can have come about,
upon which it inevitably fol-  namely, a power of absolutely
lows according to a rule. But  beginning a state, and there-
the preceding state must it-  fore also of absolutely begin-
self be something which has  ning a series of consequences
taken place (having come to  of that state; it then follows
be in a time in which it that not only will a series
previously was not); for if it  have its absolute beginning
  02
00098
had always existed, its con-  in this spontaneity, but that
sequence also would have the very determination of
always existed, and would  this spontaneity to originate
not have only just arisen.  the series, that is to say,
The causality of the cause  the causality itself, will have
through which  something  an absolute beginning; there
takes place is itself, therefore,  will be no antecedent through
something that has <1taken>1 which this act, in taking
<1place,>1 which again presup-  place, is determined in ac-
poses, in accordance with cordance with fixed laws.
the  law  of  nature,  a  pre-  But every beginning of action
ceding state and its causality,  presupposes a state of the
and this in similar manner a  not yet acting cause; and a
still earlier state, and so on.  <1dynamical>1 beginning of the
If, therefore, everything takes  action, if it is also a first be-
place solely in accordance ginning, presupposes a state
with laws of nature, there  which has no <1causal>1 con-
will always be only a relative1  nection with  the  preceding
B 44 ) and never a first beginning,  state of the cause, that is to
  and consequently no com- say, in nowise follows from
  pleteness of the series on the  it. Transcendental freedom
  side of the causes that arise  thus stands opposed to the
  the one from the other.  But  law of causality; and the kind
  the law of nature is just this,  of connection which it as-
  that nothing takes place with-  sumes as holding between the (B 44
  out a cause <1sufficiently>1 deter-  successive states of the active
  mined <1a priori.>1 The proposi-  causes renders all unity of
  tion that no causality is pos-  experience impossible. It is
  sible save in accordance with  not to be met with in any
  laws of nature, when taken  experience, and is therefore
  in unlimited universality, is  an empty thought-entity.
  therefore self - contradictory;  In nature alone, therefore,
  and this cannot, therefore,  [not in freedom], must we
  be regarded as the sole kind  seek for the connection and
  of causality.  order of cosmical events.
  We must, then, assume a Freedom (independence) from
  causality through which some- the laws of nature is no doubt
  thing takes place, the cause  a liberation from compulsion,
  of which is not itself deter-  but also from the guidance
00099
mined, in accordance with of all rules. For it is not
necessary laws, by another  permissible to say that the
cause antecedent to it, that is  <1laws>1 of freedom enter into
to say, an <1absolute spontaneity>1  the causality exhibited in the
of the cause, whereby a series  course of nature, and so take
of appearances, which pro-  the place of natural laws.
ceeds in accordance with laws  If freedom were determined
of nature, begins <1of itself.>1  in  accordance with laws,
This is transcendental free-  it would not be freedom;
dom, without which, even in  it would simply be nature
the [ordinary] course of na-  under another name. Nature
ture, the series of appearances  and transcendental freedom
on the side of the causes can  differ as do conformity to
never be complete.  law and lawlessness. Nature
  does indeed impose upon the
  understanding the exacting
  task of always seeking the
  origin of events ever higher
  in the series of causes, their
  causality being always condi-
  tioned. But in compensation
  it holds out the promise of
  thoroughgoing unity of ex-
  perience in accordance with
  laws. The illusion of freedom,
  on the other hand, offers a
  point of rest to the enquiring
  understanding in the chain
  of causes, conducting it to
  an unconditioned causality
  which begins to act of itself.
  This causality is, however,
  blind, and abrogates those
  rules through which alone
  a completely coherent ex-
  perience is possible.
00100
B 446)  OBSERVATION ON THE THIRD ANTINOMY  ( AB 449
  I. <1On the Thesis>1  II. <1On the Antithesis>1
  The transcendental idea of  The defender of an om-
freedom does not by any nipotent nature (transcend-
means constitute the whole  ental <1physiocracy),>1 in main-
content of the psychological  taining his position against
concept of that name, which  the  pseudo-rational  argu-
is mainly empirical. The tran-  ments offered in support of the
scendental idea stands only  counter-doctrine of freedom,
for the absolute spontaneity  would argue as follows. <1If>1
of an action, as the proper  <1you do not, as regards time,>1
ground of its imputability.  <1admit anything as being>1
This, however, is, for philo-  <1mathematically first in the>1
sophy, the real stumbling- <1world, there is no necessity,>1
block;  for  there  are  insur-  <1as regards causality,for seek->1
mountable difficulties in the  <1ing something that is dynamic->1
way of admitting any such  <1ally first.>1  What authority
type of unconditioned caus-  have you for inventing an
ality. What has always so  absolutely first state of the
greatly embarrassed specula-  world, and therefore an abso-
tive reason in dealing with  lute beginning of the ever-
the question of the freedom  flowing series of appearances,
of  the  will,  is  its  strictly  and so of procuring a resting-
transcendental aspect. The place for your imagination
problem, properly viewed, is  by setting bounds to limitless
solely this: whether we must  nature? Since the substances
admit a power of <1spontane->1  in the world have always
<1ously>1 beginning a series of  existed---at least the unity of
successive things or states.  experience renders necessary
How such a power is possible  such a supposition---there is
is not a question which re-  no difficulty in assuming that
quires to be answered in this  change of their states, that is,
case, any more than in regard  a series of their alterations, has
to causality in accordance likewise always existed, and
with the laws of nature. For, therefore that a first begin-
  [as we have found], we have  ning, whether mathematical
  to remain satisfied with the or dynamical, is not to be
00101
<1a priori>1 knowledge that this  looked for. The possibility of
latter type of causality must be  such an infinite derivation,
presupposed; we are not in the  without  a  first  member  to
least able to comprehend how  which all the rest is merely a
it can be possible that through  sequel, cannot indeed, in re-
one  existence  the  existence  spect of its possibility, be ren-
of another is determined, and  dered  comprehensible.  But
for this reason must be guided  if for this reason you refuse
by experience alone. The to recognise this enigma in
necessity of a first beginning,  nature, you will find yourself
due to freedom, of a series of  compelled  to  reject  many
appearances we have demon-  fundamental synthetic pro-
strated only in so far as it  perties and forces, which as
is required to make an origin  little admit of comprehension.
of the world conceivable; for  The possibility even of altera- (B 451
all the later following states  tion itself would have to be
8) can be taken as resulting ac-  denied.  For were you not
  cording to purely natural assured by experience that
  laws. But since the power alteration actually occurs,
  of spontaneously beginning  you would never be able to
  a series in time is thereby  excogitate <1a priori>1 the pos-
  proved (though not under-  sibility of such a ceaseless
  stood), it is now also per-  sequence of being and not-
  missible for us to admit being.
  within the course of the  Even if a transcendental
  world different series as cap-  power of freedom be allowed,
  able in their causality of  as supplying a beginning of
  beginning of themselves, and  happenings in the world, this
  so to  attribute to their sub-  power would in any case have
  stances a power of acting to be outside the world
  from freedom. And we must  (though any such assump-
  not  allow  ourselves to be  tion that over and above the
  prevented from drawing this  sum of all possible intuitions
  conclusion by a misapprehen-  there exists an object which
  sion, namely that, as a series  cannot be given in any pos-
  occurring  in  the  world  can  sible perception, is still a very
  have only a relatively first  bold one). But to ascribe to
  beginning, being always pre-  substances in the world itself
  ceded in the world by some  such a power, can never be
  other state of things, no permissible; for, should this
00102
absolute first beginning of a  be done, that connection of
series is possible during the  appearances determining one
course of the world. For the  another with necessity ac-
absolutely first beginning of  cording to  universal  laws,
which we are here speaking  which we entitle nature, and
is not a beginning in time,  with it the criterion of em-
but in  causality.  If,  for in-  pirical truth, whereby experi-
stance, I at this moment ence is distinguished from
arise from my chair, in com-  dreaming, would almost en-
plete freedom, without being  tirely disappear. Side by side
necessarily determined there to  with such a lawless faculty
by the influence of natural  of freedom, nature [as an
causes, a new series, with all  ordered  system]  is  hardly
its natural consequences <1in>1  thinkable; the influences of
<1infinitum,>1 has its absolute the former would so un-
beginning in this event, al-  ceasingly alter the laws of
though as regards time this  the latter that the appear-
event is only the continuation  ances which in their natural
of a preceding series. For this  course are regular and uni-
resolution and act of mine do  form would be reduced to
not form part of the succession  disorder and incoherence.
of purely natural effects, and
are not a mere continuation
of them. In respect of its
happening, natural causes
exercise over it no determin-
ing influence whatsoever. It
does indeed follow upon them,
but without arising out of
them; and accordingly, in
respect of causality though
not of time, must be entitled
  an absolutely first beginning
  of a series of appearances.
  This requirement of reason,
  that we appeal in the series
  of natural causes to a first
  beginning, due to freedom,
  is amply confirmed when
  we observe that all the philo-
00103
sophers of antiquity, with the
sole exception of the Epi-
curean School, felt them-
selves obliged, when explain-
ing cosmical movements, to
assume a <1prime mover,>1 that
is, a freely acting cause, which
first and of itself began this
series of states.  They made
no attempt to render a first be-
ginning conceivable through
nature's own resources.
A452 )  THE ANTINOMY OF PURE REASON  ( A453
  FOURTH CONFLICT OF THE TRANSCENDENTAL IDEAS
  <1Thesis  Antithesis>1
  There belongs to the world,  An absolutely necessary
either as its part or as its  being nowhere exists in the
cause, a being that is abso-  world, nor does it exist out-
lutely necessary.  side the world as its cause.
  <1Proof  Proof>1
  The sensible world, as the  If we assume that the
sum-total of all appearances,  world itself is necessary, or
contains a series of alterations.  that a necessary being exists
For without such a series even  in it, there are then two alter-
the representation of serial  natives. Either there is a be-
time, as a condition of the  ginning in the series of alter-
possibility of the sensible ations which is absolutely
world, would not be given us.a  necessary, and therefore with-
But every alteration stands  out a cause, or the series it-
underits condition, which pre-  self is without any beginning,
cedes it in time and renders  and although contingent and
  a Time, as the formal condition of the possibility of changes, is
indeed objectively prior to them; subjectively, however, in actual
consciousness, the representation of time, like every other, is given
only in connection with perceptions.
00104
it necessary. Now every con-  conditioned in all its parts.
ditioned that is given pre-  none the less, as a whole, is
supposes, in respect of its  absolutely necessary and un-
existence, a complete series of  conditioned.  The  former
conditions up to the uncon-  alternative, however, conflicts
ditioned, which alone is abso-  with the dynamical law of the
lutely necessary. Alteration  determination of all appear-
thus existingas a consequence  ances in time; and the latter
of the absolutely necessary,  alternative contradicts itself,
the  existence  of  something  since the existence of a series1
absolutely necessary must cannot be necessary if no
be granted.  But this neces-  single member of it is neces-
sary existence itself belongs  sary.
to the sensible world. For if  If, on the other hand, we
it existed outside that world,  assume that an absolutely
the series of alterations in the  necessary cause of the world
world would derive its begin-  exists outside the world, then
ning from a necessary cause  this  cause,  as  the  highest
A 454) which would not itself belong  member in the series of the (  45
  to the sensible world. This,  causes  of changes  in  the
  however, is impossible. For  world, must begin the exist-
  since the beginning of a series  ence of the latter and their
  in time can be determined  series.a Now this cause must
  only by that which precedes  itself begin to act, and its
  it in time, the highest condi-  causality would therefore be
  tion of the beginning of a  in time, and so would be-
  series of changes must exist  long to the sum of appear-
  in the time when the series  ances, that is, to the world. It
  as yet was not (for a begin-  follows thatit itself, the cause,
  ning is an existence preceded  would  not be outside the
  by a time in which the thing  world---which contradicts our
  that begins did not yet exist).  hypothesis. Therefore neither
  Accordingly  the  causality  in the world, nor outside the
  of the  necessary  cause  of  world (though in causal con-
  a The word "begin' is taken in two senses; first as <1active,>1 signify-
  ing that as cause it begins <1(infit)>1 a series of states which is its effect;
  secondly as <1passive,>1 signifying the causality which begins to operate
  (fit) in the cause itself. I reason here from the former to the latter
  meaning.
00105
alterations, and therefore the  nection with it), does there
cause itself,  must belong to  exist any absolutely necessary
time and so to appearance---  being.
time being possible only as
the form of appearance. Such
causality cannot, therefore,
be thought apart from that
sum of all appearances which
constitutes the world of sense.
Something absolutely neces-
sary is therefore contained in
the world itself, whether this
something be the whole series
of alterations in the world or
a part of the series.
  45 )  OBSERVATION ON THE FOURTH ANTINOMY  (A 457
  I. <1On the Thesis>1  II. <1On the Antithesis>1
  In proving the existence of  The difficulties in the way
a necessary being I ought  of asserting the existence of
not,  in this connection, to  an absolutely necessary high-
employ any but the <1cosmo->1  est cause, which we suppose
<1logical>1 argument, that, ourselves to meet as we
namely, which ascends from  ascend in the series of appear-
the conditioned in the [field  ances,  cannot  be  such  as
of]  appearance to  the un-  arise in connection with mere
conditioned in concept, this  concepts of the necessary
latter  being  regarded  as  the  existence of a thing in general.
necessary  condition  of the  The difficulties are not, there-
absolute totality of the series.  fore, ontological,  but  must
To seek proof of this from the  concern the causal connection
mere idea of a supreme being  of a series of appearances for
belongs to another principle  which a condition has to be
of reason, and will have to  assumed that is itself un-
be treated separately.  conditioned, and so must be
  The pure cosmological cosmological, and relate to
proof, in demonstrating the  empirical laws. It must be
existence of a necessary being,  shown  that  regress  in  the
00106
has to leave unsettled whether  series  of  causes  (in  the
this being is the world itself  sensible  world)  can  never
or a thing1 distinct from it.  terminate  in  an  empirically
To establish the latter view,  unconditioned condition, and
we should require principles  that the cosmological argu-
which are no longer cosmo-  ment from the contingency
logical and do not continue in  of states  of the  world,  as
the series of appearances. For  evidenced bytheir alterations,
we  should  have to  employ  does not Support the assump-
concepts of contingent beings  tion of a first and absolutely
in general (viewed as objects  originative cause of the series.
of the understanding alone)  A strange situation is dis- (  459
and a principle which will  closed  in  this  antinomy.
enable us to connect these,  From the same ground on
by means of mere concepts,  which, in the thesis, the ex-
with a necessary being. But  istence of an original being
all this belongs to a <1tran->1  was inferred, its non-exist-
<1scendent>1 philosophy ; and ence is inferred in the anti-
that we are not yet in a  thesis, and this with equal
position to discuss.  stringency. We were first
  If  we  begin  our  proof  assured that <1a necessary being>1
cosmologically, resting it upon  <1exists>1 because the whole of
the series of appearances and  past time comprehends the
the regress therein according  series of all conditions and
to empirical laws of causality,  therefore also the uncondi-
we must not afterwards sud-  tioned (that is, the necessary);
denly deviate from this mode  we are now assured that <1there>1
of argument, passing over to  <1is no necessary being,>1 and
something that is not a mem-  precisely for the reason that
B 48568) ber of the series. Anything  the whole of past time com-
  taken as condition must be  prehends the series of all
  viewed precisely in the same  conditions (which therefore
  manner in which we viewed  are one and all themselves
  the relation of the condi- conditioned). The explana-
  tioned to its condition in the  tion is this. The former argu-
  series which is supposed to  ment takes account only of
  carry us by continuous ad-  <1the absolute totality>1 of the
  vance to the supreme condi-  series of conditions deter-
  tion. If, then, this relation is  mining each other in time,
00107
sensible and falls within the  and so reaches what is un-
province of the possible em-  conditioned and necessary.
pirical employment of under-  The latter argument, on the
standing, the highest condi-  other hand, takes into con-
tion or cause can bring the  sideration the <1contingency>1 of
regress to a close only in  everything which is deter-
accordance with the laws of  mined in the temporal series
sensibility, and therefore only  (everything being preceded
in so far as it itself belongs  by a time in which the condi-
to the temporal series. The  tion must itself again be
necessary being must there-  determined as conditioned),
forebe regarded asthe highest  and from this point of view
member of the cosmical series.  everything unconditioned and (A 461
  Nevertheless certain think-  all absolute necessity com-
ers have allowed themselves  pletely vanish. Nevertheless,
the liberty of making such a  the method of argument in
<1saltus>1  (                     both cases is entirely in con-
     ). From the alterations  formity even with ordinary
in the world they have in-  human reason, which fre-
ferred  their  empirical  con-  quently falls into conflict with
tingency, that is, their de-  itself through considering its
pendence on empirically de-  object  from  two  different
termining causes, and so have  points of view. M. de Mairani
obtained an ascending series  regarded the controversy be-
of empirical conditions. And  tween two famous astrono-
- so far they were entirely in mers, which arose from a
  the  right.  But  since  they  similar difficulty in regard to
  could not find in such a choice of standpoint, as a
  series any first beginning, or  sufficiently remarkable phe-
  any  highest  member,  they  nomenon to justify hiswriting
  passed  suddenly  from  the  a special treatise upon it. The
  empirical concept of con- one had argued that the
  tingency, and laid hold upon  <1moon revolves on its own>1
  the pure category, which then  <1axis,>1 because it always turns
  gave rise to a strictly intelli-  the same side towards the
  gible series the completeness  earth. The other drew the
  of which rested on the exist-  opposite conclusion that <1the>1
  ence of an absolutely neces-  <1moon does not revolve on its>1
  sary cause. Since this cause  <1own axis,>1 because it always
00108
A462)  THE ANTINOMY OF PURE REASON
  Section 3
  THE INTEREST OF REASON IN THESE CONFLICTS
  We have now completely before us the dialectic play of
  cosmological ideas. The ideas are such that an object congruent
  with them can never be given in any possible experience, and
  that even in thought reason is unable to bring them into har-
  mony with the universal laws of nature. Yet they are not
  arbitrarily conceived. Reason, in the continuous advance of
  empirical synthesis, is necessarily led up to them whenever
  it endeavours to free from all conditions and apprehend in
  its unconditioned totality that which according to the rules
  of experience can never be determined save as conditioned.
  These pseudo-rational assertions are so many attempts to
  solve four natural and unavoidable problems of reason. There
  are just so many, neither more nor fewer, owing to the fact that
  there are just four series of synthetic presuppositions which
  impose <1a priori>1 limitations on the empirical synthesis.
  The proud pretensions of reason, when it strives to extend
  its domain beyond all limits of experience, we have represented
  only in dry formulas that contain merely the ground of their
B  3) legal claims. As befits a transcendental philosophy, they have
  been divested of all empirical features, although only in con-
  nection therewith can their full splendour be displayed. But
  in this empirical application, and in the progressive extension
  of the employment of reason, philosophy, beginning with the
  field of our experiences and steadily soaring to these lofty ideas,
  displays a dignity and worth such that, could it but make good
  its pretensions, it would leave all other human science far
  behind. For it promises a secure foundation for our high-
  est expectations in respect of those ultimate ends towards
  which all the endeavours of reason must ultimately converge.
  Whether the world has a beginning [in time] and any limit to
  its extension in space; whether there is anywhere, and perhaps
  in my thinking self, an indivisible and indestructible unity,
  or nothing but what is divisible and transitory; whether I am
  free in my actions or, like other beings, am led by the hand of
00109
nature and of fate; whether finally there is a supreme cause
of the world, or whether the things of nature and their order
must as the ultimate object terminate thought---an object that
even in our speculations can never be transcended: these are
questions for the solution of which the mathematician would
gladly exchange the whole of his science. For mathematics
can yield no satisfaction in regard to those highest ends that (A 464
most closely concern humanity. And yet the very dignity of
mathematics (that pride of human reason) rests upon this,
that it guides reason to knowledge of nature in its order and
regularity---alike in what is great in it and in what is small---
and in the extraordinary unity of its moving forces, thus
rising to a degree of insight far beyond what any philosophy
based on ordinary experience would lead us to expect; and
so gives occasion and encouragement to an employment of
reason that is extended beyond all experience, and at the same
time supplies it with the most excellent materials for support-
ing its investigations---so far as the character of these permits
---by appropriate intuitions.
  Unfortunately for speculation, though fortunately perhaps
for the practical interests of humanity, reason, in the midst of
its highest expectations, finds itself so compromised by the
conflict of opposing arguments, that neither its honour nor
its security allows it to withdraw and treat the quarrel with
indifference as a mere mock fight; and still less is it in a posi-
tion to command peace, being itself directly interested in the
matters in dispute. Accordingly, nothing remains for reason
save to consider whether the origin of this conflict, whereby
it is divided against itself, may not have arisen from a mere
misunderstanding In such an enquiry both parties, per chance,
may have to sacrifice proud claims; but a lasting and peaceful ( 4 5
reign1 of reason over understanding and the senses would
thereby be inaugurated.
  For the present we shall defer this thorough enquiry, in
order first of all to consider upon which side we should prefer
to fight, should we be compelled to make choice between
the opposing parties. The raising of this question, how we
should proceed if we consulted only our interest and not
the logical criterion of truth, will decide nothing in regard to
00110
the contested rights of the two parties, but has this advantage,
that it enables us to comprehend why the participants in this
quarrel, though not influenced by any superior insight into the
matter under dispute, have preferred to fight on one side
rather than on the other. It will also cast light on a number of
incidental points, for instance, the passionate zeal of the one
party and the calm assurance of the other; and will explain
why the world hails the one with eager approval, and is im-
placably prejudiced against the other.
  Comparison of the principles which form the starting-
points of the two parties is what enables us, as we shall find,
to determine the standpoint from which alone this preliminary
enquiry can be carried out with the required thoroughness. In
the assertions of the antithesis we observe a perfect uniformity
in manner of thinking and complete unity of maxims, namely
466) a principle of pure <1empiricism,>1 applied not only in explana-
  tion of the appearances within the world, but also in the
  solution of the transcendental ideas of the world itself, in its
  totality. The assertions of the thesis, on the other hand, pre-
  suppose, in addition to the empirical mode of explanation
  employed within the series of appearances, intelligible begin-
  nings; and to this extent its maxim is complex. But as its
  essential and distinguishing characteristic is the presupposi-
  tion of intelligible beginnings, I shall entitle it the <1dogmatism>1
  of pure reason.
  In the determination of the cosmological ideas, we find on
  the side of <1dogmatism,>1 that is, of the thesis:
  First, a certain <1practical interest>1 in which every right-
  thinking man, if he has understanding of what truly concerns
  him, heartily shares. That the world has a beginning, that my
  thinking self is of simple and therefore indestructible nature,
  that it is free in its voluntary actions and raised above the
  compulsion of nature, and finally that all order in the things
  constituting the world is due to a primordial being, from which
  everything derives its unity and purposive connection---these
  are so many foundation stones of morals and religion. The
  antithesis robs us of all these supports, or at least appears to
  do so.
  Secondly, reason has a <1speculative interest>1 on the side of
00111
the thesis. When the transcendental ideas are postulated and
employed in the manner prescribed by the thesis, the entire (A 467
chain of conditions and the derivation of the conditioned c  (B 495
be grasped completely <1a priori.>1 For we then start from the
unconditioned. This is not done by the antithesis, which for
this reason is at a very serious disadvantage. To the question
as to the conditions of its synthesis it can give no answer which
does not lead to the endless renewal of the same enquiry.
According to the antithesis, every given beginning compels us
to advance to one still higher; every part leads to a still smaller
part; every event is preceded by another event as its cause; and
the conditions of existence in general rest always again upon
other conditions, without ever obtaining unconditioned foot-
ing and support in any self-subsistent thing, viewed as prim-
ordial being.
  Thirdly, the thesis has also the advantage of <1popularity;>1
and this certainly forms no small part of its claim to favour.
The common understanding finds not the least difficulty in the
idea of the unconditioned beginning of all synthesis. Being
more accustomed to descend to consequences than to ascend
to grounds, it does not puzzle over the possibility of the abso-
lutely first; on the contrary, it finds comfort in such concepts,
and at the same time a fixed point to which the thread by
which it guides its movements can be attached. In the restless
ascent from the conditioned to the condition, always with one
foot in the air, there can be no satisfaction.
  In the determination of the cosmological ideas  we find on (A 468
the side of <1empiricism,>1 that is, of the <1antithesis:>1 first, no such
practical interest (due to pure principles of reason) as is pro-
vided for the thesis by morals and religion.  On the contrary,
pure empiricism appears to deprive them of all power and in-
fluence. If there is no primordial being distinct from the world,
if the world is without beginning and therefore without an
Author, if our will is not free, and the soul is divisible and
perishable like matter, <1moral>1 ideas and principles lose all
validity, and share in the fate of the <1transcendental>1 ideas
which served as their theoretical support.
  But secondly, in compensation, empiricism yields advan-
tages to the speculative1 interest of reason, which are very
00112
attractive and far surpass those which dogmatic teaching
bearing on the ideas of reason can offer. According to the
principle of empiricism the understanding is always on its own
  proper ground, namely, the field of genuinely possible experi-
 ences, investigating their laws, and by means of these laws
  affording indefinite extension to the sure and comprehensible
  knowledge which it supplies. Here every object, both in itself
  and in its relations, can and ought to be represented in in-
  tuition, or at least in concepts for which the corresponding
  images can be clearly and distinctly provided in given similar
  intuitions. There is no necessity to leave the chain of the
  A 469) natural order and to resort to ideas, the objects of which are
  not known, because, as mere thought-entities, they can never
  be given. Indeed, the understanding is not permitted to leave
  its proper business, and under the pretence of having brought
  it to completion to pass over into the sphere of idealising
  reason and of transcendent concepts---a sphere in which it
  is no longer necessary for it to observe and investigate in
  accordance with the laws of nature, but only to <1think>1 and to
  <1invent1>1 in the assurance that it cannot be refuted by the facts
  of nature, not being bound by the evidence which they yield,
  but presuming to pass them by or even to subordinate them
  to a higher authority, namely, that of pure reason.
  The empiricist will never allow, therefore, that any epoch
  of nature is to be taken as the absolutely first, or that any
  limit of his insight into the extent of nature is to be regarded
  as the widest possible. Nor does he permit any transition from
  the objects of nature---which he can analyse through observa-
  tion and mathematics, and synthetically determine in intuition
  (the extended)---to those which neither sense nor imagination
  can ever represent <1in concreto>1 (the simple). Nor will he admit
  the legitimacy of assuming in nature itself any power that
  operates independently of the laws of nature (freedom), and
  so of encroaching upon the business of the understanding,
  which is that of investigating, according to necessary rules,
  A 470) the origin of appearances.  And, lastly, he will not grant
  that a cause ought ever to be sought outside nature' in an
  original being. We know nothing but nature, since it alone can
  present objects to us and instruct us in regard to their laws.
00113
If the empirical philosopher had no other purpose in pro-
pounding his antithesis than to subdue the rashness and pre-
sumption of those who so far misconstrue the true vocation of
reason as to boast of insight and knowledge just where true in-
sight and knowledge cease, and to represent as furthering spec-
ulative interests that which is valid only in relation to practical
interests (in order, as may suit their convenience, to break the
thread of physical enquiries, and then under the pretence of ex-
tending knowledge to fasten it to transcendental ideas, through
which we really know only that we know nothing); if, I say,
the empiricist were satisfied with this, his principle would be
a maxim urging moderation in our pretensions, modesty in
our assertions, and yet at the same time the greatest possible
extension of our understanding, through the teacher fittingly
assigned to us, namely, through experience. If such were our
procedure, we should not be cut off from employing intel-  =
lectual <1presuppositions>1 and <1faith>1 on behalf of our practical
interest; only they could never be permitted to assume the (  471
title and dignity of science and rational insight. <1knowledge,>1
which as such is speculative, can have no other object than
that supplied by experience; if we transcend the limits thus
imposed, the synthesis which seeks, independently of experi-
ence, new species of knowledge, lacks that substratum of
intuition upon which alone it can be exercised.
  But when empiricism itself, as frequently happens, be-
comes dogmatic in its attitude towards ideas, and confidently
denies whatever lies beyond the sphere of its intuitive know-
ledge, it betrays the same lack of modesty; and this is all the
more reprehensible owing to the irreparable injury which is
thereby caused to the practical interests of reason.
  The above antithesis constitutes the opposition between
Epicureanisma and Platonism.
  a It is, however, open to question whether Epicurus ever pro-
pounded these principles as objective assertions. If perhaps they
were for him nothing more than maxims for the speculative employ-
ment of reason, then he showed in this regard a more genuine philo-
sophical spirit than any other of the philosophers of antiquity. That,
in explaining the appearances, we must proceed as if the field of our
enquiry were not circumscribed by any limit or beginning of the
world; that we must assume the material composing the world to
be such as it must be if we are to learn about it from experience;
00114
B 002)  Each of the two types of philosophy says more than it
  knows. The former encourages and furthers knowledge,
  though to the prejudice of the practical; the latter supplies
  excellent practical principles, but it permits reason to indulge
  in ideal explanations of natural appearances, in regard to
  which a speculative knowledge is alone possible to us---to the
  neglect of physical investigation.
  Finally, as regards the third factor which has to be con-
  sidered in a preliminary choice between the two conflicting
  parties, it is extremely surprising that empiricism should be so
  universally unpopular. The common understanding, it might
  be supposed, would eagerly adopt a programme which pro-
  mises to satisfy it through exclusively empirical knowledge
  and the rational connections there revealed---in preference to
  the transcendental dogmatism which compels it to rise to
  concepts far outstripping the insight and rational faculties
  B 473) of the most practised thinkers. But this is precisely what com-
  mends such dogmatism to the common understanding. For it
  then finds itself in a position in which the most learned can
  claim no advantage over it. If it understands little or nothing
  about these matters, no one can boast of understanding much
  more; and though in regard to them it cannot express itself in
  ing, nevertheless there is no end to the plausible arguments
  which it can propound, wandering as it does amidst mere ideas,
  about which no one knows anything, and in regard to which
  it is therefore free to be as eloquent as it pleases; whereas
  that we must postulate no other mode of the production of events
  than one which will enable them to be [regarded as] determined
  through unalterable laws of nature; and finally that no use must be
  472) made of any cause distinct from the world all these principles still
  [retain their value]. They are very sound principles (though seldom
  observed) for extending the scope of speculative philosophy, while
  at the same time [enabling us] to discover the principles of morality
  without depending for this discovery upon alien [<1i.e.>1 non-moral,
  theoretical] sources; and it does not follow in the least that those
  who require us, so long as we are occupied with mere speculation,
  to <1ignore>1 these dogmatic propositions [that there is a limit and
  beginning to the world, a Divine Cause, etc.], can justly be accused
  of wishing to <1defy>1 them.
00115
when matters that involve the investigation of nature are in
question, it has to stand silent and to admit its ignorance. Thus
indolence and vanity combine in sturdy support of these prin-
ciples. Besides, although the philosopher finds it extremely
hard to accept a principle for which he can give no justifica-
tion, still more to employ concepts the objective reality of which
he is unable to establish, nothing is more usual in the case of
the common understanding.  It insists upon having something
from which it can make a confident start. The difficulty of even
conceiving this presupposed starting-point does not disquiet
it. Since it is unaware what conceiving really means, it never
occurs to it to reflect upon the assumption; it accepts as known
whatever is familiar to it through frequent use. For the
common understanding, indeed, all speculative interests pale
before the practical; and it imagines that it comprehends and  B 5o2
knows what its fears or hopes incite it to assume or to believe.  A 474
Thus <1empiricism>1 is entirely devoid of the popularity of tran-
scendentally idealising reason; and however prejudicial such
empiricism may be to the highest practical principles, there
is no need to fear that it will ever pass the limits of the Schools,
and acquire any considerable influence in the general life or
any real favour among the multitude.
  Human reason is by nature architectonic. That is to say, it
regards all our knowledge as belonging to a possible system,
and therefore allows only such principles as do not at any rate
make it impossible for any knowledge that we may attain to
combine into a system with other knowledge. But the proposi-
tions of the antithesis are of such a kind that they render the
completion of the edifice of knowledge quite impossible. They
maintain that there is always to be found beyond every state
of the world a more ancient state, in every part yet other parts
similarly divisible, prior to every event still another event
which itself again is likewise generated, and that in existence
in general everything is conditioned, an unconditioned and
first existence being nowhere discernible. Since, therefore,
the antithesis thus refuses to admit as first or as a beginning
anything that could serve as a foundation for building, a
00116
complete edifice of knowledge is, on such assumptions, alto-
A 475) gether impossible. Thus the architectonic interest of reason---
the demand not for empirical but for pure <1a priori>1 unity of
  reason---forms a natural recommendation for the assertions
=  of the thesis.
  If men could free themselves from all such interests, and
  consider the assertions of reason irrespective of their conse-
  quences, solely in view of the intrinsic force of their grounds,
  and were the only way of escape from their perplexities to
  give adhesion to one or other of the opposing parties, their
  state would be one of continuous vacillation. To-day it would
  be their conviction that the human will is <1free;>1 to-morrow,
  dwelling in reflection upon the indissoluble chain of nature,
  they would hold that freedom is nothing but self-deception,
  that everything is simply <1nature.>1 If, however, they were
  summoned to action, this play of the merely speculative
  reason would, like a dream, at once cease, and they would
  choose their principles exclusively in accordance with practi-
  cal interests. Since, however, it is fitting that a reflective and
  enquiring being should devote a certain amount of time to
  the examination of his own reason, entirely divesting himself
  of all partiality and openly submitting his observations to the
  judgment of others, no one can be blamed for, much less pro-
  407 ) hibited from, presenting for trial the two opposing parties,
  leaving them, terrorised by no threats, to defend themselves as
  best they can, before a jury of like standing with themselves,
  that is, before a jury of fallible men.
  THE ANTINOMY OF PURE REASON
  Section 4
  THE ABSOLUTE NECESSITY OF A SOLUTION OF THE
  TRANSCENDENTAL PROBLEMS OF PURE REASON
  To profess to solve all problems and to answer all questions
  would be impudent boasting, and would argue such extrava-
  gant self-conceit as at once to forfeit all confidence. Neverthe-
  very nature of which requires that
  every question arising within their domain should be com-
00117
pletely answerable in terms of what is known, inasmuch as the
answer must issue from the same sources from which the
question proceeds. In these sciences it is not permissible to  -
plead unavoidable ignorance; the solution can be demanded.
We must be able, in every possible case, in accordance with a
rule, to know what is <1right>1 and what is <1wrong,>1 since this con-
cerns our obligation, and we have no obligation to that which
we cannot know. In the explanation of natural appearances, (  477  =
on the other hand, much must remain uncertain and man  (B 505
questions insoluble, because what we know of nature is by no
means sufficient, in all cases, to account for what has to be ex-
plained. The question, therefore, is whether in transcendental
philosophy there is any question relating to an object pre-
sented to pure reason which is unanswerable by this reason,
and whether we may rightly excuse ourselves from giving a
decisive answer. In thus excusing ourselves, we should have
to show that any knowledge which we can acquire still leaves
us in complete uncertainty as to what should be ascribed to
the object, and that while we do indeed have a concept suffi-
cient to raise a question, we are entirely lacking in materials
or power to answer the same.
  Now I maintain that transcendental philosophy is unique
in the whole field of speculative knowledge, in that no ques-
tion which concerns an object given to pure reason can be
insoluble for this same human reason, and that no excuse of
an unavoidable ignorance, or of the problem's unfathomable
depth, can release us from the obligation to answer it thor-
oughly and completely. That very concept which puts us in a
position to ask the question must also qualify us to answer it,
since, as in the case of right and wrong, the object is not to be
met with outside the concept.
  In transcendental philosophy, however, the only questions (A 47
to which we have the right to demand a sufficient answer
bearing on the constitution of the object, and from answering
which the philosopher is not permitted to excuse himself on
the plea of their impenetrable obscurity, are the cosmological.
These questions [bearing on the constitution of the object]
must refer exclusively to cosmological ideas.  For the object
must be given empirically, the question being only as to its
conformity to an idea. If, on the other hand, the object is
00118
transcendental, and therefore itself unknown; if, for instance,
the question be whether that something, the appearance of
which (in ourselves) is thought (soul), is in itself a simple being,
whether there is an absolutely necessary cause of all things,
and so forth, what we have then to do is in each case to seek
an object for our idea; and we may well confess that this object
  4079) is unknown to us, though not therefore impossible.a The cos-
  mological ideas alone have the peculiarity that they can pre-
  suppose their object, and the empirical synthesis required for
  its concept, as being given. The question which arises out of
  these ideas refers only to the advance in this synthesis, that
  is, whether it should be carried so far as to contain absolute
  totality---such totality, since it cannot be given in any experi-
  solely with a thing as object of a possible experience, not as a
  thing in itself, the answer to the transcendent cosmological
  question cannot lie anywhere save in the idea. We are not
  as regards possible experience are we enquiring what can
  be given <1in concreto>1 in any experience. Our sole question
  is as to what lies in the idea, to which the empirical synthesis
  can do no more than merely approximate; the question must
  therefore be capable of being solved entirely from the idea.
  Since the idea is a mere creature of reason, reason cannot
  disclaim its responsibility and saddle it upon the unknown
  object.
  a Although to the question, what is the constitution of a tran-
  scendental object, no answer can be given stating <1what it is,>1 we can
  yet reply that the <1question>1 itself is <1nothing,>1 because there is no
  given object [corresponding] to it. Accordingly all questions dealt
  with in the transcendental doctrine of the soul are answerable in
  this latter manner, and have indeed been so answered; its
  questions refer to the transcendental subject of all inner appear-
  ances, which is not itself appearance and consequently not <1given>1
  A 7 ) as object, and in which none of the categories (and it is to them
  B 5797) that the question is really directed) meet with the conditions re-
  quired for their application. We have here a case where the com-
  mon saying holds, that no answer is itself an answer. A question
  as to the constitution of that something which cannot be thought
  through any determinate predicate--inasmuch as it is completely
  outside the sphere of those objects which can be given to us---is
  entirely null and void.
00119
It is not so extraordinary as at first seems the case, that a (  480
science should be in a position to demand and expect none but
assured answers to all the questions within its domain <1(quae->1
<1stiones domesticae),>1 although up to the present they have per-
haps not been found. In addition to transcendental philosophy,
there are two pure rational sciences, one purely speculative,
the other with a practical content, namely, pure mathematics
and pure ethics. Has it ever been suggested that, because of
our necessary ignorance of the conditions, it must remain un-
certain what exact relation, in rational or irrational numbers,
a diameter bears to a circle? Since no adequate solution in
terms of rational numbers is possible, and no solution in terms
of irrational numbers has yet been discovered, it was con-
cluded that at least the impossibility of a solution can be
known with certainty, and of this impossibility Lambert has
given the required proof. In the universal principles of morals
nothing can be uncertain, because the principles are either
altogether void and meaningless, or must be derived from
the concepts of our reason. In natural science, on the other
hand, there is endless conjecture, and certainty is not to be
counted upon. For the natural appearances are objects which
are given to us independently of our concepts, and the key to
them lies not in us and our pure thinking, but outside us; and
therefore in many cases, since the key is not to be found, an (B
assured solution is not to be expected. I am not, of course, here
referring to those questions of the Transcendental Analytic
which concern the deduction of our pure knowledge; we are
at present  reating only of the certainty of judgments with
respect to their objects and not with respect to the source of
our concepts themselves.
  The obligation of an at least critical solution of the ques-
tions which reason thus propounds to itself, we cannot, there-
fore, escape by complaints of the narrow limits of our reason,
and by confessing, under the pretext of a humility based on self-
knowledge, that it is beyond the power of our reason to deter-
mine whether the world exists from eternity or has a begin-
ning; whether cosmical space is filled with beings to infinitude,
00120
or is enclosed within certain limits; whether anything in the
world is simple, or everything such as to be infinitely divisible;
whether there is generation and production through freedom,
or whether everything depends on the chain of events in the
natural order; and finally whether there exists any being com-
pletely unconditioned and necessary in itself, or whether every-
  thing is conditioned in its existence and therefore dependent on
  external things and itself contingent. All these questions refer
  to an object which can be found nowhere save in our thoughts,
  namely, to the absolutely unconditioned totality of the syn-
  thesis of appearances. If from our own concepts we are unable
  B 482) to assert and determine anything certain, we must not throw
  the blame upon the object as concealing itself from us. Since
  such an object is nowhere to be met with outside our idea, it is
  not possible for it to be given. The cause of failure we must
  in assuming that there is an actual object corresponding to
  the idea, the problem, as thus viewed, allows of no solution. A
  clear exposition of the dialectic which lies within our concept
  itself would soon yield us complete certainty how we ought
  to judge in reference to such a question.
  The pretext that we are unable to obtain certainty in regard
  to these problems can be at once met with the following question
  which certainly calls for a clear answer: Whence come those
  ideas, the solution of which involves us in such difficulty? Is it,
  perchance, appearances that demand explanation, and do we,
  in accordance with these ideas, have to seek only the principles
  or rules of their exposition? Even if we suppose the whole of
  nature to be spread out before us, and that of all that is pre-
  sented to our intuition nothing is concealed from our senses and
  consciousness, yet still through no experience could the object
  of our ideas be known by us <1in concreto.>1 For that purpose, in
  A 483) addition to this exhaustive intuition, we should require what
  5  is not possible through any empirical knowledge, namely, a
  completed synthesis and the consciousness of its absolute
  totality. Accordingly our question does not require to be raised
  in the explanation of any given appearance, and is therefore
  not a question which can be regarded as imposed on us by
  the object itself. The object can never come before us, since
  it cannot be given through any possible experience. In all
00121
possible perceptions we always remain involved in <1conditions,>1
whether in space or in time, and come upon nothing un-
conditioned requiring us to determine whether this uncondi-
tioned is to be located in an absolute beginning of synthesis,
or in an absolute totality of a series that has no beginning.
In its empirical meaning, the term "whole' is always only com-
parative. The absolute whole of quantity (the universe), the
whole of division, of derivation, of the condition of existence
in general, with all questions as to whether it is brought about
through finite synthesis or through a synthesis requiring infinite
extension, have nothing to do with any possible experience.
We should not, for instance, in any wise be able to explain the
appearances of a body better, or even differently, in assuming
that it consisted either of simple or of inexhaustibly com-
posite parts; for neither a simple appearance nor an infinite
composition can ever come before us. Appearances demand
explanation only so far as the conditions of their explanation
are given in perception; but all that may ever be given in this  B 512
way, when taken together in an <1absolute whole,>1 is not1 itself A 484
a perception. Yet it is just the explanation of this very
whole that is demanded in the transcendental problems of
reason.
  Thus the solution of these problems can never be found
in experience, and this is precisely the reason why we should
not say that it is uncertain what should be ascribed to the
object [of our idea]. For as our object is only in our brain,
and cannot be given outside it, we have only to take care to
be at one with ourselves, and to avoid that amphiboly which
transforms our idea into a supposed representation of an
object that is empirically given and therefore to be known
according to the laws of experience. The dogmatic solution is
therefore not only uncertain, but impossible. The critical solu-
tion, which allows of complete certainty, does not consider the
question objectively, but in relation to the foundation of the
knowledge upon which the question is based.
00122
B4 5)  THE ANTINOMY OF PURE REASON
  Section 5
  SCEPTICAL REPRESENTATION OF THE COSMOLOGICAL
  QUESTIONS IN THE FOUR TRANSCENDENTAL IDEAS
  We should of ourselves desist from the demand that our
  questions be answered dogmatically, if from the start we
  understood that whatever the dogmatic answer might turn out
  to be it would only increase our ignorance, and cast us from
  one inconceivability into another, from one obscurity into
  another still greater, and perhaps even into contradictions. If
  our question is directed simply to a yes or no, we are well
  advised to leave aside the supposed grounds of the answer, and
  first consider what we should gain according as the answer is
  in the affirmative or in the negative. Should we then find that
  in both cases the outcome is mere nonsense, there will be good
  reason for instituting a critical examination of our question, to
  determine whether the question does not itself rest on a ground-
  less presupposition, in that it plays with an idea the falsity of
  which can be more easily detected through study of its applica-
  tion and consequences than in its own separate representation.
  486) This is the great utility of the sceptical mode of dealing with
  the questions which pure reason puts to pure reason. By its
  means we can deliver ourselves, at but a small cost, from a
  great body of sterile dogmatism, and set in its place a sober
  critique, which as a true cathartic will effectively guard us
  against such groundless beliefs and the supposed polymathy
  to which they lead.
  If therefore, in dealing with a cosmological idea, I were
  able to appreciate beforehand that whatever view may be
  taken of the unconditioned in the successive synthesis of ap-
  pearances, it must either be <1too large>1 or <1too small>1 for any <1con->1
  <1cept of the understanding,>1 I should be in a position to under-
  stand that since the cosmological idea has no bearing save
  upon an object of experience which has to be in conformity
  with a possible concept of the understanding, it must be
00123
entirely empty and without meaning; for its object, view it as
we may, cannot be made to agree with it. This is in fact the
case with all cosmical concepts; and this is why reason, so
long as it holds to them, is involved in an unavoidable
antinomy. For suppose:---
  <1First,>1 that <1the world has no beginning:>1 it is then <1too large>1
for our concept, which, consisting as it does in a successive
regress, can never reach the whole eternity that has elapsed.
Or suppose that <1the world has a beginning,>1 it will then, in the
necessary empirical regress, be <1too small>1 for the concept of (B 4 7
the understanding. For since the beginning still presupposes a
time which precedes it, it is still not unconditioned; and the law
of the empirical employment of the understanding therefore
obliges us to look for a higher temporal condition; and the
world [as limited in time] is therefore obviously too <1small>1 for
this law.
  This is also true of the twofold answer to the question
regarding the magnitude of the world in space. If it is <1infinite>1
and unlimited, it is too <1large>1 for any possible empirical con-
cept. If it is <1finite>1 and limited, we have a right to ask what
determines these limits. Empty space is no self-subsistent
correlate of things, and cannot be a condition at which we
could stop; still less can it be an empirical condition, forming
part of a possible experience. (For how can there be any ex-
perience of the absolutely void?) And yet to obtain absolute
totality in the <1empirical>1 synthesis it is always necessary that
the unconditioned be an empirical concept. Consequently, a
<1limited>1 world is too <1small>1 for our concept
  <1Secondly,>1 if every appearance in space  matter) consists of
infinitely many parts, the regress in the 4-vision will always
be <1too great>1 for our concept; while if the <1division>1 of space is
to <1stop>1 at any member of the division (the simple), the regress
will be <1too small>1 for the idea of the unconditioned. For this
member always still allows of a regress to further parts con- (A 488
tained in it  (B 516
  <1Thirdly,>1 if we suppose that nothing happens in the world
save in accordance with the laws of <1nature,>1 the causality of
the cause will always itself be something that happens, making
necessary a regress to a still higher cause, and thus a con-
tinuation of the series of conditions <1a parte priori>1 without end.
00124
Nature, as working always through efficient causes, is thus
too <1large>1 for any of the concepts which we can employ in the
synthesis of cosmical events.
  If, in certain cases, we admit the occurrence of self-caused
events, that is, generation through <1freedom,>1 then by an un-
avoidable law of nature the question "why' still pursues us,
constraining us, in accordance with the law of causality
[which governs] experience, to pass beyond such events; and
  we thus find that such totality of connection is too <1small>1 for
  our necessary empirical concept.
  <1Fourthly,>1 if we admit <1an absolutely necessary being>1
  (whether it be the world itself, or something in the world, or
  the cause of the world), we set it in a time <1infinitely>1 remote
  from any given point of time, because otherwise it would be
  dependent upon another and antecedent being. But such an
  existence is then too large for our empirical concept, and is
  unapproachable through any regress, however far this be
  carried.
  B 197)  If, again, we hold that everything belonging to the world
  (whether as conditioned or as condition) is <1contingent,>1 any
  and every given existence is too <1small>1 for our concept. For
  we are constrained always still to look about for some other
  existence upon which it is dependent.
  We have said that in all these cases the cosmical idea is
  either too large or too small for the empirical regress, and
  therefore for any possible concept of the understanding. We
  have thus been maintaining that the fault lies with the idea, in
  being too large or too small for that to which it is directed,
  namely, possible experience. Why have we not expressed our-
  selves in the opposite manner, saying that in the former case
  the empirical concept is always too small for the idea, and in
  the latter too large, and that the blame therefore attaches to
  the empirical regress? The reason is this. Possible experience
  is that which can alone give reality to our concepts; in its
  absence a concept is a mere idea, without truth, that is, without
  relation to any object. The possible empirical concept is there-
  fore the standard by which we must judge whether the idea
  is a mere idea and thought-entity, or whether it finds its object
  in the world. For we can say of anything that it is too large
00125
or too small relatively to something else, only if the former is
required for the sake of the latter, and has to be adapted to it.
Among the puzzles propounded in the ancient dialectical (B 518
Schools was the question, whether, if a ball cannot pass
through a hole, we should say that the ball is too large or the
hole too small. In such a case it is a matter of indifference
how we choose to express ourselves, for we do not know which
exists for the sake of the other. In the case, however, of a man
and his coat, we do not say that a man is too tall for his coat,
but that the coat is too short for the man.
  We have thus been led to what is at least a well-grounded
suspicion that the cosmological ideas, and with them all the
mutually conflicting pseudo-rational assertions, may perhaps
rest on an empty and merely fictitious concept of the manner
in which the object of these ideas is given to us; and this sus-
picion may set us on the right path for laying bare the illusion
which has so long led us astray.
  THE ANTINOMY OF PURE REASON
  Section 6
  TRANSCENDENTAL IDEALISM AS THE KEY TO THE
  SOLUTION OF THE COSMOLOGICAL DIALECTIC
  We have sufficiently proved in the Transcendental Aesthetic
that everything intuited in space or time, and therefore all
objects of any experience possible to us, are nothing but ap-
pearances, that is, mere representations, which, in the manner (B 49
in which they are represented, as extended beings, or as series of
alterations, have no independent existence outside our thoughts.
This doctrine I entitle <1transcendental idealism.a>1 The realist, in
the transcendental meaning of this term, treats these modifica-
tions of our sensibility as self-subsistent things, that is, treats
<1mere representations>1 as things in themselves.
  It would  be unjust to ascribe to us that long - decried
  a I have also, elsewhere, sometimes entitled <1it formal>1 idealism,
to distinguish it from <1material>1 idealism, that is, from the usual type
of idealism which doubts or denies the existence of outer things
themselves. [Note added in B.]
00126
  empirical idealism, which, while it admits the genuine reality
  of space, denies the existence of the extended beings in it, or
  at least considers their existence doubtful, and so does not
  in this regard allow of any properly demonstrable distinction
  between truth and dreams. As to the appearances of inner
  sense in time, empirical idealism finds no difficulty in regard-
  ing them as real things; indeed it even asserts that this inner
  experience is the sufficient as well as the only proof of the
  actual existence of its object (in itself, with all this time-
  determination).
  B 520  Our transcendental idealism, on the contrary, admits the
  reality of the objects of outer intuition, as intuited in space, and
  of all changes in time, as represented by inner sense. For since
  space is a form of that intuition which we entitle outer, and
  A 492  since without objects in space there would be no empirical re-
  presentation whatsoever, we can and must regard the extended
  beings in it as real; and the same is true of time. But this space
  and this time, and with them all appearances, are not in them-
  selves <1things;>1 they are nothing but representations, and cannot
  exist outside our mind. Even the inner and sensible intuition
  of our mind (as object of consciousness) which is represented
  as being determined by the succession of different states in
  time, is not the self proper, as it exists in itself---that is, is not
  the transcendental subject---but only an appearance that has
  been given to the sensibility of this, to us unknown, being.
  This inner appearance cannot be admitted to exist in any such
  manner in and by itself; for it is conditioned by time, and time
  cannot be a determination of a thing in itself. The empirical
  truth of appearances in space and time is, however, sufficiently
  B 521  secured; it is adequately distinguished from dreams, if both
  dreams and genuine appearances cohere truly and completely
  in one experience, in accordance with empirical laws.
  The objects of experience, then, are <1never>1 given in <1them->1
  <1selves,>1 but only in experience, and have no existence outside it.
  A 493  That there may be inhabitants in the moon, although no one
  has ever perceived them, must certainly be admitted. This,
  however, only means that in the possible advance of experi-
  ence we may encounter them. For everything is real which
  stands in connection with a perception in accordance with the
00127
laws of empirical advance. They are therefore real if they
stand in an empirical connection with my actual consciousness,
although they are not for that reason real in themselves, that
is, outside this advance of experience.
  Nothing is really given us save perception and the empiri-
cal advance from this to other possible perceptions. For the
appearances, as mere representations, are in themselves real
only in perception, which perception is in fact nothing but the
reality of an empirical representation, that is, appearance. To
call an appearance a real thing prior to our perceiving it, either
means that in the advance of experience we must meet with
such a perception, or it means nothing at all. For if we were
speaking of a thing in itself, we could indeed say that it exists
in itself apart from relation to our senses and possible experi-
ence. But we are here speaking only of an appearance in space  B 522
and time, which are not determinations of things in them-
selves but only of our sensibility. Accordingly, that which is in
space and time is an appearance; it is not anything in itself A 494
but consists merely of representations, which, if not given in
us---that is to say, in perception---are nowhere to be met with.
  The faculty of sensible intuition is strictly only a recep-
tivity, a capacity of being affected in a certain manner with
representations, the relation of which to one another is a pure
intuition of space and of time (mere forms of our sensibility),
and which, in so far as they are connected in this manner in
space and time, and are determinable according to laws of the
unity of experience, are entitled <1objects.>1 The non-sensible cause
ofthese representations is completely unknown to us, and cannot
therefore be intuited by us as object. For such an object would
have to be represented as neither in space nor in time (these
being merely conditions of sensible representation), and apart
from such conditions we cannot think any intuition. We may,
however, entitle the purely intelligible cause of appearances in
general the transcendental object, but merely in order to have
something corresponding to sensibility viewed as a receptivity.
To this transcendental object we can ascribe the whole extent
and connection of our possible perceptions, and can say that it  B 523
is given in itself prior to all experience. But the appearances,
00128
while conforming to it, are not given in themselves, but only in
this experience, being mere representations, which as percep-
A 495  tions can mark out a real object onlyin so far as the perception
  connects with all others according to the rules of the unity of
  experience. Thus we can say that the real things of past time
  are given in the transcendental object of experience; but they
  are objects for me and real in past time only in so far as I repre-
  sent to myself (either by the light of history or by the guiding-
  clues of causes and effects) that a regressive series of possible
  perceptions in accordance with empirical laws, in a word, that
  the course of the world, conducts us to a past time-series as con-
  dition of the present time---a series which, however, can be re-
  presented as actual not in itself but only in the connection of a
  possible experience. Accordingly, all events which have taken
  place in the immense periods that have preceded my own ex-
  istence mean really nothing but the possibility of extending the
  chain of experience from the present perception back to the
  conditions which determine this perception in respect of time.
  If, therefore, I represent to myself all existing objects of
  the senses in all time and in all places, I do not set them in
  space and time [as being there] prior to experience. This
B 524  representation is nothing but the thought of a possible ex-
  perience in its absolute completeness. Since the objects are
  nothing but mere representations, only in such a possible
A 496 experience are they given. To say that they exist prior to
  all my experience is only to assert that they are to be met
  with if, starting from perception, I advance to that part of
  experience to which they belong. The cause of the empirical
  conditions of this advance (that which determines what mem-
  bers I shall meet with, or how far I can meet with any such
  in my regress) is transcendental, and is therefore necessarily
  unknown to me. We are not, however, concerned with this
  transcendental cause, but only with the rule of the advance in
  the experience in which objects, that is to say, appearances,
  are given to me. Moreover, in outcome it is a matter of in-
  difference whether I say that in the empirical advance in
  space I can meet with stars a hundred times farther removed
  than the outermost now perceptible to me, or whether I say
  that they are perhaps to be met with in cosmical space even
00129
though no human being has ever perceived or ever will per-
ceive them. For even supposing they were given as things in
themselves, without relation to possible experience, it still
remains true that they are nothing to me, and therefore are
not objects, save in so far as they are contained in the series of
the empirical regress. Only in another sort of relation, when
these appearances would be used for the cosmological idea of
an absolute whole, and when, therefore, we are dealing with a  B 525
question which oversteps the limits of possible experience,
does distinction of the mode in which we view the reality of
those objects of the senses become of importance, as serving  A 497
to guard us against a deceptive error which is bound to arise
if we misinterpret our empirical concepts.
  THE ANTINOMY OF PURE REASON
  Section 7
  CRITICAL SOLUTION OF THE COSMOLOGICAL CONFLICT
  OF REASON WITH ITSELF
  The whole antinomy of pure reason rests upon the dia-
lectical argument: If the conditioned is given, the entire series
of all its conditions is likewise given; objects of the senses are
given as conditioned; therefore, etc. Through this syllogism,
the major premiss of which appears so natural and evident, as
many cosmological ideas are introduced as there are differ-
ences in the conditions (in the synthesis of appearances) that
constitute a series. The ideas postulate absolute totality of
these series; and thereby they set reason in unavoidable
conflict with itself. We shall be in a better position to detect
what is deceptive in this pseudo-rational argument, if we first  B 526
correct and define some of the concepts employed in it.
  In the first place, it is evident beyond all possibility of
doubt, that if the conditioned is given, a regress in the series of A 498  :
all its conditions is <1set>1 us <1as a task.1>1 For it is involved in the
very concept of the conditioned that something is referred to a
condition, and if this condition is again itself conditioned, to a
more remote condition, and so through all the members of the
00130
two must be in the right. But even if this be so, none the less,
since the arguments on both sides are equally clear, it is im-
possible to decide between them. The parties may be com-
manded to keep the peace before the tribunal of reason; but the
controversy none the less continues. There can therefore be no
way of settling it once for all and to the satisfaction of both
sides, save by their becoming convinced that the very fact of
their being able so admirably to refute one another is evidence
that they are really quarrelling about nothing, and that a
certain transcendental illusion has mocked them with a reality
A 50302) where none is to be found. This is the path which we shall now
  proceed to follow in the settlement of a dispute that defies all
  attempts to come to a decision.
  *  *  *
  Zeno of Elea, a subtle dialectician, was severely repri-
  manded by Plato as a mischievous Sophist who, to show his
  skill, would set out to prove a proposition through convincing
  arguments and then immediately overthrow them by other
  arguments equally strong. Zeno maintained, for example, that
  God (probably conceived by him as simply the world) is
  neither finite nor infinite, neither in motion nor at rest, neither
  similar nor dissimilar to any other thing. To the critics of his
  procedure he appeared to have the absurd intention of denying
  both of two mutually contradictory propositions. But this ac-
  cusation does not seem to me to be justified. The first of his
  propositions I shall consider presently more in detail. As re-
  gards the others, if by the word "God' he meant the universe, he
  would certainly have to say that it is neither abidingly present
  in its place, that is, at rest, nor that it changes its place, that is,
  is in motion; because all places are in the universe, and the
  universe is not, therefore, itself in any place. Again, if the
  universe comprehends in itself everything that exists, it cannot
  be either similar or dissimilar to any other thing, because
B 531  there is no <1other>1 thing, nothing outside it, with which it could
A 503  be compared. If two opposed judgments presuppose an inad-
  missible condition, then in spite of their opposition, which does
  not amount to a contradiction strictly so-called, both fall to the
  ground, inasmuch as the condition, under which alone either
  of them can be maintained, itself falls.
00131
If it be said that all bodies have either a good smell or a
smell that is not good, a third case is possible, namely, that
a body has no smell at all; and both the conflicting proposi-
tions may therefore be false. If, however, I say: all bodies are
either good-smelling or not good-smelling <1(vel suaveolens vel>1
<1non suaveolens),>1 the two judgments are directly contradictory
to one another, and the former only is false, its contradictory
opposite, namely, that some bodies are not good-smelling,
comprehending those bodies also which have no smell at all.
Since, in the previous opposition <1(per disparata),>1 smell, the
contingent condition of the concept of the body, was not
removed by the opposed judgment, but remained attached
to it, the two judgments were not related as <1contradictory>1
opposites.
  If, therefore, we say that the world is either infinite in
extension or is not infinite <1(non est infinitus),>1 and if the former
proposition is false, its contradictory opposite, that the world
is not infinite, must be true. And I should thus deny the exist-
ence of an infinite world, without affirming in its place a finite
world. But if we had said that the world is either infinite or finite  (A 504
(non-infinite), both statements might be false. For in that case
we should be regarding the world in itself as determined in its
magnitude, and in the opposed judgment we do not merely
remove the infinitude, and with it perhaps the entire separate
existence of the world, but attach a determination to the world,
regarded as a thing actually existing in itself. This assertion
or finite. I beg permission to entitle this kind of opposition
<1dialectical,>1 and that of contradictories <1analytical.>1 Thus of
two dialectically opposed judgments both may be false; for
the one is not a mere contradictory of the other, but says
something more than is required for a simple contradiction.
  If we regard the two propositions, that the world is infinite
in magnitude and that it is finite in magnitude, as contra-
dictory opposites, we are assuming that the world, the com-
plete series of appearances, is a thing in itself that remains
even if I suspend the infinite or the finite regress in the series
of its appearances. If, however, I reject this assumption, or
00132
rather this accompanying transcendental illusion, and deny
505) that the world is a thing in itself, the contradictory opposition
  of the two assertions is converted into a merely dialectical
  opposition. Since the world does not exist in itself, independ-
  ently of the regressive series of my representations, it exists
  <1in itself>1 neither as an <1infinite>1 whole nor as <1afinite>1 whole. It
  exists only in the empirical regress of the series of appear-
  ances, and is not to be met with as something in itself. If, then,
  this series is always conditioned, and therefore can never be
  given as complete, the world is not an unconditioned whole,
  and does not exist as such a whole, either of infinite or of
  finite magnitude.
  What we have here said of the first cosmological idea,
  that is, of the absolute totality of magnitude in the [field
  of] appearance, applies also to all the others. The series of
  conditions is only to be met with in the regressive synthesis
  itself, not in the [field of] appearance viewed as a thing given
  in and by itself, prior to all regress. We must therefore say that
  the number of parts in a given appearance is in itself neither
  finite nor infinite. For an appearance is not something existing
  in itself, and its parts are first given in and through the regress
  of the decomposing synthesis, a regress which is never given
  in absolute completeness, either as finite or as infinite. This
  also holds of the series of subordinated causes, and of the
  series that proceeds from the conditioned to unconditioned
506) necessary existence. These series can never be regarded as
  being in themselves in their totality either finite or infinite.
  Being series of subordinated <1representations,>1 they exist only
  in the dynamical regress, and prior to this regress can have no
  existence in themselves as self-subsistent series of things.
  Thus the antinomy of pure reason in its cosmological ideas
  vanishes when it is shown that it is merely dialectical, and
  that it is a conflict due to an illusion which arises from our
  earances that exist only in our representations,
  and therefore, so far as they form a series, not otherwise than
  in a successive regress, that idea of absolute totality which
  holds only as a condition of things in themselves. From this
  antinomy we can, however, obtain, not indeed a dogmatic, but
  a critical and doctrinal advantage. It affords indirect proof of
00133
the transcendental ideality of appearances---a proof which
ought to convince any who may not be satisfied by the direct
proof given in the Transcendental Aesthetic. This proof would
consist in the following dilemma. If the world is a whole exist-
ing in itself, it is either finite or infinite. But both alternatives
are false (as shown in the proofs of the antithesis and thesis
respectively).  It is therefore also false that the world (the
sum of all appearances) is a whole existing in itself. From this (B 535
it then follows that appearances in general are nothing outside
our representations---which is just what is meant by their
transcendental ideality.
  This remark is of some importance. It enables us to see
that the proofs given in the fourfold antinomy are not merely
baseless deceptions. On the supposition that appearances, and
the sensible world which comprehends them all, are things
in themselves, these proofs are indeed well-grounded. The
conflict which results from the propositions thus obtained
shows, however, that there is a fallacy in this assumption, and
so leads us to the discovery of the true constitution of things,
as objects of the senses. While the transcendental dialectic does
not by any means favour scepticism, it certainly does favour
the sceptical method, which can point to such dialectic as an
example of its great services. For when the arguments of
reason are allowed to oppose one another in unrestricted
freedom, something advantageous, and likely to aid in the
correction of our judgments, will always accrue, though it
may not be what we set out to find.
  THE ANTINOMY OF PURE REASON  (A508
  Section 8
THE REGULATIVE PRINCIPLE OF PURE REASON IN ITS
  APPLICATION TO THE COSMOLOGICAL IDEAS
  Since no maximum of the series of conditions in a sensible
world, regarded as a thing in itself, is <1given>1 through the cos-
mological principle of totality, but can only be <1set as a task>1
that calls for regress in the series of conditions, the principle
of pure reason has to be amended in these terms; and it
00134
then preserves its validity, not indeed as the <1axiom>1 that we
think the totality as actually in the object, but as a <1problem>1 for
the understanding, and therefore for the subject, leading it to
undertake and to carry on, in accordance with the completeness
prescribed by the idea, the regress in the series of conditions of
any given conditioned. For in our sensibility, that is, in space
and time, every condition to which we can attain in the
exposition of given appearances is again conditioned. For
they are not objects in themselves---were they such, the abso-
lutely unconditioned might be found in them---but simply
empirical representations which must always find in intui-
tion the condition that determines them in space and time.
The principle of reason is thus properly only a <1rule,>1 pre-
509) scribing a regress in the series of the conditions of given
  appearances, and forbidding it to bring the regress to a close
  by treating anything at which it may arrive as absolutely un-
  conditioned. It is not a principle of the possibility of experience
  and of empirical knowledge of objects of the senses, and there-
  fore not a principle of the understanding; for every experience,
  in conformity with the given [forms of] intuition, is enclosed
  within limits. Nor is it a <1constitutive>1 principle of reason, en-
  abling us to extend our concept of the sensible world beyond all
  possible experience. It is rather a principle of the greatest pos-
  sible continuation and extension of experience, allowing no em-
  pirical limit to hold as absolute. Thus it is a principle of reason
  which serves as a <1rule,>1 postulating what we ought to do in the
  regress, but <1not anticipating>1 what is present <1in the object as>1
  <1it is in itself, prior to all regress.>1 Accordingly I entitle it a
  <1regulative>1 principle of reason, to distinguish it from the prin-
  ciple of the absolute totality of the series of conditions, viewed
  as actually present in the object (that is, in the appearances) 2
  which would be a constitutive cosmological principle. I have
  tried to show by this distinction that there is no such con-
  stitutive principle, and so to prevent what otherwise, through
  a transcendental subreption, inevitably takes place, namely,
  the ascribing of objective reality to an idea that serves merely
  as a rule.
  In order properly to determine the meaning of this rule of
00135
pure reason, we must observe, first, that it cannot tell us <1what>1 (B 5 08
<1the object is,>1 but only <1how the empirical regress is to be carried>1
<1out>1 so as to arrive at the complete concept of the object. If it
attempted the former task, it would be a constitutive principle,
such as pure reason can never supply. It cannot be regarded
as maintaining that the series of conditions for a given con-
ditioned is in itself either finite or infinite. That would be to
treat a mere idea of absolute totality, which is only produced
in the idea, as equivalent to thinking an object that cannot be
given in any experience. For in terms of it we should be as-
cribing to a series of appearances an objective reality which
is independent of empirical synthesis. This idea of reason can
therefore do no more than prescribe a rule to the regressive
synthesis in the series of conditions; and in accordance with
this rule the synthesis must proceed from the conditioned,
through all subordinate conditions, up to the unconditioned.
Yet it can never reach this goal, for the absolutely un-
conditioned is not to be met with in experience.
  We must therefore first of all determine what we are to
mean by the synthesis of a series, in cases in which the syn-
thesis is never complete. In this connection two expressions
are commonly employed, which are intended to mark a dis-
tinction, though without correctly assigning the ground of the
distinction. Mathematicians speak solely of a <1progressus in>1
<1infinitum.>1 Philosophers, whose task it is to examine concepts, (  511
refuse to accept this expression as legitimate, substituting fo  39
it the phrase <1progressus in indefinitum.>1 We need not stop to
examine the reasons for such a distinction, or to enlarge upon
its useful or useless employment. We need only determine
these concepts with such accuracy as is required for our par-
ticular purposes.
  Of a straight line we may rightly say that it can be pro-
duced to infinity. In this case the distinction between an in-
finite and an indeterminately great advance <1(progressus in in->1
<1definitum)>1 would be mere subtlety. When we say, " Draw a line',
it sounds indeed more correct to add <1in indefinitum>1 than <1in>1
<1infinitum.>1  Whereas the latter means that you <1must>1 not cease
producing it---which is not what is intended---the former means
only, produce it as far as you <1please;>1 and if we are referring
only to what it is in our <1power>1 to do, this expression is quite
00136
correct, for we can always make the line longer, without end.
So is it in all cases in which we speak only of <1the progress,>1 that
is, of the <1advance>1 from the condition to the conditioned: this
possible advance proceeds, without end, in the series of ap-
pearances. From a given pair of parents the descending line
of generation may proceed without end, and we can quite
512) well regard the line as actually so continuing in the world.
  For in this case reason never requires an absolute totality
  of the series, since it does not presuppose that totality as a
  condition and as given <1(datum),>1 but only as something con-
  ditioned, that allows of being given <1(dabile),>1 and is added to
  without end.
  Quite otherwise is it with the problem: how far the regress
  extends, when it ascends in a series from something given as
  conditioned to its conditions. Can we say that the regress is <1in>1
  <1infinitum,>1 or only that it is indeterminately far extended <1(in>1
  <1indefinitum)?>1 Can we, for instance, ascend from the men now
  living, through the series of their.ancestors, <1in infinitum;>1 or
  can we only say that, so far as we have gone back, we have
  never met with an empirical ground for regarding the series as
  limited at any point, and that we are therefore justified and at
  the same time obliged, in the case of every ancestor, to search
  further for progenitors, though not indeed to presuppose them?
  We answer: when the whole is given in empirical intui-
  tion, the regress in the series of its inner conditions pro-
  ceeds <1in infinitum;>1 but when a member only of the series is
  given, starting from which the regress has to proceed to abso-
  lute totality, the regress is only of indeterminate character <1(in>1
B 541) <1indefinitum).>1 Accordingly, the division of a body, that is, of a
   portion of matter given between certain limits, must be said to
  proceed <1in infinitum.>1 For this matter is given as a whole, and
  therefore with all its possible parts, in empirical intuition.
  Since the condition of this whole is its part, and the condition
  this regress of decomposition an unconditioned (indivisible)
  member of this series of conditions is never met with, not only
  is there never any empirical ground for stopping in the divi-
  sion, but the further members of any continued division are
  themselves empirically given prior to the continuation of the
  division  The division, that is to say, goes on <1in infinitum.>1 On
00137
the other hand, since the series of ancestors of any given man
is not given in its absolute totality in any possible experience,
the regress proceeds from every member in the series of genera-
tions to a higher member, and no empirical limit is encoun-
tered which exhibits a member as absolutely unconditioned.
And since the members, which might supply the condition, are
not contained in an empirical intuition of the whole, prior to
the regress, this regress does not proceed <1in infinitum,>1 by divi-
sion of the given, but only indefinitely far, searching for further
members additional to those that are given, and which are
themselves again always given as conditioned.
  In neither case, whether the regress be <1in infinitum>1 or <1in>1 (B 514
<1indefniitum,>1 may the series of conditions be regarded as being
given as infinite in the object. The series are not things in
themselves, but only appearances, which, as conditions of one
another, are given only in the regress itself. The question,
therefore, is no longer how great this series of conditions may
be in itself, whether it be finite or infinite, for it is nothing in
itself; but how we are to carry out the empirical regress, and
how far we should continue it. Here we find an important dis-
tinction in regard to the rule governing such procedure. When
the whole is empirically given; it is <1possible>1 to proceed back in
the series of its inner conditions <1in infinitum.>1 When the whole
is not given, but has first to be given through empirical regress,
we can only say that the <1search>1 for still higher conditions of the
series is <1possible in infinitum.>1 In the former case we could say:
there are always more members, empirically given, than I can
reach through the regress of decomposition; in the latter case,
however, the position is this: we can always proceed still further
in the regress, because no member is empirically given as abso-
lutely unconditioned; and since a higher member is therefore
always possible, the enquiry regarding it is necessary. In the
one case we necessarily <1find>1 further members of the series; in
the other case, since no experience is absolutely limited, the (B 515
necessity is that we <1enquire>1 for them. For either we have n
perception which sets an absolute limit to the empirical re-
gress, in which case we must not regard the regress as com-
pleted, or we have a perception limiting our series, in which
case the perception cannot be part of the series traversed
(for that which <1limits>1 must be distinct from that which <1is>1
00138
thereby <1limited),>1 and we must therefore continue our regress
to this condition also, and the regress is thus again resumed.
  These observations will be set in their proper light by
their application in the following section.
  THE ANTINOMY OF PURE REASON
  Section 9
THE EMPIRICAL EMPLOYMENT OF THE REGULATIVE
  PRINCIPLE OF REASON, IN RESPECT OF ALL COSMO-
  LOGICAL IDEAS
  We have already, on several occasions, shown that no trans-
cendental employment can be made of the pure concepts either
of the understanding or of reason; that the [assertion of] abso-
lute totality of the series of conditions in the sensible world
rests on a transcendental employment of reason in which reason
516)  demands this unconditioned completeness from what it assumes
  to be a thing in itself; and that since the sensible world contains
  no such completeness, we are never justified in enquiring, as
  regards the absolute magnitude of the series in the sensible
  world, whether it be limited or <1in itself>1 unlimited, but only
  how far we ought to go in the empirical regress, when we trace
  experience back to its conditions, obeying the rule of reason,
  and therefore resting content with no answer to its questions
  save that which is in conformity with the object.
  What therefore alone remains to us is the validity of the
  principle of reason as a rule forthe <1continuation>1 and magnitude
  of a possible experience; its invalidity as a constitutive prin-
  ciple of appearances [viewed as things] in themselves has been
  sufficiently demonstrated. If we can keep these conclusions
  steadily in view, the self-conflict of reason will be entirely at an
  end. For not only will this critical solution destroy the illusion
  which set reason at variance with itself, but will replace it by
  teaching which, in correcting the misinterpretation that has
  been the sole source of the conflict, brings reason into agree-
  ment with itself. A principle which otherwise would be <1dialec->1
  <1tical>1 will thus be converted into a <1doctrinal>1 principle. In fact,
  if this principle can be upheld as determining, in accordance
00139
with its subjective significance, and yet also in conformity with
the objects of experience, the greatest possible empirical use of
understanding, the outcome will be much the same as if it
were---what is impossible from pure reason---an axiom which (B 517
determined <1apriori>1 the objects in themselves. For only in pro-
portion as the principle is effective in directing the widest
possible <1empirical>1 employment of the understanding, can it
exercise, in respect of the objects of experience, any influence
in extending and correcting our knowledge.
  <1Solution of the Cosmological Idea of the Totality of the>1
  <1Composition of the Appearances of a Cosmic Whole>1
  Here, as in the other cosmological questions, the regula-
tive principle of reason is grounded on the proposition that in
the empirical regress we can have <1no experience of an absolute>1
<1limit,>1 that is, no experience of any condition as being one
that <1empirically>1 is absolutely unconditioned. The reason is
this: such an experience would have to contain a limitation
of appearances by nothing, or by the void, and in the con-
tinued regress we should have to be able to encounter this
limitation in a perception---which is impossible.
  This proposition, which virtually states that the only con-
ditions which we can reach in the empirical regress are con- (A 518
ditions which must themselves again be regarded as empiric-
ally conditioned, contains the rule <1in terminis,>1 that however
far we may have advanced in the ascending series, we must
always enquire for a still higher member of the series, which
may or may not become known to us through experience.
  For the solution, therefore, of the first cosmological prob-
lem we have only to decide whether in the regress to the un-
conditioned magnitude of the universe, in time and space, this
never limited ascent can be called a regress to infinity, or only
an indeterminately continued regress <1(in indefinitum).>1
  The quite general representation of the series of all past
states of the world, as well as of all the things which coexist
in cosmic space, is itself merely a possible empirical regress
which I think to myself, though in an indeterminate manner.
Only in this way can the concept of such a series of conditions
00140
for a given perception arise at all.a Now we have the cosmic
B 519) whole only in concept, never, as a whole, in intuition. We
  cannot, therefore, argue from the magnitude of the cosmic
  whole to the magnitude of the regress, determining the
  latter in accordance with the former; on the contrary, only
  by reference to the magnitude of the empirical regress am I
  in a position to make for myself a concept of the magnitude of
  the world. But of this empirical regress the most that we can
  ever know is that from every given member of the series of
  conditions we have always still to advance empirically to a
  higher and more remote member. The magnitude of the
  whole of appearances is not thereby determined in any abso-
  lute manner; and we cannot therefore say that this regress
  proceeds to infinity. In doin  so we should be anticipating
  members which the regress has not yet reached, represent-
  ing their number as so great that no empirical synthesis could
  attain thereto, and so should be determining the magnitude of
  the world (although only negatively) prior to the regress---
  which is impossible. Since the world is not given me, in its
  totality, through any intuition, neither is its magnitude given
  me prior to the regress. We cannot, therefore, say anything at
  all in regard to the magnitude of the world, not even that there
  is in it a regress <1in infinitum.>1 All that we can do is to seek
  for the concept of its magnitude according to the rule which
  determines the empirical regress in it. This rule says no more
  than that, however far we may have attained in the series of
  empirical conditions, we should never assume an absolute
B 5208) limit, but should subordinate every appearance, as con-
  ditioned, to another as its condition, and that we must
  advance to this condition. This is the <1regressus in indefni->1
  <1tum,>1 which, as it determines no magnitude in the object,
  is clearly enough distinguishable from the <1regressus in infini->1
  <1tum.>1
  a  This cosmic series can, therefore, be neither greater nor smaller
  than the possible empirical regress upon which alone its concept
  rests. And since this regress can yield neither a determinate infinite
  nor a determinate finite (that is, anything absolutely limited), it is
  evident that the magnitude of the world can be taken neither as
  finite nor as infinite. The regress, through which it is represented,
  allows of neither alternative.
00141
I cannot say, therefore, that the world is <1infinite>1 in space
or as regards past time. Any such concept of magnitude, as
being that of a given infinitude, is empirically impossible, and
therefore, in reference to the world as an object of the senses,
also absolutely impossible. Nor can I say that the regress from
a given perception to all that limits it in a series, whether in
space or in past time, proceeds to <1infinity;>1 that would be to
presuppose that the world has infinite magnitude. I also can-
not say that the regress is <1finite;>1 an absolute limit is likewise
empirically impossible. Thus I can say nothing regarding the
whole object of experience, the world of sense; I must limit
my assertions to the rule which determines how experience,
in conformity with its object, is to be obtained and further
extended.
  Thus the first and negative answer to the cosmological
problem regarding the magnitude of the world is that the
world has no first beginning in time and no outermost limit
in space.
  For if we suppose the opposite, the world would be limited
on the one hand by empty time and on the other by empty (B 52
space. Since, however, as appearance, it cannot in itself be
limited in either manner---appearance not being a thing in
itself---these limits of the world would have to be given in a
possible experience, that is to say, we should require to have
a perception of limitation by absolutely empty time or space.
But such an experience, as completely empty of content, is
impossible. Consequently, an absolute limit of the world is
impossible empirically, and therefore also absolutely.a
  The affirmative answer likewise directly follows, namely,
that the regress in the series of appearances, as a determina-
tion of the magnitude of the world, proceeds <1in indefinitum.>1
  a  It may be noted that this proof is presented in a very different
manner from the dogmatic proof of the antithesis of the first
antinomy. In that argument we regarded the sensible world, in
accordance with the common and dogmatic view, as a thing given
in itself, in its totality, prior to any regress; and we asserted that
unless it occupies all time and all places, it cannot have any deter-
minate position whatsoever in them. The conclusion also was there-
fore different from that given above; for in the dogmatic proof we
inferred the actual infinity of the world.
00142
This is equivalent to saying that, although the sensible world
has no absolute magnitude, the empirical regress (through
which alone it can be given on the side of its conditions) has
its own rule, namely, that it must always advance from every
member of the series, as conditioned, to one still more remote;
doing so by means either of our own experience, or of the
B 522) guiding-thread of history, or of the chain of effects and causes.
  And as the rule further demands, our sole and constant aim
  must be the extension of the possible empirical employment
  of the understanding, this being the only proper task of reason
  in the application of its principles.
  This rule does not prescribe a determinate empirical regress
  that must proceed without end in some one kind of appearance,
  <1e.g.>1 that in proceeding from a living person through a series
  of progenitors we must never expect to meet with a first pair,
  or that in the series of cosmic bodies we must never admit an
  outermost sun. All that the rule requires is that the advance
  from appearances be to appearances; for even if these latter
  yield no actual perception (as is the case when for our con-
  sciousness they are too weak in degree to become experience),
  as appearances they none the less still belong to a possible
  experience.
  All beginning is in time and all limits of the extended are
  in space. But space and time belong only to the world of sense.
  Accordingly, while appearances <1in the world>1 are conditionally
  limited, <1the world itself>1 is neither conditionally nor uncon-
  ditionally limited.
  Similarly, since the world can never be given as <1complete,>1
  and since even the series of conditions for that which is given
  as conditioned cannot, as a cosmic series, be given as <1complete,>1
  the concept of the magnitude of the world is given only through
  523) the regress and not in a collective intuition prior to it. But the
  regress consists only in the <1determining>1 of the magnitude, and
  does not give any <1determinate>1 concept. It does not, therefore,
  yield any concept of a magnitude which, in relation to a certain
  [unit-] measure, can be described as infinite. In other words,
  the regress does not proceed to the infinite, as if the infinite
  could be given, but only indeterminately far, in order [by
  means of the regress] to give that empirical magnitude which
  first becomes actual in and through this very regress.
00143
  II
<1Solution of the Cosmological Idea of the Totality of>1
  <1Division of a Whole given in Intuition>1
If we divide a whole which is given in intuition, we pro-
ceed from something conditioned to the conditions of its pos-
sibility. The division of the parts <1(subdivisio>1 or <1decompositio)>1
is a regress in the series of these conditions. The absolute
totality of this series would be given only if the regress could
reach <1simple>1 parts. But if all the parts in a continuously pro-
gressing decomposition are themselves again divisible, the
division, that is, the regress from the conditioned to its con-
ditions, proceeds <1in infinitum.>1 For the conditions (the parts)
are themselves contained in the conditioned, and since this
is given complete in an intuition that is enclosed between (A 524
limits  the parts are one and all given together with the co -
ditioned. The regress may not, therefore, be entitled merely
a regress <1in indefinitum.>1 This was permissible in regard to the
first cosmological idea, since it required an advance from the
conditioned to its conditions, which, as outside it, were not given
through and along with it, but were first added to it in the em-
pirical regress. We are not, however, entitled to say of a whole
which is divisible to infinity, that <1it is made up of infinitely>1
<1many parts.>1  For although all parts are contained in the intuition
of the whole, <1the whole division>1 is not so contained, but consists
only in the continuous decomposition, that is, in the regress
itself, whereby the series first becomes actual. Since this regress
is infinite, all the members or parts at which it arrives are
contained in the given whole, viewed as an <1aggregate.>1 But the
whole <1series of the division>1 is not so contained, for it is a
successive infinite and never <1whole,>1 and cannot, therefore,
exhibit an infinite multiplicity, or any combination of an
infinite multiplicity in a whole.
  This general statement is obviously applicable to space.
Every space intuited as within limits is such a whole, the parts
of which, as obtained by decomposition, are always themselves
spaces. Every limited space is therefore infinitely divisible.
  From this a second application of the statement quite (AB 5 5
naturally follows, namely, to an outer appearance enclosed
00144
within limits, that is, to body. Its divisibility is grounded in
the divisibility of space, which constitutes the possibility of the
body as an extended whole. Body is therefore infinitely divis-
ible, without consisting, however, of infinitely many parts.
  It may seem, indeed, that a body, since it has to be repre-
sented in space as <1substance,>1 will, as regards the law of the
divisibility of space, differ from space. We may certainly grant
that decomposition can never remove all compositeness from
space; for that would mean that space, in which there is
nothing self-subsistent, had ceased to be space, which is impos-
sible.  On the other hand, the assertion that if all compositeness
of matter be thought away nothing at all will remain, does not
appear to be compatible with the concept of a substance which
is meant to be the subject of all compositeness, and which
must persist in the elements of the composite, even although
the connection in space, whereby they constitute a body, be
removed. But while this is true of a thing in itself, as thought
through a pure concept of the understanding, it does not hold
of that which we entitle substance in the [field of] <1appearance.>1
For this latter is not an absolute subject, but only an abiding
A 526) image1 of sensibility; it is nothing at all save as an intuition,
  in which unconditionedness is never to be met with.
  But although this rule of progress <1in infinitum>1 undoubtedly
  applies to the subdivision of an appearance, viewed as a mere
  filling of space, it cannot be made to apply to a whole in which
  already, as given, the parts are so definitely distinguished off
  from one another that they constitute a <1quantum discretum.>1
  We cannot assume that every part of an organised whole is
  itself again so organised that, in the analysis of the parts to
  infinity, still other organised parts are always to be met with;
  in a word, that the whole is organised to infinity. This is not a
  thinkable hypothesis.  It is true, indeed, that the parts of matter,
  [as found] in their decomposition <1in infinitum,>1 may be organ-
  ised. The infinitude of the division of a given appearance in
  space is grounded solely on the fact that, through this infini-
  tude, only the divisibility (in itself, as regards the number of its
  parts, absolutely indeterminate) is given---the parts themselves
  being given and determined only through the subdivision. In
  a word, the whole is not in itself already divided. The number
00145
of parts, therefore, which a division may determine in a whole,
will depend upon how far we care to advance in the regress of
the division. On the other hand, in the case of an organic body (A 527
conceived as organised <1in infinitum>1 the whole is represented (B 555
as already divided into parts, and as yielding to us, prior to all
regress, a determinate and yet infinite number of parts. This,
however, is self-contradictory. This infinite involution is re-
garded as an infinite (that is, never to be completed) series,
and yet at the same time as completed in a [discrete] com-
plex. Infinite divisibility belongs to appearance only in so
far as it is a <1quantum continuum;>1 it is inseparable from the
occupation of space, which is indeed its ground. To view any-
thing as being a <1quantum discretum,>1 is to taae the number of
units in it as being determined, and therefore as being in every
case equal to some number. How far organisation can go in an
organised body, only experience can show; and although, so
far as our experience has gone, we may not have arrived with
certainty at any inorganic part, the <1possibility>1 of experiencing
such parts must at least be recognised. When, however, we
have in mind the transcendental division of an appearance
in general, the question how far it may extend does not await
an answer from experience; it is decided by a principle of
reason which prescribes that, in the decomposition of the ex-
tended, the empirical regress, in conformity with the nature of
this appearance, be never regarded as absolutely completed.
  <1Concluding Note on the Solution of the Mathematical-trans->1 (A 528
<1cendental Ideas, and Preliminary Observation on the Solution of>1 (556
<1the Dynamical-transcendental Ideas.>1
  In representing the antinomy of pure reason, through all
the transcendental ideas, in tabular form, and in showing that
the ground of this conflict and the only means of removing it
is by declaring both the opposed assertions to be false, we have
represented the conditions as, in all cases, standing to the con-
ditioned in relations of space and time. This is the assumption
ordinarily made by the common understanding, and to it the
conflict is exclusively due. On this view all the dialectical
representations of totality, in the series of conditions for a
given conditioned, are throughout of the same character. The
00146
condition is always a member of a series along with the con-
ditioned, and so is <1homogeneous>1 with it. In such a series
the regress was never thought as completed, or if it had to be
so thought, a member, in itself conditioned, must have been
falsely supposed to be a first member, and therefore to be
unconditioned; the object, that is, the conditioned, might not
always be considered merely according to its magnitude, but at
B 557) leastthe series of its conditions was so regarded. Thus arose the
  difficulty---a difficulty which could not be disposed of by any
  compromise but solely by cutting the knot---that reason made
  the series either too long or too short for the understanding, so
  that the understanding could never be equal to the prescribed
  idea.
  But in all this we have been overlooking an essential dis-
  tinction that obtains among the objects, that is, among those
  concepts of understanding which reason endeavours to raise
  to ideas. According to the table of categories given above, two
  of these concepts imply a <1mathematical,>1 the other two a
  <1dynamical>1 synthesis of appearances. Hitherto it has not been
  necessary to take account of this distinction; for just as in the
  general representation of all transcendental ideas we have
  been conforming to conditions within the [field of] appearance,
  so in the two mathematical-transcendental ideas the only
  object we have had in mind is object as appearance. But now
  that we are proceeding to consider how far <1dynamical>1 con-
  cepts of the understanding are adequate to the idea of reason,
  the distinction becomes of importance, and opens up to us an
  entirely new view of the suit in which reason is implicated.
  This suit, in our previous trial of it, has been <1dismissed>1 as
  resting, on both sides, on false presuppositions. But since in
B 558) the dynamical antinomy a presupposition compatible with the
  pretensions of reason may perhaps be found, and since the
  judge may perhaps make good what is lacking in the pleas
  which both sides have been guilty of misstating, the suit may
  be settled to the satisfaction of both parties, a procedure im-
  possible in the case of the mathematical antinomies.
  If we consider solely the <1extension>1 of the series of condi-
  tions, and whether the series are adequate to the idea, or the
  idea too large or too small for the series, the series are indeed in















00001
these respects all homogeneous. But the concept of the under-
standing, which underlies these ideas, may contain either a
synthesis solely of the <1homogeneous>1 (which is presupposed
alike in the composition and in the division of every magni-
tude), or a synthesis of the <1heterogeneous.>1 For the hetero-
geneous can be admitted as at least possible in the case of
dynamical synthesis, alike in causal connection and in the
connection of the necessary with the contingent.
  Hence in the mathematical connection of the series of
appearances no other than a <1sensible>1 condition is admissible,
that is to say, none that is not itself a part of the series. On the
other hand, in the dynamical series of sensible conditions, a
heterogeneous condition, not itself a part of the series, but
<1purely intelligible,>1 and as such outside the series, can be
allowed. In this way reason obtains satisfaction and the (531
unconditioned is set prior to the appearances, while yet the
invariably conditioned character of the appearances is not
obscured, nor their series cut short, in violation of the
principles prescribed by the understanding.
  Inasmuch as the dynamical ideas allow of a condition of
appearances outside the series of the appearances, that is, a
condition which is not itself appearance, we arrive at a con-
clusion altogether different from any that was possible in the
case of the mathematical antinomy. In it we were obliged
to denounce both the opposed dialectical assertions as false.
In the dynamical series, on the other hand, the completely
conditioned, which is inseparable from the series considered
as appearances, is bound up with a condition which, while
indeed empirically unconditioned, is also <1non-sensible.>1 We
are thus able to obtain satisfaction for <1understanding>1 on
the one hand and for <1reason>1 on the other.a The dialectical
  a Understanding does not admit <1among appearances>1 any condi-
tion which can itself be empirically unconditioned. But if for some
conditioned in the [field of] appearance we can conceive an <1intellig->1
<1ible>1 condition, not belonging to the series of appearances as one of
its members, and can do so without in the least interrupting the
series of empirical conditions, such a condition may be accepted as
<1empirically unconditioned,>1 without prejudice to the continuity of the
empirical regress.
00002
arguments, which in one or other way sought unconditioned
B 5630) totality in mere appearances, fall to the ground, and the pro-
  positions of reason, when thus given this more correct inter-
  pretation, may <1both>1 alike be <1true.>1 This can never be the case
  with those cosmological ideas which refer only to a mathe-
  matically unconditioned unity; for in them no condition of the
  series of appearances can be found that is not itself appear-
  ance, and as appearance one of the members of the series.
  III
  <1Solution of the Cosmological Idea of Totality in the>1
  <1Derivation of Cosmical Events from their Causes>1
  When we are dealing with what happens there are only two
  kinds of causality conceivable by us; the causality is either
  according to <1nature>1 or arises from <1freedom.>1 The former is
  the connection in the sensible world of one state with a pre-
  ceding state on which it follows according to a rule.  Since the
  causality of appearances rests on conditions of time, and the
  preceding state, if it had always existed, could not have pro-
  duced an effect which first comes into being in time, it follows
  that the causality of the cause of that which happens or comes
  into being must itself also have <1come into being,>1 and that in
  accordance with the principle of the understanding it must
  in its turn itself require a cause.
B 5633)  By freedom, on the other hand, in its cosmological mean-
  ing, I understand the power of beginning a state <1spontane->1
  <1ously.>1 Such causality will not, therefore, itself stand under
  another cause determining it in time, as required by the law of
  nature. Freedom, in this sense, is a pure transcendental idea,
  which, in the first place, contains nothing borrowed from ex-
  perience, and which, secondly, refers to an object that cannot
  be determined or given in any experience. That everything
  which happens has a cause is a universal law, conditioning the
  very possibility of all experience. Hence the causality of the
  cause, which <1itself happens>1 or comes to be, must itself in turn
  have a cause; and thus the entire field of experience, however
  far it may extend, is transformed into a sum-total of the
  merely natural. But since in this way no absolute totality of
00003
conditions determining causal relation can be obtained, reason
creates for itself the idea of a spontaneity which can begin to
act of itself, without requiring to be determined to action by
an antecedent cause in accordance with the law of causality.
  It should especially be noted that the practical concept of
freedom is based on this <1transcendental>1 idea, and that in the
latter lies the real source of the difficulty by which the ques-
tion of the possibility of freedom has always been beset.
Freedom in the practical sense is the will's independence of (A 534
coercion through sensuous impulses. For a will is sensuous, in
so far as it is <1pathologically affected, i.e.>1 by sensuous motives;
it is <1animal (arbitrium brutum),>1 if it can be pathologically
<1necessitated.>1 The human will is certainly an <1arbitrium sensi->1
<1tivum,>1 not, however, <1brutum>1 but <1liberum.>1 For sensibility does
not necessitate its action. There is in man a power of self-
determination, independently of any coercion through sensuous
impulses.
  Obviously, if all causality in the sensible world were mere
nature, every event would be determined by another in time,
in accordance with necessary laws. Appearances, in determin-
ing the will, would have in the actions of the will their natural
effects, and would render the actions necessary. The denial of
transcendental freedom must, therefore, involve the elimina-
tion of all practical freedom. For practical freedom presup-
poses that although something has not happened, it <1ought>1 to
have happened, and that its cause, [as found] in the [field of]
appearance, is not therefore, so determining that it excludes a
causality of our will---a causality which, independently of those
natural causes, and even contrary to their force and influence,
can produce something that is determined in the time-order
in accordance with empirical laws, and which can therefore
begin a series of events <1entirely of itself.>1
  Here then, as always happens when reason, in venturing (A 535
beyond the limits of possible experience, comes into conflict
with itself the problem is not really <1physiological>1 but <1trans->1
<1cendental.>1 The question as to the possibility of freedom
does indeed concern psychology; since it rests on dialectical
arguments of pure reason, its treatment and solution belong
exclusively to transcendental philosophy. Before attempting
00004
this solution, a task which transcendental philosophy cannot
decline, I must define somewhat more accuratelythe procedure
of transcendental philosophy in dealing with the problem.
  If appearances were things in themselves, and space and
time forms of the existence of things in themselves, the condi-
tions would always be members of the same series as the con-
ditioned; and thus, in the present case, as in the other transcen-
dental ideas, the antinomy would arise, that the series must be
too large or too small for the understanding. But the dynami-
cal concepts of reason, with which we have to deal in this and
the following section, possess this peculiarity that they are not
concerned with an object considered as a magnitude, but only
with its existence. Accordingly we can abstract from the mag-
nitude of the series of conditions, and consider onlythe dynami-
A 536) cal relation of the condition to the conditioned. The difficulty
  which then meets us, in dealing with the question regarding
  nature and freedom, is whether freedom is possible at all, and
  if it be possible, whether it can exist along with the universality
  of the natural law of causality. Is it a truly disjunctive propo-
  sition to say that every effect in the world must arise <1either>1
  from nature <1or>1 from freedom; or must we not rather say that
  in one and the same event, in different relations, both can be
  found? That all events in the sensible world stand in thorough-
  going connection in accordance with unchangeable laws of
  nature is an established principle of the Transcendental Ana-
  lytic, and allows of no exception. The question, therefore, can
  only be whether freedom is completely excluded by this inviol-
  able rule, or whether an effect, notwithstanding its being thus
  determined in accordance with nature, may not at the same
  time be grounded in freedom. The common but fallacious pre-
  supposition of the <1absolute reality>1 of appearances here mani-
  fests its injurious influence, to the confounding of reason. For
  if appearances are thing  in themselves, freedom cannot be up-
  held. Nature will then be the complete and sufficient deter-
  mining cause of every event. The condition of the event will be
  such as can be found only in the series of appearances; both it
  and its effect will be necessary in accordance with the law of
B 537) nature. If, on the other hand, appearances are not taken for
  more than they actually are; if they are viewed not as things in
  themselves, but merely as representations, connected accord-
00005
ing to empirical laws, they must themselves have grounds
which are not appearances. The effects of such an intelligible
cause appear, and accordingly can be determined through
other appearances, but its causality is not so determined.
While the effects are to be found in the series of empirical con-
ditions, the intelligible cause, together with its causality, is
outside the series. Thus the effect may be regarded as free in
respect of its intelligible cause, and at the same time in respect
of appearances as resulting from them according to the neces-
sity of nature. This distinction, when stated in this quite general
and abstract manner, is bound to appear extremely subtle and
obscure, but will become clear in the course of its application.
My purpose has only been to point out that since the thorough-
going connection of all appearances, in a context of nature, is
an inexorable law, the inevitable consequence of obstinately
insisting upon the reality of appearances is to destroy all
freedom. Those who thus follow the common view have never
been able to reconcile nature and freedom.
  Whatever in an object of the senses is not itself appearance,
I entitle <1intelligible.>1 If, therefore, that which in the sensible
world must be regarded as appearance has in itself a faculty
which is not an object of sensible intuition, but through which
it can be the cause of appearances, the <1causality>1 of this being
can be regarded from two points of view. Regarded as the
causality of a thing in itself, it is <1intelligible>1 in its <1action;>1 re-
garded as the causality of an appearance in the world of sense,
it is <1sensible>1 in its <1effects.>1 We should therefore have to form both
an empirical and an intellectual concept of the causality of the
faculty of such a subject, and to regard both as referring to one
and the same effect. This twofold manner of conceiving the
faculty possessed by an object of the senses does not contradict
any of the concepts which we have to form of appearances and
of a possible experience. For since they are not things in them-
selves, they must rest upon a transcendental object which deter-
mines them as mere representations; and consequently there is
nothing to prevent us from ascribing to this transcendental (A 539
00006
object, besides the quality in terms of which1 it appears, a
<1causality>1 which is not appearance, although its <1effect>1 is to be
met with in appearance. Every efficient cause must have a
<1character,>1 that is, a law of its causality, without which it
would not be a cause. On the above supposition, we should,
therefore, in a subject belonging to the sensible world have,
first, an <1empirical character,>1 whereby its actions, as appear-
ances, stand in thoroughgoing connection with other appear-
ances in accordance with unvarying laws of nature. And since
these actions can be derived from the other appearances, they
constitute together with them a single series in the order of
nature. Secondly, we should also have to allow the subject an
<1intelligible character,>1 by which it is indeed the cause of those
same actions [in their quality] as appearances, but which does
not itself stand under any conditions of sensibility, and is not
itself appearance. We can entitle the former the character of
the thing in the [field of] appearance, and the latter its char-
acter as thing in itself.
  Now this acting subject would not, in its intelligible
character, stand under any conditions of time; time is only a
condition of appearances, not of things in themselves. In this
subject no <1action>1 would <1begin>1 or <1cease,>1 and it would not, there-
A 540)  fore, have to conform to the lawof the determination of all that
  1s alterable in time, namely, that everything <1which happens>1
  must have its cause in the <1appearances>1 which precede it. In
  a word, its causality, so far as it is intelligible, would not have
  a place in the series of those empirical conditions through
  which the event is rendered necessary in the world of sense.
  This intelligible character can never, indeed, be immediately
  known, for nothing can be perceived except in so far as it
  appears. It would have to be <1thought>1 in accordance with the
  empirical character-- just as we are constrained to think a
  transcendental object as underlying appearances, though we
  know nothing of what it is in itself.
  In its empirical character, therefore, this subject, as ap-
  pearance, would have to conform to all the laws of causal
  determination. To this extent it could be nothing more than
  a part of the world of sense, and its effects, like all other
00007
appearances, must be the inevitable outcome of nature. In
proportion as outer appearances are found to influence it, and
in proportion as its empirical character, that is, the law of its
causality, becomes known through experience, all its actions
must admit of explanation in accordance with the laws of
nature. In other words, all that is required for their complete
and necessary determination must be found in a possible
experience.
  In its intelligible character (though we can only have a (B 569
general concept of that character) this same subject must be
considered to be free from all influence of sensibility and from
all determination through appearances. Inasmuch as it is
<1noumenon,>1 nothing <1happens>1 in it; there can be no change
requiring dynamical determination in time, and therefore no
causal dependence upon appearances. And consequently,
since natural necessity is to be met with only in the sensible
world, this active being must in its actions be independent
of, and free from all such necessity. No action begins <1in>1 this
active being itself; but we may yet quite correctly say that the
active being <1of itself>1 begins its effects in the sensible world. In
so doing, we should not be asserting that the effects in the
sensible world can begin of themselves; they are always prede-
termined through antecedent empirical conditions, though
solely through their empirical character (which is no more
than the appearance of the intelligible), and so are only pos-
sible as a continuation of the series of natural causes. In this
way freedom and nature, in the full sense of these terms, can
exist together, without any conflict, in the same actions, accord-
ing as the actions are referred to their intelligible or to their
sensible cause.
  <1Explanation of the Cosmological Idea of Freed  i>1  (A 542
<1nection with Universal Natural Necessity.>1
  I have thought it advisable to give this outline sketch of  :
the solution of our transcendental problem, so that we may
be the better enabled to survey the course which reason has
to adopt in arriving at the solution. I shall now proceed to set
forth the various factors involved in this solution, and to con-
sider each in detail.
  That everything which happens has a cause, is a law of
nature. Since the causality of this cause, that is, the <1action>1 of
00008
the cause, is antecedent in time to the effect which has <1ensued>1
upon it, it cannot itself have always existed, but must have
<1happened,>1 and <1among the appearances>1 must have a cause by
which it in turn is determined. Consequently, all events are
empirically determined in an order of nature. Only in virtue
of this law can appearances constitute a <1nature>1 and become
objects of experience. This law is a law of the understanding,
from which no departure can be permitted, and from which
no appearance may be exempted. To allow such exemption
would be to set an appearance outside all possible experience,
B 571) to distinguish it from all objects of possible experience,  nd so
  to make of it a mere thought-entity, a phantom of th  brain.
  This would seem to imply the existence of a chain of  auses
  which in the regress to their conditions allows of no <1absolute tot->1
  <1ality.>1 But that need not trouble us. The point has already been
  dealt with in the general discussion of the antinomy into which
  reason falls when inthe series of appearances it proceeds to the
  unconditioned. Were we to yield to the illusion of transcendental
  realism, neither nature nor freedom would remain. The only
  question here is this:---Admitting that in the whole series of
  events there is nothing but natural necessity, is it yet possible
  to regard one and the same event as being in one aspect merely
  an effect of nature and in another aspect an effect due to free-
  dom; or is there between these two kinds of causality a direct
  contradiction?
  Among the causes in the [field of] appearance there cer-
  tainly cannot be anything which could begin a series abso-
  lutely and of itself. Every action, [viewed] as appearance, in so
  far as it gives rise to an event, is itself an event or happening,
  and presupposes another state wherein its cause is to be found.
  Thus everything which happens is merely a continuation of
  the series, and nothing that begins of itself is a possible mem-
A 544) ber of the series. The actions of natural causes in the time-
  sequence are thus themselves effects; they presuppose causes
  antecedent to them in the temporal series. An <1original>1 act,
  such as can by itself bring about what did not exist before, is
  not to be looked for in the causally connected appearances.
  Now granting that effects are appearances and that their
  cause is likewise appearance, is it necessary that the causality
  of their cause should be exclusively empirical? May it not
00009
rat  r be, that while for every effect in the [field of] appear-
ance a connection with its cause in accordance with the
  of empirical causality is indeed required, this empirical
causality, without the least violation of its connection with
natural causes, is itself an effect of a causality that is not
empirical but intelligible? This latter causality would be the
action of a cause which, in respect of appearances, is original,
and therefore, as pertaining to this faculty, not appearance but
intelligible; although it must otherwise, in so far as it is a link
in the chain of nature, be regarded as entirely belonging to
the world of sense.
  The principle of the causal connection of appearances is
required in order that we may be able to look for and to
determine the natural conditions of natural events  that is to
say, their causes in the [field of] appearance. If this principle
be admitted, and be not weakened through any exception
the requirements of the understanding, which in its empirical
employment sees in all happenings nothing but nature, and is (A 545
justified in so doing, are completely satisfied; and physical ex-
planations may proceed on their own lines without interference.  -
These requirements are not in any way infringed, if we assume,
even though the assumption should be a mere fiction, that some
among the natural causes have a faculty which is intelligible
only, inasmuch as its determination to action never rests upon
empirical conditions, but solely on grounds of understanding.
We must, of course, at the same time be able to assume that
the <1action>1 of these causes <1in the [field of] appearance>1 is in con-
formity with all the laws of empirical causality. In this way
the acting subject, as <1causa phaenomenon,>1 would be bound up
with nature through the indissoluble dependence of all its
actions, and only as we ascend from the empirical object to
the transcendental should we find that this subject, together
with all its causality in the [field of] appearance, has in its
<1noumenon>1 certain conditions which must be regarded as
purely intelligible. For if in determining in what ways appear-
ances can serve as causes we follow the rules of nature, we
need not concern ourselves what kind of ground for these
appearances and their connection may have to be thought as
existing in the transcendental subject, which is empirically
00010
unanown to us. This intelligible ground does not have to be
considered in empirical enquiries; it concerns only thought
B) in the pure understanding; and although the effects of this
  thought and action of the pure understanding are to be met
  with in the appearances, these appearances must none the less
  be capable of complete causal explanation in terms of other
  appearances in accordance with natural laws. We have to take
  their strictly empirical character as the supreme ground of
  explanation, leaving entirely out of account their intelligible
  character (that is, the transcendental cause of their empirical
  character) as being completely unknown, save in so far as the
  empirical serves for its sensible sign.
  Let us apply this to experience. Man is one of the appear-
  ances of the sensible world, and in so far one of the natural
  causes the causality of which must stand under empirical
  laws. Like all other things in nature, he must have an em-
  pirical character. This character we come to know through
  the powers and faculties which he reveals in his actions. In
  lifeless, or merely animal, nature we find no ground for
  -  thinking that any faculty is conditioned otherwise than in a
  merely sensible manner. Man, however, who knows all the
  rest of nature solely through the senses, knows himself also
  through pure apperception; and this, indeed, in acts and inner
  determinations which he cannot regard as impressions of the
  senses. He is thus to himself, on the one hand phenomenon,
  and on the other hand, in respect of certain faculties the
B 575) action of which cannot be ascribed to the receptivity of
  sensibility, a purely  intelligible  object.  We  entitle  these
  faculties understanding and reason. The latter, in particular,
   we distinguish in a quite peculiar and especial way from all
  empirically conditioned powers. For it views its objects ex-
  clusively in the light of ideas, and in accordance with them
  determines the understanding, which then proceeds to make
  an empirical use of its own similarly pure concepts.
  That our reason has causality, or that we at least represent
  it to ourselves as having causality, is evident from the <1impera->1
  <1tives>1 which in all matters of conduct we impose as rules upon
  our active powers. <1"Ought'>1 expresses a kind of necessity and of
  connection with grounds which is found nowhere else in the
00011
whole of nature. The understanding can know in nature only
what is, what has been, or what will be. We cannot say that
anything in nature <1ought to be>1 other than what in all these
time-relations it actually is. When we have the course of
nature alone in view, <1"ought'>1 has no meaning whatsoever. It
is just as absurd to ask what ought to happen in the natural
world as to ask what properties a circle ought to have. All
that we are justified in asking is: what happens in nature?
what are the properties of the circle?
  This <1"ought'>1 expresses a possible action the ground of
which cannot be anything but a mere concept; whereas in the
case of a merely natural action the ground must always be an (B 546  =
appearance. The action to which the <1"ought'>1 applies must in-
deed be possible under natural conditions. These conditions,
however, do not play any part in determining the will itself,
but only in determining the effect and its consequences in the
[field of] appearance. No matter how many natural grounds
or how many sensuous impulses may impel me to <1will,>1 they
can never give rise to the <1"ought',>1 but only to a willing which,
while very far from being necessary, is always conditioned; and
the <1"ought'>1 pronounced by reason confronts such willing with a
limit and an end---nay more, forbids or authorises it. Whether
what is willed be an object of mere sensibility (the pleasant) or
of pure reason (the good),reason will not give way to any ground
which is empirically given. Reason does not here follow the
order of things as they present themselves in appearance, but
frames to itself with perfect spontaneity an order of its own ac-
cording to ideas, to which it adapts the empirical conditions,
and according to which it declares actions to be necessary,
even although they have never taken place, and perhaps never
will take place. And at the same time reason also presupposes
that it can have causality in regard to all these actions, since
otherwise no empirical effects could be expected from its ideas.
  Now, in view of these considerations, let us take our
stand, and regard it as at least possible for reason to have
causality with respect to appearances. Reason though it be, (A 549
it must none the less exhibit an empirical character. For every  577
cause presupposes a rule according to which certain appear-
ances follow as effects; and every rule requires uniformity in
the effects. This uniformity is, indeed, that upon which the
00012
concept of cause (as a faculty) is based, and so far as it must
be exhibited by mere appearances may be named the em-
pirical character of the cause. This character is permanent,
but its effects, according to variation in the concomitant and
in part limiting conditions, appear in changeable forms.
  Thus the will of every man has an empirical character,
which is nothing but a certain causality of his reason, so far as
that causality exhibits, in its effects in the [field of] appearance,
a rule from which we may gather what, in their kind and de-
grees, are the actions of reason and the grounds thereof, and so
may form an estimate concerning the subjective principles of
his will. Since this empirical character must itself be dis-
covered from the appearances which are its effect and from
the rule to which experience shows them to conform, it
follows that all the actions of men in the [field of] appear-
ance are determined in conformity with the order of nature,
by their empirical character and by the other causes which co-
A 550) moderate with that character; and if we could exhaustively in-
  vestigate all the appearances of men's wills, there would not
  be found a single human action which we could not predict
  with certainty, and recognise as proceeding necessarily from
  its antecedent conditions. So far, then, as regards this em-
  pirical character there is no freedom; and yet it is only in the
  light of this character that man can be studied---if, that is to
  say, we are simply <1observing,>1 and in the manner of anthro-
  pology seeking to institute a physiological investigation into
  the motive causes of his actions.
  But when we consider these actions in their relation to
  reason---I do not mean speculative reason, by which we en-
  deavour <1to explain>1 their coming into being, but reason in so
  far as it is itself the cause <1producing>1 them---if, that is to say,
  we compare them with [the standards of] reason in <1its practical>1
  bearing, we find a rule and order altogether different from the
  order of nature. For it may be that all that <1has happened>1 in the
  course of nature, and in accordance with its empirical grounds
  must inevitably have happened, <1ought not to have happened.>1
  Sometimes, however, we find, or at least believe that we find,
  that the ideas of reason have in actual fact proved their caus-
  ality in respect of the actions of men, as appearances; and
  that these actions have taken place, not because they were
00013
determined by empirical causes, but because they were deter-
mined by grounds of reason.
  Granted, then, that reason may be asserted  h  (A 551
ality in respect of appearance, its action can still be said to
be free, even although its empirical character (as a mode of
sense1) is completely and necessarily determined in all its
detail. This empirical character is itself determined in the in-
telligible character (as a mode of thought2). The latter, how-
ever, we do not know; we can only indicate its nature by
means of appearances; and these really yield an immediate
knowledge only of the mode of sense, the empirical char-
acter.a The action, in so far as it can be ascribed to a mode
of thought as its cause, does not <1follow>1 therefrom in accord-
ance with empirical laws; that is to say, it is not <1preceded>1
by the conditions of pure reason, but only by their effects in
the [field of] appearance of inner sense. Pure reason, as a
purely intelligible faculty, is not subject to the form of time,
nor consequently to the conditions of succession in time. The
causality of reason in its intelligible character does not, in pro-
ducing an effect, <1arise>1 or begin to be at a certain time. For in (B 5852
that case it would itself be subject to the natural law of appear-
ances, in accordance with which causal series are determined
in time; and its causality would then be nature, not freedom.
Thus all that we are justified in saying is that, if reason can
have causality in respect of appearances, it is a faculty <1through>1
which the sensible condition of an empirical series of effects
first begins. For the condition which lies in reason is not
sensible, and therefore does not itself begin to be. And thus
what we failed to find in any empirical series is disclosed as
being possible, namely, that the condition of a successive
series of events may itself be empirically unconditioned. For
  a The real morality of actions, their merit or guilt, even that of
our own conduct, thus remains entirely hidden from us. Our im-
putations can refer only to the empirical character. How much of
this character is ascribable to the pure effect of freedom, how much
to mere nature, that is, to faults of temperament for which there is
no responsibility, or to its happy constitution <1(merit ofortunae),>1 can
never be determined; and upon it therefore no perfectly just judg-
ments can be passed.
00014
here the condition is <1outside>1 the series of appearances (in the
intelligible), and therefore is not subject to any sensible con-
dition, and to no time-determination through an antecedent
cause.
  The same cause does, indeed, in another relation, belong
to the series of appearances. Man is himself an appearance.
His will has an empirical character, which is the empirical
cause of all his actions. There is no condition determining
man in accordance with this character which is not contained
  ies of natural effects, or which is not subject to their
law---the law according to which there can be no empirically
unconditioned causality of that which happens in time. There-
B 581) fore no given action (since it can be perceived only as appear-
  ance) can begin absolutely of itself. But of pure reason we
  cannot say that the state wherein the will is determined is
  preceded and itself determined by some other state. For since
  reason is not itself an appearance, and is not subject to any
  conditions of sensibility, it follows that even as regards its
  causality there is in it no time-sequence, and that the dyna-
  mical law of nature, which determines succession in time in
  accordance with rules, is not applicable to it.
  Reason is the abiding condition of all those actions of the
  will under [the guise of] which man appears. Before ever they
  have happened, they are one and all predetermined in the
  empirical character. In respect of the intelligible character, of
  which the empirical character is the sensible schema, there can
  be no <1before>1 and <1after;>1 every action, irrespective of its relation
  in time to other appearances, is the immediate effect of the
  intelligible character of pure reason. Reason therefore acts
  freely; it is not dynamically determined in the chain of natural
  causes through either outer or inner grounds antecedent in
  time. This freedom ought not, therefore, to be conceived only
  negatively as independence of empirical conditions. The
  faculty of reason, so regarded, would cease to be a cause of
5852) appearances. It must also be described in positive terms, as
  the power of originating a series of events. In reason itself
  nothing begins; as unconditioned condition of every voluntary
  act, it admits of no conditions antecedent to itself in time. Its
  effect has, indeed, a beginning in the series of appearances,
  but never in this series an absolutely first beginning.
00015
In order to illustrate this regulative principle of reason by
an example of its empirical employment---not, however, to con-
firm it, for it is useless to endeavour to prove transcendental
propositions by examples---let us take a voluntary action, for
example, a malicious lie by which a certain confusion has been
caused in society. First of all, we endeavour to discover the
motives to which it has been due, and then, secondly, in the
light of these, we proceed to determine how far the action and
its consequences can be imputed to the offender. As regards the
first question, we trace the empirical character of the action to
its sources, finding these in defective education, bad company,
in part also in the viciousness of a natural disposition insensitive
to shame, in levity and thoughtlessness, not neglecting to take
into account also the occasional causes that may have inter-
vened. We proceed in this enquiry just as we should in ascer-
taining for a given natural effect the series of its determining
causes. But although we believe that the action is thus deter- (A 555
mined, we none the less blame the agent, not indeed on account (B 583
of his unhappy disposition, nor on account of the circum-
stances that have influenced him, nor even on account of his
previous way of life; for we presuppose that we can leave out of
consideration what this way of life may have been, that we can
regard the past series of conditions as not having occurred and
the act as being completely unconditioned by any preceding
state, just as if the agent in and by himself began in this action
an entirely new series of consequences. Our blame is based on
a law of reason whereby we regard reason as a cause that
irrespective of all the above-mentioned empirical conditions
could have determined, and ought to have determined, the
agent to act otherwise. This causality of reason we do not re-
gard as only a co-operating agency, but as complete in itself,
even when the sensuous impulses do not favour but are directly
opposed to it; the action is ascribed to the agent's intelligible
character; in the moment when he utters the lie, the guilt is
entirely his. Reason, irrespective of all empirical conditions of
the act, is completely free, and the lie is entirely due to its
default.
  Such imputation clearly shows that we consider reason to
be unaffected by these sensible influences, and not liable to
alteration. Its appearances---the modes in which it manifests
00016
585  ) itself in its effects---do alter; but in itself [so we consider] there
  is no preceding state determining the state that follows. That
  is to say, it does not belong to the series of sensible conditions
  which render appearances necessary in accordance with laws
  of nature. Reason is present in all the actions of men at all
  times and under all circumstances, and is always the same;
  but it is not itself in time, and does not fall into any new state
  in which it was not before. In respect to new states, it is <1deter->1
  <1mining,>1 not <1determinable.>1 We may not, therefore, ask why
  reason has not determined <1itself>1 differently, but only why it
  has not through its causality determined the <1appearances>1 differ-
  ently. But to this question no answer is possible. For a different
  intelligible character would have given a different empirical
  character. When we say that in spite of his whole previous
  course of life the agent could have refrained from lying, this
  only means that the act is under the immediate power of reason,
  and that reason in its causality is not subject to any conditions
  of appearance or of time. Although difference of time makes a
  fundamental difference to appearances in their relations to one
  another---for appearances are not things in themselves and
  therefore not causes in themselves---it can make no difference
  to the relation in which the action stands to reason.
A 557)  Thus in our judgments in regard to the causality of free
  actions, we can get as far as the intelligible cause, but not be-
  yond it. We can know that it is free, that is, that it is deter-
  mined independently of sensibility, and that in this way it may
  be the sensibly unconditioned condition of appearances. But
  to explain why in the given circumstances the intelligible char-
  acter should give just these appearances and this empirical
  character transcends all the powers of our reason, indeed all
  its rights of questioning, just as if we were to ask why the trans-
  cendental object of our outer sensible intuition gives intuition
  in <1space>1 only and not some other mode of intuition. But the
  problem which we have to solve does not require us to raise any
  such questions. Our problem was this only: whether freedom
  and natural necessity can exist without conflict in one and the
  same action; and this we have sufficiently answered. We have
  shown that since freedom may stand in relation to a quite
  different kind of conditions from those of natural necessity,
  the law of the latter does not affect the former, and that both
00017
may exist, independently of one another and without inter-
fering with each other
  *  *  *
  The reader should be careful to observe that in what has
been said our intention has not been to establish the <1reality>1
of freedom as one of the faculties which contain the cause of (B 5856
the appearances of our sensible world. For that enquiry, as it
does not deal with concepts alone, would not have been trans-
cendental. And further, it could not have been successful,
since we can never infer from experience anything which can-
not be thought in accordance with the laws of experience. It
has not even been our intention to prove the <1possibility>1 of
freedom. For in this also we should not have succeeded, since
we cannot from mere concepts <1a priori>1 know the possibility
of any real ground and its causality. Freedom is here being
treated only as a transcendental idea whereby reason is led to
think that it can begin the series of conditions in the [field of]
appearance by means of the sensibly unconditioned, and so
becomes involved in an antinomy with those very laws which
it itself prescribes to the empirical employment of the under-
standing. What we have alone been able to show, and what we
have alone been concerned to show, is that this antinomy rests
on a sheer illusion, and that causality through freedom is at
least <1not incompatible with>1 nature.
  IV
<1Solution of the Cosmological Idea of the Totality of the De->1 (B 5859
  <1pendence of Appearances as regards their Existence in>1
  <1general>1
  In the preceding subsection we have considered the changes
of the sensible world in so far as they form a dynamical
series, each member being subordinate to another as effect to
cause. We shall now employ this series of states merely to
guide us in our search for an existence that may serve as
the supreme condition of all that is alterable, that is, in
our search for <1necessary being.>1 We are concerned here, not
with unconditioned causality, but with the unconditioned
existence of substance itself. The series which we have in
00018
view is, therefore, really a series of concepts, not a series
of intuitions in which one intuition is the condition of the
other.
  But it is evident that since everything in the sum-total
of appearances is alterable, and therefore conditioned in its
existence, there cannot be in the whole series of dependent ex-
istence any unconditioned member the existence of which can
be regarded as absolutely necessary. Hence, if appearances
were things in themselves, and if, as would then follow, the
condition and the conditioned always belonged to one and the
same series of intuitions, by no possibility could a necessary
5808) being exist as the condition of the existence of appearances in
  the world of sense.
  The dynamical regress is distinguished in an important re-
  spect from the mathematical. Since the mathematical regress
  is concerned only with the combining of parts to form a whole.
  or the division of a whole into parts, the conditions of this
  series must always be regarded as parts of the series, and there-
  fore as homogeneous and as appearances. In the dynamical
  regress, on the other hand, we are concerned, not with the pos-
  sibility of an unconditioned whole of given parts, or with an
  unconditioned part for a given whole, but with the derivation
  of a state from its cause, or of the contingent existence of sub-
  stance itself from necessary existence.1 In this latter regress, it
  is not, therefore, necessary that the condition should form part
  of an empirical series along with the conditioned.
  A way of escape from this apparent antinomy thus lies
  open to us. Both of the conflicting propositions may be true,
  if taken in different connections. All things in the world of
  sense may be contingent, and so have only an empirically
  conditioned existence, while yet there may be a non-empirical
  condition of the whole series; that is, there may exist an un-
  conditionally necessary being. This necessary being, as the
  intelligible condition of the series, would not belong to it as a
B58 ) member, not even as the highest member of it, nor would 1t
  render any member of the series empirically unconditioned.
  The whole sensible world, so far as regards the empirically
  conditioned existence of all its various members, would be left
  unaffected. This way of conceiving how an unconditioned
00019
being may serve as the ground of appearance differs from that
which we followed in the preceding subsection, in dealing with
the empirically unconditioned causality of freedom.  For there
the thing itself was as cause <1(substantia phaenomenon)>1 con-
ceived to belong to the series of conditions, and only its
<1causality>1 was thought as intelligible. Here, on the other hand,
the necessary being must be thought as entirely outside the
series of the sensible world (as <1ens extramundanum),>1 and as
purely intelligible. In no other way can it be secured against
the law which renders all appearances contingent and de-
pendent.
  The <1regulative principle of reason,>1 so far as it bears upon
our present problem, is therefore this, that everything in the
sensible world has an empirically conditioned existence, and
that in no one of its qualities can it be unconditionally neces-
sary; that for every member in the series of conditions we must
expect, and as far as possible seek, an empirical condition in
some possible experience; and that nothing justifies us in
deriving an existence from a condition outside the empirical
series or even in regarding it in its place within the series as
absolutely independent and self-sufficient. At the same time
this principle does not in any way debar us from recognis-
ing that the whole series may rest upon some intelligible being (A 562
that is free from all empirical conditions and itself contains  590
the ground of the possibility of all appearances.
  In these remarks we have no intention of proving the un-
conditionally necessary existence of such a being, or even of
establishing the possibility of a purely intelligible condition of
the existence of appearances in the sensible world. Just as, on
the one hand, we limit reason, lest in leaving the guiding-
thread of the empirical conditions it should go straying into
the <1transcendent,>1 adopting grounds of explanation that are
incapable of any representation <1in concreto,>1 so, on the other
hand, we limit the law of the purely empirical employment of
the understanding, lest it should presume to decide as to the
possibility of things in general, and should declare the in-
telligible to be <1impossible,>1 merely on the ground that it is
not of any use in explaining appearances. Thus all that we
have shown is that the thoroughgoing contingency of all
natural things, and of all their empirical conditions, is quite
00020
consistent with the optional assumption of a necessary, though
purely intelligible, condition; and that as there is no real con-
tradiction between the two assertions, <1both may be true.>1 Such
an absolutely necessary being, as conceived by the under-
standing, may be in itself impossible, but this can in no wise
53 ) be inferred from the universal contingency and dependence of
  everything belonging to the sensible world, nor from the prin-
  ciple which interdicts us from stopping at any one of its con-
  tingent members and from appealing to a cause outside the
  world. Reason proceeds by one path in its empirical use, and
  by yet another path in its transcendental use.
  The sensible world contains nothing but appearances, and
  these are mere representations which are always sensibly con-
  ditioned; in this field things in themselves are never objects to
  us. It is not therefore surprising that in dealing with a member
  of sensibility. To do so is to treat the appearances as if they
  were things in themselves which exist apart from their tran-
  scendental ground, and which can remain standing while we
  seek an outside cause of their existence. This certainly would
  ultimately be the case with contingent <1things,>1 but not with
  mere <1representatioms>1 of things, the contingency of which is
  itself merely phenomenon, and can lead to no other regress
  than that which determines the phenomena, that is, solely to
  the empirical regress. On the other hand, to think an <1intelli->1
  <1gible>1 ground of the appearances, that is, of the sensible world,
  and to think it as free from the contingency of appearances,
  does not conflict either with the unlimited empirical regress in
  the series of appearances nor with their thoroughgoing con-
 A 564 ) tingency. That, indeed, is all that we had to do in order to
 B 592 ) remove the apparent antinomy; and it can be done in this way
  only. If for everything conditioned in its existence the con-
  condition is always sensible, and therefore belongs to the series,
  it must itself in turn be conditioned, as we have shown in the
  antithesis of the fourth antinomy. Either, therefore, reason
  through its demand for the unconditioned must remain in
  conflict with itself, or this unconditioned must be posited out-
  side the series, in the intelligible. Its necessity will not then
00021
require, or allow of, any empirical condition; so far as appear-
ances are concerned, it will be unconditionally necessary.
  The empirical employment of reason, in reference to the
conditions of existence in the sensible world, is not affected by
the admission of a purely intelligible being; it proceeds, in
accordance with the principle of thoroughgoing contingency,
from empirical conditions to higher conditions which are
always again empirical. But it is no less true, when what we
have in view is the pure employment of reason, in reference
to ends, that this regulative principle does not exclude the
assumption of an intelligible cause which is <1not>1 in the series.
For the intelligible cause then signifies only the purely tran-
scendental and to us unknown ground of the possibility of the
sensible series in general. Its existence as independent of all
sensible conditions and as in respect of these conditions un-
conditionally necessary, is not inconsistent with the unlimited (A 565
ending regress in the series of empirical conditions.
  <1Concluding Note on the whole Antinomy of Pure Reason.>1
  So long as reason, in its concepts, has in view simply the
totality of conditions in the sensible world, and is considering
what satisfaction in this regard it can obtain for them, our
ideas are at once transcendental and <1cosmological.>1 Immedi-
ately, however, the unconditioned (and it is with this that we
are really concerned) is posited in that which lies entirely outside
the sensible world, and therefore outside all possible experi-
ence, the ideas become <1transcendent.>1 They then no longer serve
only for the completion of the empirical employment of reason
---an idea [of completeness] which must always be pursued,
though it can never be completely achieved. On the contrary,
they detach themselves completely from experience, and make
for themselves objects for which experience supplies no
material, and whose objective reality is not based on comple-
tion of the empirical series but on pure <1a priori>1 concepts. Such
transcendent ideas have a purely intelligible object; and this
object may indeed be admitted as a transcendental object, but
only if we likewise admit that, for the rest, we have no know-
00022
ledge in regard to it, and that it cannot be thought as a deter-
minate thing in terms of distinctive inner predicates. As it is
independent of all empirical concepts, we are cut off from any
A 566 ) reasons that could establish the possibility of such an object,
B 594 ) and have not the least justification for assuming it. It is a mere
  thought-entity. Nevertheless the cosmological idea which has
  given rise to the fourth antinomy impels us to take this step.  For
  the existence of appearances, which is never self-grounded but
  always conditioned, requires us to looa around for something
  different from all appearances, that is, for an intelligible object
  in which this contingency may terminate. But once we have
  allowed ourselves to assume a self-subsistent reality entirely
  outside the field of sensibility, appearances can only be viewed1
  as contingent modes whereby beings that are themselves intelli-
  gences represent intelligible objects. Consequently, the only
  resource remaining to us is the use of analogy, by which we
  employ the concepts of experience in order to form some
  sort of concept of intelligible things---things of which as
  they are in themselves we have yet not the least knowledge.
  Since the contingent is not to be known save through ex-
  perience, and we arc here concerned with things which are
  not to be in any way objects of experience, we must derive
  the knowledge of them from that which is in itself necessary,
  that is, from pure concepts of things in general. Thus the
  A 567 ) very first step which we take beyond the world of sense
  B 595 ) obliges us, in seeking for such new knowledge, to begin with
  an enquiry into absolutely necessary being, and to derive from
  the concepts of itthe concepts of all things in so far as they
  are purely intelligible. This we propose to do in the next
  chapter.
00023
  CHAPTER III
  THE IDEAL OF PURE REASON
  Section I
  THE IDEAL IN GENERAL
WE have seen above that no objects can be represented
through pure <1concepts of understanding,>1 apart from the con-
ditions of sensibility. For the conditions of the objective
reality of the concepts are then absent, and nothing is to be
found in them save the mere form of thought. If, however,
they are applied to appearances, they can be exhibited <1in>1
<1concreto,>1 because in the appearances they obtain the appro-
priate material for concepts of experience---a concept of ex-
perience being nothing but a concept of understanding <1in>1
<1concreto.>1 But <1ideas>1 are even further removed from objective
reality than are categories, for no appearance can be found in
which they can be represented <1in concreto.>1 They contain a
certain completeness to which no possible empirical know- (B 596)
ledge ever attains. In them reason aims only at a systematic
unity, to which it seeks to approximate the unity that is em-
pirically possible, without ever completely reaching it.
  But what I entitle the <1ideal>1 seems to be further removed
from objective reality even than the idea. By the ideal I under-
stand the idea, not merely <1in concreto,>1 but <1in individuo,>1 that is,
as an individual thing, determinable or even determined by
the idea alone.
  Humanity [as an idea] in its complete perfection contains
not only all the essential qualities which belong to human
nature and constitute our concept of it---and these so extended
00024
as to be in that complete conformity with their ends which
would be our idea of perfect humanity---but also everything
which, in addition to this concept, is required for the complete
determination of the idea. For of all contradictory predicates
one only [of each pair] can apply to the idea of the perfect
man. What to us is an ideal was in Plato's view an <1idea of>1
<1the divine understanding,>1 an individual1 object of its pure
intuition, the most perfect of every kind of possible being,
and the archetype of all copies in the [field of] appearance.
A 569)  Without soaring so high, we are yet bound to confess that
B 597) human reason contains not only ideas, but ideals also, which
  although they do not have, like the Platonic ideas, creative
  power, yet have <1practical>1 power (as regulative principles), and
  form the basis of the possible perfection of certain <1actions.>1
  Moral concepts, as resting on something empirical (pleasure
  or displeasure), are not completely pure concepts of reason.
  None the less, in respect of the principle whereby reason sets
  bounds to a freedom which is in itself without law, these con-
  cepts (when we attend merely to their form) may well serve as
  examples of pure concepts of reason. Virtue, and therewith
  human wisdom in its complete purity, are ideas. The wise
  man (of the Stoics) is, however, an ideal, that is, a man exist-
  ing in thought only, but in complete conformity with the idea
  of wisdom. As the idea gives the <1rule,>1 so the ideal in such a
  case serves as the <1archetype>1 for the complete determination
  of the copy; and we have no other standard for our actions
  than the conduct of this divine man within us, with which
  we compare and judge ourselves, and so reform ourselves,
  although we can never attain to the perfection thereby pre-
  scribed. Although we cannot concede to these ideals objective
  reality (existence), they are not therefore to be regarded as
  figments of the brain; they supply reason with a standard
  which is indispensable to it, providing it, as they do, with a
  A 570) concept of that which is entirely complete in its kind, and
  B 598) thereby enabling it to estimate and to measure the degree and
  the defects of the incomplete. But to attempt to realise the
  ideal in an example, that is, in the [field of] appearance, as, for
  instance, to depict the [character of the perfectly] wise man in
  a romance, is impracticable. There is indee something absurd,
00025
and far from edifying, in such an attempt, inasmuch as the
natural limitations, which are constantly doing violence to the
completeness of the idea, make the illusion that is aimed at
altogether impossible, and so cast suspicion on the good itself
---the good that has its source in the idea---by giving it the air
of being a mere fiction.
  Such is the nature of the ideal of reason, which must
always rest on determinate concepts and serve as a rule and
archetype, alike in our actions and in our critical judgments.
The products of the imagination are of an entirely different
nature; no one can explain or give an intelligible concept of
them; each is a kind of <1monogram,>1 a mere set of particular
qualities, determined by no assignable rule, and forming
rather a blurred sketch drawn from diverse experiences than a
determinate image---a representation such as painters and
physiognomists profess to carry in their heads, and which they
treat as being an incommunicable shadowy image1 of their
creations or even of their critical judgments. Such repre-
sentations may be entitled, though improperly, ideals of
sensibility, inasmuch as they are viewed as being models
(not indeed realisable) of possible empirical intuitions, and yet (A 571
furnish no rules that allow of being explained and examined  (B 599
  Reason, in its ideal, aims, on the contrary, at complete
determination in accordance with <1a priori>1 rules. Accordingly
it thinks for itself an object which it regards as being com-
pletely determinable in accordance with principles. The
conditions that are required for such determination are not,
however, to be found in experience, and the concept itself is
therefore transcendent.
  CHAPTER III
  Section 2
  THE TRANSCENDENTAL IDEAL
  <1(Prototypon Transcendentale)>1
  Every concept is, in respect of what is not contained in it,
undetermined, and is subject to the principle of <1determin->1
00026
<1ability>1 According to this principle, of <1every two>1 contradict-
orily opposed predicates only one can belong to a concept.
This principle is based on the law of contradiction, and is
therefore a purely logical principle. As such, it abstracts from
the entire content of knowledge and is concerned solely with
its logical form.
  But every <1thing,>1 as regards its possibility, is likewise sub-
A 572) ject to the principle of <1complete>1 determination, according to
B 600) which if <1all the possible>1 predicates of <1things>1 be taken together
  with their contradictory opposites, then one of each pair of
  contradictory opposites must belong to it. This principle1 does
  not rest merely on the law of contradiction; for, besides con-
  sidering each thing in its relation to the two contradictory
  predicates, it also considers it in its relation to <1the sum of>1
  <1all possibilities,>1 that is, to the sum-total of all predicates of
  things. Presupposing this sum as being an <1apriori>1 condition,
  it proceeds to represent everything as deriving its own pos-
  sibility from the share which it possesses in this sum of all
  possibilities.a The principle of complete determination con-
  cerns, therefore, the content, and not merely the logical form.
  It is the principle of the synthesis of all predicates which are
  intended to constitute the complete concept of a thing, and not
  simply a principle of analytic representation in reference merely
A 573 ) to one of two contradictory predicates. It contains a transcend-
B 601 ) ental presupposition, namely, that of the material <1for all>1
  <1possibility,>1 which in turn is regarded as containing <1a priori>1
  the data <1for theparticular possibility>1 of each and every thing.
  The proposition, <1everything which exists is completely de->1
  <1termined,>1 does not mean only that one of every pair of <1given>1
  contradictory predicates, but that one of every [pair of] <1possible>1
  a  In accordance with this principle, each and every thing is there-
  fore related to a common correlate, the sum of all possibilities. If this
  correlate (that is, the material for all possible predicates) should be
  found in the idea of some one thing, it would prove an affinity of all
  possible things, through identity of the ground of their complete
  determination. Whereas the <1determinability>1 of every <1concept>1 is sub-
  ordinate to the <1universality (universalitas)>1 of the principle of ex-
  cluded middle, the <1determination>1 of a <1thing>1 is subordinate to the
  <1totality (universitas)>1 or sum of all possible predicates.
00027
predicates, must always belong to it. In terms of this proposi-
tion the predicates are not merely compared with one another
logically, but the thing itself is compared, in transcendental
fashion, with the sum of all possible predicates. What the pro-
position therefore asserts is this: that to know a thing com-
pletely, we must know every possible [predicate], and must
determine it thereby, either affirmatively or negatively. The
complete determination is thus a concept, which, in its
totality, can never be exhibited <1in concreto.>1 It is based upon
an idea, which has its seat solely in the faculty of reason---
the faculty which prescribes to the understanding the rule of
its complete employment.
  Although this idea of the <1sum of allpossibility,>1 in so far
as it serves as the condition of the complete determination of
each and every thing, is itself undetermined in respect of the
predicates which may constitute it, and is thought by us as
being nothing more than the sum of all possible predicates,
we yet find, on closer scrutiny, that this idea, as a primordial
concept, excludes a number of predicates which as derivative
are already given through other predicates or which are in- (B 602
compatible with others; and that it does, indeed, define itself
as a concept that is completely determinate <1a priori.>1 It thus
becomes the concept of an individual object which is com-
pletely determined through the mere idea, and must there-
fore be entitled an <1ideal>1 of pure reason.
  When we consider all possible predicates, not merely
logically, but transcendentally, that is, with reference to such
content as can be thought <1a priori>1 as belonging to them, we
find that through some of them we represent a being, through  =
others a mere not-being. Logical negation, which is indi-
cated simply through the word <1not,>1 does not properly refer
to a concept, but only to its relation to another concept in a
judgment, and is therefore quite insufficient to determine a
concept in respect of its content. The expression <1non-mortal>1
does not enable us to declare that we are thereby representing
in the object a mere not-being; the expression leaves all con-
tent unaffected. A transcendental negation, on the other hand,
signifies not-being in itself, and is opposed to transcendental
affirmation, which is a something the very concept of which
00028
in itself expresses a being. Transcendental  affirmation is there-
fore entitled reality,1 because through it alone, and so far only
A 575) as it reaches, are objects something (things), whereas its
  opposite, negation, signifies a mere want, and, so far as it
  alone is thought, represents the abrogation of all thinghood.
  Now no one can think a negation determinately, save by
  basing it upon the opposed affirmation. Those born blind can-
  not have the least notion of darkness, since they have none of
  light. The savage knows nothing of poverty, since he has no
  acquaintance with wealth. The ignorant have no concept of
  their ignorance, because they have none of knowledge etc.a
  All concepts of negations are thus derivative; it is the realities
  which cont in the data, and, so to speak, the material or
  transcendental content, for the possibility and complete
  determination of all things.
  If, therefore, reason employs in the complete determina-
  tion of things a transcendental substrate that contains, as
  it were, the whole store of material from which all possible
  predicates of things must be taken, this substrate cannot be
  576) anything else than the idea of an <1omnitudo realitatis.>1 All
  true negations are nothing but limitations---a title which
  would be inapplicable, were they not thus based upon the
  unlimited, that is, upon ""the All.''
  But the concept of what thus possesses all reality is just the
  concept of a <1thing in itself>1 as completely determined; and since
  in all possible [pairs of] contradictory predicates one predi-
  cate, namely, that which belongs to being absolutely, is to be
  found in its determination, the concept of an <1ens realissimum>1
  is the concept of an individuals being. It is therefore a tran-
  scendental <1ideal>1 which serves as basis for the complete deter-
  a The observations and calculations of astronomers have taught
  us much that is wonderful; but the most important lesson that they
  have taught us has been by revealing the abyss of our <1ignorance,>1
  which otherwise we could never have conceived to be so great.
  Reflection upon the ignorance thus disclosed must produce a great
  change in our estimate of the purposes for which our reason should
  be employed. [In both A and B this note is attached, presumably
  by inadvertence, to the preceding sentence.]
00029
mination that necessarily belongs to all that exists. This ideal
is the supreme and complete material condition of the possi-
bility of all that exists---the condition to which all thought of
objects, so far as their content is concerned, has to be traced
back.  It is also the only true ideal of which human reason is
capable. For only in this one case is a conceptof a thing---a con-
cept which is in itself universal---completely determined in and
through itself, and known as the representation of an individual.
  The logical determination of a concept by reason is based
upon a disjunctive syllogism, in which the major premiss
contains a logical division (the division of the sphere of a
universal concept), the minor premiss limiting this sphere to
a certain part, and the conclusion determining the concept by (B 605
means of this part. The universal concept of a reality in general
cannot be divided <1a priori,>1 because without experience we do
not know any determinate kinds of reality which would be con-
tained under that genus. The transcendental major premiss
which is presupposed in the complete determination of all
things is therefore no other than the representation of the sum
of all reality; it is not merely a concept which, as regards its
transcendental content, comprehends all predicates <1under>1
<1itself;>1 it also contains them <1within itself;>1 and the complete
determination of any and every thing rests on the limitation of
this <1total>1 reality, inasmuch as part of it is ascribed to the thing,
and the rest is excluded---a procedure which is in agreement
with the  either---or' of the disjunctive major premiss and with
the determination of the object, in the minor premiss, through
one of the members of the division. Accordingly, reason, in em-
ploying the transcendental ideal as that by reference to which
it determines all possible things, is proceeding in a manner
analogous with its procedure in disjunctive syllogisms---this,
indeed, is the principle upon which I have based the system-
atic division of all transcendental ideas, as parallel with, and
corresponding to, the three kinds of syllogism.
  It is obvious that reason, in achieving its purpose, that,
namely, of representing the necessary complete determination
of things, does not presuppose the existence of a being that (A 578
corresponds to this ideal, but only the idea of such a being, and
this only for the purpose of deriving from an unconditioned
00030
totality of complete determination the conditioned totality,
that is, the totality of the limited. The ideal is, therefore, the
archetype1 <1(prototypon)>1 of all things, which one and all, as
imperfect copies <1(ectypa),>1 derive from it the material of their
possibility, and while approximating to it in varying degrees,
yet always fall very far short of actually attaining it.
  All possibility of things (thatis, of the synthesis of the mani-
fold, in respect of its content) must therefore be regarded as
derivative, with only one exception, namely, the possibility of
that which includes in itself all reality. This latter possibility
must be regarded as original. For all negations (which are the
only predicates through which anything can be distinguished
  from the <1ens realissimum)>1 are merely limitations of a greater,
  and ultimately of the highest, reality; and they therefore pre-
  suppose this reality, and are, as regards their content, derived
  from it. All manifoldness of things is only a correspondingly
  varied mode of limiting the concept of the highest reality which
  forms their common substratum, just as all figures are only pos-
  sible as so many different modes of limiting infinite space. The
  object of the ideal of reason, an object which is present to us only
  in and through reason, is therefore entitled the <1primordial being>1
  <1ens originarium)>1 As it has nothing above it, it is also entitled
  the <1highest being (ens summum);>1 and as everything that is con-
  A 579) ditioned is subject to it, the <1being of all beings (ens entium).>1
  B 607) These terms are not, however, to be taken as signifying the
  objective relation of an actual object to other things, but of an
  <1idea to concepts.>1 We are left entirely without knowledge as to
  the existence of a being of such outstanding pre-eminence.
  We cannot say that a primordial being consists of a number
  of derivative beings, for since the latter presuppose the former
  they cannot themselves constitute it. The idea of the prim-
  ordial being must therefore be thought as simple.
  Consequently, the derivation of all other possibility from
  this primordial being cannot, strictly speaking, be regarded as
  a <1limitation>1 of its supreme reality, and, as it were, a <1division>1
  of it. For in that case the primordial being would betreated as a
  mere aggregate of derivative beings; and this, as we have just
  shown, is impossible, although in our first rough statements
  we have used such language. On the contrary, the supreme
00031
reality must condition the possibility of all things as their
<1ground,>1 not as their <1sum;>1 and the manifoldness of things
must therefore rest, not on the limitation of the primordial
being itself, but on all that follows from it, including therein
all our sensibility, and all reality in the [field of] appearance
---existences of a kind which cannot, as ingredients, belong
to the idea of the supreme being.
  If, in following up this idea of ours, we proceed to hypos- (B 650808
tatise it, we shall be able to determine the primordial being
through the mere concept of the highest reality, as a being that
is one, simple, all-sufficient, eternal, etc. In short, we shall be  ==
able to determine it, in its unconditioned completeness, through
all predicaments. The concept of such a being is the concept of
<1God,>1 taken in the transcendental sense; and the ideal of pure
reason, as above defined, is thus the object of a transcendental
<1theology.>1
  In any such use of the transcendental idea we should, how-
ever, be overstepping the limits of its purpose and validity.
For reason, in employing it as a basis for the complete deter-
mination of things, has used it only as the <1concept>1 of all reality,
without requiring that all this reality be objectively given and
be itself a thing. Such a thing is a mere fiction in which we
combine and realise the manifold of our idea in an ideal,
as an individual1 being. But we have no right to do this,
nor even to assume the possibility of such an hypothesis. Nor
do any of the consequences which flow from such an ideal have
any bearing upon the complete determination of things, or
exercise in that regard the leastinfluence; and it is solely as
aiding in their determination that the idea has been shown to
be necessary.
  But merely to describe the procedure of our reason and its   (A 581
dialectic does not suffice; we must also endeavour to discover (B 609
the sources of this dialectic, that we may be able to explain, as
a phenomenon of the understanding, the illusion to which it
has given rise. For the ideal, of which we are speaking, is
based on a natural, not on a merely arbitrary idea. The ques-
tion to be raised is therefore this: how does it happen that
reason regards all possibility of things as derived from one
single fundamental possibility, namely, that of the highest
00032
reality, and thereupon presupposes this to be contained in an
individual1 primordial being?
  The answer is obvious from the discussions in the Tran-
scendental Analytic. The possibility of the objects of the senses
is a relation of these objects to our thought, in which some-
thing (namely, the empirical form) can be thought <1a priori,>1
while that which constitutes the matter, reality in the [field of]
appearance (that which corresponds to sensation), must be
given, since otherwise it could not even be thought, nor its
possibility represented. Now an object of the senses can be
completely determined only when it is compared with all the
predicates that are possible in the [field of] appearance, and
by means of them is represented either affirmatively or nega-
tively. But since that which constitutes the thing itself, namely,
the real in the [field of] appearance, must be given---other-
A 582 ) wise the thing could not be conceived at all---and since that
B 610 ) wherein the real of all appearances is given is experience,
  considered as single and all-embracing, the material for the
  possibility of all objects of the senses must be presupposed as
  given in one whole; and it is upon the limitation of this whole
  that all possibility of empirical objects, their distinction from
  each other and their complete determination, can alone be
  based. No other objects, besides those of the senses, can, as a
  matter of fact, be given to us, and nowhere save in the con-
  text of a possible experience; and consequently nothing is an
  object <1for us,>1 unless it presupposes the sum of all empirical
  reality as the condition of its possibility. Now owing to a
  natural illusion we regard this principle, which applies only
  to those things which are given as objects of our senses, as
  being a principle which must be valid of things in general.
  Accordingly, omitting this limitation, we treat the empirical
  principle of our concepts of the possibility of things, viewed as
  appearances, as being a transcendental principle of the pos-
  sibility of things in general.
  If we thereupon proceed to hypostatise this idea of the sum
  of all reality, that is because we substitute dialectically for
  the <1distributive>1 unity of the empirical employment of the
  understanding, the <1collective>1 unity of experience as a whole;
00033
and then thinking this whole [realm] of appearance as one
single thing that contains all empirical reality in itself; and
then again, in turn, by means of the above-mentioned tra  (A 583
scendental subreption, substituting for it the concept of a thing
which stands at the source of the possibility of all things, and
supplies the real conditions for their complete determination.a
  CHAPTER III
  Section 3
  THE ARGUMENTS OF SPECULATIVE REASON IN PROOF
  OF THE EXISTENCE OF A SUPREME BEING
  Notwithstanding this pressing need of reason to presup-
pose something that may afford the understanding a sufficient
foundation for the complete determination of its concepts, it
is yet much too easily conscious of the ideal and merely fic-
titious character of such a presupposition to allow itself, on
this ground alone, to be persuaded that a mere creature of its (A 584
own thought is a real being---were it not that it is impelled fro
another direction to seek a resting-place in the regress from
the conditioned, which is given, to the unconditioned. This
unconditioned is not, indeed, given as being in itself real, nor
as having a reality that follows from its mere concept; it is,
however, what alone can complete the series of conditions
when we proceed to trace these conditions to their grounds.
This is the course which our human reason, by its very nature,
leads all of us, even the least reflective, to adopt, though not
everyone continues to pursue it. It begins not with concepts,
but with common experience, and thus bases itself on some-
  a  This ideal of the <1ens realissimum,>1 although it is indeed a mere
representation, is first <1realised,>1 that is, made into an object, then
<1hypostatised,>1 and finally, by the natural progress of reason towards
the completion of unity, is, as we shall presently show, <1personified.>1
For the regulative unity of experience is not based on the appear-
ances themselves (on sensibility alone), but on the connection of the
manifold through the <1understanding>1 (in an apperception); and con-
sequently the unity of the supreme reality and the complete deter-
minability (possibility) of all things seems to lie in a supreme
understanding, and therefore in an <1intelligence.>1
00034
thing actually existing. But if this ground does not rest upon
the immovable rock of the absolutely necessary, it yields be-
neath our feet. And this latter support is itself in turn without
  support, if there be any empty space beyond and under it, and
  if it does not itself so fill all things as to leave no room for any
  further question---unless, that is to say, it be infinite in its
  reality.
  If we admit something as existing, no matter what this
  something may be, we must also admit that there is something
  which exists <1necessarily.>1 For the contingent exists only under
  the condition of some other contingent existence as its cause,
  and from this again we must infer yet another cause, until we
  are brought to a cause which is not contingent, and which is
  therefore unconditionally necessary. This is the argument upon
  which reason bases its advance to the primordial being.
A 585)  Now reason looks around for a concept that squares with
B 613) so supreme a mode of existence as that of unconditioned ne-
  cessity---not for the purpose of inferring <1a priori>1 from the con-
  cept the existence of that for which it stands (for if that were
  what it claimed to do, it ought to limit its enquiries to mere
  concepts, and would not then require a given existence as its
  basis), but solely in order to find among its various concepts
  that concept which is in no respect incompatible with absolute
  necessity. For that there must be something that exists with
  absolute necessity, is regarded as having been established by
  the first step in the argument. If, then, in removing every-
  thing which is not compatible with this necessity, only one
  existence remains, this existence must be the absolutely
  necessary being, whether or not its necessity be comprehen-
  sible, that is to say, deducible from its concept alone.
  Now that which in its concept contains a therefore for
  every wherefore, that which is in no respect defective, that
  which is in every way sufficient as a condition, seems to be
  precisely the being to which absolute necessity can fittingly
  be ascribed. For while it contains the conditions of all that
  is possible, it itself does not require and indeed does not
  allow of any condition, and therefore satisfies, at least in this
  one feature, the concept of unconditioned necessity. In this
  B 5 ) respect all other concepts must fall short of it; for since they
  -  4  re deficient and in need of completion, they cannot have as
00035
  IDEAL OF PURE REASON  497
their characteristic this independence of all further conditions.
We are not indeed justified in arguing that what does not con-
tain the highest and in all respects complete condition is there-
fore itself conditioned in its existence. But we are justified in
saying that it does not possess that one feature through which
alone reason is in a position, by means of an <1a priori>1 concept,
to know, in regard to any being, that it is unconditioned.
  The concept of an <1ens realissi-mum>1 is therefore, of all con-
cepts of possible things, that which best squares with the con-
cept of an unconditionally necessary being; and though it may
not be completely adequate to it, we have no choice in the
matter, but find ourselves constrained to hold to it. For we
cannot afford to dispense with the existence of a necessary
being; and once its existence is granted, we cannot, in the
whole field of possibility, find anything that can make a
better grounded claim [than the <1ens realissimum]>1 to such
pre-eminence in the mode of its existence.
  Such, then, is the natural procedure of human reason. It
begins by persuading itself of the existence of <1some>1 necessary
being. This being it apprehends as having an existence that
is unconditioned. It then looks around for the concept of that
which is independent of any condition, and finds it in that
which is itself the sufficient condition of all else, that is, in that (A 587
which contains all reality. But that which is all-containin  (B 615
without limits is absolute unity, and involves the concept of a
single being that is likewise the supreme being. Accordingly,
we conclude that the supreme being, as primordial ground
of all things, must exist by absolute necessity.
  If what we have in view is the <1coming to a decision->1--if, that
is to say, the existence of some sort of necessary being is taken
as granted, and if it be agreed further that we must come to
a decision as to what it is---then the foregoing way of thinking
must be allowed to have a certain cogency. For in that case
no better choice can be made, or rather we have no choice
at all, but find ourselves compelled to decide in favour of the
absolute unity of complete reality, as the ultimate source of
possibility. If, however, we are not required to come to any
decision, and prefer to leave the issue open until the weight
of the evidence is such as to compel assent; if, in other words,
what we have to do is merely to <1estimate>1 how much we really
00036
  know in the matter, and how much we merely flatter ourselves
  that we know, then the foregoing argument is far from ap-
  pearing in so advantageous a light, and special favour is
  required to compensate for the defectiveness of its claims.
  For if we take the issue as being that which is here stated,
  A 588) namely <1first,>1 that from any given existence (it may be, merely
  my own existence) we can correctly infer the existence of an
  unconditionally necessary being; <1secondly,>1 that we must regard
  a being which contains all reality, and therefore every condi-
  tion, as being absolutely unconditioned, and that in this con-
  cept of an <1ens realissimum>1 we have therefore found the concept
  of a thing to which we can also ascribe absolute necessity---
  granting all this, it by no means follows that the concept of a
  limited being which does not have the highest reality is for
  that reason incompatible with absolute reality. For although
  I do not find in its concept that unconditioned which is in-
  volved in the concept of the totality of conditions, we are not
  justified in concluding that its existence must for this reason
  be conditioned; just as I cannot say, in the case of a hypo-
  thetical syllogism, that where a certain condition (in the case
  under discussion, the condition of completeness in accordance
  with [pure] concepts) does not hold, the conditioned also does
  not hold. On the contrary, we are entirely free to hold that
  any limited beings whatsoever, notwithstanding their being
  limited, may also be unconditionally necessary, although we
  cannot infer their necessity from the universal concepts which
  we have of them. Thus the argument has failed to give us the
  least concept of the properties of a necessary being, and indeed
  is utterly ineffective.
  But this argument continues to have a certain importance
  and to be endowed with an authority of which we cannot,
  A 589) simply on the ground of this objective insufficiency, at once
  proceed to divest it. For granting that there are in the idea of
  reason obligations which are completely valid, but which in
  their application to ourselves would be lacking in all reality---
  that is, obligations to which there would be no motives---save
  on the assumption that there exists a supreme being to give
  effect and confirmation to the practical laws, in such a situa-
  tion we should be under an obligation to follow those concepts
  which, though they may not be objectively sufficient, are yet,
00037
according to the standard of our reason, preponderant, and in
comparison with which we know of nothing that is better and
more convincing. The duty of deciding would thus, by a practi-
cal addition, incline the balance so delicately preserved by the
indecisiveness of speculation. Reason would indeed stand con-
demned in its own judgment---and there is none more circum-
spect---if, when impelled by such urgent motives, it should
fail, however incomplete its insight, to conform its judgment
to those pleas which are at least of greater weight than any
others known to us.
  Though this argument, as resting on the inner insuffi-
ciency of the contingent, is in actual fact transcendental, it is
yet so simple and natural that, immediately it is propounded,
it commends itself to the commonest understanding. We see
things alter, come into being, and pass away; and these, or
at least their state, must therefore have a cause. But the same
question can be raised in regard to every cause that can be (B590
given in experience. Where, therefore, can we more suitably
locate the <1ultimate>1 causality than where there also exists the
<1highest>1 causality, that is, in that being which contains prim-
ordially in itself the sufficient ground of every possible
effect, and the concept of which we can also very easily enter-
tain by means of the one attribute of an all-embracing per-
fection. This supreme cause we then proceed to regard as
absolutely necessary, inasmuch as we find it absolutely  :
necessary that we should ascend to it, and find no ground for
passing beyond it. And thus, in all peoples, there shine amidst
the most benighted polytheism some gleams of monotheism,
to which they have been led, not by reflection and profound
speculation, but simply by the natural bent of the common
understanding, as step by step it has come to apprehend its
own requirements.
  <1There are only three possible ways ofproving the existence>1
<1of God by means of speculative reason.>1
  All the paths leading to this goal begin either from deter-
minate experience and the specific constitution of the world of
sense as thereby known, and ascend from it, in accordance
with laws of causality, to the supreme cause outside the
00038
  world; or they start from experience which is purely indeter-
  minate, that is, from experience of existence in general; or
  finally they abstract from all experience, and argue completely
  <1a priori,>1 from mere concepts, to the existence of a supreme
  591)  cause. The first proof is the <1physico-theological,>1 the second the
  <1cosmological,>1 the third the <1ontological.>1 There are, and there
  can be, no others.
  I propose to show that reason is as little able to make pro-
  gress on the one path, the empirical, as on the other path, the
  transcendental, and that it stretches its wings in vain in thus
  attempting to soar above the world of sense by the mere power
  of speculation. As regards the order in which these arguments
  should be dealt with, it will be exactly the reverse of that
  which reason takes in the progress of its own development, and
  therefore of that which we have ourselves followed in the above
  account. For it will be shown that, although experience is what
  first gives occasion to this enquiry, it is the <1transcendental>1
  <1concept>1 which in all such endeavours marks out the goal that
  reason has set itself to attain, and which is indeed its sole
  guide in its efforts to achieve that goal. I shall therefore
  begin with the examination of the transcendental proof, and
  afterwards enquire what effect the addition of the empirical
  factor can have in enhancing the force of the argument
  A592)  C  III
  B620)  CHAPTER III
  Section 4
  THE IMPOSSIBILITY OF AN ONTOLOGICAL PROOF
  OF THE EXISTENCE OF GOD
  It is evident, from what has been said, that the concept of
  an absolutely necessary being is a concept of pure reason, that
  is,a mere idea the objective reality of which is very far from
  being proved by the fact that reason requires it. For the idea
  instructs us only in regard to a certain unattainable complete-
  ness, and so serves rather to limit the understanding than to
  extend it to new objects. But we are here faced by what is
  indeed strange and perplexing, namely, that while the infer-
00039
ence from a given existence in general to some absolutely
necessary being seems to be both imperative and legitimate,
all those conditions under which alone the understanding can
form a concept of such a necessity are so many obstacles in
the way of our doing so.
  In all ages men have spoken of an <1absolutely necessary>1
being, and in so doing have endeavoured, not so much to
understand whether and how a thing of this kind allows even
of being thought, but rather to prove its existence. There is,
of course, no difficulty in giving a verbal definition of the con-
cept, namely, that it is something the non-existence of which
is impossible. But this yields no insight into the conditions (A593
which make it necessary1 to regard the non-existence of a
thing as absolutely unthinkable. It is precisely these condi-
tions that we desire to know, in order that we may determine
whether or not, in resorting to this concept, we are thinking
anything at all. The expedient of removing all those condi-
tions which the understanding indispensably requires in order
to regard something as necessary, simply through the intro-
duction of the word <1unconditioned,>1 is very far from sufficing
to show whether I am still thinking anything in the concept
of the unconditionally necessary, or perhaps rather nothing
at all.
  Nay more, this concept, at first ventured upon blindly,
and now become so completely familiar, has been supposed
to have its meaning exhibited in a number of examples; and
on this account all further enquiry into its intelligibility has
seemed to be quite needless. Thus the fact that every geo-
metrical proposition, as, for instance, that a triangle has three
angles, is absolutely necessary, has been taken as justifying us
in speaking of an object which lies entirely outside the sphere
of our understanding as if we understood perfectly what it is
that we intend to convey by the concept of that object.
  All the alleged examples are, without exception, taken
<1from judgments,>1 not from <1things>1 and their existence. But the
unconditioned necessity of judgments is not the same as an
absolute necessity of things. The absolute necessity of the
judgment is only a conditioned necessity of the thing, or of the
predicate in the judgment. The above proposition does not (A594
00040
  declare that three angles are absolutely necessary, but that,
  under the condition that there is a triangle (that is, that a tri-
  angle is given), three angles will necessarily be found in it. So
  great, indeed, is the deluding influence exercised by this logi-
  cal necessity that, by the simple device of forming an <1a priori>1
  concept of a thing in such a manner as to include existence
  within the scope of its meaning, we have supposed ourselves
  to have justified the conclusion that because existence neces-
  sarily belongs to the object of this concept---always under the
  condition that we posit the thing as given (as existing)---we are
  also of necessity, in accordance with the law of identity, re-
  quired to posit the existence of its object, and that this being
  is therefore itself absolutely necessary---and this, to repeat, for
  the reason that the existence of this being has already been
  thought in a concept which is assumed arbitrarily and on con-
  dition that we posit its object.
  If, in an identical proposition, I reject the predicate while
  retaining the subject, contradiction results; and I therefore say
  that the former belongs necessarily to the latter. But if we
  reject subject and predicate alike, there is no contradiction;
  for nothing is then left that can be contradicted. To posit a
  triangle, and yet to reject its three angles, is self-contradictory;
  but there is no contradiction in rejecting the triangle together
  with its three angles. The same holds true of the concept of an
  AB652 ) absolutely necessary being. If its existence is rejected, we re-
  ject the thing itself with all its predicates; and no question of
  contradiction can then arise. There is nothing outside it that
  would then be contradicted, since the necessity of the thing
  is not supposed to be derived from anything external; nor is
  there anything internal that would be contradicted, since in
  rejecting the thing itself we have at the same time rejected all
  its internal properties. "God is omnipotent' is a necessary
  judgment. The omnipotence cannot be rejected if we posit a
  Deity, that is, an infinite being; for the two concepts are
  identical. But if we say, "There is no God', neither the omni-
  potence nor any other of its predicates is given; they are one
  and all rejected together with the subject, and there is there-
  fore not the least contradiction in such a judgment.
  We have thus seen that if the predicate of a judgment is
  rejected together with the subject, no internal contradiction
00041
can result  and that this holds no matter what the predicate
may be. The only way of evading this conclusion is to argue
that there are subjects which cannot be removed, and must
always remain. That, however, would only be another way of
saying that there are absolutely necessary subjects; and that is
the very assumption which I have called in question, and the
possibility of which the above argument professes to establish.
For I cannot form the least concept of a thing which, should
it be rejected with all its predicates, leaves behind a contra- (B65
diction; and in the absence of contradiction I have, through
pure <1a priori>1 concepts alone, no criterion of impossibility.
  Notwithstanding all these general considerations, in which
every one must concur, we may be challenged with a case
which is brought forward as proof that in actual fact the
contrary holds, namely, that there is one concept, and indeed
only one, in reference to which the not-being or rejection of its
object is in itself contradictory, namely, the concept of the <1ens>1
<1realissimum.>1 It is declared that it possesses all reality, and
that we are justified in assuming that such a being is possible
(the fact that a concept does not contradict itself by no means
proves the possibility of its object: but the contrary assertion
I am for the moment willing to allow).a Now [the argument
proceeds] "all reality' includes existence; existence is therefore
contained in the concept of a thing that is possible. If, then,
this thing is rejected, the internal possibility of the thing is (B625
rejected---which is self-contradictory.
  My answer is as follows. There is already a contradiction
in introducing the concept of existence---no matter under what
title it may be disguised---into the concept of a thing which
we profess to be thinking solely in reference to its possibility.
 victory has been
  a A concept is always possible if it is not self-contradictory.
This is the logical criterion of possibility, and by it the object of the
concept is distinguishable from the <1nihil negativum.>1 But it may
none the less be an empty concept, unless the objective reality of the
synthesis through which the concept is generated has been specific-
ally proved; and such proof, as we have shown above, rests on prin-
ciples of possible experience, and not on the principle of analysis
(the law of contradiction). This is  a warning against arguing
directly from the logical possibility of concepts to the real possibility
of things.
00042
  won; but in actual fact nothing at all is said: the assertion
  is a mere tautology. We must ask: Is the proposition that
  <1this or that thing>1 (which, whatever it may be, is allowed
  as possible) <1exists,>1 an analytic or a synthetic proposition? If
  it is analytic, the assertion of the existence of the thing adds
  nothing to the thought of the thing; but in that case either
  the thought, which is in us, is the thing itself, or we have pre-
  supposed an existence as belonging to the realm of the possible,
  and have then, on that pretext, inferred its existence from its
  internal possibility---which is nothing but a miserable tauto-
  logy. The word "reality', which in the concept of the thing
  sounds other than the word "existence' in the concept of the
  predicate, is of no avail in meeting this objection. For if all
  positing (no matter what it may be that is posited) is entitled
  reality, the thing with all its predicates is already posited in
  the concept of the subject, and is assumed as actual; and in the
  B6598) predicate this is merely repeated. But if, on the other hand,
  we admit, as every reasonable person must, that all existential
  propositions are synthetic, how can we profess to maintain
  that the predicate of existence cannot be rejected without con-
  tradiction? This is a feature which is found only in analytic
  propositions, and is indeed precisely what constitutes their
  analytic character.
  I should have hoped to put an end to these idle and fruit-
  less disputations in a direct manner, by an accurate deter-
  mination of the concept of existence, had I not found that
  the illusion which is caused by the confusion of a logical with
  a real predicate (that is, with a predicate which determines a
  thing) is almost beyond correction. Anything we please can
  be made to serve as a logical predicate; the subject can even be
  predicated of itself; for logic abstracts from all content. But a
  <1determining>1 predicate is a predicate which is added to the con-
  cept of the subject and enlarges it. Consequently, it must not
  be already contained in the concept.
  <1"Being'>1 is obviously not a real predicate; that is, it is not a
  concept of something which could1 be added to the concept of
  a thing. It is merely the positing of a thing, or of certain deter-
  minations, as existing in themselves. Logically, it is merelythe
  copula of a judgment. The proposition, "God is omnipotent',
00043
contains two concepts, each of which has its object---God and
omnipotence. The small word "is' adds no new predicate, but
only serves to positthe predicate <1in its relation>1 to the subject. If,  (B 627
now, we take the subject (God) with all its predicates (among
which is omnipotence), and say "God is', or "There is a God', we
attach no new predicate to the concept of God, but only posit the
subjectin itselfwith all its predicates, and indeed posit it as being
an <1object>1 that stands in relation to my <1concept.>1 The content of
both must be one and the same; nothing can have been added
to the concept, which expresses merely what is possible, by
my thinking its object (through the expression "it is') as given
absolutely. Otherwise stated, the real contains no more than
the merely possible. A hundred real thalers do not contain
the least coin more than a hundred possible thalers. For as the
latter signify the concept, and the former the object and the
positing of the object, should the former contain more than the
latter, my concept would not, in that case, express the whole
object, and would not therefore be an adequate concept of it.
My financial position is, however, affected very differently by
a hundred real thalers than it is by the mere concept of them
(that is, of their possibility). For the object, as it actually exists,
is not analytically contained in my concept, but is added to my
concept (which is a determination of my state) synthetically;
and yet the conceived hundred thalers are not themselves in
the least increased through thus acquiring existence outside
my concept.
  By whatever and by however many predicates we may (A 6060
think a thing---even if we completely determine it---we do not
make the least addition to the thing when we further declare
that this thing <1is.>1 Otherwise, it would not be exactly the same
thing that exists, but something more than we had thought in
the concept; and we could not, therefore, say that the exact
object of my concept exists. If we think in a thing every feature
of reality except one, the missing reality is not added by my
saying that this defective thing exists. On the contrary, it
exists with the same defect with which I have thought it, since
otherwise what exists would be something different from what
I thought. When, therefore, I think a being as the supreme
reality, without any defect, the question still remains whether
  R2
00044
idea was therefore used only for the more definite knowledge
of that necessary being, of the necessary existence of which
we were already convinced, or persuaded, on other grounds.
This natural procedure of reason was, however, concealed
from view, and instead of ending with this concept, the attempt
was made to begin with it, and so to deduce from it that
o4) necessity of existence which it was only fitted to supplement.
  Thus arose the unfortunate ontological proof, which yields
  satisfaction neither to the natural and healthy understanding
  nor to the more academic demands of strict proof.
  The <1cosmological proof,>1 which we are now about to ex-
  amine, retains the connection of absolute necessity with the
  highest reality, but instead of reasoning, like the former proof,
  from the highest reality to necessity of existence, it reasons
  from the previously given unconditioned necessity of some
  being to the unlimited reality of that being. It thus enters upon
  a course of reasoning which, whether rational or only pseudo-
  rational, is at any rate natural, and the most convincing not
  only for common sense but even for speculative understand-
  ing. It also sketches the first outline of all the proofs in natural
  theology, an outline which has always been and always will
  be followed, however much embellished and disguised by
  superfluous additions. This proof, termed by Leibniz the proof
  <1a contingentia mundi,>1 we shall now proceed to expound and
  examine.
  It runs thus: If anything exists, an absolutely necessary
  being must also exist. Now I, at least, exist. Therefore an
  absolutely necessary being exists. The minor premiss contains
A 605) an experience, the major premiss the inference from there
  being any experience at all to the existence of the necessary.a
  The proof therefore really begins with experience, and is not
  wholly <1a priori>1 or ontological. For this reason, and because
  the object of all possible experience is called the world, it is en-
  titled the <1cosmological>1 proof. Since, in dealing with the objects
  a This inference is too well known to require detailed state-
  ment. It depends on the supposedly transcendental law of natural
  causality: that everything contingent has a cause, which, if itself
  contingent, must likewise have a cause, till the series of subordinate
  causes ends with an absolutely necessary cause, without which it
  would have no completeness.
00045
of experience, the proof abstracts from all special properties
through which this world may differ from any other possible
world, the title also serves to distinguish it from the physico-
theological proof, which is based upon observations of the par-
ticular properties of the world disclosed to us by our senses.
  The proof then proceeds as follows: The necessary being
can be determined in one way only, that is, by one out of each
possible pair of opposed predicates. It must therefore be <1com->1
<1pletely>1 determined through its own concept. Now there is only
one possible concept which determines a thing completely
<1a priori,>1 namely, the concept of the <1ens realissimum.>1 The
concept of the <1ens realissimum>1 is therefore the only concept (B
through which a necessary being can be thought. In othe
words, a supreme being necessarily exists.
  In this cosmological argument there are combined so many
pseudo-rational principles that speculative reason seems in
this case to have brought to bear all the resources of its dia-
lectical skill to produce the greatest possible transcendental
illusion. The testing of the argument may meantime be post-
poned while we detail in order the various devices whereby
an old argument is disguised as a new one, and by which
appeal is made to the agreement of two witnesses, the one with
credentials of pure reason and the other with those of experi-
ence. In reality the only witness is that which speaks in the
name of pure reason; in the endeavour to pass as a second
witness it merely changes its dress and voice. In order to lay
a secure foundation for itself, this proof takes its stand on
experience, and thereby makes profession of being distinct
from the ontological proof, which puts its entire trust in pure
<1apriori>1 concepts. But the cosmological proof uses this experi-
ence only for a single step in the argument, namely, to con-
clude the existence of a necessary being. What properties this
being may have, the empirical premiss cannot tell us. Reason
therefore abandons experience altogether, and endeavours to
discover from mere concepts what properties an absolutely (B 635
necessary being must have, that is, which among all possible
things contains in itself the conditions <1(requisita)>1 essential to
absolute necessity. Now these, it is supposed, are nowhere to
be found save in the concept of an <1ens realissimum;>1 and the
conclusion is therefore drawn, that the <1ens realissimum>1 is the
00046
absolutely necessary being. But it is evident that we are here
presupposing that the concept of the highest reality is com-
pletely adequate to the concept of absolute necessity of existence;
that is, that the latter can be inferred from the former. Now
this is the proposition maintained by the ontological proof; it
is here being assumed in the cosmological proof, and indeed
made the basis of the proof; and yet it is an assumption with
which this latter proof has professed to dispense. For ab-
solute necessity is an existence determined from mere con-
cepts. If I say, the concept of the <1ens realissimum>1 is a con-
cept, and indeed the only concept, which is appropriate and
adequate to necessary existence, I must also admit that neces-
sary existence can be inferred from this concept. Thus the so-
called cosmological proof really owes any cogency which it
may have to the ontological proof from mere concepts. The
appeal to experience is quite superfluous; experience may per-
haps lead us to the concept of absolute necessity, but is unable
to demonstrate this necessity as belonging to any determinate
thing. For immediately we endeavour to do so, we must
abandon all experience and search among pure concepts
to discover whether any one of them contains the condi-
B 608) tions of the possibility of an absolutely necessary being. If
  in this way we can determine the possibility of a necessary
  being, we likewise establish its existence. For what we are
  then saying is this: that of all possible beings there is one
  which carries with it absolute necessity, that is, that this being
  exists with absolute necessity.
  Fallacious and misleading arguments are most easily
  detected if set out in correct syllogistic form. This we now
  proceed to do in the instance under discussion.
  If the proposition, that every absolutely necessary being is
  likewise the most real of all beings, is correct (and this is the
  <1nervus probandi>1 of the cosmological proof), it must, like all
  affirmative judgments, be convertible, at least <1per accidens.>1
  It therefore follows that some <1entia realissima>1 are likewise
  absolutely necessary beings. But one <1ens realissimum>1 is in no
  respect different from another, and what is true of <1some>1 under
  this concept is true also of <1all.>1 In this case, therefore, I can
  convert the proposition <1simpliciter,>1 not only <1per accidens,>1
  and say that every <1ens realissimum>1 is a necessary being. But
00047
since this proposition is determined from its <1a priori>1 concepts
alone, the mere concept of the <1ens realissimum>1 must carry
with it the absolute necessityof thatbeing; and this is precisely
what the ontological proof has asserted and what the cosmo-
logical proof has refused to admit, although the conclusions (B 6
of the latter are indeed covertly based on it.
  Thus the second path upon which speculative reason enters
in its attempt to prove the existence of a supreme being is not
only as deceptive as the first, but has this additional defect,
that it is guilty of an <1ignoratio elenchi.>1 It professes to lead
us by a new path, but after a short circuit brings us back to
the very path which we had deserted at its bidding.
  I have stated that in this cosmological argument there lies
hidden a whole nest of dialectical assumptions, which the
transcendental critique can easily detect and destroy. These
deceptive principles I shall merely enumerate, leaving to the
reader, who by this time will be sufficiently expert in these
matters, the task of investigating them further, and of re-
futing them.
  We find, for instance, (I) the transcendental principle
whereby from the contingent we infer a cause. This principle
is applicable only in the sensible world; outside that world it
has no meaning whatsoever. For the mere intellectual concept
of the contingent cannot give rise to any synthetic proposition,
such as that of causality. The principle of causality has no
meaning and no criterion for its application save only in the
sensible world. But in the cosmological proof it is precisely in
order to enable us to advance beyond the sensible world that
it is employed. (2) The inference to a first cause, from the im- (A 610
possibility of an infinite series of causes, given one after the
other, in the sensible world. The principles of the employment
of reason do not justify this conclusion even within the world
of experience; still less beyond this world in a realm into
which this series can never be extended. (3) The unjustified  -
self-satisfaction of reason in respect of the completion of this
series. The removal of all the conditions without which no
concept of necessity is possible is taken by reason to be a com-
pletion of the concept of the series, on the ground that we can
then conceive nothing further. (4) The confusion between the
00048
logical possibility of a concept of all reality united into one
(without inner contradiction) and the transcendental possi-
bility of such a reality. In the case of the latter there is
needed a principle to establish the practicability of such a
synthesis, a principle which itself, however, can apply only
to the field of possible experiences---etc.
  The procedure of the cosmological proof is artfully designed
to enable us to escape having to prove the existence of a neces-
sary being <1a priori>1 through mere concepts.  Such proof would
require to be carried out in the ontological manner, and that
is an enterprise for which we feel ourselves to be altogether in-
competent. Accordingly, we take as the starting-point of our
inference an actual existence (an experience in general), and ad-
vance, in such manner as we can, to some absolutely necessary
condition of this existence. We have then no need to show the
A 611) possibility of this condition. For if it has been proved to exist,
  the question as to its possibility is entirely superfluous. If now
  we want to determine more fully the nature of this necessary
  being, we do not endeavour to do so in the manner that would
  be really adequate, namely, by discovering from its concept the
  necessity of its existence. For could we do that, we should be
  in no need of an empirical starting-point. No, all we seek is
  the negative condition <1(conditio sine qua non),>1 without which a
  being would not be absolutely necessary. And in all other kinds
  of reasoning from a given consequenceto its ground this would
  be legitimate; but in the present case it unfortunately happens
  that the condition which is needed for absolute necessity is only
  to be found in one single being. This being must therefore
  contain in its concept all that is required for absolute necessity,
  and consequently it enables me to infer this absolute necessity
  <1a priori.>1  I must therefore be able also to reverse the inference,
  and to say: Anything to which this concept (of supreme reality)
  applies is absolutely necessary. If I cannot make this inference
  (as I must concede, if I am to avoid admitting the ontological
  proof), I have come to grief in the new way that I have been
  following, and am back again at my starting-point. The con-
  cept of the supreme being satisfies all questions <1a priori>1 which
  can be raised regarding the inner determinations of a thing,
  612) and is therefore an ideal that is quite unique, in that the con-
  cept, while universal, also at the same time designates an
00049
individual as being among the things that are possible. But it
does not give satisfaction concerning the question of its own
existence--though this is the real purpose of our enquiries---
and if anyone admitted the existence of a necessary being but
wanted to know which among all [existing] things is to be
identified with that being, we could not answer: ""This, not
that. is the necessary being.''
  We may indeed be allowed to <1postulate>1 the existence of an
all-sufficient being, as the cause of all possible effects, with a
view to lightening the task of reason in its search for the unity
of the grounds of explanation. But in presuming so far as to
say that such a being <1necessarily exists,>1 we are no longer
giving modest expression to an admissible hypothesis, but
are confidently laying claim to apodeictic certainty. For the
knowledge of what we profess to know as absolutely necessary
must itself carry with it absolute necessity.
  The whole problem of the transcendental ideal amounts to
this: either, given absolute necessity, to find a concept which
possesses it, or, given the concept of something, to find that
something to be absolutely necessary.  If either task be possible,
so must the other; for reason recognises that only as absolutely
necessary which follows of necessity from its concept. But both
tasks are quite beyond our utmost efforts to <1satisfy>1 our under- (B 63
standing in this matter; and equally unavailing are all attempts
to induce it to acquiesce in its incapacity.
  Unconditioned necessity, which we so indispensably re-
quire as the last bearer of all things, is for human reason the
veritable abyss. Eternity itself, in all its terrible sublimity, as
depicted by a Haller,1 is far from makingthe same overwhelm-
ing impression on the mind; for it only <1measures>1 the duration
of things, it does not <1support>1 them. We cannot put aside, and
yet also cannot endure the thought, that a being, which we
represent to ourselves as supreme amongst all possible beings,
should, as it were, say to itself: "I am from eternity to eternity,
and outside me there is nothing save what is through my will-
<1but whence then am I>1?' All support here fails us; and the
<1greatest>1 perfection, no less than the <1least>1 perfection, is unsub-
stantial and baseless for the merely speculative reason, which
00050
makes not the least effort to retain either the one or the other,
and feels indeed no loss in allowing them to vanish entirely.
  Many forces in nature, which manifest their existence
through certain effects, remain for us inscrutable; for we cannot
track them sufficiently far by observation. Also, the transcend-
ental object lying at the basis of appearances (and with it the
reason why our sensibility is subject to certain supreme con-
B 642) ditions rather than to others) is and remains for us inscrutable.
  The thing itself is indeed given, but we can have no insight
  into its nature. But it is quite otherwise with an ideal of pure
  reason; it can never be said to be inscrutable. For since it is
  not required to give any credentials of its reality save only
  the need on the part of reason to complete all synthetic unity
  by means of it; and since, therefore, it is in no wise given as
  thinkable <1object,>1 it cannot be inscrutable in the manner in
  which an object is. On the contrary it must, as a mere idea,
  find its place and its solution in the nature of reason, and
  must therefore allow of investigation. For it is of the very
  essence of reason that we should be able to give an account
  of all our concepts, opinions, and assertions, either upon
  objective or, in the case of mere illusion, upon subjective
  grounds.
  DISCOVERY AND EXPLANATION
  of the Dialectical Illusion in all Transcendental Proofs of the Existence of
  a Necessary Being
  Both the above proofs were transcendental, that is, were
  attempted independently of empirical principles. For although
  the cosmological proof presupposes an experience in general,
  it is not based on any particular property of this experience
  but on pure principles of reason, as applied to an existence
A 615)  iven through empirical consciousness in general. Further, it
  soon abandons this guidance and relies on pure concepts alone.
  What, then, in these transcendental proofs is the cause of the
  dialectical but natural illusion which connects the concepts of
  necessity and supreme reality, and which realises and hypos-
  tatises what can be an idea only? Why are we constrained
  to assume that some one among existing things is in itself
00051
necessary, and yet at the same time to shrink back from the
existence of such a being as from an abyss? And how are
we to secure that reason may come to an agreement with
itself in this matter, and that from the wavering condition of
a diffident approval, ever again withdrawn, it may arrive at
settled insight?
  There is something very strange in the fact, that once we
assume something to exist we cannot avoid inferring that
something exists necessarily. The cosmological argument rests
on this quite natural (although not therefore certain) infer-
ence. On the other hand, if I take the concept of anything, no
matter what, I find that the existence of this thing can never
be represented by me as absolutely necessary, and that, what-
ever it may be that exists, nothing prevents me from think-
ing its non-existence. Thus while I may indeed be obliged to
assume something necessary as a condition of the existent in
general, I cannot think any particular thing as in itself neces-  A 616
sary. In other words, I can never <1complete>1 the regress to the B 644
conditions of existence save by assuming a necessary being
and yet am never in a position to <1begin>1 with such a being.
  If I am constrained to think something necessary as a
condition of existing things, but am unable to think any
particular thing as in itself necessary, it inevitably follows that
necessity and contingency do not concern the things them-
selves; otherwise there would be a contradiction. Conse-
quently, neither of these two principles can be objective. They
may, however, be regarded as subjective principles of reason.
The one calls upon us to seek something necessary as a con-
dition of all that is given as existent, that is, to stop nowhere
until we have arrived at an explanation which is complete
<1apriori;>1 the other forbids us ever to hope for this completion,
that is, forbids us to treat anything empirical as uncondi-
tioned and to exempt ourselves thereby from the toil of its
further derivation. Viewed in this manner, the two principles,
as merely heuristic and <1regulative,>1 and as concerning only the
formal interest of reason, can very well stand side by side. The
one prescribes that we are to philosophise about nature as if
there were a necessary first ground for all that belongs to
existence---solely, however, for the purpose of bringing sys-
tematic unity into our anowledge, by always pursuing such
00052
an idea, as an imagined ultimate ground. The other warns us
A 617) not to regard any determination whatsoever of existing things
  as such an ultimate ground, that is, as absolutely necessary,
  but to keep the way always open for further derivation, and
  so to treat each and every determination as always condi-
  tioned by something else. But if everything which is perceived
  in things must necessarily be treated by us as conditioned,
  nothing that allows of being empirically given can be re-
  garded as absolutely necessary.
  Since, therefore, the absolutely necessary is only intended
  to serve as a principle for obtaining the greatest possible
  unity among appearances, as being their ultimate ground;
  and since---inasmuch as the second rule commands us al-
  ways to regard all empirical causes of unity as themselves
  derived---we can never reach this unity within the world, it
  follows that we must regard the absolutely necessary as being
  <1outside>1 the world.
  While the philosophers of antiquity regard all form in
  nature as contingent, they follow the judgment of the common
  man in their view of matter as original and necessary. But if,
  instead of regarding matter relatively, as <1substratum>1 of ap-
  pearances, they had considered it <1in itself,>1 and as regards its
  existence, the idea of absolute necessity would at once have
  disappeared. For there is nothing which absolutely binds
  reason to accept such an existence; on the contrary it can al-
  ways annihilate it in thought, without contradiction; absolute
  necessity is a necessity that is to be found in thought alone.
A 618) This belief must therefore have been due to a certain regu-
  lative principle. In fact extension and impenetrability (which
  between them make up the concept of matter) constitute the
  supreme empirical principle of the unity of appearances;
  and this principle, so far as it is empirically unconditioned,
  has the character of a regulative principle. Nevertheless,
  since every determination of the matter which constitutes what
  is real in appearances, including impenetrability, is an effect
  (action) which must have its cause and which is therefore
  always derivative in character, matter is not compatible with
  the idea of a necessarybeing as a principle of all derived unity.
  (For its real properties, being derivative, are one and all only
00053
conditionally necessary, and so allow of being removed---
wherewith the whole existence of matter would be removed.)
If this were not the case, we should have reached the ulti-
mate ground of unity by empirical means---which is for-
bidden by the second regulative principle. It therefore follows
that matter, and in general whatever belongs to the world,
is not compatible with the idea of a necessary original being,
even when the latter is regarded simply as a principle of the
greatest empirical unity. That being or principle must be set
outside the world, leaving us free to derive the appearances
of the world and their existence from other appearances, with
unfailing confidence, just as if there were no necessary being,
while yet we are also free to strive unceasingly towards the
completeness of that derivation, just as if such a being were (A 619
presupposed as an ultimate ground  47
  As follows from these considerations, the ideal of the
supreme being is nothing but a <1regulative principle>1 of reason,
which directs us to look upon all connection in the world <1as if>1
it originated from an all-sufficient necessary cause. We can
base upon the ideal the rule of a systematic and, in accord-
ance with universal laws, necessary unity in the explanation
of that connection; but the ideal is not an assertion of an
existence necessary in itself. At the same time we cannot avoid
the transcendental subreption, by which this formal principle
is represented as constitutive, and bywhich this unity is hypos-
tatised. We proceed here just as we do in the case of space.
Space is only a principle of sensibility, but since it is the
primary source and condition of all shapes, which are only so
many limitations of itself, it is taken as something absolutely
necessary, existing in its own right, and as an object given <1a>1
<1Priori>1 in itself. In the same way, since the systematic unity of
nature cannot be prescribed as a principle for the empirical
employment of our reason, except in so far as we presuppose
the idea of an <1ens realissimum>1 as the supreme cause, it is
quite natural that this latter idea should be represented as an
actual object, which, in its character of supreme condition, is
also necessary---thus changing a <1regulative>1 into a <1constitutive>1 (A 620
principle. That such a substitution has been made becomes
evident, when we consider this supreme being, which relatively
00054
to the world is absolutely (unconditionally) necessary, as a
thing in and by itself. For we are then unable to conceive
what can be meant by its necessity. The concept of necessity
is only to be found in our reason, as a formal condition of
thought; it does not allow of being hypostatised as a material
condition of existence.
  CHAPTER III
  Section 6
THE IMPOSSIBILITY OF THE PHYSICO-THEOLOGICAL PROOF
  If, then, neither the concept of things in general nor the
experience of any <1existence in general>1 can supply what is re-
quired, it remains only to try whether a <1determinate experience,>1
the experience of the things of the present world, and the con-
stitution and order of these, does not provide the basis of a
proofwhich may help us to attain to an assured conviction of a
supreme being. Such proof we propose to entitle <1thephysico->1
<1theological.>1 Should this attempt also fail, it must follow that
no satisfactory proof of the existence of a being corresponding
to our transcendental idea can be possible by pure speculative
reason.
A 621)  In view of what has already been said, it is evident that we
  can count upon a quite easy and conclusive answer to this
  enquiry. For how can any experience ever be adequate to an
  idea? The peculiar nature of the latter consists just in the fact
  that no experience can ever be equal to it. The transcendental
  idea of a necessary and all-sufficient original being is so
  overwhelmingly great, so high above everything empirical,
  the latter being always conditioned, that it leaves us at a
  loss, partly because we can never find in experience material
  sufficient to satisfy such a concept, and partly because it is
  always in the sphere of the conditioned that we carry out our
  search, seeking there ever vainly for the unconditioned---no
  law of any empirical synthesis giving us an example of any
  such unconditioned or providing the least guidance in its
  pursuit.
  If the supreme being should itself stand in this chain of
00055
conditions, it would be a member of the series, and like the
lower members which it precedes, would call for further en-
quiry as to the still higher ground from which it follows. If, on
the other hand, we propose to separate it from the chain, and
to conceive it as a purelyintelligible being, existing apart from
the series of natural causes, by what bridge can reason contrive
to pass over to it? For all laws governing the transition from
effects to causes, all synthesis and extension of our knowledge,
refer to nothing but possible experience, and therefore solely
to objects of the sensible world, and apart from them can have (A 622
no meaning whatsoever.  50
  This world presents to us so immeasurable a stage of
variety, order, purposiveness, and beauty, as displayed alike in
its infinite extent and in the unlimited divisibility of its parts,
that even with such knowledge as our weak understanding
can acquire of it, we are brought face to face with so many
marvels immeasurably great, that all speech loses its force, all
numbers their power to measure, our thoughts themselves all
definiteness, and that our judgment of the whole resolves itself
into an amazement which is speechless, and only the more elo-
quent on that account. Everywhere we see a chain of effects
and causes, of ends and means, a regularity in origination and
dissolution. Nothing has of itself come into the condition in
which we find it to exist, but always points to something
else as its cause, while this in turn commits us to repetition
of the same enquiry. The whole universe must thus sink into
the abyss of nothingness, unless, over and above this infinite
chain of contingencies, we assume something to support it---
something which is original and independently self-subsistent,
and which as the cause of the origin of the universe secures
also at the same time its continuance. What magnitude are we
to ascribe to this supreme cause---admitting that it is supreme
in respect of all things in the world? We are not acquainted
with the whole content of the world, still less do we know (A623
how to estimate its magnitude by comparison with all that is
possible. But since we cannot, as regards causality, dispense
with an ultimate and supreme being,1 what is there to pre-
vent us ascribing to it a degree of perfection that sets it <1above>1
<1everything else that is possible?>1 This we can easily do---though
00056
only through the slender outline of an abstract concept---by
representing this being to ourselves as combining in itself all
possible perfection, as in a single substance. This concept is
in conformity with the demand of our reason for parsimony
of principles; it is free from self-contradiction, and is never
decisively contradicted by any experience; and it is likewise
of such a character that it contributes to the extension of
  the employment of reason within experience, through the
  guidance which it yields in the discovery of order and
  purposiveness.
  This proof always deserves to be mentioned with respect.
  It is the oldest, the clearest, and the most accordant with the
  common reason of mankind. It enlivens the study of nature,
  just as it itself derives its existence and gains ever new vigour
  from that source. It suggests ends and purposes, where our
  o  ervation would not have detected them by itself, and extends
  o  r knowledge of nature by means of the guiding-concept of a
  special unity, the principle of which is outside nature. This
  knowledge again reacts on its cause, namely, upon the idea
  624) which has led to it, and so strengthens the belief in a supreme
  Author [of nature] that the belief acquires the force of an irre-
  sistible conviction.
  It would therefore not only be uncomforting but utterly
  vain to attempt to diminish in any way the authority of this
  argument. Reason, constantly upheld by this ever-increasing
  evidence, which, though empirical, is yet so powerful, can-
  not be so depressed through doubts suggested by subtle and
  abstruse speculation, that it is not at once aroused from the
  indecision of all melancholy reflection, as from a dream, by
  one glance at the wonders of nature and the majesty of the
  universe--ascending from height to height up to the all-
  highest, from the conditioned to its conditions, up to the
  supreme and unconditioned Author [of all conditioned
  being] .
  But although we have nothing to bring against the ration-
  ality and utility of this procedure, but have rather to commend
  and to further it, we still cannot approve the claims, which this
  mode of argument would fain advance, to apodeictic certainty
  and to an assent founded on no special favour or support from
  other quarters. It cannot hurt the good cause, if the dogmatic
00057
language of the overweening sophist be toned down to the (A625
more moderate and humble requirements of a belief adequate
to quieten our doubts, though not to command unconditional
submission. I therefore maintain that the physico-theological
proof can never by itself establish the existence of a supreme
being, but must always fall back upon the ontological argu-
ment to make good its deficiency. It only serves as an intro-
duction to the ontological argument; and the latter therefore
contains (in so far as a speculative proof is possible at all) <1the>1
<1one possible ground of proof>1 with which human reason can
never dispense.
  The chief points of the physico-theological proof are as
follows: (I) In the world we everywhere find clear signs of an
order in accordance with a determinate purpose, carried out
with great wisdom; and this in a universe which is indescrib-
ably varied in content and unlimited in extent. (2) This pur-
posive order is quite alien to the things of the world, and only
belongs to them contingently; that is to say, the diverse things
could not of themselves have co-operated, by so great a com-
bination of diverse means, to the fulfilment of determinate
final purposes, had they not been chosen and designed for
these purposes by an ordering rational principle in conformity
with underlying ideas. (3) There exists, therefore, a sublime
and wise cause (or more than one), which must be the cause
of the world not merely as a blindly working all-powerful
nature, by <1fecundity,>1 but as intelligence, through <1freedom.>1
(4) The unity of this cause may be inferred from the unity of
the reciprocal relations existing between the parts of the world,
as members of an artfully arranged structure--inferred with (A 626
certainty in so far as our observation suffices for its verification
and beyond these limits with probability, in accordance with
the principles of analogy.
  We need not here criticise natural reason too strictly in
regard to its conclusion from the analogy between certain
natural products and what our human art produces when we
do violence to nature, and constrain it to proceed not according
to its own ends but in conformity with ours---appealing to the
similarity of these particular natural products with houses,
ships, watches. Nor need we here question its conclusion that
00058
there lies at the basis of nature a causality similar to that
responsible for artificial products, namely, an understand-
ing and a will; and that the inner possibility of a self-acting1
nature (which is what makes all art, and even, it may be,
reason itself, possible) is therefore derived from another,
though superhuman, art---a mode of reasoning which could
not perhaps withstand a searching transcendental criticism.
But at any rate we must admit that, if we are to specify a
cause at all, we cannot here proceed more securely than by
analogy with those purposive productions of which alone the
cause and mode of action are fully known to us. Reason could
never be justified in abandoning the causality which it knows
for grounds of explanation which are obscure, of which it
does not have any knowledge, and which are incapable of
proof.
  On this method of argument, the purposiveness and har-
monious adaptation of so much in nature can suffice to prove
A 627) the contingency of the form merely, not of the matter, that is,
B 655)  not of the substance in theworld. To prove the latter we should
  have to demonstrate that the things in the world would not
  of themselves be capable of such order and harmony, in
  accordance with universal laws, if they were not <1in their>1
  <1substance>1 the product of supreme wisdom. But to prove this
  we should require quite other grounds of proof than those
  which are derived from the analogy with human art. The
  utmost, therefore, that the argument can prove is an <1architect>1
  of the world who is always very much hampered by the
  adaptability of the material in which he works, not a <1creator>1
  of the world to whose idea everything is subject. This, how-
  ever, is altogether inadequate to the lofty purpose which we
  have before our eyes, namely, the proof of an all-sufficient
  primordia being. To prove the contingency of matter itself,
  we should have to resort to a transcendental argument, and
  this is precisely what we have here set out to avoid.
  The inference, therefore, is that the order and purposive-
  ness everywhere observable throughout the world may be
  regarded as a completely contingent arrangement, and that
  we may argue to the existence of a cause <1proportioned>1 to it.
  But the concept of this cause must enable us to know some-
00059
thing quite <1determinate>1 about it, and can therefore be no
other than the concept of a being who possesses all might,
wisdom, etc., in a word, all the perfection which is proper to
an all-sufficient being. For the predicates---"very great', "as- (B 656
tounding', "immeasurable' in power and excellence---give no
determinate concept at all, and do not really tell us what the
thing is in itself. They are only relative representations of the
magnitude of the object, which the observer, in contemplat-
ing the world, compares with himself and with his capacity
of comprehension, and which are equally terms of eulogy
whether we be magnifying the object or be depreciating the
observing subject in relation to that object. Where we are
concerned with the magnitude (of the perfection) of a thing,
there is no determinate concept except that which compre-
hends all possible perfection; and in that concept only the
allness <1(omnitudo)>1 of the reality is completely determined.
  Now no one, I trust, will be so bold as to profess that he
comprehends the relation of the magnitude of the world as he
has observed it (alike as regards both extent and content) to
omnipotence, of the world order to supreme wisdom, of the
world unity to the absolute unity of its Author, etc. Physico-
theology is therefore unable to give any determinate concept
of the supreme cause of the world, and cannot therefore serve
as the foundation of a theology which is itself in turn to
form the basis of religion.
  To advance to absolute totality by the empirical road is
utterly impossible. None the less this is what is attempted in
the physico-theological proof. What, then, are the means (A 629
which have been adopted to bridge this wide abyss?
  The physico-theological argument can indeed lead us to
the point of admiring the greatness, wisdom, power, etc., of
the Author of the world, but can take us no further. Accord-
ingly, we then abandon the argument from empirical grounds
of proof, and fall back upon the contingency which, in the
first steps of the argument, we had inferred from the order and
purposiveness of the world. With this contingency as our sole
premiss, we then advance, by means of transcendental con-
cepts alone, to the existence of an absolutely necessary being,
and [as a final step] from the concept of the absolute necessity
of the first cause to the completely determinate or determin-
00060
able concept of that necessary being, namely, to the concept of
an all-embracing reality. Thus the physico-theological proof,
failing in its undertaking, has in face of this difficulty suddenly
fallen back upon the cosmological proof; and since the latter
is only a disguised ontological proof, it has really achieved
its purpose by pure reason alone---although at the start it
disclaimed all kinship with pure reason and professed to
establish its conclusions on convincing evidence derived from
experience.
  Those who propound the physico-theological argument
have therefore no ground for being so contemptuous in their
attitude to the transcendental mode of proof, posing as clear-
sighted students of nature, and complacently looking down
  upon that proof as the artificial product of obscure speculative
  refinements. For were they willing to scrutinise their own pro-
  cedure, they would find that, after advancing some considerable
  B 6308) way on the solid ground of nature and experience, and finding
  themselves just as far distant as ever fromthe object which dis-
  closes itself to their reason, they suddenly leave this ground, and
  pass over into the realm of mere possibilities, where they hope
  upon the wings of ideas to draw near to the object---the object
  that has refused itself to all their <1empirical>1 enquiries. For after
  this tremendous leap, when they have, as they think, found firm
  ground, they extend their concept---the <1determinate>1 concept,
  into the possession of which they have now come, they know not
  how---over the whole sphere of creation. And the ideal, [which
  this reasoning thus involves, and] which is entirely a product
  of pure reason, they then elucidate by reference to experience,
  though inadequately enough, and in a manner far below the
  dignity of its object; and throughout they persist in refusing
  to admit that they have arrived at this knowledge or hypo-
  thesis by a road quite other than that of experience.
  Thus the physico-theological proof of the existence of an
  original or supreme being rests upon the cosmological proof,
  and the cosmological upon the ontological. And since, besides
  these three, there is no other path open to speculative reason,
  the ontological proof from pure concepts of reason is the only
  possible one, if indeed any proof of a proposition so far exalted
  above all empirical employment of the understanding is pos-
  sible at all.
00061
  CHAPTER III  (A 631
               (B 659
  Section 7
CRITIQUE OF ALL THEOLOGY BASED UPON SPECULATIVE
  PRINCIPLES OF REASON
  If I understand by theology knowledge of the original
being, it is based either solely upon reason <1(theologia rationa->1
<1lis)>1 or upon revelation <1(revelata).>1 The former thinks its object
either through pure reason, solely by means of transcendental
concepts <1(ens originarium, realissimum, ens entium),>1 in which
case it is entitled <1transcendental>1 theology, or through a con-
cept borrowed from nature (from the nature of our soul)---a
concept of the original being as a supreme intelligence---and
it would then have to be called <1natural>1 theology. Those who
accept only a transcendental theology are called <1deists;>1 those
who also admit a natural theology are called <1theists.>1 The
former grant that we can know the existence of an original
being solely through reason, but maintain that our concept
of it is transcendental only, namely, the concept of a being
which possesses all reality, but which we are unable to de-
termine in any more specific fashion. The latter assert that
reason is capable of determining its object more precisely
through analogy with nature, namely, as a being which,
through understanding and freedom, contains in itself the
ultimate ground of everything else. Thus the deist repre-
sents this being merely as a <1cause of the world>1 (whether by )A 632
the necessity of its nature or through freedom, remains un-     )B 660
decided), the theist as the <1Author of the world.>1
  Transcendental theology, again, either proposes to deduce
the existence of the original being from an experience in
general (without determining in any more specific fashion the
nature of the world to which the experience belongs), and is
then entitled <1cosmo-theology;>1 or it believes that it can know the
existence of such a being through mere concepts, without the
help of any experience whatsoever, and is then entitled <1onto->1
<1theology.>1
<1Natural theology>1 infers the properties and the existence of
00062
  If we infer from the existence of <1things>1 in the world the
existence of their cause, we are employing reason, not in the
knowledge of nature, but in <1speculation.>1 For the former type
of knowledge treats as empirically contingent, and refers to a
cause, not the things themselves (substances), but only that
which <1happens,>1 that is, their <1states.>1 That substance (matter) is
itself contingent in its existence would have to be known in a
B  36) purely speculative manner. Again, even if we were speaking
  only of the form of the world, the way in which things are con-
  nected and change, and sought to infer from this a cause
  entirely distinct from the world, this would again be a judg-
  ment of purely speculative reason, since the object which we
  are inferring is not an object of a possible experience. So em-
  ployed, the principle of causality, which is only valid within
  the field of experience, and outside this field has no applica-
  tion, nay, is indeed meaningless, would be altogether diverted
  from its proper use
  Now I maintain that all attempts to employ reason in theo-
  logy in any merely speculative manner are altogether fruit-
  less and by their very nature null and void, and that the prin-
  ciples of its employment in the study of nature do not lead to
  any theology whatsoever. Consequently, the only theology of
  reason which is possible is that which is based upon moral laws
  or seeks guidance from them. All synthetic principles of reason
  allow only of an immanent employment; and in order to have
  knowledge of a supreme being we should have to put them to
  a transcendent use, for which our understanding is in no way
  fitted. If the empirically valid law of causality is to lead to the
  original being, the latter must belong to the chain of objects of
  experience, and in that case it would, like all appearances, be
  6637) itself again conditioned. But even if the leap beyond the limits
  of experience, by means of the dynamical law of the relation of
  effects to their causes, be regarded as permissible, what sort of
  a concept could we obtain by this procedure? It is far from pro-
  viding the concept of a supreme being, since experience never
  gives us the greatest of all possible effects, such as would be re-
  quired to provide the evidence for a cause of that kind. Should
  we seek to make goodthis lack of determination in ourconcept,
  by means of a mere idea of [a being that possesses] the highest
  perfection and original necessity, this may indeed be granted
00063
as a favour; it cannot be demanded as a right on the strength
of an incontrovertible proof. The physico-theological proof, as
combining speculation and intuition, might therefore perhaps
give additional weight to other proofs (if such there be); but
taken alone, it serves only to prepare the understanding for
theological knowledge, and to give it a natural leaning in this
direction, not to complete the work in and by itself.
  All this clearly points to the conclusion that transcendental
questions allow only of transcendental answers, that is, an-
swers exclusively based on concepts that are <1a priori,>1 without
the least empirical admixture.  But the question under con-
sideration is obviously synthetic, calling for an extension of our
knowledge beyond all limits of experience, namely, to the
existence of a being that is to correspond to a mere idea
of ours, an idea that cannot be paralleled in any experience  )A 638
Now as we have already proved, synthetic <1a priori>1 knowledge
is possible only in so far as it expresses the formal conditions
of a possible experience; and all principles are therefore only
of immanent validity, that is, they are applicable only to ob-
jects of empirical knowledge, to appearances. Thus all attempts
to construct a theology through purely speculative reason, by
means of a transcendental procedure, are without result.
  But even if anyone prefers to call in question all those
proofs which have been given in the Analytic, rather than
allow himself to be robbed of his conviction of the conclusive-
ness of the arguments upon which he has so long relied, he
still cannot refuse to meet my demand that he should at least
give a satisfactory account how, and by what kind of inner
illumination, he believes himself capable of soaring so far
above all possible experience, on the wings of mere ideas.
New proofs, or attempts to improve upon the old ones, I
would ask to be spared. There is not indeed, in this field, much
room for choice, since all merely speculative proofs in the
end bring us always back to one and the same proof, namely,
the ontological; and I have therefore no real ground to fear
the fertile ingenuity of the dogmatic champions of super-
sensible reason. I shall not, however, decline the challenge )A 639
to discover the fallacy in any attempt of this kind, and     )B 667
so to nullify its claims; and this I can indeed do without
00064
considering myself a particularly combative person. But by
such means I should never succeed in eradicating the hope
of better fortune in those who have once become accustomed
to dogmatic modes of persuasion; and I therefore confine
myself to the moderate demand, that they give, in terms
which are universal and which are based on the nature of the
human understanding and of all our other sources of know-
ledge, a satisfactory answer to this one question: how we can
so much as make a beginning in the proposed task of ex-
tending our knowledge entirely <1a priori,>1 and of carrying it
into a realm where no experience is possible to us, and in
which there is therefore no means of establishing the object-
tive reality of any concept that we have ourselves invented.
  In whatever manner the understanding may have arrived at
 a concept, the existence of its object is never, by any process
 of analysis, discoverable within it; for the knowledge of the
 <1existence>1 of the object consists precisely in the fact that the
  object is posited in itself, <1beyond the [mere] thought of it.1>1
  Through concepts alone, it is quite impossible to advance to
  the discovery of new objects and supernatural beings; and it
  is useless to appeal to experience, which in all cases yields only
  appearances.
  But although reason, in its merely speculative employ-
  ment, is very far from being equal to so great an undertak-
  ing, namely, to demonstrate the existence of a supreme being,
  A 640)  it is yet of very great utility in <1correcting>1 any knowledge of this
  being which may be derived from other sources, in making it
  consistent with itself and with every point of view from which
  intelligible objects may be regarded, and in freeing it from
  everything incompatible with the concept of an original
  being and from all admixture of empirical limitations
  Transcendental theology is still, therefore, in spite of all
  its disabilities, of great importance in its negative employ-
  ment, and serves as a permanent censor of our reason, in so
  far as the latter deals merely with pure ideas which, as such,
  allow of no criterion that is not transcendental. For if, in some
  other relation, perhaps on practical grounds, the <1presupposi->1
  <1tion>1 of a supreme and all-sufficient being, as highest intelli-
00065
gence, established its validity beyond all question, it would be
of the greatest importance accurately to determine this con-
cept on its transcendental side, as the concept of a necessary
and supremely real being, to free it from whatever, as be-
longing to mere appearance (anthropomorphism in its wider
sense), is out of keeping with the supreme reality, and at
the same time to dispose of all counter-assertions, whether
<1atheistic, deistic,>1 or <1anthropomorphic.>1 Such critical treatment
is, indeed, far from being difficult, inasmuch as the same
grounds which have enabled us to demonstrate the inability of
human reason to maintain the existence of such a being must (A 641
also suffice to prove the invalidity of all counter-assertions.
For from what source could we, through a purely speculative
employment of reason, derive the knowledge that there is no
supreme being as ultimate ground of all things, or that it has
none of the attributes which, arguing from their consequences,
we represent to ourselves as analogical with the dynamical
realities of a thinking being, or (as the anthropomorphists
contend) that it must be subject to all the limitations which
sensibility inevitably imposes on those intelligences which are
known to us through experience.
  Thus, while for the merely speculative employment of
reason the supreme being remains a mere <1ideal,>1 it is yet <1an>1
<1ideal without a flaw,>1 a concept which completes and crowns
the whole of human knowledge. Its objective reality cannot
indeed be proved, but also cannot be disproved, by merely
speculative reason. If, then, there should be a moral theology
that can make good this deficiency, transcendental theology,
which before was problematic only, will prove itself indis-
pensable in determining the concept of this supreme being-
and in constantly testing reason, which is so often deceived by
sensibility, and which is frequently out of harmony with its
own ideas. Necessity, infinity, unity, existence outside the
world (and not as world-soul), eternity as free from conditions
of time, omnipresence as free from conditions of space, omni- (B 64
potence, etc. are purely transcendental predicates, and for
this reason the purified concepts of them, which every theology
finds so indispensable, are only to be obtained from tran-
scendental theology.
00066
     APPENDIX TO THE TRANSCENDENTAL DIALECTIC
  THE REGULATIVE EMPLOYMENT OF THE IDEAS OF PURE
                   REASON
  The outcome of all dialectical attempts of pure reason
  does not merely confirm what we have already proved in the
  Transcendental Analytic, namely, that all those conclusions of
  ours which profess to lead us beyond the field of possible ex-
  perience are deceptive and without foundation; it likewise
  teaches us this further lesson, that human reason has a natural
  tendency to transgress these limits, and that transcendental
  ideas are just as natural to it as the categories are to under-
  standing---though with this difference, that while the categories
  lead to truth, that is, to the conformity of our concepts with
  the object, the ideas produce what, though a mere illusion,
  is none the less irresistible, and the harmful influence of
  which we can barely succeed in neutralising even by means
  of the severest criticism.
  Everything that has its basis in the nature of our powers
  must be appropriate to, and consistent with, their right em-
  ployment---if only we can guard against a certain misunder-
A 643( standing and so can discover the proper direction of these
B 671( powers. We are entitled, therefore, to suppose that tran-
  scendental ideas have their own good, proper, and therefore
  <1immanent>1 use, although, when their meaning is misunder-
  stood, and they are taken for concepts of real things, they
  become transcendent in their application and for that very
  reason can be delusive. For it is not the idea in itself, but its
  use only, that can be either transcendent or immanent (that
  is, either range beyond all possible experience or find em-
  ployment within its limits), according as it is applied to an
  object which is supposed to correspond to it, or is directed
  solely to the use of understanding in general, in respect of
  those objects that fall to be dealt with by the understand-
  ing. All errors of subreption are to be ascribed to a defect
  of judgment,1 never to understanding or to reason.
  Reason is never in immediate relation to an object, but
00067
only to the understanding; and it is only through the under-
standing that it has its own [specific] empirical employment.
It does not, therefore, <1create>1 concepts (of objects) but only
<1orders>1 them, and gives them that unity which they can have
only if they be employed in their widest possible application,
that is, with a view to obtaining totality in the various series.
The understanding does not concern itself with this totality,
but only with that connection through which, in accordance
with <1concepts,>1 such <1series>1 of conditions <1come into being.>1
Reason has, therefore, as its sole object, the understanding (A 644
and its effective application. Just as the understanding unifies
the manifold in the object by means of concepts, so reason
unifies the manifold of concepts by means of ideas, positing
a certain collective unity as the goal of the activities of the
understanding, which otherwise are concerned solely with
distributive unity.
  I accordingly maintain that transcendental ideas never
allow of any constitutive employment. When regarded in
that mistaken manner, and therefore as supplying concepts
of certain objects, they are but pseudo-rational, merely dia-
lectical concepts. On the other hand, they have an excellent,
and indeed indispensably necessary, regulative employment,
namely, that of directing the understanding towards a certain  -
goal upon which the routes marked out by all its rules con-
verge, as upon their point of intersection. This point is indeed
a mere idea, a <1focus imaginarius,>1 from which, since it lies
quite outside the bounds of possible experience, the concepts
of the understanding do not in reality proceed; none the less
it serves to give to these concepts the greatest [possible] unity
combined with the greatest [possible] extension. Hence arises
the illusion that the lines have their source in a real object
lying outside the field of empirically possible knowledge-- just
as objects reflected in a mirror are seen as behind it. Never-
theless this illusion (which need not, however, be allowed
to deceive us) is indispensably necessary if we are to direct (B 6
the understanding beyond every given experience (as part of
the sum of possible experience), and thereby to secure its
greatest possible extension, just as, in the case of mirror-
vision, the illusion involved is indispensably necessary if,
00068
besides the objects which lie before our eyes, we are also to
see those which lie at a distance behind our back.
  If we consider in its whole range the knowledge obtained
for us by the understanding, we find that what is peculiarly
distinctive of reason in its attitude to this body of knowledge,
is that it prescribes and seeks to achieve its <1systematisation,>1
that is, to exhibit the connection of its parts in conformity
with a single principle. This unity of reason always presup-
  poses an idea, namely, that of the form of a whole of know-
  ledge---a whole which is prior to the determinate knowledge
  of the parts and which contains the conditions that deter-
  mine <1a priori>1 for every part its position and relation to
  the other parts. This idea accordingly postulates a complete
  unity in the knowledge obtained by the understanding, by
  which this knowledge is to be not a mere contingent aggregate,
  but a system connected according to necessary laws. We may
  not say that this idea is a concept of the object, but only of the
  thoroughgoing unity of such con epts, in so far as that unity
  serves as a rule for the under anding. These concepts of
  reason are not derived from nature; on the contrary, we in-
  terrogate nature in accordance with these ideas, and consider
  646) our knowledge as defective so long as it is not adequate to
  them. By general admission, <1pure earth, pure water, pure air,>1
  etc., are not to be found. We require, however, the concepts of
  them (though, in so far as their complete purity is concerned,
  they have their origin solely in reason) in order properly to
  determine the share which each of these natural causes has in
  producing appearances. Thus in order to explain the chemical
  interactions of bodies in accordance with the idea of a mechan-
  ism, every kind of matter is reduced to earths <1(qua>1 mere
  weight), to salts and inflammable substances <1(qua>1 force), and
  to water and air as vehicles (machines, as it were, by which
  the first two produce their effects). The modes of expression
  usually employed are, indeed, somewhat different; but the
  influence of reason on the classifications of the natural
  scientist is still easily detected.
  If reason is a faculty of deducing the particular from the
  universal, and if the universal is already <1certain in itself>1 and
  given, <1only judgment>1 is required to execute the process of
00069
subsumption, and the particular is thereby determined in a
necessary manner. This I shall entitle the apodeictic use of
reason. If, however, the universal is admitted as <1Problem->1
<1atic>1 only, and is a mere idea, the particular is certain, but
the universality of the rule of which it is a consequence
is still a problem. Several particular instances, which are
one and all certain, are scrutinised in view of the rule, to
see whether they follow from it. If it then appears that all
particular instances which can be cited follow from the rule,  )A 647
we argue to its universality, and from this again to all parti )B 675
lar instances, even to those which are not themselves given.
This I shall entitle the hypothetical employment of reason.
  The hypothetical employment of reason, based upon ideas  .
viewed as problematic concepts, is not, properly speaking,
<1constitutive,>1 that is, it is not of such a character that, judging
in all strictness, we can regard it as proving the truth of the
universal rule which we have adopted as hypothesis. For how
are we to know all the possible consequences which, as actually
following from the adopted principle, <1prove>1 its universality?
The hypothetical employment of reason is regulative only; its
sole aim is, so far as may be possible, to bring unity into the
body of our detailed knowledge, and thereby to <1approximate>1
the ule to universality.
  he hypothetical employment of reason has, therefore, as
its aim the systematic unity of the knowledge of understand-
ing, and this unity is the <1criterion of the truth>1 of its rules. The
systematic unity (as a mere idea) is, however, only a <1projected>1
unity, to be regarded not as given in itself, but as a problem
only. This unity aids us in discovering a principle for the
understanding in its manifold 1 and special modes of employ-
ment, directing its attention to cases which are not given, and
thus rendering it more coherent
  But the only conclusion which we are justified in drawing )A 648
from these considerations is that the systematic unity of the
manifold knowledge of understanding, as prescribed by reason,
is <1alogical>1 principle. Its function is to assist the understanding
by means of ideas, in those cases in which the understanding
cannot by itself establish rules, and at the same time to give
00070
to the numerous and diverse rules of the understanding unity
or system under a single principle, and thus to secure co-
herence in every possible way. But to say that the constitu-
tion of the objects or the nature of the understanding which
knows them as such, is in itself determined to systematic
unity, and that we can in a certain measure postulate this
unity <1a priori,>1 without reference to any such special interest
of reason, and that we are therefore in a position to maintain
that knowledge of the understanding in all its possible modes
(including empirical knowledge) has the unity required by
reason, and stands under common principles from which all
its various modes can, in spite of their diversity, be deduced
---that would be to assert a <1transcendental>1 principle of reason,
and would make the systematic unity necessary, not only
subjectively and logically, as method, but objectively also.
  We may illustrate this by an instance of the employment
of reason. Among the various kinds of unity which conform
to the concepts of the understanding, is that of the causality
of a substance, which is called power. The various appear-
ances of one and the same substance show at first sight so
great a diversity, that at the start we have to assume just as
many different powers as there are different effects. For in-
A 649) stance  in the human mind we have sensation, conscious-
B 677) ness, imagination, memory, wit, power of discrimination
  pleasure, desire, etc. Now there is a logical maxim which
  requires that we should reduce, so far as may be possible, this
  seeming diversity, by comparing these with one another and
  detecting their hidden identity. We have to enquire whether
  imagination combined with consciousness may not be the same
  thing as memory, wit, power of discrimination, and perhaps
  even identical with understanding and reason. Though logic
  is not capable of deciding whether a <1fundamental power>1
  actually exists, the idea of such a power is the problem in-
  volved in a systematic representation of the multiplicity of
  powers. The logical principle of reason calls upon us to bring
  about such unity as completely as possible; and the more the
  appearances of this and that power are found to be identical
  with one another, the more probable it becomes that they are
  simply different manifestations of one and the same power,
00071
which may be entitled, relatively to the more specific powers,
the <1fundamental Power.>1 The same is done with the other
powers.
  The relatively fundamental powers must in turn be com-
pared with one another, with a view to discovering their har-
mony, and so to bring them nearer to a single radical, that
is, absolutely fundamental, power. But this unity of reason is
purely hypothetical. We do not assert that such a power must
necessarily be met with, but that we must seek it in the
interests of reason, that is, of establishing certain principles
for the manifold rules which experience may supply to us. B 678
We must endeavour, wherever possible, to bring in this way
systematic unity into our knowledge.
  On passing, however, to the transcendental employment
of understanding, we find that this idea of a fundamental
power is not treated merely as a problem for the hypothetical
use of reason, but claims to have objective reality, as postulat-
ing the systematic unity of the various powers of a substance,
and as giving expression to an apodeictic principle of reason.
For without having made any attempt to show the harmony
of these various powers, nay, even after all attempts to do so
have failed, we yet presuppose that such a unity does actually
exist, and this not only, as in the case cited, on account of the
unity of the substance, but also in those cases in which, as with
matter in general, we encounter powers which, though to a
certain extent homogeneous, are likewise diverse. In all such
cases reason presupposes the systematic unity of the various
powers, on the ground that special natural laws fall under more
general laws, and that parsimony in principles is not only an
economical requirement of reason, but is one of nature's own
laws.
  It is, indeed, difficult to understand how there can be a
logical principle by which reason prescribes the unity of rules,
unless we also presuppose a transcendental principle whereby
such a systematic unity is <1a priori>1 assumed to be necessarily
inherent in the objects. For with what right can reason, in its B 651
logical employment, call upon us to treat the multiplicity of
powers exhibited in nature as simply a disguised unity  and
to derive this unity, so far as may be possible, from a funda-
mental power---how can reason do this, if it be free to admit
00072
as likewise possible that all powers may be heterogeneous, and
that such systematic unity of derivation may not be in con-
formity with nature? Reason would then run counter to its own
vocation, proposing as its aim an idea quite inconsistent with
the constitution of nature. Nor can we say that reason, while
proceeding in accordance with its own principles, has arrived at
knowledge of this unity through observation of the accidental
constitution of nature. The law of reason which requires us to
seek for this unity, is a necessarylaw, since without it we should
have no reason at all, and without reason no coherent em-
ployment of the understanding, and in the absence of this no
sufficient criterion of empirical truth. In order, therefore, to
secure an empirical criterion we have no option save to pre-
suppose the systematic unity of nature as objectively valid and
necessary.
  Although philosophers have not always acknowledged this
transcendental principle, even to themselves, or indeed been
conscious of employing it, we none the less find it covertly im-
plied, in remarkable fashion, in the principles upon which they
proceed. That the manifold respects in which individual things
differ do not exclude identity of species, that the various species
A 652 must be regarded merely as different determinations of a few
  genera, and these, in turn, of still higher genera, and so on; in
  short, that we must seek for a certain systematic unity of all
  possible empirical concepts, in so far as they can be deduced
  from higher and more general concepts---this is a logical
  principle, a rule of the Schools, without which there could
  be no employment of reason. For we can conclude from the
  universal to the particular, only in so far as universal pro-
  perties are ascribed to things as being the foundation upon
  which the particular properties rest.
  That such unity is to be found in nature, is presupposed by
  philosophers in the well-known scholastic maxim, that rudi-
  ments or principles must not be unnecessarily multiplied <1(entia>1
  <1praeter necessitatem non esse multiplicanda).>1 This maxim de-
  clares that things by their very nature supply material for the
  unity of reason, and that the seemingly in nite variety need
  not hinder us from assuming that behind this variety there is
  a unity of fundamental properties---properties from which the
00073
diversity can be derived through repeated determination. This
unity, although it is a mere idea, has been at all times so eagerly
sought, that there has been need to moderate the desire for it,
not to encourage it. A great advance was made when chemists
succeeded in reducing all salts to two main genera, acids and
alkalies; and they endeavour to show that even this difference
                                                              A 653
is merely a variety, or diverse manifestation, of one and the B 681
same fundamental material. Chemists have sought, step by
step, to reduce the different kinds of earths (the material of
stones and even of metals) to three, and at last to two; but, not
content with this, they are unable to banish the thought that
behindthese varieties there is but one genus, nay, that there
may even be a common principle for the earths and the salts.
It might be supposed that this is merely an economical con-
trivance whereby reason seeks to save itself all possible trouble,
a hypothetical attempt, which, if it succeeds, will, through the
unity thus attained, impart probability to the presumed prin-
ciple of explanation. But such a selfish purpose can very easily
be distinguished from the idea. For in conformity with the
idea everyone presupposes that this unity of reason accords
with nature itself, and that reason---although indeed unable
to determine the limits of this unity---does not here beg but
command.
  If among the appearances which present themselves to us,
there were so great a variety---I do not say in form, for in that
respect the appearances might resemble one another; but in
content, that is, in the manifoldness of the existing entities---
that even the acutest human understanding could never by
comparison of them detect the slightest similarity (a possi-
bility which is quite conceivable), the logical law of genera
would have no sort of standing; we should not even have the
                                                                A 654
concept of a genus, or indeed any other universal concept; and  B 682
the understanding itself, which has to do solely with such con-
cepts, would be non-existent. If, therefore, the logical prin-
ciple of genera is to be applied to nature (by which I here under-
stand those objects only which are given to us), it presupposes
a transcendental principle. And in accordance with this latter
principle, homogeneity is necessarily presupposed in the mani-
fold of possible experience (although we are not in a position
to determine in <1a priori>1 fashion its degree); for in the absence
00074
of homogeneity, no empirical concepts, and therefore no ex-
perience, would be possible.
  The logical principle of genera, which postulates identity,
is balanced by another principle, namely, that of <1species,>1
which calls for manifoldness and diversity in things, notwith-
standing their agreement as coming under the same genus,
and which prescribes to the understanding that it attend to the
diversity no less than to the identity. This principle (of discrimi-
native observation, that is, of the faculty of distinction) sets
a limit to possible indiscretion in the former principle (of the
faculty of wit); and reason thus exhibits a twofold, self-con-
flicting interest, on the one hand interest in <1extent>1 (universal-
ity) in respect of genera, and on the other hand in <1content>1 (de-
terminateness) in respect of the multiplicity of the species. In
the one case the understanding thinks more <1under>1 its concepts,
A 655 in the other more <1in>1 them. This twofold interest manifests it-
  self also among students of nature in the diversity of their ways
  of thinking. Those who are more especially speculative are,
  we may almost say, hostile to heterogeneity, and are always on
  the watch for the unity of the genus; those, on the other hand,
  who are more especially empirical, are constantly endeavour-
  ing to differentiate nature in such manifold fashion as almost
  to extinguish the hope of ever being able to determine its ap-
  pearances in accordance with universal principles.
  This latter mode of thought is evidently based upon a logi-
  cal principle which aims at the systematic completeness of all
  knowledge---prescribing that, in beginning with the genus, we
  descend to the manifold which may be contained thereunder,
  in such fashion as to secure extension for the system, just as in
  the alternative procedure, that of ascending to the genus, we
  endeavour to secure the unity of the system. For if we limit
  our attention to the sphere of the concept which marks out a
  genus, we can no more determine how far it is possible to pro-
  ceed in the [logical] division of it, than we can judge merely
  from the space which a body occupies how far it is possible to
  proceed in the [physical] division of its parts. Consequently,
00075
every genus requires diversity of species, and these in turn
diversity of subspecies; and since no one of these subspecies is
ever itself without a sphere (extent as <1conceptus communis),>1
reason, in being carried to completion, demands that no
species be regarded as being in itself the lowest. For since the
species is always a concept, containing only what is common
to different things, it is not completely determined. It cannot,
therefore, be directly related to an individual, and other con  A 656
cepts, that is, subspecies, must always be contained under it.
This law of specification can be formulated as being the prin-
ciple: <1entium varietates non temere esse minuendas.>1
  But it is easily seen that this logical law would be without
meaning and application if it did not rest upon a <1transcendental>1
law of specification, which does not indeed demand an actual
<1infinity>1 of differences in the things which can be objects to us
---the logical principle, as affirming only the <1indeterminateness>1  --
of the logical sphere in respect of possible division, gives no
occasion for any such assertion---but which none the less im-
poses upon the understanding the obligation of seeking under
every discoverable species for subspecies, and under every dif-
ference for yet smaller differences. For if there were no <1lower>1
concepts, there could not be <1higher>1 concepts. Now the under-
standing can have knowledge only through concepts, and
therefore, however far it carries the process of division, never
through mere intuition, but always again through <1lower>1
concepts. The knowledge of appearances in their complete
determination, which is possible only through the under-
standing, demands an endless progress in the specification of
our concepts, and an advance to yet other remaining differ-
ences, from which we have made abstraction in the concept of
the species, and still more so in that of the genus.
  This law of specification cannot be derived from experi- A 657
ence, which can never open to our view any such extensive
prospects. Empirical specification soon comes to a stop in the
distinction of the manifold, if it be not guided by the ante-
cedent transcendental law of specification, which, as a prin-
ciple of reason, leads us to seek always for further differences,
and to suspect their existence even when the senses are unable
to disclose them. That absorbent earths are of different kinds
(chalk and muriatic earths), is a discovery that was possible
00076
only under the guidance of an antecedent rule of reason---reason
proceeding on the assumption that nature is so richly diversi-
fied that we may presume the presence of such differences,
and therefore prescribing to the understanding the task of
searching for them. Indeed it is only on the assumption of
differences in nature, just as it is also only under the condition
that its objects exhibit homogeneity, that we can have any
faculty of understanding whatsoever. For the diversity of that
which is comprehended under a concept is precisely what gives
occasion for the employment of the concept and the exercise
of the understanding.
  Reason thus prepares the field for the understanding: (I)
through a principle of the <1homogeneity>1 of the manifold under
higher genera; (2) through a principle of the <1variety>1 of the
homogeneous under lower species; and (3) in order to complete
the systematic unity, a further law, that of the <1affinity>1 of all
concepts---a law which prescribes that we proceed from each
A 658 species to every other by gradual increase of the diversity.
  These we may entitle the principles of <1homogeneity, specifica->1
  <1tion,>1 and <1continuity>1 of forms. The last named arises from
  union of the other two, inasmuch as only through the pro-
  cesses of ascending to the higher genera and of descending to
  the lower species do we obtain the idea of systematic connec-
  tion in its completeness.  For all the manifold differences are
  then related to one another, inasmuch as they one and all
  spring from one highest genus, through all degrees of a more
  and more widely extended determination.
  The systematic unity, prescribed by the three logical
  principles, can be illustrated in the following manner.  Every
  concept may be regarded as a point which, as the station for
  an observer, has its own horizon, that is, a variety of things
  which can be represented, and, as it were, surveyed from that
  standpoint. This horizon must be capable of containing an
  infinite number of points, each of which has its own narrower
  horizon; that is, every species contains subspecies, according
  to the principle of specification, and the logical horizon con-
  sists exclusively of smaller horizons (subspecies), never of
  points which possess no extent (individuals). But for different
  horizons, that is, genera, each of which is determined by its
  own concept, there can be a common horizon, in reference to
00077
which, as from a common centre, they can all be surveyed; and
from this higher genus we can proceed until we arrive atthe B 687
highest of all genera, and so at the universal and true horizon,
which is determined from the standpoint of the highest con-
cept, and which comprehends under itself all manifoldness---
genera, species, and subspecies.
  We are carried to this highest standpoint by the law of
homogeneity, and to all lower standpoints, and their greatest
possible variety, by the law of specification.  And since there
is thus no void in the whole sphere of all possible concepts,
and since nothing can be met with outside this sphere,
there arises from the presupposition of this universal horizon
and of its complete division, the principle: <1non datur vacuum>1
<1formarum,>1 that is, that there are not different, original, first
genera, which are isolated from one another, separated, as it
were, by an empty intervening space; but that all the manifold
genera are simply divisions of one single highest and universal
genus. From this principle there follows, as its immediate con-
sequence: <1datur continuum formarum,>1 that is, that all differ-
ences of species border upon one another, admitting of no
transition from one to another <1Per saltum,>1 but only through
all the smaller degrees of difference that mediate between
them. In short, there are no species or subspecies which (in
the view of reason) are the nearest possible to each other; still
other intermediate species are always possible, the difference
of which from each of the former is always smaller than the A 660
difference between these.
  The first law thus keeps us from resting satisfied with an
excessive number of different original genera, and bids us pay
due regard to homogeneity; the second, in turn, imposes a
check upon this tendency towards unity, and insists that be-
fore we proceed to apply a universal concept to individuals we
distinguish subspecies within it. The third law combines these
two laws by prescribing that even amidst the utmost mani-
foldness we observe homogeneity in the gradual transition
from one species to another, and thus recognise a relationship
of the different branches, as all springing from the same stem.
  This logical law of the <1continuum specierum (formarum>1
<1logicarum)>1 presupposes, however, a transcendental law <1(lex>1
00078
<1continui in natura),>1 without which the former law would only
lead the understanding astray, causing it to follow a path
which is perhaps quite contrary to that prescribed by nature
itself. This law must therefore rest upon pure transcendental,
not on empirical, grounds. For if it rested on empirical
grounds, it would come later than the systems, whereas in
actual fact it has itself given rise to all that is systematic in
our knowledge of nature. The formulation of these laws is
not due to any secret design of making an experiment, by
putting them forward as merely tentative suggestions. Such
B 681 anticipations, when confirmed, yield strong evidence in sup-
  port of the view that the hypothetically conceived unity is
  well-grounded; and such evidence has therefore in this re-
  spect a certain utility. But it is evident that the laws contem-
  plate the parsimony of fundamental causes, the manifoldness
  of effects, and the consequent affinity of the parts of nature
  as being in themselves in accordance both with reason and
  with nature. Hence these principles carry their recommend-
  ation directly in themselves, and not merely as methodo-
  logical  devices.
  But it is easily seen that this continuity of forms is a mere
  idea, to which no congruent object can be discovered in ex-
  perience. For in the first place, the species in nature are actually
  divided, and must therefore constitute a <1quantum discretum.>1
  Were the advance in the tracing of their affinity continuous,
  there would be a true infinity of intermediate members be-
  tween any two given species, which is impossible. And further,
  in the second place, we could not make any determinate em-
  pirical use of this law, since it instructs us only in quite general
  terms that we are to seek for grades of affinity, and yields no
  criterion whatsoever as to how far, and in what manner, we
  are to prosecute the search for them.
B 602  If we place these principles of systematic unity in the order
  appropriate to their empirical employment, they will stand
  thus: <1manifoldness, affinity, unity,>1 each being taken, as an
  idea, in the highest degree of its completeness. Reason pre-
  supposes the knowledge which is obtained by the understand-
  ing and which stands in immediate relation to experience, and
00079
seeks for the unity of this knowledge in accordance with ideas
which go far beyond all possible experience. The affinity of
the manifold (as, notwithstanding its diversity, coming under
a principle of unity) refers indeed to things, but still more to
their properties and powers. Thus, for instance, if at firstour im-
perfect experience leads us to regard the orbits of the planets
as circular, and if we subsequently detect deviations therefrom,
we trace the deviations to that which can change the circle,
in accordance with a fixed law, through all the infinite inter-
mediate degrees, into one of these divergent orbits.  That is to
say, we assume that the movements of the planets which are
not circular will more or less approximate to the properties of a
circle; and thus we come upon the idea of an ellipse. Since the
comets do not, so far as observation reaches, return in any such
courses, their paths exhibit still greater deviations. What we
then do is to suppose that they proceed in a parabolic course,
which is akin to the ellipse, and which in all our observation  A 663
is indistinguishable from an ellipse that has its major axis in-
definitely extended. Thus, under the guidance of these prin-
ciples, we discover a unity in the generic forms of the orbits,
and thereby a unity in the cause of all the laws of planetary
motion, namely, gravitation. And we then extend our con-
quests still further, endeavouring to explain by the same prin-
ciple all variations and seeming departures from these rules;
finally, we even go on to make additions such as experience
can never confirm, namely, to conceive, in accordance with
the rules of affinity, hyperbolic paths of comets, in the course
of which these bodies entirely leave our solar system, and
passing from sun to sun, unite the most distant parts of the
universe---a universe which, though for us unlimited, is
throughout held together by one and the same moving force.
  The remaraable feature of these principles, and what in
them alone concerns us, is that they seem to be transcendental,
and that although they contain mere ideas for the guidance of
the empirical employment of reason---ideas which reason
follows only as it were asymptotically, <1i.e.>1 ever more closely
without ever reaching them---they yet possess, as synthetic
<1a priori>1 propositions, objective but indeterminate validity, and
serve as rules for possible experience. They can also be em-
ployed with great advantage in the elaboration of experience,
00080
  as heuristic principles. A transcendental deduction of them
A 664  ot however be effected; in the case of ideas, as we have
  shown above, such a deduction is never possible.
  In the Transcendental Analytic we have distinguished the
  <1dynamical>1 principles of the understanding, as merely regula-
  tive principles of <1intuition,>1 from the <1mathematical,>1 which, as
  regards intuition, are constitutive. None the less these dyna-
  mical laws are constitutive in respect of <1experience,>1 since they
  render the <1concepts,>1 without which there can be no experi-
  ence, possible <1a priori.>1 But principles of pure reason can
  never be constitutive in respect of empirical <1concepts;>1 for since
  no schema of sensibility corresponding to them can ever be
  given, they can never have an object <1in concreto.>1 If, then, we
  disallow such empirical employment of them, as constitutive
  principles, how are we to secure for them a regulative em-
  ployment, and therewith some sort of objective validity, and
  what can we mean by such regulative employment?
  The understanding is an object for reason, just as sensi-
  bility is for the understanding. It is the business of reason to
  render the unity of all possible empirical acts of the under-
  standing systematic; just as it is of the understanding to con-
  nect the manifold of the appearances by means of concepts,
  and to bring it under empirical laws. But the acts of the under-
  standing are, without the schemata of sensibility, <1undeter->1
B 665 <1mined;>1 just as the <1unity of reason>1 is in itself <1undetermined,>1 as
  regards the conditions under which, and the extent to which,
  the understanding ought to combine its concepts in systematic
  fashion. But although we are unable to find in <1intuition>1 a
  schema for the complete systematic unity of all concepts of the
  understanding, an <1analogon>1 of such a schema must necessarily
  allow of being given. This analogon is the idea of the <1maxi->1
  <1mum>1 in the division and unification of the knowledge of the
  understanding under one principle. For what is greatest and
  absolutely complete can be determinately thought, all re-
  stricting conditions, which give rise to an indeterminate
  manifoldness, being left aside. Thus the idea of reason is
  an analogon of a schema of sensibility; but with this differ-
  ence, that the application of the concepts of the understanding
  to the schema of reason does not yield knowledge of the object
  itself (as is the case in the application of categories to their
00081
sensible schemata)  but only a rule or principle for the system-
atic unity of all employment of the understanding. Now
since every principle which prescribes <1a priori>1 to the under-
standing thoroughgoing unity in its employment, also holds,
although only indirectly, of the object of experience, the
principles of pure reason must also have objective reality
anything in it, but only in order to indicate the procedure
whereby the empirical and determinate employment of the B 694
understanding can  e brought into complete harmony with A 666
itself.  This is acheived by bringing its employment, so far as
may be possible, into connection with the principle of thorough-
going unity, and by determining its procedure in the light of
this principle.
  I entitle all subjective principles which are derived, not
from the constitution of an object but from the interest of
reason in respect of a certain possible perfection of the
knowledge of the object, <1maxims>1 of reason. There are there-
fore maxims of speculative reason, which rest entirely on its
speculative interest, although they may seem to be objective
principles.
  When merely regulative principles are treated as constitu-
tive, and are therefore employed as objective principles, they
may come into conflict with one another.  But when they
are treated merely as <1maxims,>1 there is no real conflict, but
merely those differences in the interest of reason that give rise
to differing modes of thought. In actual fact, reason has only
one single interest, and the conflict of its maxims is only a
difference in, and a mutual limitation of, the methods where-
by this interest endeavours to obtain satisfaction.
  Thus one thinker may be more particularly interested in  -
<1manifoldness>1 (in accordance with the principle of specifica-
tion), another thinker in <1unity>1 (in accordance with the prin-
ciple of aggregation). Each believes that his judgment has A 667
been arrived atthrough insight into the object, whereas it really B 695
rests entirely on the greater or lesser attachment to one of the
two principles. And since neither of these principles is based
on objective grounds, but solely on the interest of reason, the
00082
title "principles' is not strictly applicable; they may more fit-
tingly be entitled "maxims'. When we observe intelligent people
disputing in regard to the characteristic properties of men,
animals, or plants---even of bodies in the mineral realm---some
assuming, for instance, that there are certain special heredit-
ary characteristics in each nation, certain well-defined inherited
differences in families, races, etc., whereas others are bent upon
maintaining that in all such cases nature has made precisely
the same provision for all, and that it is solely to external
accidental conditions that the differences are due, we have
only to consider what sort of an object it is about which they
are making these assertions, to realise that it lies too deeply
hidden to allow of their speaking from insight into its nature.
The dispute is due simply to the twofold interest of reason,
the one party setting its heart upon, or at least adopting, the
one interest, and the other party the other. The differences
between the maxims of manifoldness and of unity in nature
thus easily allow of reconciliation. So long, however, as the
B 696 maxims are taken as yielding objective insight, and until a
  way has been discovered of adjusting their conflicting claims,
  and of satisfying reason in that regard, they will not only
  give rise to disputes but will be a positive hindrance, and
  cause long delays in the discovery of truth.
  Similar observations are relevant in regard to the assertion
  or denial of the widely discussed law of the <1continuous grada->1
  <1tion>1 of created beings, which was propounded by Leibniz, and
  admirably supported by Bonnet. It is simply the following
  out of that principle of affinity which rests on the interest of
  reason. For observation and insight into the constitution of
  nature could never justify us in the objective assertion of the
  law. The steps of this ladder, as they are presented to us in
  experience, stand much too far apart; and what may seem to
  us small differences are usually in nature itself such wide gaps,
  that from any such observations we can come to no decision
  in regard to nature's ultimate design---especially if we bear in
  mind that in so great a multiplicity of things there can never
  be much difficulty in finding similarities and approximations.
  On the other hand, the method of looking for order in nature
00083
in accordance with such a principle, and the maxim which
prescribes that we regard such order---leaving, however, un-
determined where and how far---as grounded in nature as
such, is certainly a legitimate and excellent regulative prin-
ciple of reason. In this regulative capacity it goes far beyond
what experience or observation can verify; and though not
itself determining anything, yet serves to mark out the path
towards systematic unity.

  THE FINAL PURPOSE OF THE NATURAL DIALECTIC  A 669
                OF HUMAN REASON               B 697

  The ideas of pure reason can never be dialectical in them-
selves; any deceptive illusion to which they give occasion
must be due solely to their misemployment. For they arise
from the very nature of our reason; and it is impossible that
this highest tribunal of all the rights and claims of speculation
should itself be the source of deceptions and illusions. Pre-
sumably, therefore, the ideas have their own good and ap-
propriate vocation as determined by the natural disposition of
our reason. The mob of sophists, however, raise against reason
the usual cry of absurdities and contradictions, and though
unable to penetrate to its innermost designs, they none the less
inveigh against its prescriptions. Yet it is to the beneficent in-
fluences exercised by reason that they owe the possibility of
their own self-assertiveness, and indeed that very culture
which enables them to blame and to condemn what reason
requires of them.
  We cannot employ an <1a priori>1 concept with any certainty
without having first given a transcendental deduction of it.
The ideas of pure reason do not, indeed, admit of the kind of
deduction that is possible in the case of the categories. But if
they are to have the least objective validity, no matter how
indeterminate that validity may be, and are not to be mere
empty thought-entities <1(entia rationis ratiocinantis),>1 a deduc-
tion of them must be possible, however greatly (as we admit) A 670
it may differ from that which we have been able to give of the
categories. This will complete the critical work of pure reason,
and is what we now propose to undertake.
00084
  There is a great difference between something being given
to my reason as an <1object absolutely,>1 or merely as an <1object in>1
<1the idea.>1 In the former case our concepts are employed to deter-
mine which no object not even a hypothetical one is directly
given, and which only enables us to represent to ourselves
other objects in an indirect manner, namely in their systematic
unity, by means of their relation to this idea. Thus I say that
the concept of a highest intelligence is a mere idea, that is
to say, its objective reality is notto be taken as consisting in
its referring directly to an object (for in that sense we should
not be able to justify its objective validity). It is only a schema
constructed in accordance with the conditions of the greatest
possible unity of reason---the schema of the concept of a thing
in general, which serves only to secure the greatest possible sys-
tematic unity in the empirical employment of our reason. We
then, as it were, derive the object of experience from the sup-
posed object of this idea, viewed as the ground or cause of the
object of experience. We declare, for instance, that the things
A 671 of the world must be viewed <1as if>1 they received their existence
  from a highest intelligence. The idea is thus really only a heur-
  istic, not an ostensive concept. It does not show us how an
  object is constituted, but how, under its guidance, we should
  <1seek>1 to determine the constitution and connection of the objects
  of experience. If, then, it can be shown that the three transcen-
  dental ideas (the psychological, the cosmological, and the theo-
  logical), although they do not directly relate to, or determine,
  any object corresponding to them, none the less, as rules of the
  empirical employment of reason, lead us to systematic unity,
  under the presupposition of such an <1object in the idea;>1 and
  that they thus contribute to the extension of empirical know-
  ledge, without ever being in a position to run counter to it,
  we may conclude that it is a necessary maxim of reason to
  proceed always in accordance with such ideas. This, indeed,
  is the transcendental deduction of all ideas of speculative
  reason, not as <1constitutive>1 principles for the extension of our
  knowledge to more objects than experience can give, but as
  <1regulative>1 principles of the systematic unity of the manifold
  of empirical knowledge in general, whereby this empirical
00085
knowledge is more adequately secured within its own Limits
and more effectively improved than would be possible, in the
absence of such ideas, through the employment merely of the
principles of the understanding.
  I shall endeavour to make this clearer. In conformity with A 672
these ideas as principles we shall, <1first,>1 in psychology, under
the guidance of inner experience, connect all the appearances,
all the actions and receptivity of our mind, <1as if>1 the mind were
a simple substance which persists with personal identity (in
this life at least), while its states, to which those of the body
belong only as outer conditions, are in continual change.
<1Secondly,>1 in cosmology, we must follow up the conditions of
both inner and outer natural appearances, in an enquiry which
is to be regarded as never allowing of completion, just <1as if>1
the series of appearances were in itself endless, without any
first or supreme member. We need not, in so doing, deny that,
outside all appearances, there are purely intelligible grounds
of the appearances; but as we have no knowledge of these
whatsoever, we must never attempt to make use of them in our
explanations of nature. <1Thirdly,>1 and finally, in the domain
of theology, we must view everything that can belong to the
context of possible experience <1as if>1 this experience formed
an absolute but at the same time completely dependent and
<1sensibly>1 conditioned unity, and yet also at the same time <1as if>1
the sum of all appearances (the sensible world itself) had a
single, highest and all-sufficient ground beyond itself, namely,
a self-subsistent, original, creative reason. For it is in the light
of this idea of a creative reason that we so guide the empirical B 673
employment of <1our>1 reason as to secure its greatest possible
extension---that is, by viewing all objects <1as if>1 they drew their
origin from such an archetype. In other words, we ought not
to derive the inner appearances of the soul from a simple
thinking substance but from one another, in accordance with
the idea of a simple being; we ought not to derive the order
and systematic unity of the world from a supreme intelligence,
but to obtain from the idea of a supremely wise cause the rule
according to which reason in connecting empirical causes and
effects in the world may be employed to best advantage, and in
such manner as to secure satisfaction of its own demands.
  Now there is nothing whatsoever to hinder us from <1as->1
00086
<1suming>1 these ideas to be also objective, that is, from hyposta-
tising them---except in the case of the cosmological ideas,
where reason, in so proceeding, falls into antinomy. The
psychological and theological ideas contain no antinomy,
and involve no contradiction. How, then, can anyone dispute
their [possible] objective reality? He who denies their possi-
bility must do so with just as little knowledge [of this possi-
bility] as we can have in affirming it. It is not, however, a
sufficient ground for assuming anything, that there is no
positive hindrance to our so doing; we are not justified in
introducing thought-entities which transcend all our con-
cepts, though without contradicting them, as being real and
determinate objects, merely on the authority of a speculative
reason that is bent upon completing the tasks which it has
A 74 set itself. They ought not to be assumed as existing in
  themselves, but only as having the reality of a schema---the
  schema of the regulative principle of the systematic unity of
  all knowledge of nature. They should be regarded only as
  analoga of real things, not as in themselves real things. We
  remove from the object of the idea the conditions which limit
  the concept provided by our understanding, but which also
  alone make it possible for us to have a determinate con-
  cept of anything. What we then think is a something of
  which, as it is in itself, we have no concept whatsoever, but
  which we none the less represent to ourselves as standing to
  the sum of appearances in a relation analogous to that in
  which appearances stand to one another.
  If, in this manner, we assume such ideal beings, we do not
  really extend our knowledge beyond the objects of possible
  experience; we extend only the empirical unity of such experi-
  ence, by means of the systematic unity for which the schema
  is provided by the idea---an idea which has therefore no claim
  to be a constitutive, but only a regulative principle. For
  to allow that we posit a thing, a something, a real being,
  corresponding to the idea, is not to say that we profess
  to extend our knowledge of things by means of transcen-
  dental concepts. For this being is posited onlyin the idea and
  not in itself; and therefore only as expressing the systematic
00087
unity which is to serve as a rule for the empirical emplo  A 675
ment of reason. It decides nothing in regard to the ground of
this unity or as to what may be the inner character of the being  -
on which as cause the unity depends.
  Thus the transcendental, and the only determinate, con-
cept which the purely speculative reason gives us of God is, in
the strictest sense, <1deistic;>1 that is, reason does not determine
the objective validity of such a concept, but yields only the
idea of something which is the ground of the highest and
necessary unity of all empirical reality. This something we
cannot think otherwise than on the analogy of a real sub-
stance that, in conformity with laws of reason, is the cause
of all things. This, indeed, is how we must think it, in
so far as we venture to think it as a special object, and do
not rather remain satisfied with the mere idea of the regu-
lative principle of reason, leaving aside the completion of
all conditions of thought as being too surpassingly great
for the human understanding. The latter procedure is, how-
ever, inconsistent with the pursuit of that complete system-
atic unity in our knowledge to which reason at least sets
no limits.
  This, then, is how matters stand: if we assume a divine
being, we have indeed no concept whatsoever either of the
inner possibility of its supreme perfection or of the necessity
of its existence; but, on the other hand, we are in a position A 676
to give a satisfactory answer to all those questions which
relate to the contingent, and to afford reason the most com-
plete satisfaction in respect to that highest unity after which
it is seeking in its empirical employment. The fact, however,
that we are unable to satisfy reason in respect to the assump-
tion itself, shows that it is the speculative interest of reason,
not any insight, which justifies it in thus starting from a point
that lies so far above its sphere; and in endeavouring, by this
device, to survey its objects as constituting a complete whole.
  We here come upon a distinction bearing on the procedure
of thought in dealing with one and the same assumption, a
distinction which is somewhat subtle, but of great importance
in transcendental philosophy. I may have sufficient ground to
assume something, in a relative sense <1(suppositio relativa),>1 and
yet have no right to assume it absolutely <1(suppositio absoluta).>1
00088
This distinction has to be reckoned with in the case of a
merely regulative principle. We recognise the necessity of the
principle, but have no anowledge of the source of its neces-
sity; and in assuming that it has a supreme ground, we do so
solely in order to think its universality more determinately.
Thus, for instance, when I think as existing a being that
corresponds to a mere idea, indeed to a transcendental idea,
I have no right to assume any such thing as in itself exist-
ing, since no concepts through which I am able to think any
B 705 object as determined suffice for such a purpose---the condi-
  tions which are required for the objective validity of my con-
  cepts being excluded by the idea itself. The concepts of reality,
  substance, causality, even that of necessity in existence, apart
  from their use in making possible the empirical knowledge of
  an object, have no meaning whatsoever, such as might serve
  to determine any object. They can be employed, therefore, to
  explain the possibility of things in the world of sense, but not
  to explain the possibility of the <1universe itself.>1 Such a ground
  of explanation would have to be outside the world, and could
  not therefore be an object of a possible experience. None the
  less, though I cannot assume such an inconceivable being [as
  existing] in itself, I may yet assume it as the object of a mere
  idea, relatively to the world of sense. For if the greatest
  possible empirical employment of my reason rests upon an
  idea (that of systematically complete unity, which I shall
  presently be defining more precisely), an idea which, al-
  though it can never itself be adequately exhibited in experi-
  ence, is yet indispensably necessary in order that we may
  approximate to the highest possible degree of empirical unity,
  I shall not only be entitled, but shall also be constrained, to
  realise this idea, that is, to posit for it a real object. But I may
  posit it only as a something which I do not at all know in
  itself, and to which, as a ground of that systematic unity, I
B 706 ascrlbe, in relation to this unity, such properties as are ana-
  logous to the concepts employed by the understanding in the
  empirical sphere. Accordingly, in analogy with realities in
  the world, that is, with substances, with causality and with
  necessity, I think a being which possesses all this in the
  highest perfection; and since this idea depends merely on
  my reason, I can think this being as <1self-subsistent reason,>1
00089
which through ideas of the greatest harmony and unity is
the cause of the universe. I thus omit all conditions which
might limit the idea, solely in order, under countenance of
such an original ground, to make possible systematic unity
of the manifold in the universe, and thereby the greatest
possible empirical employment of reason. This I do by repre-
senting all connections <1as if>1 they were the ordinances of a
supreme reason, of which our reason is but a faint copy. I then
proceed to think this supreme being exclusively through con-
cepts which, properly, are applicable only in the world of
sense. But since I make none but a relative use of the trans-
cendental assumption, namely, as giving the substratum of
the greatest possible unity of experience, I am quite in order in
thinking a being which I distinguish from the world of sense,
through properties which belong solely to that world. For I
do not seek, nor am I justified in seeking, to know this object
of my idea according to what it may be in itself. There are no
concepts available for any such purpose; even the concepts of B 679
reality, substance, causality, nay, even that of necessity in
existence, lose all meaning, and are empty titles for [possible]
concepts, themselves entirely without content, when we thus
venture with them outside the field of the senses. I think to
myself merely the relation of a being, in itself completely un-
known to me, to the greatest possible systematic unity of the
universe, solely for the purpose of using it as a schema of the
regulative principle of the greatest possible empirical employ-
ment of my reason.
  If it be the transcendental object of our idea that we have
in view, it is obvious that we cannot thus, in terms of the
concepts of reality, substance, causality, etc., presuppose its
reality <1in itself,>1 since these concepts have not the least applica-
tion to anything that is entirely distinct from the world of sense.
The supposition which reason makes of a supreme being, as
the highest cause, is, therefore relative only; it is devised solely
for the sake of systematic unity in the world of sense, and is a
mere something in idea, of which, as it may be <1in itself,>1 we
have no concept This explains why, in relation to what is
given to the senses as existing, we require the idea of a prim-
ordial being <1necessary in itself,>1 and yet can never form the
slightest concept of it or of its absolute necessity.
00090
  We are nowin a positionto have a clearview of the outcome
B 808 of the whole Transcendental Dialectic, and accurately to define
  the final purpose of the ideas of pure reason, which become
  dialectical only through heedlessness and misapprehension.
  Pure reason is in fact occupied with nothing but itself. It can
  have no other vocation. For what is given to it does not consist
  in objects that have to be brought to the unity of the empirical
  concept, but in those modes of knowledge supplied by the
  understanding that require to be brought to the unity of the
  concept of reason---that is, to unity of connection in conform-
  ity with a principle. The unity of reason is the unity of system;
  and this systematic unity does not serve objectively as a prin-
  ciple that extends the application of reason to objects, but sub-
  jectively as a maxim that extends its application to all possible
  empirical knowledge of objects. Nevertheless, since the system-
  atic connection which reason can give to the empirical em-
  ployment of the understanding not only furthers -  s extension,
  but also guarantees its correctness, the principle o  such system-
  atic unity is so far also objective, but in an indeterminate
  manner <1(princi pium vagum).>1 It is not a constitutive principle
  that enables us to determine anything in respect of its direct
  object, but only a merely regulative principle and maxim, to
  further and strengthen <1in infinitum>1 (indeterminately) the
  empirical employment of reason---never in any way proceed-
  ing counter to the laws of its empirical employment, and yet
  at the same time opening out new paths which are not within
  the cognisance of the understanding.
A 681  But reason cannot think this systematic unity otherwise
  than by giving to the idea of this unity an object; and since
  experience can never give an example of complete systematic
  unity, the object which we have to assign to the idea is not
  such as experience can ever supply. This object, as thus enter-
  tained by reason <1(ens rationis ratiocinatae),>1 is a mere idea;
  it is not assumed as a something that is real absolutely and
  <1in itself,>1 but is postulated only problematically (since we
  cannot reach it through any of the concepts of the under-
  standing) in order that we may view all connection of the
  things of the world of sense <1as if>1 they had their ground in such
  a being. In thus proceeding, our sole purpose is to secure
  that systematic unity which is indispensable to reason, and
00091
which while furthering in every way the empirical knowledge
obtainable by the understanding can never interfere to hinder
or obstruct it.
  We misapprehend the meaning of this idea if we regard
it as the assertion or even as the assumption of a real thing,
to which we may proceed to ascribe the ground of the sys-
tematic order of the world. On the contrary, what this ground
which eludes our concepts may be in its own inherent con-
stitution is left entirely undetermined; the idea is posited only
as being the point of view from which alone that unity, which
is so essential to reason and so beneficial to the understand-
                                                            A 682
ing, can be further extended. In short, this transcendental B 710
thing is only the schema of the regulative principle by which
reason, so far as lies in its power, extends systematic unity
over the whole field of experience.
  The first object of such an idea is the "I' itself, viewed
simply as thinking nature or soul. If I am to investigate the
properties with which a thinking being is in itself endowed, I
must interrogate experience. For I cannot even apply any one
of the categories to this object, except in so far as the schema
of the category is given in sensible intuition. But I never there-
by attain to a systematic unity of all appearances of inner sense.
Instead, then, of the empirical concept (of that which the soul
actually is), which cannot carry us far, reason takes the concept
of the empirical unityof all thought; and bythinking this unity
as unconditioned and original, it forms from it a concept of
reason, that is, the idea of a simple substance, which, unchange-
able in itself (personally identical), stands in association with
other real things outside it; in a word, the idea of a simple self-
subsisting intelligence. Yet in so doing it has nothing in view
                                                              A 683
save principles of systematic unity in the explanation of the B 711
appearances of the soul. It is endeavouring to represent all
determinations as existing in a single subject, all powers, so
far as possible, as derived from a single fundamental power, all
change as belonging to the states of one and the same per-
manent being, and all <1appearances>1 in space as completely dif-
ferent from the actions of <1thought.>1 The simplicity and other
properties of substance are intended to be only the schema of
the principle, and are not presupposed as being the
actual group of the properties of the soul. For these may rest
00092
on altogether different grounds, of which we can know nothing.
The soul in itself could not be known through these assumed
predicates, not even if we regarded them as absolutely valid
in respect of it. For they constitute a mere idea which cannot
be represented <1in concreto.>1 Nothing but advantage can result
from the psychological idea thus conceived, if only we take
heed that it is not viewed as more than a mere id a, and that
it is therefore taken as valid only relatively to the systematic
employment of reason in determining the appearances of our
soul. For no empirical laws of bodily appearance, which are
of a totally different kind, will then intervene in  e explana-
tion of what belongs exclusively to <1inner sense.>1 No windy
hypotheses of generation, extinction, and palingenesis of souls
will be permitted. The consideration of this object of inner
sense will thus be kept completely pure and will not be con-
fused by the introduction of heterogeneous properties. Also,
reason's investigations will be directed to reducing the grounds
of explanation in this field, so far as may be possible, to a
A 684
B 712 single principle. All this will be best attained through such a
  schema, viewed <1as if>1 it were a real being; indeed it is attain-
  able in no other way. The psychological idea can signify
  nothing but the schema of a regulative concept. For were
  I to enquire whether <1the soul in itself>1 is of spiritual nature,
  the question would have no meaning. In employing such a
  concept I not only abstract from corporeal nature, but from
  nature in general, that is, from all predicates of any possible
  experience, and therefore from all conditions requisite for
  thinking an object for such a concept; yet only as related to
  an object can the concept be said to have a meaning.
  The second regulative idea of merely speculative reason
  is the concept of the world in general. For nature is properly
  the only given object in regard to which reason requires regu-
  lative principles. This nature is twofold, either thinking or
  corporeal. To think the latter, so far as regards its inner
  possibility, that is, to determine the application of the cate-
  gories to it, we need no idea, that is, no representation which
  transcends experience. Nor, indeed, is any idea possible in this
  connection, since in dealing with corporeal nature we are
  guided solely by sensible intuition. The case is different from
  that of the fundamental psychological concept  ("I'), which
00093
contains <1apriori>1 a certain form of thought, namely, the unity
of thought. There therefore remains for pure reason nothing A 685
but nature in general, and the completeness of the conditions
in nature in accordance with some principle. The absolute
totality of the series of these conditions, in the derivation of
their members, is an idea which can never be completely
realised in the empirical employment of reason, but which
yet serves as a rule that prescribes how we ought to proceed
in dealing with such series, namely, that in explaining appear-
ances, whether in their regressive or in their ascending order,
we ought to treat the series <1as if>1 it were in itself infinite, that
is, <1as if it>1 proceeded <1in indefinitum.>1 When, on the other hand,
reason is itself regarded as the determining cause, as in [the
sphere of] freedom, that is to say, in the case of practical prin-
ciples, we have to proceed as if we had before us an object, not
of the senses, but of the pure understanding. In this practical
sphere the conditions are no longer in the series of appear-
ances; they can be posited outside the series, and the series of
states can therefore be regarded <1as if>1 it had an absolute be-
ginning, through an intelligible cause. All this shows that the
cosmological ideas are nothing but simply regulative prin-
ciples, and are very far from positing, in the manner of con-
stitutive principles, an actual totality of such series. The fuller
treatment of this subject will be found in the chapter on the
antinomy of pure reason.
  The third idea of pure reason, which contains a merely
relative supposition of a being that is the sole and sufficient
cause of all cosmological series, is the idea of <1God.>1 We have
not the slightest ground to assume in an absolute manner to
suppose in itself) the object of this idea; for what can enable
us to believe in or assert a being of the highest perfection and
one absolutely necessary by its very nature, merely on the basis
of its concept, or if we did how could we justify our procedure?
It is only by way of its relation to the world that we can attempt
to establish the necessityof this supposition; and itthen becomes
evident that the idea of such a being, like all speculative ideas,
seeks only to formulate the command of reason, that all con-
nection in the world be viewed in accordance with the prin-
ciples of a systematic unity---<1as if>1 all such connection had its
source in one single all-embracing being, as the supreme and
00094
all-sufficient cause. It is thus evident that reason has here no
other purpose than to prescribe its own formal rule for the
extension of its empirical employment, and not any extension
<1beyond all limits of empirical employment.>1 Consequently it is
evident that this idea does not, in any concealed fashion, in-
volve any principle that claims, in its application to possible
experience, to be constitutive in character.
  This highest formal unity, which rests solely on concepts
of reason, is the <1purposive>1 unity of things. The <1speculative>1
interest of reason makes it necessary to regard all order in the
world as if it had originated in the purpose of a supreme
reason. Such a principle opens out to our reason, as applied
B 617 in the field of experience, altogether new views as to how the
  things ofthe world may be connected according to teleological
  laws, and so enables it to arrive at their greatest systematic
  unity. The assumption of a supreme intelligence, as the one
  and only cause of the universe, though in the idea alone, can
  therefore always benefit reason and can never injure it. Thus
  if, in studying the shape of the earth (which is round, but some-
  what flattened),a of the mountains, seas, etc., we assume it to be
  the outcome of wise purposes on the part of an Author of the
  world, we are enabled to make in this way a number of dis-
  coveries. And provided we restrict ourselves to a merely regu-
  lative use of this principle, even error cannot do us any serious
  harm. For the worst that can happen would be that where we
  expected a teleological connection <1(nexusfinalis),>1 we find only
B  8186 a mechanical or physical connection <1(nexus effectivus).>1 In such
  a case, we merely fail to find the additional unity; we do not
  destroy the unity upon which reason insists in its empirical
  a The advantage arising from the spherical shape of the earth
  is well known. But few are aware that its spheroidal flattening alone
  prevents the continental elevations, or even the smaller hills, thrown
  up perhaps by earthquakes, from continuously, and indeed quite
  appreciably in a comparatively short time, altering the position of
  the axis of the earth. The protuberance of the earth at the equator
  forms so vast a mountain that the impetus of all the other moun-
  tains can never produce any observable effect in changing the posi-
  tion of the earth's axis. And yet, wise as this arrangement is, we feel
  no scruples in explaining it from the equilibrium of the formerly
  fluid mass of the earth.
00095
employment. But even a disappointment of this sort cannot
affect the teleological law itself, in its general bearing. For
although an anatomist can be convicted of error when he
assigns to some member of an animal body an end which
it can be clearly shown not to subserve, it is yet quite im-
possible to <1prove>1 in any given case that an arrangement
of nature, be it what it may, subserves no end whatsoever.
Accordingly, medical physiology extends its very limited em-
pirical knowledge of the ends served by the articulation of an
organic body, by resorting to a principle for which pure reason
has alone been responsible; and itcarries this principle so far as
to assume confidently, and with general approval, that every-
thing in an animal has its use, and subserves some good pur-
pose. If this assumption be treated as constitutive it goes much
further than observation has thus far been able to justify; and
we must therefore conclude that it is nothing more than a
regulative principle of reason, to aid us in securing the highest
possible systematic unity, by means of the idea of the pur-
posive causality of the supreme cause of the world---<1as if>1 this
being, as supreme intelligence, acting in accordance with a
supremely wise purpose, were the cause of all things.
  If, however, we overlook this restriction of the idea to a A 689
merely regulative use, reason is led away into mistaken paths.
For it then leaves the ground of experience, which alone can
contain the signs that mark out its proper course, and ventures
out beyond it to the incomprehensible and unsearchable,
rising to dizzy heights where it finds itself entirely cut off
from all possible action in conformity with experience.
  The first error which arises from our using the idea of a
supreme being in a manner contrary to the nature of an idea,
that is, constitutively, and not regulatively only, is the error of
<1ignava ratio.a>1 We may so entitle every principle which makes
  a This was the title given by the ancient dialecticians to a
sophistical argument, which ran thus: If it is your fate to recover
from this illness, you will recover, whether you employ a physician
or not. Cicero states that this mode of argument has been so named,
because, if we conformed to it, reason would be left without any use
in life. On the same ground I apply the name also to the sophistical
argument of pure reason.
00096
us regard our investigation into nature, on any subject, as
A690 absolutely complete, disposing reason to cease from further
  enquiry, as if it had entirely succeeded 1n the task which it had
  set itself. Thus the psychological idea, when it is employed as
  a constitutive principle to explain the appearances of our soul,
  and thereby to extend our knowledge of the self beyond the
  limits of experience (its state after death), does indeed simplify
  the task of reason; but it interferes with, and entirely ruins,
  our use of reason in dealing with nature under the guidance
  of our experiences. The dogmatic spiritualist explains the
  abiding and unchanging unity of a person throughout all
  change of state, by the unity of the thinking substance, of
  which, as he believes, he has immediate perception in the "I';
  or he explains the interest which we take in what can happen
  only after our death, by means of our consciousness of the im-
  material nature of the thinking subject;  and so forth.  He thus
  dispenses with all empirical investigation of the cause of these
  inner appearances, so far as that cause is to be found in physi-
  cal grounds of explanation; and to his own great convenience,
  though at the sacrifice of all real insight, he professes, in re-
  liance upon the assumed authority of a transcendent reason, to
  have the right to ignore those sources of knowledge which are
  immanent in experience. These detrimental consequences are
  even more obvious in the dogmatic treatment of our idea of a
  supreme intelligence, and in the theological system of nature
A 691 (physico-theology) which  is falsely based upon  it.  For in
  this field of enquiry, if instead of looking for causes in the
  universal laws of material mechanism, we appeal directly to
  the unsearchable decree of supreme wisdom, all those ends
  which are exhibited in nature, together with the many ends
  which are only ascribed by us to nature, make our investi-
  gation of the causes a very easy task, and so enable us to
  regard the labour of reason as completed, when, as a matter
  of fact, we have merely dispensed with its employment---an
  employment which is wholly dependent for guidance upon the
  order of nature and the series of its alterations, in accordance
  with the universal laws which they are found to exhibit. This
  error can be avoided, if we consider from the teleological point
  of view not merely certain parts of nature, such as the distribu-
00097
tion of land, its structure, the constitution and location of
the mountains, or only the organisation of the vegetable and
animal kingdoms, but make this systematic unity of nature
completely <1universal,>1 in relation to the idea of a supreme in-
telligence. For we then treat nature as resting upon a purpos-
iveness, in accordance with universal laws, from which no
special arrangement is exempt, however difficult it may be to
establish this in any given case. We then have a regulative
principle of the systematic unity of teleological connection---
a connection which we do not, however, predetermine. What
we may presume to do is to follow out the physico-mechanical B 692
connection in accordance with universal laws in the hope of B 720
discovering what the teleological connection actually is. In this
way alone can the principle of purposive unity aid always in
extending the employment of reason in reference to experience
without being in any instance prejudicial to it.
  The second error arising from the misapprehension of the
above principle of systematic unity is that of <1perversa ratio>1
<3u1/@teron pro/teron>3). The idea of systematic unity should be
used only as a regulative principle to guide us in seeking for
such unity in the connection of things, according to universal
laws of nature; and we ought, therefore, to believe that we
have approximated to completeness in the employment of the
principle only in proportion as we are in a position to verify
such unity in empirical fashion---a completeness which is
never, of course, attainable. Instead of this the reverse pro-
cedure is adopted. The reality of a principle of purposive
unity is not only presupposed but hypostatised; and since the
concept of a supreme intelligence is in itself completely be-
yond our powers of comprehension, we proceed to determine
it in an anthropomorphic manner, and so to impose ends
upon nature, forcibly and dictatorially, instead of pursuing
the more reasonable course of searching for them by the path
of physical investigation. And thus teleology, which is in-
tended to aid us merely in completing the unity of nature in
accordance with universal laws, not only tends to abrogate
such unity, but also prevents reason from carrying out its own A 693
professed purpose, that of proving from nature, in conformit  B 721
with these laws, the existence of a supreme intelligent cause.
00098
For if the most complete purposiveness cannot be presupposed
a priori <1in>1 nature, that is, <1as belonging to its essence,>1 how can
we be required to search for it, and through all its gradations
to approximate to the supreme perfection of an Author of all
things, a perfection that, as absolutely necessary, must be
knowable <1a priori?>1 The regulative principle prescribes that
systematic unity as a <1unity in nature,>1 which is not known
merely empirically but is presupposed <1a priori>1 (although in
an indeterminate manner), be presupposed absolutely, and
consequently as following from the essence of things. If,
however, I begin with a supreme purposive being as the
ground of all things, the unity of nature is really surrendered,
as being quite foreign and accidental to the nature of things,
and as not capable of being known from its own universal laws.
There then arises a vicious circle; we are assuming just that
very point which is mainly in dispute.
  To take the regulative principle of the systematic unity of
nature as being a constitutive principle, and to hypostatise, and
presuppose as a cause, that which serves, merely in idea, as the
B 694 ground of the consistent employment of reason, is simply to
  confound reason.  The investigation of nature takes its own
  independent course, keeping to the chain of natural causes
  in conformity with their universal laws. It does indeed, in so
  doing, proceed in accordance with the idea of an Author of the
  universe, but not in order to deduce therefrom the purposive-
  ness for which it is ever on the watch, but in order to obtain
  knowledge of the existence of such an Author from this pur-
  posiveness. And by seeking this purposiveness in the essence
  of the things of nature, and so far as may be possible in the
  essence of things in general, it seeks to know the existence of
  this supreme being as absolutely necessary. Whether this latter
  enterprise succeed or not, the idea remains always true in itself,
  and justified in its use, provided it be restricted to the condi-
  tions of a merely regulative principle.
  Complete purposive unity constitutes what is, in the ab-
  solute sense, perfection. If we do not find this unity in the
  essence of the things which go to constitute the entire object of
  experience, that is, of all our objectively valid knowledge, and
  therefore do not find it in the universal and necessary laws of
  nature, how can we profess to infer directly from this unity the
00099
idea of a supreme and absolutely necessary perfection of an
original being, as the source of all causality? The greatest pos-
sible systematic unity, and consequently also purposive unity, is
the training school for the use of reason, and is indeed the very
foundation of the possibility of its greatest possible employ-
ment. The idea of such unity is, therefore, inseparably bound A 695
up with the very nature of our reason. This same idea is  B 723
that account legislative for us; and it is therefore very natural
that we should assume a corresponding legislative reason
<1(intellectus archetypus),>1 from which, as the object of our reason
all systematic unity of nature is to be derived.
  In discussing the antinomy of pure reason we have stated
that the questions propounded by pure reason must in every
case admit of an answer, and that in their regard it is not per-
missible to plead the limits of our knowledge (a plea which
in many questions that concern nature is as unavoidable as
it is relevant). For we are not here asking questions in regard
to the nature of things, but only such questions as arise from
the very nature of reason, and which concern solely its own
inner constitution. We are now in a position to confirm this
assertion---which at first sight may have appeared rash---so
far as regards the two questions in which pure reason is most
of all interested; and thus finally to complete our discussion of
the dialectic of pure reason.
  If, in connection with a transcendental theology,<1a>1 we ask,
<1first,>1 whether there is anything distinct from the world, which A 696
contains the ground of the order of the world and of its  B 724
nection in accordance with universal laws the answer is that
there <1undoubtedly>1 is. For the world is a sum of appearances;
and there must therefore be some transcendental ground of
the appearances, that is, a ground which is thinkable only by
the pure understanding. If, <1secondly,>1 the question be, whether
this being is substance, of the greatest reality, necessary, etc.,
a After what I have already said regarding the psychological
idea and its proper vocation, as a principle for the merely regulative
employment of reason, I need not dwell at any length upon the
transcendental illusion by which the systematic unity of all the mani-
foldness of inner sense is hypostatised. The procedure is very similar
to that which is under discussion in our criticism of the theological
ideal.
00100
we reply that <1this question is entirely without meaning.>1 For
all categories through which we can attempt to form a concept
of such an object allow only of empirical employment, and
have no meaning whatsoever when not applied to objects of
possible experience, that is, to the world of sense. Outside this
field they are merely titles of concepts, which we may admit,
but through which [in and by themselves] we can understand
nothing. If, <1thirdly,>1 the question be, whether we may not at
least think this being, which is distinct from the world, in
<1analogy>1 with the objects of experience, the answer is: cer-
A 697 tainly, but only as object in <1idea>1 and not in reality, namely,
  only as being a substratum, to us unknown, of the systematic
  unity, order, and purposiveness of the arrangement of the
  world---an idea which reason is constrained to form as the
  regulative principle of its investigation of nature. Nay, more,
  we may freely, without laying ourselves open to censure, admit
  into this idea certain anthropomorphisms which are helpful
  to the principle in its regulative capacity. For it is always an
  idea only, which does not relate directly to a being distinct
  from the world, but to the regulative principle of the systematic
  unity of the world, and only by means of a schema of this
  unity, namely, through the schema of a supreme intelligence
  which, in originating the world, acts in accordance with wise
  purposes. What this primordial ground of the unity of the
  world may be in itself, we should not profess to have thereby
  decided, but only how we should use it, or rather its idea, in
  relation to the systematic employment of reason in respect of
  the things of the world.
  But the question may still be pressed: Can we, on such
  grounds, assume a wise and omnipotent Author of the world?
  <1Undoubtedly>1 we may; and we not only may, but <1must,>1 do so.
  But do we then extend our knowledge beyond the field of pos-
  sible experience? <1By no means.>1 All that we have done is merely
B 695 to presuppose a something, a merely transcendental object, of
  which, as it is in itself, we have no concept whatsoever. It is
  only in relation to the systematic and purposive ordering of
  the world, which, if we are to study nature, we are constrained
  to presuppose, that we have thought this unknown being
  <1by analogy>1 with an intelligence (an empirical concept); that
  is, have endowed it, in respect of the ends and perfection
00101
which are to be grounded upon it, with just those properties
which, in conformity with the conditions of our reason, can
be regarded as containing the ground of such systematic unity.
This idea is thus valid only in respect of the <1employment>1 of our
reason <1in reference to the world.>1 If we ascribed to it a validity
that is absolute and objective, we should be forgetting that
what we are thinking is a being in idea only; and in thus taking
our start from a ground which is not determinable through
observation of the world, we should no longer be in a position
to apply the principle in a manner suited to the empirical
employment of reason.
  But, it will still be asked, can I make any such use of the
concept and of the presupposition of a supreme being in the
rational consideration of the world? Yes, it is precisely for
this purpose that reason has resorted to this idea. But may I
then proceed to regard seemingly purposive arrangements as
purposes,1 and so derive them from the divine will, though, A 699
of course, mediately through certain special natural means,
themselves established in furtherance of that divine will? Yes,
we can indeed do so; but only on condition that we regard
it as a matter of indifference whether it be asserted that
divine wisdom has disposed all things in accordance with its
supreme ends, or that the idea of supreme wisdom is a regu-
lative principle in the investigation of nature and a principle
of its systematic and purposive unity, in accordance with
universal laws, even in those cases in which we are unable
to detect that unity. In other words, it must be a matter of
complete indifference to us, when we perceive such unity,
whether we say that God in his wisdom has willed it to be
so, or that nature has wisely arranged it thus. For what has
justified us in adopting the idea of a supreme intelligence as
a schema of the regulative principle is precisely this greatest
possible systematic and purposive unity---a unity which our
reason has required as a regulative principle that must under-
lie all investigation of nature. The more, therefore, we dis-
cover purposiveness in the world, the more fully is the legiti-
macy of our idea confirmed. But since the sole aim of that
principle was to guide us in seeking a necessary unity of nature,
and that in the greatest possible degree, while we do indeed,
00102
in so far as we attain that unity, owe it to the idea of a supreme
A 678 being, we cannot, without contradicting ourselves, ignore the
  universal laws of nature---with a view to discovering which the
  idea was alone adopted---and look upon this purposiveness
  of nature as contingent and hyperphysical in its origin. For we
  were not justified in assuming above nature a being with those
  qualities, but only in adopting the idea of such a being in order
  to view the appearances as systematically connected with one
  another in accordance with the principle of a causal deter-
  mination.
  For the same reasons, in thinking the cause of the world,
  we are justified in representing it in our idea jot only in
  terms of a certain subtle anthropomorphism (without which
  we could not think anything whatsoever in regard to it),
  namely, as a being that has understanding, feelings of pleasure
  and displeasure, and desires and volitions corresponding to
  these, but also in ascribing to it a perfection which, as infinite,
  far transcends any perfection that our empirical knowledge of
  the order of the world can justify us in attributing to it. For
  the regulative law of systematic unity prescribes that we should
  study nature <1as if>1 systematic and purposive unity, combined
  with the greatest possible manifoldness, were everywhere to be
  met with, <1in infnitum.>1 For although we may succeed in dis-
  covering but little of this perfection of the world, it is never-
  theless required by the legislation of our reason that we must
A 7021 always search for and surmise it; and it must always be bene-
  ficial, and can never be harmful, to direct our investigations
  into nature in accordance with this principle. But it is evident
  that in this way of representing the principle as involving the
  idea of a supreme Author, I do not base the principle upon the
  existence and upon the knowledge of such a being, but upon
  its idea only, and that I do not really derive anything from this
  being, but only from the idea of it---that is, from the nature of
  the things of the world, in accordance with such an idea. A
  certain, unformulated consciousness of the true use of this
  concept of reason seems indeed to have inspired the modest
  and reasonable language of the philosophers of all times,
  since they speak of the wisdom and providence of nature and
  of divine wisdom, just as if nature and divine wisdom were
00103
equivalent expressions---indeed, so long as they are dealing
solely with speculative reason, giving preference to the former
mode of expression, on the ground that it enables us to avoid
making profession of more than we are justified in asserting,
and that it likewise directs reason to its own proper field,
namely, nature.
  Thus pure reason, which at first seemed to promise nothing
less than the extension of anowledge beyond all limits of ex-
perience, contains, if properly understood, nothing but regu-
lative principles, which, while indeed prescribing greater unity
than the empirical employment of understanding can achieve,
yet still, by the very fact that they place the goal of its
endeavours at so great a distance, carry its agreement with A 702
                                                            B 730
itself, by means of systematic unity, to the highest possible
degree. But if, on the other hand, they be misunderstood,
and be treated as constitutive principles of transcendent
knowledge, they give rise, by a dazzling and deceptive
illusion, to persuasion and a merely fictitious knowledge,
and therewith to contradictions and eternal disputes.
  Thus all human knowledge begins with intuitions, pro-
ceeds from thence to concepts, and ends with ideas. Although
in respect of all three elements it possesses <1a priori>1 sources of
knowledge, which on first consideration seem to scorn the
limits of all experience, a thoroughgoing critique convinces us
that reason, in its speculative employment, can never with
these elements transcend the field of possible experience, and
that the proper vocation of this supreme faculty of knowledge
is to use all methods, and the principles of these methods,
solely for the purpose of penetrating to the innermost secrets
of nature, in accordance with every possible principle of unity
---that of ends being the most important---but never to soar
beyond its limits, outside which there is <1for us>1 nothing but
empty space. The critical examination, as carried out in the
Transcendental Analytic, of all propositions which may seem A 703
                                                            B 731
to extend our knowledge beyond actual experience, has doubt-
less sufficed to convince us that they can never lead to any-
thing more than a possible experience. Were it not that we are
suspicious of abstract and general doctrines, however clear,
00104
and were it not that specious and alluring prospects tempt us
to escape from the compulsion which these doctrines impose,
we might have been able to spare ourselves the laborious in-
terrogation of all those dialectical witnesses that a transcen-
dent reason brings forward in support of its pretensions. For
we should from the start have known with complete certainty
that all such pretensions, while perhaps honestly meant, must
be absolutely groundless, inasmuch as they relate to a kind
of knowledge to which man can never attain. But there is no
end to such discussions, unless we can penetrate to the true
cause of the illusion by which even the wisest are deceived.
Moreover, the resolution of all our transcendent knowledge
into its elements (as a study of our inner nature) is in itself
of no slight value, and to the philosopher is indeed a matter
of duty. Accordingly, fruitless as are all these endeavours of
speculative reason, we have none the less found it necessary
to follow them up to their primary sources. And since the
dialectical illusion does not merely deceive us in our judg-
B 732  ments, but also, because of the interest which we take in these
A 704  judgments, has a certain natural attraction which it will always
  continue to possess, we have thought it advisable, with a view
  to the prevention of such errors in the future, to draw up in
  full detail what we may describe as being the records of this
  lawsuit, and to deposit them in the archives of human reason.
                         II
              TRANSENDENTAL DOCTERINE OF    A 705
                       METHOD               B 733





























00001
IF we look upon the sum of all knowledge of pure speculative (A 707
reason as an edifice for which we have at least the idea withi  (B 735
ourselves, it can be said that in the Transcendental Doctrine
of Elements we have made an estimate of the mat rials, and
have determined for what sort of edifice and for what height
and strength of building they suffice. We have Found, in-
deed, that although we had contemplated building a tower
which should reach to the heavens, the supply of materials
suffices only for a dwelling-house, just sufficiently commodious
for our business on the level of experience, and just sufficiently
high to allow of our overlooking it. The bold undertaking that
we had designed is thus bound to fail through lack of material
---not to mention the babel of tongues, which inevitably gives
rise to disputes among the workers in regard to the plan to be
followed, and which must end by scattering them over all the
world, leaving each to erect a separate building for himself,
according to his own design. At present, however, we are con-
cerned not so much with the materials as with the plan; and
inasmuch as we have been warned not to venture at random
upon a blind project which may be altogether beyond our
capacities, and yet cannot well abstain from building a secure
home for ourselves, we must plan our building in conformity
with the material which is given to us, and which is also at
the same time appropriate to our needs.
  I understand, therefore, by Transcendental Doctrine of
Method the determination of the formal conditions of a com  (A708
plete system of pure reason. In this connection, we shall have
to treat of a <1discipline,>1 a <1canon,>1 an <1architectonic,>1 and finally
a <1history>1 of pure reason, and to provide (in its transcendental
reference) what, in relation to the use of the understanding
in general, the Schools have attempted, though very unsatis-
00002
factorily, under the title of a <1practical logic.>1  For since universal
logic is not confined to any particular kind of knowledge made
possible by the understanding (for instance, not to its pure
knowledge) and is also not confined to certain objects, it cannot,
save by borrowing knowledge from other sciences, do more
than present the titles of <1possible methods>1 and the technical
terms which are used for purposes of systematisation in all
kinds of sciences; and this serves only to acquaint the novice
in advance with names the meaning and use of which he will
not learn till later.
  TRANSCENDENTAL DOCTRINE OF METHOD
  CHAPTER I
  THE DISCIPLINE OF PURE REASON
  Owing to the general desire for knowledge, negative judg-
ments, that is, those which are such not merely as regards their
form but also as regards their content, are not held in any very
high esteem. They are regarded rather as the jealous enemies
B7 9-) of our unceasing endeavour to extend our knowledge, and it
  almost requires an apology to win for them even tolerance, not
  to say favour and high repute.
  As far as <1logical>1 form is concerned, we can make negative
  any proposition we like; but in respect to the content of our
  knowledge in general, which is either extended or limited by
  a judgment, the task peculiar to negative judgments is that of
  <1rejecting error.>1 Accordingly, negative propositions intended to
  reject false knowledge, where yet no error is possible, are indeed
  true but empty, that is, are not suited to their purpose, and
  just for this reason are often quite absurd, like the proposition
  of the Schoolman, that Alexander could not have conquered
  any countries without an army.
  But where the limits of our possible knowledge are very
  narrow, where the temptation to judge is great, where the illu-
  sion that besets us is very deceptive and the harm that results
  from the error is considerable, there the <1negative>1 instruction,
  which serves solely to guard us from errors, has even more
  importance than many a piece of positive information by
00003
which our knowledge is increased. The compulsion, by which
the constant tendency to disobey certain rules is restrained and
finally extirpated, we entitle <1discipline.>1 It is distinguished
from <1culture,>1 which is intended solely to give a certain kind
of skill, and not to cancel any habitual mode of action already
present. Towards the development of a talent, which has al- (A 710
ready in itself an impulse to manifest itself, discipline will  '
therefore contribute in a negative,a culture and doctrine in a
positive,  fashion.
  That temperament and our various talents (such as imagi-
nation and wit) which incline to allow themselves a free and
unlimited activity are in many respects in need of a discipline,
everyone will readily admit. But that reason, whose proper
duty it is to prescribe a discipline for all other endeavours,
should itself stand in need of such discipline may indeed seem
strange; and it has, in fact, hitherto escaped this humiliation,
only because, in view of its stately guise and established stand-
ing, nobody could lightly come to suspect it of idly substituting
fancies for concepts, and words for things.
  There is no need of a critique of reason in its empirical em- (A 711
ployment, because in this field its principles are always sub- (B 739
ject to the test of experience. Nor is it needed in mathematics,
where the concepts of reason must be forthwith exhibited <1in>1
<1concreto>1 in pure intuition, so that everything unfounded and
arbitrary in them is at once exposed. But where neither em-
pirical nor pure intuition keeps reason to a visible track, when,
that is to say, reason is being considered in its transcendental
employment, in accordance with mere concepts, it stands so
greatly in need of a discipline, to restrain its tendency towards
extension beyond the narrow limits of possible experience and
to guard it against extravagance and error, that the whole
a  I am well aware that in the terminology of the Schools the title
<1discipline>1 is commonly used as synonymous with instruction. How-
ever, there are so many other cases where discipline in the sense of
<1training by constraint>1 is carefully distinguished from instruction in
the sense of <1teaching,>1 and the very nature of things itself makes it so
i1nperative that we should prese1ve the only expressions suitable for
this distinction, that it is desirable that the former term should never
be used in any but the negative sense.
00004
philosophy of pure reason has no other than this strictly
negative utility. Particular errors can be got rid of by <1censure,>1
and their causes by <1criticism.>1 But where, as in the case of pure
reason, we come upon a whole system of illusions and fallacies,
intimately bound together and united under com  n prin-
ciples, a quite special negative legislation seems to be
erecting a system of precautions and self-examination under
the title of a <1discipline,>1 founded on the nature of reason and
the objects of its pure employment---a system in face of
which no pseudo-rational illusion will be able to stand, but
will at once betray itself, no matter what claims it may ad-
vance for exceptional treatment.
B 712)  But it is well to note that in this second main division of the
  transcendental Critique the discipline of pure reason is not
  directed to the content but only to the method of knowledge
  through pure reason. The former has already been considered
  in the Doctrine of Elements. But there is so much similarity in
  the mode of employing reason, whatever be the object to which
  it is applied, while yet, at the same time, its transcendental
  employment is so essentially different from every other, that
  without the admonitory negative teaching of a discipline,
  specially devised for the purpose, we cannot hope to avoid
  the errors which inevitably arise from pursuing in improper
  fashion methods which are indeed suitable to reason in other
  fields, only not in this transcendental sphere.
  CHAPTER I
  Section I
  THE DISCIPLINE OF PURE REASON IN ITS DOGMATIC
  EMPLOYMENT
  Mathematics presents the most splendid example of the suc-
  cessful extension of pure reason, withoutthe help of experience.
  Examples are contagious, especially as they quite naturally
  flatter a faculty which has been successful in one field, [leading
  it] to expect the same good fortune in other fields. Thus pure
A 713) reason hopes to be able to extend its domain as successfully
  and securely in its transcendental as in its mathematical em-
00005
ployment, especially when it resorts to the same method as
has been of such obvious utility in mathematics. It is therefore
highly important for us to know whether the method of attain-
ing apodeictic certainty which is called <1mathematical>1 is identi-
cal with the method by which we endeavour to obtain the
same certainty in philosophy, and which in that field would
have to be called <1dogmatic.>1
  <1Philosophical>1 knowledge is the <1knowledge gained by reason>1
<1from concepts;>1 mathematical knowledge is the knowledge
gamed by reason from the <1construction>1 of concepts. To <1con->1
<1struct>1 a concept means to exhibit <1a priori>1 the intuition which
corresponds to the concept. For the construction of a concept
we therefore need a <1non-empirical>1 intuition. The latter must,
as intuition, be a <1single>1 object, and yet none the less, as the
construction of a concept (a universal representation), it must
in its representation express universal validity for all possible
intuitions which fall under the same concept. Thus I construct
a triangle by representing the object which corresponds to this
concept either by imagination alone, in pure intuition, or in
accordance therewith also on paper, in empirical intuition---in
both cases completely <1a priori,>1 without having borrowed the
pattern from any experience. The single figure which we draw
is empirical, and yet it serves to express the concept, without (  714
impairing its universality. For in this empirical intuition we
consider only the act whereby we construct the ccncept, and
abstract from the many determinations (for instance, the mag-
nitude of the sides and of the angles), which are  quite indif-
ferent, as not altering the concept "triangle'.
  Thus philosophical knowledge considers the particular
only in the universal, mathematical knowledge the universal
in the particular, or even in the single instance, though still
always <1a priori>1 and by means of reason. Accordingly, just as
this single object is determined by certain universal conditions
of construction, so the object of the concept, to which the single
object corresponds merely as its schema, must likewise be
thought as universally determined.
  The essential difference between these two kinds of know-
ledge through reason consists therefore in this formal differ-
ence, and does not depend on difference of their material or
objects. Those who propose to distinguish philosophy from
00006
mathematics bysaying that the former has as its object <1quality>1
only and the latter <1quantity>1 only, have mistaken the effect for
the cause. The form of mathematical knowledge is the cause
why it is limited exclusively to quantities. For it is the concept
of quantities only that allows of being constructed, that is, ex-
B 715) hibited <1a priori>1 in intuition; whereas qualities cannot be pre-
  sented in any intuition that is not empirical. Consequently
  reason can obtain a knowledge of qualities only through con-
  cepts. No one can obtain an intuition corresponding to the con-
  cept of reality otherwise than from experience; we can never
  come into possession of it <1a priori>1 out of our own resources,
  and prior to the empirical consciousness of reality. The shape
  of a cone we can form for ourselves in intuition, unassisted by
  any experience, according to its concept alone, but the colour
  of this cone must be previously given in some experience or
  other. I cannot represent in intuition the concept of a cause
  in general except in an example supplied by experience; and
  similarly with other concepts. Philosophy, as well as mathe-
  matics, does indeed treat of quantities, for instance, of totality,
  infinity, etc. Mathematics also concerns itself with qualities,
  for instance, the difference between lines and surfaces, as
  spaces of different quality, and with the continuity of extension
  as one of its qualities. But although in such cases they have a
  common object, the mode in which reason handles that object
  is wholly different in philosophy and in mathematics. Philo-
  sophy confines itself to universal concepts; mathematics can
  achieve nothing by concepts alone but hastens at once to intui-
  tion, in which it considers the concept <1in concreto,>1 though not
  A 716) empirically, but only in an intuition which it presents <1apriori,>1
  4  that is, which it has constructed, and in which whatever follows
  from the universal conditions of the construction must be uni-
  versally valid of the object of the concept thus constructed.
  Suppose a philosopher be given the concept of a triangle
  and he be left to find out, in his own Way, what relation the
  sum of its angles bears to a right angle. He has nothing
  but the concept of a figure enclosed by three straight lines,
  and possessing three angles. However long he meditates on
  this concept, he will never produce anything new. He can
  analyse and clarify the concept of a straight line or of an angle
  or of the number three, but he can never arrive at any proper-
00007
ties not already contained in these concepts. Now let the geo-
metrician take up these questions. He at once begins by con-
structing a triangle. Since he knows that the sum of two right
angles is exactly equal to the sum of all the adjacent angles
which can be constructed from a single point on a straight line,
he prolongs one side of his triangle and obtains two adjacent
angles, which together are equal to two right angles. He then
divides the external angle by drawing a line parallel to the
opposite side of the triangle, and observes that he has thus ob-
tained an external adjacent angle which is equal to an internal
angle---and so on. In this fashion, through a chain of in- (A 717
ferences guided throughout by intuition, he arrives at a full  (B 745
evident and universally valid solution of the problem.
  But mathematics does not only construct magnitudes
<1(quanta)>1 as in geometry; it also constructs magnitude as such
<1(quantitas),>1 as in algebra  In this it abstracts completely from
the properties of the object that is to be thought in terms of
such a concept of magnitude. It then chooses a certain nota-
tion for all constructions of magnitude as such (numbers),
that is, for addition, subtraction, extraction of roots, etc. Once
it has adopted a notation for the general concept of magni-
tudes so far as their different relations are concerned, it ex-
hibits in intuition, in accordance with certain universal rules,
all the various operations through which the magnitudes are
produced and modified. When, for instance, one magnitude is
to be divided by another, their symbols are placed together, in
accordance with the sign for division, and similarly in the other
processes; and thus in algebra by means of a symbolic construc-
tion, just as in geometry by means of an ostensive construction
(the geometrical construction of the objects themselves), we
succeed in arriving at results which discursive knowledge
could never have reached by means of mere concepts.
  Now what can be the reason of this radical difference in
the fortunes of the philosopher and the mathematician, both
of whom practise the art of reason, the one making his way by
means of concepts, the other by means of intuitions which he
exhibits <1a priori>1 in accordance with concepts? The cause is (A 718
evident from what has been said above, in our exposition of the
00008
fundamental transcendental doctrines. We are not here con-
cerned with analytic propositions, which can be produced by
mere analysis of concepts (in this the philosopher would
certainly have the advantage over his rival), but with syn-
thetic propositions, and indeed with just those synthetic
propositions that can be known <1a priori.>1 For I must not
restrict my attention to what I am actually thinking in my
concept of a triangle (this is nothing more than the mere
definition); I must pass beyond it to properties which are
not contained in this concept, but yet belong to it. Now
this is impossible unless I determine my object in accord-
ance with the conditions either of empirical or of pure
intuition. The former would only give us an empirical pro-
position (based on the measurement of the angles), which
would not have universality, still less necessity; and so would
  not at all serve our purpose. The second method of procedure
  is the mathematical one, and in this case is the method of geo-
  metrical construction, by means of which I combine in a pure
  intuition (just as I do in empirical intuition) the manifold
  which belongs to the schema of a triangle in general, and
  therefore to its concept. It is by this method that universal
  synthetic propositions must be constructed.
  It would therefore be quite futile for me to philosophise
  upon the triangle, that is, to think about it discursively. I
  B 74197) should not be able to advance a single step beyond the mere
  definition, which was what I had to begin with. There is indeed
  a transcendental synthesis [framed] from concepts alone, a
  synthesis with which the philosopher is alone competent to
  deal; but it relates only to a thing in general, as defining the
  conditions under which the perception of it can belong to
  possible experience. But in mathematical problems there is
  no question of this, nor indeed of existence at all, but only of
  the properties of the objects in themselves, [that is to say],
  solely in so far as these properties are connected with the con-
  cept of the objects.
  In the above example we have endeavoured only to make
  clear the great difference which exists between the discursive
  employment of reason in accordance with concepts and its
  intuitive employment by means of the construction of concepts.
  This naturally leads on to the question, what can be the cause
00009
  THE DISCIPLINE OF PURE REASON  581
which necessitates such a twofold employment of reason, and
how we are to recognise whether it is the first or the second
method that is being employed.
  All our knowledge relates, finally, to possible intuitions,
for it is through them alone that an object is given. Now an a
<1priori>1 concept, that is, a concept which is not empirical, either
already includes in itself a pure intuition (and if so, it can
be constructed), or it includes nothing but the synthesis of
possible intuitions which are not given <1a priori.>1 In this latter
case we can indeed make use of it in forming synthetic <1a>1 (A 720
<1priori>1 judgments, but only discursively in accordance with (B 748
concepts, never intuitively through the construction of the
concept.
  The only intuition that is given <1a priori>1 is that of the mere
form of appearances, space and time. A concept of space and
time, as quanta, can be exhibited <1a priori>1 in intuition, that is,
constructed, either in respect of the quality (figure) of the
quanta, or through number in their quantity only (the mere
synthesis of the homogeneous manifold). But the matter of
appearances, by which <1things>1 are given us in space and time,
can only be represented in perception, and therefore <1a poste->1
<1riori.>1 The only concept which represents <1apriori>1 this empirical
content of appearances is the concept of a <1thing>1 in general,
and the <1a priori>1 synthetic knowledge of this thing in general
can give us nothing more than the mere rule of the synthesis
of that which perception may give <1a posteriori.>1 It can never
yield an <1a priori>1 intuition of the real object, since this must
necessarily be empirical.
  Synthetic propositions in regard to <1things>1 in general, the
intuition of which does not admit of being given <1a priori,>1 are
transcendental. Transcendental propositions can never be
given through construction of concepts, but only in accordance
with concepts that are <1a priori.>1 They contain nothing but the
rule according to which we are to seek empirically for a certain
synthetic unity of that which is incapable of intuitive repre-
sentation <1a priori>1 (that is, of perceptions). But these synthetic ( A 721
principles cannot exhibit <1apriori>1 any one of their concepts (B 749
in a specific instance; they can only do this <1a posteriori,>1 by
means of experience, which itself is possible only in con-
formity with these principles
00010
  If we are to judge synthetically in regard to a concept,
we must go beyond this concept and appeal to the intui-
tion in which it is given. For should we confine ourselves to
what is contained in the concept, the judgment would be
merely analytic, serving only as an explanation of the thought,
in terms of what is actually contained in it. But I can pass
from the concept to the corresponding pure or empirical in-
tuition, in order to consider it in that intuition <1in concreto,>1
and so to know, either <1a priori>1 or <1a posteriori,>1 what are the
properties of the object of the concept. The <1a priori>1 method
gives us our rational and mathematical knowledge through
the construction of the concept, the <1a posteriori>1 method our
merely empirical (mechanical) knowledge, which is incapable
of yielding necessary and apodeictic propositions. Thus I might
analyse my empirical concept of gold without gaining anything
more than merely an enumeration of everything that I actually
think in using the word, thus improving the logical character
of my knowledge but not in any way adding to it. But I take
the material body, familiarly known by this name, and obtain
perceptions by means of it; and these perceptions yield various
722) propositions which are synthetic but empirical. When the con-
  cept is mathematical, as in the concept of a triangle, I am in a
  position to construct the concept, that is, to give it <1a priori>1 in
  intuition, and in this way to obtain knowledge which is at once
  synthetic and rational.  But if what is given me is the <1transcend->1
  <1ental>1 concept of a reality, substance, force, etc., it indicates
  neither an empirical nor a pure intuition, but only the synthesis
  of empirical intuitions, which, as being empirical, cannot be
  given <1a priori.>1 And since the synthesis is thus unable to ad-
  vance <1a priori,>1 beyond the concept, to the corresponding in-
  tuition, the concept cannot yield any determining synthetic
  proposition, but only a principle of the synthesisa of possible
  a With the concept of cause I do really go beyond the empirical
  concept of an event (something happening), yet I do not pass to the
  intuition which exhibits the concept of cause <1in concreto,>1 but to the
  time-conditions in general, which in experience may be found to be
  in accord with this concept. I therefore proceed merely
  with concepts; I cannot proceed by means of the construction of
  concepts, since the concept is a rule of the synthesis of percep-
  tions, and the latter are not pure intuitions, and so do not permit of
  being <1given a priori.>1
00011
empirical intuitions. A transcendental proposition is therefore
synthetic knowledge through reason, in accordance with mere
concepts; and it is discursive, in that while it is what alone
makes possible any synthetic unity of empirical knowledge, it
yet gives us no intuition <1a priori.>1
  There is thus a twofold employment of reason; and while (A 723
the two modes of employment resemble each other in the uni-
versality and <1a priori>1 origin of their knowledge, in outcome
they are very different. The reason is that in the [field of]
appearance, in terms of which all objects are given us,
there are two elements, the form of intuition (space and time),
which can be known and determined completely <1a priori,>1 and
the matter (the physical element) or content---the latter signi-
fying something which is met with in space and time and which
therefore contains an existent corresponding to sensation.
In respect to this material element, which can never be given
in any determinate fashion otherwise than empirically, we can
have nothing <1a priori>1 except indeterminate concepts of the syn-
thesis of possible sensations, in so far as they belong, in a pos-
sible experience, to the unity of apperception. As regards the
formal element, we can determine our concepts in <1a priori>1
intuition, inasmuch as we create for ourselves, in space and
time, through a homogeneous synthesis, the objects themselves
---these objects being viewed simply as <1quanta.>1 The former
method is called the employment of reason in accordance with
concepts; in so employing its we can do nothing more than bring
appearances under concepts, according to their actual content.
The concepts cannot be made determinate in this manner,
save only empirically, that is, <1a posteriori>1 (although always in
accordance with these concepts as rules of an empirical syn-
thesis). The other method is the employment of reason through
the construction of concepts; and since the concepts here re- (A 724
late to an <1apriori>1 intuition, they are for this very reason them-
selves <1apriori>1 and can be given in a quite determinate fashion
in pure intuition, without the help of any empirical data. The
consideration of everything which exists in space or time, in
regard to the questions, whether and how far it is a quantum
00012
or not, whether we are to ascribe to it positive being or the ab-
sence of such, how far this something occupying space or time
is a primary substratum or a mere determination [of substance],
whether there be a relation of its existence to some other ex-
istence, as cause or effect, and finally in respect of its existence
whether it is isolated or is in reciprocal relation to and depend-
ence upon others---these questions, as also the question of the
possibility of this existence, its actuality and necessity, or the
opposites of these, one and all belong altogether to knowledge
obtained by reason from concepts, such knowledge being
termed <1philosophical.>1 But the determination of an intuition <1a>1
<1priori>1 in space (figure), the division of time (duration), or even
just the knowledge of the universal element in the synthesis of
one and the same thing in time and space, and the magnitude
of an intuition that is thereby generated (number),---all this is
the work of reason through construction of concepts, and is
called <1mathematical.>1
  The great success which attends reason in its mathematical
employment quite naturally gives rise to the expectation that
it, or at any rate its method, will have the same success in other
fields as in that of quantity. For this method has the advantage
A725) of being able to realise all its concepts in intuitions, which it
753  can provide <1a priori,>1 and by which it becomes, so to speak,
  master of nature; whereas pure philosophy is all at sea when it
  seeks through <1a priori>1 discursive concepts to obtain insight in
  regard to the natural world, being unable to intuit <1a priori>1
  (and thereby to confirm) their reality. Nor does there seem
  to be, on the part of the experts in mathematics, any lack
  of self-confidence as to this procedure---or on the part of the
  vulgar of great expectations from their saill---should they
  apply themselves to carry out their project. For, since they
  have hardly ever attempted to philosophise in regard to their
  mathematics (a hard task!), the specific difference between the
  two employments of reason has never so much as occurred to
  them. Current, empirical rules, which they borrow from ordin-
  ary consciousness, they treat as being axiomatic. In the ques-
  tion as to the source of the concepts of space and time they are
  not in the least interested, although it is precisely with these
  concepts (as the only original quanta) that they are themselves
  occupied. Similarly, they think it unnecessary to investigate
00013
doing to determine the extent of their validity; they care only
to make use of them. In all this they are entirely in the right,
provided only they do not overstep the proper limits, that is,
the limits of the natural world. But, unconsciously, they pass
from the field of sensibility to the precarious ground of pure and
even transcendental concepts, a ground <1(instabilis tellus, in->1
<1nabilis unda)>1 that permits them neither to stand norto swim, and  (A 726
where their hasty tracks are soon obliterated. In mathematics,
on the other hand, their passage gives rise to a broad highway,
which the latest posterity may still tread with confidence.
  We have made it our duty to determine, with exactitude
and certainty, the limits of pure reason in its transcendental
employment. But the pursuit of such transcendental know-
ledge has this peculiarity, that in spite of the plainest and most
urgent warnings Men still allow themselves to be deluded by
false hopes, and therefore to postpone the total abandonment
of all proposed attempts to advance beyond the bounds of ex-
perience into the enticing regions of the intellectual world. It
therefore becomes necessary to cut away the last anchor of
these fantastic hopes, that is, to show that the pursuit of the
mathematical method cannot be of the least advantage in this
kind of knowledge (unless it be in exhibiting more plainly
the limitations of the method); and that mathematics and
philosophy, although in natural science they do, indeed, go
hand in hand, are none the less so completely different, that
the procedure of the one can never be imitated by the other.
  The exactness of mathematics rests upon definitions, axioms
and demonstrations. I shall content myself with showing that
none of these, in the sense in which they are understood by the
mathematician, can be achieved or imitated by the philosopher.  (A 727
I shall show that in philosophy the geometrician can by his
method build only so many houses of cards, just as in mathe-
matics the employment of a philosophical method results only
in mere talk. Indeed it is precisely in knowing its limits that
philosophy consists; and even the mathematician, unless his
talent is of such a specialised character that it naturally confines
itself to its proper field, cannot afford to ignore the warnings
of philosophy, or to behave as if he were superior to them.
00014
  I. <1Definitions.>1 To <1define,>1 as the word itself indicates,
really only means to present the complete, original concept of
a thing within the limits of its concept.a If this be ourstandard,
an <1empirical>1 concept cannot be defined at all, but only <1made>1
<1explicit.>1 For since we find in it only a few characteristics of a
certain species of sensible object, it is never certain that we
are not using the word, in denoting one and the same object,
sometimes so as to stand for more, and sometimes so as to
B 726) stand for fewer characteristics. Thus in the concept of <1gold>1
  one man may think, in addition to its weight, colour, malle-
  ability, also its property of resisting rust, while another will
  perhaps know nothing of this quality. We make use of certain
  characteristics only so long as they are adequate for the pur-
  pose of making distinctions; new observations remove some
  properties and add others; and thus the limits of the concept
  are never assured. And indeed what useful purpose could be
  served by defining an empirical concept, such, for instance, as
  that of water? When we speak of water and its properties, we
  do not stop short at what is thought in the word, water, but
  proceed to experiments. The word, with the few characteristics
  which we attach to it, is more properly to be regarded as
  merely a designation than as a concept of the thing; the so-
  called definition is nothing more than a determining of the
  word. In the second place, it is also true that no concept given
  <1a priori,>1 such as substance, cause, right, equity, etc., can,
  strictly speaking, be defined. For I can never be certain that
  the clear representation of a given concept, which as given may
  still be confused, has been completely effected, unless I know that
  it is adequate to its object. But since the concept of it may, as
  given, include many obscure representations, which we over-
  look in our analysis, although we are constantly making use of
  them in our application of the concept, the completeness of the
  analysis of my concept is always in doubt, and a multiplicity
  a <1Completeness>1 means clearness and sufficiency of character-
  istics; by <1limits>1 is meant the precision shown in there not being more
  of these characteristics than belong to the complete concept; by
  <1original>1 is meant that this determination of these limits is not
  derived from anything else, and therefore does not require any proof;
  for if it did, that would disqualify the supposed explanation from
  standing at the head of all the judgments regarding its object.
00015
of suitable examples suffices only to make the completeness (B 757
<1probable,>1 never to make it <1apodeictically>1 certain. Instead of the
term, definition, I prefer to use the term, <1exposition,>1 as being a
more guarded term, which the critic can accept as being up to
a certain point valid, though still entertaining doubts as to the
completeness of the analysis.  Since, then, neither empirical con-  '
cepts nor concepts given <1a priori>1 allow of definition, the only
remaining kind of concepts, upon which this mental operation1
can be tried, are arbitrarily invented concepts. A concept which
I have invented I can always define; for since it is not given to
me either by the nature of understanding or by experience, but
is such as I have myself deliberately made it to be, I must know
what I have intended to think in using it. I cannot, however,
say that I have thereby defined a true object. For if the concept
depends on empirical conditions, as <1e.g.>1 the concept of a ship's
clock, this arbitrary concept of mine does not assure me of the
existence or of the possibility of its object. I do not even know
from it whether it has an object at all, and my explanation
may better be described as a declaration of my project than
as a definition of an object. There remain, therefore, no
concepts which allow of definition, except only those which
contain an arbitrary synthesis that admits of <1a priori>1 construc-
tion. Consequently, mathematics is the only science that has
definitions. For the object which it thinks it exhibits <1apriori>1 in
intuition, and this object certainly cannot contain either more
or less than the concept, since it is through the definition that (B 730
the concept of the object is given---and given originally, that
is, without its being necessary to derive the definition from
any other source. The German language has for the [Latin]
terms <1exposition, explication, declaration,>1 and <1definition>1 only
one word, <1Erkla%rung,i>1 and we need not, therefore, be so
stringent in our requirements as altogether to refuse to philo-
sophical explanations the honourable title, definition. We
shall confine ourselves simply to remarking that while philo-
sophical definitions are never more than expositions of given
concepts, mathematical definitions are constructions of con-
00016
cepts, originally framed by the mind itself; and that while the
former can be obtained only by analysis (the completeness of
which is never apodeictically certain), the latter are produced
synthetically.  Whereas,  therefore,  mathematical  definitions
<1make>1 their concepts, in philosophical definitions concepts are
only <1explained.>1 From this it follows:
  (a) That in philosophy we must not imitate mathematics
by beginning with definitions, unless it be by way simply of
experiment. For since the definitions are analyses of given
concepts, they presuppose the prior presence of the concepts,
although in a confused state; and the incomplete exposition
must precede the complete. Consequently, we can infer a good
deal from a few characteristics, derived from an incomplete
A 731( analysis, without having yet reached the complete exposition,
B 759(  that is, the definition. In short,the definition in all its precision
  and clarity ought, in philosophy, to come rather at the end
  than at the beginning of our enquiries.a In mathematics, on
  the other hand, we have no concept whatsoever prior to the
  definition, through which the concept itself is first given. For
  this reason mathematical science must always begin, and it can
  always begin, with the definition.
  <1(b)>1 That mathematical definitions can never be in error.
  For since the concept is first given through the definition, it
  includes nothing except precisely what the definition intends
  should be understood by it. But although nothing incorrect can
  be introduced into its content, there may sometimes, though
  rarely, be a defect in the form in which it is clothed, namely as
  regards precision. Thus the common explanation of the circle
  that it is a <1curved>1 line every point in which is equidistant
  a  philosophy is full of faulty definitions, especially of definitions
  which, while indeed containing some of the elements required, are
  yet not complete. If we could make no use of a concept till we
  had defined it, all philosophy would be in a pitiable plight. But
  since a good and safe use can still be made of the elements obtained
  by analysis so far as they go, defective indefinitions, that is, propositions
  which are properly not definitions, but are yet true, and are therefore
  approximations to definitions, can be employed with great advantage.
  In mathematics definition belongs <1ad esse,>1 in philosophy <1ad melius>1
  <1esse.>1 It is desirable to attain an adequate definition, but often very
  difficult. The jurists are still without a definition of their concept of
  right.
00017
from one and the same point (the centre), has the defect that (B 763
the determination, curved, is introduced unnecessarily. For
there must be a particular theorem, deduced from the de-
finition and easily capable of proof, namely, that if all points
in a line are equidistant from one and the same point, the line
is curved (no part of it straight). Analytic definitions, on the
other hand, may err in many ways, either through introducing
characteristics which do not really belong to the concept, or by
lacking that completeness which is the essential feature of a
definition. The latter defect is due to the fact that we can never
be quite certain of the completeness of the analysis. For these
reasons the mathematical method of definition does not admit
of imitation in philosophy.
  2. <1Axioms.>1 These,  in  so far  as they  are immediately
certain, are synthetic <1a priori>1 principles. Now one concept
cannot be combined with another synthetically and also at the
same time immediately, since, to be able to pass beyond either
concept, a third something is required to mediate our know-
ledge. Accordingly, since philosophy is simply what reason
knows by means of concepts, no principle deserving the name
of an axiom is to be found in it. Mathematics, on the other
hand, can have axioms, since by means of the construction of
concepts in the intuition of the object it can combine the pre-
dicates of the object both <1a priori>1 and immediately, as, for
instance, in the proposition that three points always lie in a (A733
plane. But a synthetic principle derived from concepts alone
can never be immediately certain, for instance, the proposition
that everything which happens has a cause. Here I must look
round for a third something, namely, the condition of time-
determination in an experience;  I cannot obtain knowledge of
such a principle directly and immediately from the concepts
alone. Discursive principles are therefore quite different from
intuitive principles, that is, from axioms; and always require
a deduction. Axioms, on the other hand, require no such de-
duction, and for the same reason are evident---a claim which
the philosophical principles can never advance, however great
their certainty. Consequently, the synthetic propositions of pure,
transcendental reason are, one and all, infinitely removed from
being as evident---which is yet so often arrogantly claimed
on their behalf---as the proposition that <1twice two make four.>1
00018
In the Analytic I have indeed introduced some axioms of in-
tuition into the table of the principles of pure understanding;
but the principle there applied is not itself an axiom, but
serves only to specify the principle of the possibility of axioms
in general, and is itself no more than a principle derived from
concepts. For the possibility of mathematics must itself be
demonstrated in transcendental philosophy. Philosophy has
therefore no axioms, and may never prescribe its <1a>1 <1priori>1
B 762 principles in any such absolute manner, but must resign itself
  to establishing its authority in their regard by a thorough
  deduction.
  3. <1Demonstrations.->1--An apodeictic proof can be called a
  demonstration, only in so far as it is intuitive. Experience
  teaches us what is, but does not teach us that it could not
  be other than what it is. Consequently, no empirical grounds
  of proof can ever amount to apodeictic proof. Even from <1a>1
  <1priori>1 concepts, as employed in discursive knowledge, there
  can never arise intuitive certainty, that is, [demonstrative]
  evidence, however apodeictically certain the judgment may
  otherwise be. Mathematics alone, therefore, contains demon-
  strations, since it derives its knowledge not from concepts
  but from the construction of them, that is, from intuition,
  which can be given <1a priori>1 in accordance with the concepts.
  Even the method of algebra with its equations, from which
  the correct answer, together with its proof, is deduced by re-
  duction, is not indeed geometrical in nature, but is still con-
  structive in a way characteristic of the science. The concepts
  attached to the symbols, especially concerning the relations
  of magnitudes, are presented in intuition; and this method,
  in addition to its heuristic advantages, secures all inferences
  against error by setting each one before our eyes. While
  philosophical knowledge must do without this advantage,
  inasmuch as it has always to consider the universal <1in>1
  <1abstracto>1 (by means of concepts), mathematics can consider
A 7635 the universal <1in concreto>1 (in the single intuition) and yet at the
  same time through pure <1a priori>1 representation, whereby all
  errors are at once made evident. I should therefore prefer to
00019
call the first kind <1acroamatic>1 (discursive) <1proofs,>1 since they
may be conducted by the agency of words alone (the object
in thought), rather than <1demonstrations>1 which, as the term
itself indicates, proceed in and through the intuition of the
object.
  From all this it follows that it is not in keeping with the
nature of philosophy, especially in the field of pure reason, to
take pride in a dogmatic procedure, and to deck itself out with
the title and insignia of mathematics, to whose ranks it does
not belong, though it has every ground to hope for a sisterly
union with it. Such pretensions are idle claims which can never
be satisfied, and indeed must divert philosophy from its true
purpose, namely, to expose the illusions of a reason that forgets
its limits, and by sufficiently clarifying our concepts to recall
it from its presumptuous speculative pursuits to modest but
thorough self-knowledge. Reason must not, therefore, in its
transcendental endeavours, hasten forward with sanguine
expectations, as though the path which it has traversed led
directly to the goal, and as though the accepted premisses
could be so securely relied upon that there can be no need of
constantly returning to them and of considering whether we
may not perhaps, in the course of the inferences, discover de-
fects which have been overlooked in the principles, and which
render it necessary either to determine these principles more B 736
fully or to change them entirely.
  I divide all apodeictic propositions, whether demonstrable
or immediately certain, into <1dogmata>1 and <1mathemata.>1 A syn-
thetic proposition directly derived from concepts is a <1dogma;>1
a synthetic proposition, when directly obtained through the
construction of concepts, is a <1mathema.>1 Analytic judgments
really teach us nothing more about the object than what the
concept which we have of it already contains; they do not
extend our knowledge beyond the concept of the object, but
only clarify the concept. They cannot therefore rightly be
called dogmas (a word which might perhaps be translated
<1doctrines).>1 Of the two kinds of synthetic <1a priori>1 propositions
only those belonging to philosophical knowledge can, accord-
ing to the ordinary usage of words, be entitled dogmas; the
propositions of arithmetic or geometry would hardly be so
00020
named. The customary use of words thus confirms our in-
terpretation of the term, namely, that only judgments derived
from concepts can be called dogmatic, not those based on the
construction of concepts.
  Now in the whole domain of pure reason, in its merely
speculative employment, there is not to be found a single
synthetic judgment directly derived from concepts. For, as we
have shown, ideas cannot form the basis of any objectively
valid synthetic judgment. Through concepts of understanding
B 637 pure reason does, indeed, establish secure principles, not how-
  ever directly from concepts alone, but always only indirectly
  through relation of these concepts to something altogether con-
  tingent, namely, <1possible experience.>1 When such experience
  (that is, something as object of possible experiences) is pre-
  supposed, these principles are indeed apodeictically certain;
  but in themselves, directly, they can never be known <1a priori.>1
  Thus no one can acquire insight into the proposition that
  everything which happens has its cause, merely from the con-
  cepts involved. It is not, therefore, a dogma, although from
  another point of view, namely, from that of the sole field of
  its possible employment, that is, experience, it can be proved
  with complete apodeictic certainty. But though it needs proof,
  it should be entitled a <1principle,>1 not a <1theorem,>1 because it has
  the peculiar character that it makes possible the very experi-
  ence which is its own ground of proof, and that in this ex-
  perience it must always itself be presupposed.
  Now if in the speculative employment of pure reason there
  are no dogmas, to serve as its special subject-matter, all
  <1dogmatic>1 methods, whether borrowed from the mathematician
  or specially invented, are as such inappropriate. For they only
  serve to conceal defects and errors, and to mislead philosophy,
  whose true purpose is to present every step of reason in the
  clearest light. Nevertheless its method can always be <1system->1
A 738  <1tic>1  For our reason is itself, subjectively, a system, though in
  its pure employment, by means of mere concepts, it is no more
  than a system whereby our investigations can be conducted
  in accordance with principles of unity, the material being pro-
  vided by <1experience>1 alone. We cannot here discuss the method
  peculiar to transcendental philosophy; we are at present con-
00021
cerned only with a critical estimate of what may be expected
from our faculties---whether we are in a position to build at all;
and to what height, with the material at our disposal (the pure
<1a priori>1 concepts), we may hope to carry the edifice.
  CHAPTER I
  Section 2
THE DISCIPLINE OF PURE REASON IN RESPECT OF ITS
  POLEMICAL EMPLOYMENT
  Reason must in all its undertakings subject itself to criti-
cism; should it limit freedom of criticism by any prohibi-
tions, it must harm itself, drawing upon itself a damaging
suspicion. Nothing is so important through its usefulness,
nothing so sacred, that it may be exempted from this search-
ing examination, which knows no respect for persons. Reason
depends on this freedom for its very existence. For reason
has no dictatorial authority; its verdict is always simply the  A739
agreementof free citizens, of whom each one must be permitted   B767
to express, without let or hindrance, his objections or even his
veto.
  But while reason can never refuse to submit to criticism,
it does not always have cause to fear it. In its dogmatic (non-
mathematical) employment it is not, indeed, so thoroughly
conscious of such exact observation of its own supreme laws,
as not to feel constrained to present itself with diffidence, nay,
with entire renunciation of all assumed dogmatic authority,
to the critical scrutiny of a <1higher>1 judicial reason.
  The situation is, however, quite otherwise, when reason
has to deal not with the verdict of a judge, but with the claims
of a fellow-citizen, and against these has only to act in self-
defence. For since these are intended to be just as dogmatic
in denial as its own are in affirmation, it is able to justify itself
<3kat a2/nqrwpon>3, in a manner which ensures it against all inter-
ference, and provides it with a title to secure possession that
need fear no outside claims, although <3kat' a2lh/qeian>3 the title
cannot itself be conclusively proved.
  By the polemical employment of pure reason I mean the
00022
defence of its propositions as against the dogmatic counter-
propositions through which they are denied. Here the conten-
tion is not that its own assertions may not, perhaps, be false,
7468 but only that no one can assert the opposite with apodeictic
  certainty, or even, indeed, with a greater degree of likelihood.
  We do not here hold our possessions upon sufferance; for
  although our title to them may not be satisfactory, it is yet
  quite certain that no one can ever be in a position to prove the
  illegality of the title.
  It is grievous, indeed, and disheartening, that there should
  be any such thing as an antithetic of pure reason, and that
  reason, which is the highest tribunal for all conflicts, should
  thus be at variance with itself. We had to deal, in a previous
  chapter, with such an antithetic; but it turned out to be only
  an apparent conflict, resting upon a misunderstanding. In ac-
  cordance with the common prejudice, it took appearances as
  being things in themselves, and then required an absolute
  completeness of their synthesis in the one mode or in the  other
  (this being equally impossible in eitherway)---a demand which
  is not at all permissible in respect of appearances. There was,
=  therefore, no real <1self-contradiction of reason>1 in the propound-
  ing of the two propositions, that the series of appearances <1given>1
  <1in themselves>1 has an absolutely first beginning, and that this
  series is absolutely and <1in itself>1 without any beginning. For
  the two propositions are quite consistent with each other, inas-
  much as <1appearances,>1 in respect of their existence (as appear-
  ances), are <1in themselves>1 nothing at all, that is, [so regarded]
  are something self-contradictory; for the assumption [that
  they do thus exist in themselves] must naturally lead to self-
  contradictory inferences.
 B741  But there are other cases in which we cannot allege any
  such misunderstanding, and in which we cannot, therefore,
  dispose of the conflict of reason in the above manner---when,
  for instance, it is asserted, on the one hand, theistically, that
  there is a supreme being, and on the other hand, atheistically,
  that there is no supreme being; or as in psychology, that every-
  thing which thinks is endowed with absolute and abiding unity
  and is therefore distinct from all transitory material unity,
  and, in opposition thereto, that the soul is not immaterial unity
00023
and cannot be exempt from transitoriness. For since in these
cases the understanding has to deal only with <1things in them->1
<1selves>1 and not with appearances, the object of such questions
is free from any foreign element that is in contradiction with
its nature. There would indeed be a real conflict, if pure reason
had anything to say on the negative side which amounted to
a positive ground for its negative contentions. For so far as
concerns criticism of the grounds of proof offered by those
who make dogmatic affirmations, the criticism can be freely
admitted, without our having on that account to give up these
affirmations, which have at least the interest of reason in
their favour---an interest to which the opposite party cannot
appeal.
  I do not at all share the opinion which certain excel-
lent and thoughtful men (such as Sulzer), in face of the
weakness of the arguments hitherto employed, have so often
been led to express, that we may hope sometime to discover
conclusive demonstrations of the two cardinal propositions of
our reason---that there is a God, and that there is a future life.
On the contrary, I am certain that this will never happen  For A742
whence will reason obtain ground for such synthetic assertions,
which do not relate to objects of experience and their inner
possibility. But it is also apodeictically certain that there will
never be anyone who will be able to assert the <1opposite>1 with
the least show [of proof], much less, dogmatically. For since he
could prove this only through pure reason, he must undertake
to prove that a supreme being, and the thinking subject in
us [viewed] as pure intelligence, are <1impossible.>1 But whence
will he obtain the modes of knowledge which could justify
him in thus judging synthetically in regard to things that lie
beyond all possible experience. We may therefore be so com-
pletely assured that no one will ever prove the opposite, that
there is no need for us to concern ourselves with formal argu-
ments. We are always in a position to accept these propositions
---propositions which are so very closely bound up with the
speculative interest of our reason in its empirical employment,
and which, moreover, are the sole means of reconciling the
00024
speculative with the practical interest. As against our opponent
who must not be considered here as a critic only, we are equipped
with our <1non liquet,>1 which cannot fail to disconcert him. At
the same time we do not mind his turning this argument
A 743 upon ourselves, since we always have in reserve the subjective
B 771 maxim of reason, which is necessarily lacking to our opponent,
  and under its protection can look upon all his vain attacks with
  a tranquil indifference.
  There is thus no real antithetic of pure reason. For the
  arena for such an antithetic would have to be located in the
  domain of pure theology and psychology; and in that domain
  no combatant can be adequately equipped, or have weapons
  that we need fear.  Ridicule and1 boasting form his whole
  armoury, and these can be laughed at, as mere child's play.
    This is a comforting consideration, and affords reason fresh
  courage; for upon what could it rely, if, while it alone is called
  upon to remove all errors, it should yet be at variance with
  itself, and without hope of peace and quiet possession.
    Everything which nature has itself instituted is good for
  some purpose. Even poisons have their use. They serve to
  counteract other poisons generated in our bodily humours,
  and must have a place in every complete pharmacopoeia. The
  objections against the persuasions and complacency of our
  purely speculative reason arise from the very nature of reason
  itself, and must therefore have their own good use and purpose,
  which ought not to be disdained. Why has Providence placed
  many things which are closely bound up with our highest in-
  A 744 terests so far beyond our reach that we are only permitted to
  B 772 apprehend them in a manner lacking in clearness and subject
  to doubt---in such fashion that our enquiring gaze is more ex-
  cited than satisfied? We may, indeed, be in doubt whether it
  serves any useful purpose, and whether it is not perhaps even
  harmful, to venture upon bold utterances in regard to such
  uncertain matters. But there can be no manner of doubt that
  it is always best to grant reason complete liberty, both of
  enquiry and of criticism, so that it may not be hindered in
  attending to its own proper interests. These interests are no
  less furthered by the limitation than by the extension of its
  speculations, and will always suffer when outside influences
00025
intervene to divert it from its proper path, and to constrain
it by what is irrelevant to its own proper ends.
  Allow, therefore, your opponent to speak in the name of
reason, and combat him only with weapons of reason. For the
rest, have no anxiety as to the outcome in its bearing upon
our practical interests, since in a merely speculative dispute
they are never in any way affected. The conflict serves only to
disclose a certain antinomy of reason which, inasmuch as it
is due to the very nature of reason, must receive a hearing
and be scrutinised. Reason is benefited by the consideration
of its object from both sides, and its judgment is corrected in
being thus limited. What is here in dispute is not the practical
interests of reason but the mode of their presentation. For
although we have to surrender the language of <1knowledge,>1 A745
we still have sufficient ground to employ, in the presence of B 773
the most exacting reason, the quite legitimate language of a
firm <1faith.>1
  If we should ask the dispassionate David Hume, [by
temperament] so peculiarly fitted for balanced judgment,
what led him to undermine, through far-fetched subtleties
so elaborately thought out, the conviction which is so com-
forting and beneficial for mankind, that their reason has
sufficient insight for the assertion and for the determinate
conception of a supreme being, he would answer: "Solely in
order to advance reason in its self-knowledge, and because of
a certain indignation at the violence that is done to reason by
those who, while boasting of its powers, yet hinder it from
candid admission of the weaknesses which have become ob-
vious to it through its own self-examination'. If, on the other
hand, we should ask Priestley, who was wholly devoted to the
<1empirical>1 employment of reason and out of sympathy with
all transcendent speculation, what motives had induced him---
himself a pious and zealous teacher of religion---to pull down
two such pillars of all religion as the freedom and immortality
of the soul (the hope of a future life is for him onlythe expecta-
tion of the miracle of resurrection), he would notbe able to give
00026
any other answer than that he was concerned for the interest
of reason, which must suffer when we seek to exempt certain
objects from the laws of material nature, the only laws which
A746 we can know and determine with exactitude. It would be
  unjust to decry the latter (who knew how to combine his para-
  doxical teaching with the interests of religion), and so to give
  pain to a well-intentioned man, simply because he is unable
  to find his bearings, having strayed outside the field of natural
  science. And the same favour must be accorded to the no
  less well disposed and in his moral character quite blameless
  Hume, when he insists upon the relevance, in this field, of
  his subtly thought-out speculations. For, as he rightly held,
  their object lies entirely outside the limits of natural science,
  in the domain of pure ideas.
  What, then, is to be done, especially in view of the danger
  which would thus seem to threaten the best interests of man-
  kind? Nothing is more natural, nothing is more reasonable,
  than the decision which we are hereby called upon to make.
    Leave such thinkers free to take their own line. If they exhibit
  talent, if they initiate new and profound enquiries, in a word,
  if they show reason, reason always stands to gain. If we resortto
  other means than those of untrammelled reason, if we raise the
  cry of high treason, and act as if we were summoning the vulgar
  to extinguish a conflagration---the vulgar who have no under-
  standing of such subtle enquiries---we make ourselves ridicu-
  lous. Forthe question at issue is not as to what, in these enquiries,
  is beneficial or detrimental to the best interests of mankind,
  but only how far reason can advance by means of speculation
 B747 that abstracts from all interests, and whether such speculation
  can count for anything, or must not rather be given up in ex-
  change for the practical. Instead, therefore, of rushing into the
  fight, sword in hand, we should rather play the part of the
  peaceable onlooker, from the safe seat of the critic.  The struggle
  is indeed toilsome to the combatants, but for us can be enter-
  taining; and its outcome---certain to be quite bloodless---must
  be of advantage as contributing to our theoretical insight. For
  it is indeed absurd to look to reason for enlightenment, and
  yet to prescribe beforehand which side she must necessarily
  favour. Besides, reason is already of itself so confined and held
00027
within limits by reason, that we have no need to call out the
guard, with a view to bringing the civil power to bear upon
that party whose alarming superiority may seem to us to be
dangerous. In this dialectic no victory is gained that need give
us cause for anxiety.
  Reason does indeed stand in sore need of such dialectical
debate;  and it is greatly to be wished that the debate had been
instituted sooner and with unqualified public approval.  For in
that case criticism would sooner have reached a ripe maturity,
and all these disputes would of necessity at once have come to
an end, the opposing parties having learned to recognise the
illusions and prejudices which have set them at variance.
  There is in human nature a certain disingenuousness,
which, like everything that comes from nature, must finally A 748
contribute to good ends, namely, a disposition to conceal our
real sentiments, and to make show of certain assumed senti-
ments which are regarded as good and creditable. This
tendency to conceal ourselves and to assume the appearance
of what contributes to our advantage, has, undoubtedly, not
only <1civilised>1 us, but gradually, in a certain measure, <1moral->1
<1ised>1 us. For so long as we were not in a position to see
through the outward show of respectability, honesty, and
modesty, we found in the seemingly genuine examples of
goodness with which we were surrounded a school for self-
improvement. But this disposition to represent ourselves as
better than we are, and to give expression to sentiments which
we do not share, serves as a merely <1provisional>1 arrangement,
to lead us from the state of savage rudeness, and to allow of
our assuming at least the <1outward bearing>1 of what we know to
be good. But later, when true principles have been developed,
and have become part of our way of thought, this duplicity
must be more and more earnestly combated; otherwise it cor-
rupts the heart, and checks the growth of good sentiments
with the rank weeds of fair appearances.
  I am sorry to observe the same disingenuousness, mis-
representation, and hypocrisy even in the utterances of specu-
lative thought, where there are far fewer hindrances to our
making, as is fitting, frank and unreserved admission of our
thoughts, and no advantage whatsoever in acting otherwise A 749
00028
00029
00030
For what can be more prejudicial to the interests of knowledge
than to communicate even our very thoughts in a falsified
form, to conceal doubts which we feel in regard to our
own assertions, or to give an appearance of conclusiveness
to grounds of proofs which we ourselves recognise to be in-
sufficient. So long as mere personal vanity is what breeds
these secret devices---and this is generally the case with those
speculative judgments which concern no special interest and
do not easily allow of apodeictic certainty---it is counteracted,
<1in the process of enlisting general acceptance,>1 by the vanity of
others; and thus in the end the result is the same as would have
been obtained, though much sooner, by entirely sincere and
honest procedure. When the common people are of opinion
that those who indulge in subtle questionings aim at nothing
less than to shake the very foundations of public welfare, it
may, indeed, seem not only prudent but permissible, and in-
deed even commendable, to further the good cause through so-
phistical arguments rather than allow its supposed antagonists
the advantage of having made us lower our tone to that of a
merely practical conviction, and of having compelled us to
admit our lack of speculative and apodeictic certainty. I
cannot, however, but think that nothing is so entirely incom-
patible with the purpose of maintaining a good cause as deceit,
A 750 hipocrisy and fraud. Surely the least that can be demanded
  is that in a matter of pure speculation, when weighing the con-
  siderations cited by reason, we should proceed in an entirely
  sincere manner. If we could confidently count even upon this
  little, the conflict of speculative reason regarding the im-
  portant questions of God, the immortality of the soul, and
  freedom, would long ago have been decided, or would very
  soon be brought to a conclusion. Thus it often happens that
  purity of purpose is in inverse ratio to the goodness of the
  cause, and that candour and honesty are perhaps more likely
  to be found among its assailants than among its defenders.
  I shall therefore assume that I have readers who do not
  wish to see a righteous cause defended in an unrighteous
  manner; and that they will consequently take it as agreed,
  that, according to our principles of criticism, and having regard
  not to what commonly happens, but to what ought to happen,
  there can, properly speaking, be no polemic of pure reason.
00031
For how can two persons carry on a dispute about a thing the
reality of which neither of them can present in actual or even in
possible experience---a dispute in which they brood over the
mere idea of the thing, in order to extract from it something
<1more than the idea,>1 namely, the reality of the object itself? What
means have they of ending the dispute, since neither of them
can make his thesis genuinely comprehensible and certain, but
only attack and refute that of his opponent? For this is the fate
of all assertions of pure reason: that since they transcend the A 751
conditions of all possible experience, outside which the authen-
tication of truth is in no wise possible, while at the same time
they have to make use of the laws of the understanding---laws
which are adapted only for empirical employment, but without
which no step can be taken in synthetic thought---neither side
can avoid exposing its weakness, and each can therefore take
advantage of the weakness of the other.
  The critique of pure reason can be regarded as the true
tribunal for all disputes of pure reason; for it is not involved
in these disputes---disputes which are immediately concerned
with objects---but is directed to the determining and esti-
mating of the rights of reason in general, in accordance with
the principles of their first institution.
  In the absence of this critique reason is, as it were, in the
state of nature, and can establish and secure its assertions and
claims only through <1war.>1 The critique, on the other hand,
arriving at all its decisions in the light of fundamental prin-
ciples of its own institution, the authority of which no one can
question, secures to us the peace of a legal order, in which our
disputes have to be conducted solely by the recognised methods
of <1legal action.>1 In the former state, the disputes are ended by
a victory to which both sides lay claim, and which is generally
followed by a merely temporary armistice, arranged by some
mediating authority; in the latter, by a <1judicial sentence>1 B 782
which, as it strikes at the very root of the conflicts, effectively
secures an eternal peace. The endless disputes of a merely
dogmatic reason thus finally constrain us to seek relief in
some critique of reason itself, and in a legislation based upon
such criticism. As Hobbes maintains, the state of nature is a
state of injustice and violence, and we have no option save to
abandon it and submit ourselves to the constraint of law, which
00032
limits our freedom solely in order that it may be consistent
with the freedom of others and with the common good of all.
  This freedom will carry with it the right to submit openly
for discussion the thoughts and doubts with which we find our-
selves unable to deal, and to do so without being decried as
troublesome and dangerous citizens. This is one of the original
rights of human reason, which recognises no other judge than
that universal human reason in which everyone has his say. And
since all improvement of which our state is capable must be ob-
tained from this source, such a right is sacred and must not be
curtailed. Indeed we are very ill-advised in decrying as danger-
ous any bold assertions against, or audacious attacks upon,
the view which already has on its side the approval of the
largest and best portion of the community; in so doing we
A 753 are ascribing to them an importance which they are not
  entitled to claim. Whenever I hear that a writer of real ability
  has demonstrated away the freedom of the human will, the
  hope of a future life, and the existence of God, I am eager to
  read the book, for I expect him by his talents to increase my
  insight into these matters. Already, before having opened it, I
  am perfectly certain that he has not justified any one of his
  specific claims; not because I believe that I am in possession
  of conclusive proofs of these important propositions, but
  because the transcendental critique, which has disclosed to
  me all the resources of our pure reason, has completely con-
  vinced me that, as reason is incompetentto arrive at affirmative
  assertions in this field, it is equally unable, indeed even less
  able, to establish any negative conclusion in regard to these
  questions. For from what source will the freethinker derive his
  professed knowledge1 that there is, for example, no supreme
  being? This proposition is outside the field of possible experi-
  ence, and therefore beyond the limits of all human insight.
  The reply of the <1dogmatic>1 defender of the good cause I should
  not read at all. I know beforehand that he will attack the
  sophistical arguments of his opponent simply in order to gain
  acceptance for his own; and I also know that a quite familiar
  line of false argument does not yield so much material for new
  observations as one that is novel and ingeniously elaborated.
00033
The opponent of religion is indeed, in his own way, no less A 754
dogmatic, but he affords me a welcome opportunity of apply- B 782
ing and, in this or that respect, amending the principles of my
Critique, while at the same time I need be in no fear of these
principles being in the least degree endangered.
  But must not the young, at least, when entrusted to our
academical teaching, be warned against such writings, and
preserved from a premature knowedge of such dangerous
propositions, until their faculty of judgment is mature, or
rather until the doctrine which we seek to instil into them has
taken such firm root, that they are able effectively to with-
stand all persuasion to contrary views, from whatever quarter
it may come?
  If we are to insist on holding to dogmatic procedure in
matters of pure reason, and on disposing of our opponents
in strictly polemical fashion, that is, by ourselves taking sides
in the controversy, and therefore equipping ourselves with
proofs in support of the opposite assertions, certainly this
procedure wouldfor <1the time being>1 be the most expedient; but
<1in the long run>1 nothing would be more foolish and ineffective
than to keep youthful reason thus for a period under tutelage.
This will indeed guard the young temporarily against per-
version. But when, later, either curiosity or the fashion of the
age brings such writings under their notice, will their youthful
conviction then stand the test?  Whoever, in withstanding the
attacks of his opponent, has at his disposal only dogmatic
weapons, and is unable to develop the dialectic which lies
concealed in his own breast no less than in that of his an- A755
tagonist,  [is in a dangerous position].  He sees sophistical B 783
arguments, which have the attraction of novelty, set in oppo-
sition to sophistical arguments which no longer have that
attraction, but, on the contrary, tend to arouse the suspicion
that advantage has been taken of his youthful credulity. And
accordingly he comes to believe that there can be no better
way of showing that he has outgrown childish discipline than
by casting aside these well-meant warnings; and accustomed
as he is to dogmatism, he drinks deep draughts of the poison,
which destroys his principles by a counter-dogmatism.
  In academic teaching we ought to pursue the course
exactly opposite to that which is here recommended, pro-
00034
vided always that the teaching is based on thorough instruc-
tion in the criticism of pure reason. For in order to bring the
principles of this criticism into operation as soon as possible,
and to show their sufficiency even when dialectical illusion is
at its height, it is absolutely necessary that the attacks which
seem so terrible to the dogmatist should be made to exercise
their full force upon the pupil's reason, which though still
weak has been enlightened through criticism, and that the pupil
should thus be allowed the opportunity of testing for himself,
one by one, by reference to the critical principles, how ground-
less are the assertions of those who have launched these attacks.
As it is by no means difficult for himto resolvethese arguments
into thin air, he early begins to feel his own capacity to secure
himself against such injurious deceptions, which must finally
B 675  lose for him all their illusory power. Those same blows which
  destroy the structures of the enemy must indeed be equally
  destructive to any speculative structure which he may per-
  chance himself wish to erect. This does not, however, in the
  least disturb him, since he has no need of any such shelter,
  being still in possession of good expectations in the practical
  sphere, where he may confidently hope to find firmer ground
  upon which to erect his own rational and beneficial system.
  There is, therefore, properly speaking, no polemic in the
  field of pure reason. Both parties beat the air, and wrestle with
  their own shadows, since they go beyond the limits of nature,
  where there is nothing that they can seize and hold with their
  dogmatic grasp. Fight as they may, the shadows which they
  cleave asunder grow together again forthwith, like the heroes
  in el halla, to disport themselves anew in the bloodless con-
  tests.
  But neither can we admit that there is any sceptical em-
  ployment of pure reason, such as might be entitled the prin-
  ciple of <1neutrality>1 in all its disputes. To set reason at variance
  with itself, to supply it with weapons on both sides, and then
  to look on, quietly and scoffingly, at the fierce struggle, is not,
  from the dogmatic point of view, a seemly spectacle, but ap-
  pears to suggest a mischievous and malevolent disposition.
  If, however, we consider the invincible obstinacy and the
  boastfulness of those who argue dogmatically, and who refuse
A 757 to allow their claims to be moderated by any criticism, there
B 785
00035
is really no other available course of action than to set against
the boasting of the one side the no less justified boasting of the
other, in the hope that the resistance thus offered to reason
may at least serve to disconcert it, to awaken some doubts as
to its pretensions, and to make it willing to give a hearing to
criticism. But to allow ourselves simply to acquiesce in these
doubts, and thereupon to set out to commend the conviction
and admission of our ignorance not merely as a remedy against
the complacency of the dogmatists, but likewise as the right
method of putting an end to the conflict of reason with itself,
is a futile procedure, and can never suffice to overcome the
restlessness of reason. At best it is merely a means of awaken-
ing it from its sweet dogmatic dreams, and of inducing it to
enter upon a more careful examination of its own position.
Since, however, the sceptical method of escaping from the
troublesome affairs of reason appears to be, as it were, a short
cut by which we can arrive at a permanentpeace in philosophy,
or [if it be not that], is at least the road favoured by those who
would feign make show of having a philosophical justification
for their contemptuous dislike of all enquiries of this kind, I
consider it necessary to exhibit this way of thinking in its true
light.
  <1The Impossibility of a Sceptical Satisfacti  p>1  A 758
  <1Reason in its Internal Conflicts>1
  The consciousness of my ignorance (unless at the same
time this ignorance is recognised as being necessary), instead
of ending my enquiries, ought rather to be itself the reason
for entering upon them. All ignorance is either ignorance of
things or ignorance of the function and limits of knowledge.
If ignorance is only 1 accidental, it must incite me, in the former
regard to a <1dogmatic>1 enquiry concerning things (objects), in
the latter regard to a <1critical>1 enquiry concerning the limits of
my possible knowledge. But that my ignorance is absolutely
necessary, and that I am therefore absolved from all further
enquiry, cannot be established empirically, from <1observation,>1
but only through an <1examination,>1 critically conducted, of the
primary sources of our knowledge. The determination of the
limits of our reason cannot, therefore, be made save on <1a priori>1
00036
grounds; on the other hand, that limitation of it which con-
sists merely in an indeterminate knowledge of an ignorance
never to be completely removed, can be recognised <1a posteriori>1
by reference to that which, notwithstanding all we know, still
remains to be known. The former knowledge of our ignor-
ance, which is possible only through criticism of reason itself,
is <1science;>1 the latter is nothing but <1perception,>1 and we can-
A759 not say how far the inferences from perception may extend.
  If I represent the earth as it appears to my senses, as a flat
  surface, with a circular horizon, I cannot know how far it
  extends. But experience teaches me that wherever I may go,
  I always see a space around me in which I could proceed
  further; and thus I know the limits of my actual knowledge
  of the earth at any given time, but not the limits of all possible
  geography. But if I have got so far as to know that the earth
  is a sphere and that its surface is spherical, I am able even
  from a small part of it, for instance, from the magnitude of a
  degree, to know determinately, in accordance with principles
  <1a priori,>1 the diameter, and through it the total superficial area
  of the earth; and although I am ignorant of the objects which
  this surface may contain, I yet have knowledge in respect of
  its circuit, magnitude, and limits.
  The sum of all the possible objects of our knowledge ap-
  pears to us to be a plane, with an apparent horizon---namely,
  that which in its sweep comprehends it all, and which has been
  entitled by us the idea of unconditioned totality. To reach
  this concept empirically is impossible, and all attempts to
  determine it <1a priori>1 in accordance with an assured principle
A 760 have proved vain. None the less all the questions raised by our
  pure reason are as to what may be outside the horizon, or, it
  may be, on its boundary line.
  The celebrated David Hume was one of those geographers
  of human reason who have imagined that they have sufficiently
  disposed of all such questions by setting them outside the hori-
  ion of human reason---a horizon which yet he was not able
  to determine. Hume dwelt in particular upon the principle of
  causality, and quite rightly observed that its truth, and even
  the objective validity of the concept of efficient cause in
00037
general, is based on no insight, that is, on no <1a priori>1 know-
ledge, and that its authority cannot therefore be ascribed to
its necessity, but merely to its general utility in the course of
experience, and to a certain subjective necessity which it
thereby acquires, and which he entitles custom. From the
incapacity of our reason to make use of this principle in any
manner that transcends experience, he inferred the nullity of
all pretensions of reason to advance beyond the empirical.
  A procedure of this kind---subjecting the facts1 of reason
to examination, and if necessary to blame---may be entitled
the <1censorship>1 of reason. This censorship must certainly lead
to <1doubt>1 regarding all transcendent employment of principles.
But this is only the second step, and does not by any means A 761
complete the work of enquiry. The first step in matters of  u  B 789
reason, marking its infancy, is <1dogmatic.>1 The second step is
<1sceptical;>1 and indicates that experience has rendered our judg-
ment wiser and more circumspect. But a third step, such as
can be taken only by fully matured judgment, based on as-
sured principles of proved universality, is now necessary,
namely, to subject to examination, not the facts of reason, but
reason itself, in the whole extent of its powers, and as regards
its aptitude for pure <1a priori>1 modes of knowledge. This is not
the censorship but the <1criticism>1 of reason, whereby not its
present <1bounds>1 but its determinate [and necessary] <1limits>1
not its ignorance on this or that point but its ignorance in
regard to all possible questions of a certain kind, are demon-
strated from principles, and not merely arrived at by way of
conjecture. Scepticism is thus a resting-place for human
reason, where it can reflect upon its dogmatic wanderings and
make survey of the region in which it finds itself, so that for
the future it may be able to choose its path with more certainty.
But itis no dwelling-place for permanent settlement. Such can
be obtained only through perfect certainty in our knowledge,
alike of the objects themselves and of the limits within which
all our knowledge of objects is enclosed.  A 762
  Our reason is not liae a plane indefinitely far extended  B 790
the limits of which we know in a general way only; but must
rather be compared to a sphere, the radius of which can be
determined from the curvature of the arc of its surface---that
00038
is to say, from the nature of synthetic <1a priori>1 propositions
---and whereby we can likewise specify with certainty its
volume and its limits. Outside this sphere (the field of experi-
ence) there is nothing that can be an object for reason; nay, the
very questions in regard to such supposed objects relate only
to subjective principles of a complete determination of those
relations which can come under the concepts of the under-
standing and which can be found within the empirical sphere
  We are actually in possession of <1a priori>1 synthetic modes
of knowledge,1 as is shown by the principles of understanding
which anticipate experience. If anyone is quite unable to
comprehend the possibility of these principles, he may at first
be inclined to doubt whether they actually dwell in us <1a>1
<1priori;>1 but he cannot on this account declare that they are
beyond the powers of the understanding, and so represent all
the steps which reason takes undertheir guidance as being null
and void. All that he can sayis that if we could have insightinto
their origin and authenticity, we should be able to determine
the scope and limits of our reason, but that until we can have
A 763 such insight any assertions as to the limits of reason are made
    at random. And on this ground a general doubt regarding all
  dogmatic philosophy, proceeding as such philosophy does with-
  out criticism of reason itself, is entirely justified; but we cannot
  therefore altogether deny to reason the right to take such for-
  ward steps, once we have prepared and secured the way for
  them by a more thorough preparation of the ground. For all
  the concepts, nay, all the questions, which pure reason presents
  to us, have their source not in experience, but exclusively in
  reason itself, and must therefore allow of solution and of being
  determined in regard to their validityor invalidity. We have no
  right to ignore these problems, as if their solution really de-
  pended on the nature of things, and as if we might therefore,
  on the plea of our incapacity, decline to occupy ourselves with
  their further investigation; for since reason is the sole begetter
  of these ideas, it is under obligation to give an account of their
  validity or of their illusory, dialectical nature.
  All sceptical polemic should properly be directed only
  against the dogmatist, who, without any misgivings as to his
  fundamental objective principles, that is, without criticism,
00039
proceeds complacently upon his adopted path; it should be
designed simply to put him out of countenance and thus to
bring him to self-knowledge. In itself, however, this polemic
is of no avail whatsoever in enabling us to decide what it is
that we can and what it is that we cannot know. All unsuccess-
ful dogmatic attempts of reason are facts,1 and it is always of A 764
advantage to submit them to the censorship of the scepti. B 792
But this can decide nothing regarding those expectations of
reason which lead it to hope for better success in its future
attempts, and to build claims on this foundation; and con-
sequently no mere censorship can put an end to the dispute
regarding the rights of human reason.
  Hume is perhaps the most ingenious of all the sceptics, and
beyond all question is without rival in respect of the influence
which the sceptical procedure can exercise in awakening
reason to a thorough self-examination. It will therefore well
repay us to make clear to ourselves, so far as may be relevant to
our purpose, the course of the reasoning, and the errors, of so
acute and estimable a man---a course of reasoning which at
the start was certainly on the track of truth.
  Hume was perhaps aware, although he never followed the
matter out, that in judgments of a certain kind we pass beyond
our concept of the object. I have entitled this kind of judg-
ments <1synthetic.>1 There is no difficulty as to how, by means of
experience, I can pass beyond the concept which I previously
have. Experience is in itself a synthesis of perceptions,
whereby the concept which I have obtained by means of a
perception is increased through the addition of other per-
ceptions. But we suppose ourselves to be able to pass <1a priori>1
beyond our concept, and so to extend our knowledge. This we A 765
attempt to do either through the pure understanding, in respect B 793
of that which is at least capable of being an <1object of experi->1
<1ence,>1 or through pure reason, in respect of such properties of
things, or indeed even of the existence of such things, as can
never be met with in experience. Our sceptical philosopher did
not distinguish these two kinds of judgments, as he yet ought
to have done, but straightway proceeded to treat this self-
increment of concepts, and, as we may say, this spontaneous
generation on the part of our understanding and of our reason,
00040
without impregnation by experience, as being impossible.
He therefore regarded all the supposed <1a priori>1 principles
of these faculties as fictitious, and concluded that they are
nothing but a custom-bred habit arising from experience
and its laws, and are consequently merely empirical, that is,
rules that are in themselves contingent, and to which we
ascribe a supposititious necessity and universality. In support
of his assertion of this startling thesis, he cited the universally
recognised principle of the relation between cause and effect.
For since no faculty of understanding can carry us from the
concept of a thing to the existence of something else that is
thereby universally and necessarily given, he believed that he
was therefore in a position to conclude that in the absence of
experience we have nothing that can increase our concept and
  justify us in propounding a judgment which thus enlarges
  itself <1a priori.>1 That sunlight should melt wax and yet also
  harden clay, no understanding, he pointed out, can discover
  from the concepts which we previously possessed of these
  things, much less infer them according to a law. Only experi-
  ence is able to teach us such a law. But, as we have discovered
  in the Transcendental Logic, although we can never pass
  <1immediately>1 beyond the content of the concept which is given
  us, we are nevertheless able, in relation to a third thing,
  namely, <1possible>1 experience, to know the law of its connection
  with other things, and to do so in an <1a priori>1 manner. If,
  therefore, wax, which was formerly hard, melts, I can anow
  <1a priori>1 that <1something>1 must have preceded, ([that something
  being] for instance [in this case] theheatof the sun), upon which
  the melting has followed according to a fixed law, although
  <1a priori,>1 independently of experience, I could not determine,
  <1in any specific manner,>1 either the cause from the effect, or the
  effect from the cause. Hume was therefore in error in inferring
  from the contingency of our determination <1in accordance with>1
  <1the law>1 the contingency of the <1law>1 itself. The passing be-
  yond the concept of a thing to possible experience (which
  takes place <1a priori>1 and constitutes the objective reality of the
  concept) he confounded with the synthesis of the objects of
  actual experience, which is always empirical. He thus con-
  founds a principle of affinity, which has its seat in the under-
  standing and affirms necessary connection, with a rule of
00041
association, which exists only in the imitative faculty of im- A767
agination, and which can exhibit only contingent, not objectiv
connections.
  The sceptical errors of this otherwise singularly acute
thinker arose chiefly from a defect which he shares in common
with all dogmatists, namely, that he did not make a system-
atic review of all the various kinds of <1a priori>1 synthesis as-
cribable to the understanding. For he would then have found,
to mention only one of many possible examples, that <1the prin->1
<1ciple of permamence>1 is a principle of this character, and that,
like the principle of causality, it anticipates experience. He
would thus have been able to prescribe determinate limits
to the activities whereby the understanding and pure reason
extend themselves <1a priori.>1 Instead of so doing, he merely
<1restricts>1 the understanding, without defining its <1limits,>1 and
while creating a general mistrust fails to supply any deter-
minate knowledge of the ignorance which for us is un-
avoidable. For while subjecting to censorship certain prin-
ciples of the understanding, he makes no attempt to assess
the understanding itself, in respect of all its powers, by
the assay-balance of criticism; while rightly denying to the
understanding what it cannot really supply, he goes on to
deny it all power of extending itself <1a priori,>1 and this in
spite of his never having tested it as a whole. Thus the fate
that waits upon all scepticism likewise befalls Hume, namely,
that his own sceptical teaching comes to be doubted, as being
based only on facts which are contingent, not on principles A 768
which can constrain to a necessary renunciation of all right
to dogmatic assertions.
  Further, he draws no distinction between the well-
grounded claims of the understanding and the dialectical
pretensions of reason, though it is indeed chiefly against
the latter that his attacks are directed. Accordingly that
peculiarly characteristic ardour with which reason insists
upon giving free rein to itself, has not in the least been disturbed
but only temporarily impeded.  It does not feel that it has been
shut out from the field in which it is wont to disport itself;
and so, in spite of its being thwarted in this and that direc-
tion, it cannot be made entirely to desist from these ventures.
On the contrary, the attacks lead only to counter-preparations,
00042
and make us the more obstinate in insisting upon our own views.
But a complete review of all the powers of reason---and the
conviction thereby obtained of the certainty of its claims to a
modest territory, as also of the vanity of higher pretensions---
puts an end to the conflict, and induces it to rest satisfied with
a limited but undisputed patrimony.
  To the uncritical dogmatist, who has not surveyed the
sphere of his understanding, and therefore has not determined,
in accordance with principles, the limits of his possible know-
ledge, these sceptical attacks are not only dangerous but even
destructive. For he does not know beforehand how far his
powers extend, and indeed believes that their limits can be
determined by the simple method of trial and failure. In con-
sequence of this, if on being attacked there is a single one of
B 797 his assertions that he is unable to justify, or which involves
  illusion for which he also cannot account in terms of any
  principles, suspicion falls on all his contentions, however
  plausible they may appear.
  The sceptic is thus the taskmaster who constrains the dog-
  matic reasoner to develop a sound critique of the understand-
  ing and reason. When we have advanced thus far, we need
  fear no further challenge, since we have learned to distinguish
  our real possessions from thatwhich lies entirely outside them;
  and as we make no claims in regard to this latter domain,
  we cannot become involved in any dispute in respect to it.
  While, therefore, the sceptical procedure cannot of itself yield
  any <1satisfying>1 answer to the questions of reason, none the
  less it <1prepares the way>1 by arousing reason to circumspection,
  and by indicating the radical measures which are adequate
  to secure it in its legitimate possessions.
  CHAPTER I
  Section 3
  THE DISCIPLINE OF PURE REASON IN REGARD TO
  HYPOTHESES
  Since criticism of our reason has at last taught us that
  we cannot by means of its pure and speculative employment
  arrive at any knowledge whatsoever, may it not seem that a
00043
proportionately wider field is opened for <1hypotheses?>1 For are
we not at liberty, where we cannot make assertions, at least
to invent theories and to have opinions?
  If the imagination is not simply to be <1visionary,>1 but is to
be <1inventive >1 under the strict surveillance of reason, there must A 770
always previously be something that is completely certain, and
not invented or merely a matter of opinion, namely, the
<1possibility>1 of the object itself. Once that is established, it is
then permissible to have recourse to opinion in regard to its
actuality; but this opinion, if it is not to be groundless, must
be brought into connection with what is actually given and so
far certain, as serving to account for what is thus given. Then,
and only then, can the supposition be entitled an <1hypothesis.>1
  As we cannot form the least conception <1a priori>1 of the
possibility of dynamical connection, and as the categories
of the pure understanding do not suffice for devising any such
conception, but only for apprehending it when met with in
experience, we cannot, in accordance with these categories,
creatively imagine any object in terms of any new quality
that does not allow of being given in experience; and we
cannot, therefore, make use of such an object in any legiti-
mate hypothesis; otherwise we should be resting reason on
empty figments of the brain, and not on concepts of things.
Thus it is not permissible to invent any new original powers,
as, for instance, an understanding capable of intuiting its
objects without the aid of senses; or a force of attraction with-
out any contact; or a new kind of substance existing in space
and yet not impenetrable. Nor is it legitimate to postulate
a form of communion of substances which is different from
any revealed in experience, a presence that is not spatial, A 771
a duration that is not temporal. In a word, our reason can  B799
employ as conditions of the possibility of things only the
conditions of possible experience; it can never proceed to
form concepts of things quite independently of these con-
ditions.  Such concepts, though not self-contradictory, would
be without an object.
00044
  The concepts of reason are, as we have said, mere ideas,
and have no object that can be met with in any experience.
None the less they do not on this account signify objects
that having been invented are thereupon assumed to be
possible. They are thought only problematically, in order
that upon them (as heuristic fictions), we may base regu-
lative principles of the systematic employment of the under-
standing in the field of experience. Save in this connection
they are merely thought-entities, the possibility of which is
not demonstrable, and which therefore do not allow of being
employed, in the character of hypotheses, in explanation of
the actual appearances. It is quite permissible to <1think>1 the
soul as simple, in order, in conformity with this <1idea,>1 to employ
as the principle of our interpretation of its inner appearances
a complete and necessary unity of all its faculties; and this in
spite of the fact that this unity is such as can never be appre-
hended <1in concreto.>1 But to <1assume>1 the soul as a simple sub-
stance (a transcendent concept), would be [to propound] a
A 772 proposition which is not only indemonstrable---as is the case
  with many physical hypotheses---but is hazarded in a quite
  blind and arbitrary fashion. For the simple can never be
  met with in any experience whatsoever; and if by substance
  be here meant the permanent object of sensible intuition, the
  possibility of a <1simple appearance>1 is quite incomprehensible
  Reason does not afford any sufficient ground for assuming,
  [even] as a matter of opinion, merely intelligible beings, or
  merely intelligible properties of things belonging to the sen-
  sible world, although (as we have no concepts of their pos-
  sibility or impossibility) we also cannot lay claim to any insight
  that justifies us in dogmatically denying them.
  In the explanation of given appearances, no things or
  grounds of explanation can be adduced other than those
  which have been found to stand in connection with given
  appearances in accordance with the already known laws of the
  appearances. A <1transcendental hypothesis,>1 in which a mere
  idea of reason is used in explanation of natural existences
  would really be no explanation; so to proceed would be to
  explain something, which in terms of known empirical prin-
  ciples we do not understand sufficiently, by something which
00045
we do not understand at all. Moreover, the principle of such
an hypothesis would at most serve only for the satisfaction of
reason, not for the furtherance of the employment of the
understanding in respect of objects. Order and purposiveness
in nature must themselves be explained from natural grounds
and according to natural laws; and the wildest hypotheses, if B 801
only they are physical, are here more tolerable than a hyper-
physical hypothesis, such as the appeal to a divine Author,
assumed simply in order that we may have an explanation.
That would be a principle of <1ignava ratio;>1 for we should be
passing over all causes the objective reality of which, at least
as regards their possibility, can be ascertained in the course
of experience, in order to rest in a mere idea---an idea that is
very comforting to reason. As regards the absolute totality of
the ground of explanation of the series of these causes, such
totality need suggest no difficulty in respect of natural exist-
ences; since these existences are nothing but appearances, we
need never look to them for any kind of completeness in the
synthesis of the series of conditions.
  It can never be permissible, in the speculative employment
of reason, to resort to transcendental hypotheses, and to pre-
sume that we can make good the lack of physical grounds of
explanation by appealing to the hyperphysical. The objection
to such procedure is twofold: partly, that reason, so far from
being in the least advanced thereby, is cut off from all progress
in its own employment; partly, that this license would in the
end deprive reason of all the fruits that spring from the cul-
tivation of its own proper domain, namely, that of experience.
For whenever the explanation of natural existences is found
to be difficult, there is always at hand a transcendental ground
of explanation which relieves us from further investigation, A 774
and our enquiry is brought to an end not through insight, but
by the aid of a principle which while utterly incomprehensible
has from the start been so constructed as necessarily to con-
tain the concept of what is absolutely primordial.
  The second requirement for the admissibility of an hypo-
thesis is its adequacy in accounting <1a priori>1 for those con-
sequences which are <1[de facto]>1 given. If for this purpose we
have to call in auxiliary hypotheses, they give rise to the sus-
00046
picion that they are mere fictions; for each of them requires the
same justification as is necessary in the case of the fundamental
hypothesis, and they are not, therefore, in a position to bear
reliable testimony. If we assume an absolutely perfect cause,
we need not be at a loss in explaining the purposiveness, order,
and vastness which are displayed in the world; but in view of
what, judged at least by our concepts, are the obvious devia-
tions and evils, other new hypotheses are required in order to
uphold the original hypothesis in face of the objections which
these suggest.  If the simple self-sufficiency of the human soul
has been employed to account for its appearances, it is contro-
verted by certain difficulties, due to those phenomena which
are similar to the changes that take place in matter (growth
and decay), and we have therefore to seek the aid of new
hypotheses, which are not indeed without plausibility, but
A 775 which yet have no credentials save what is conferred upon
  them by that opinion---the fundamental hypothesis---which
  they have themselves been called in to support.
  If the instances here cited as examples of the assertions
  made by reason---the incorporeal unity of the soul and the
  existence of a supreme being---are propounded not as hypo-
  theses, but as dogmas proved <1a priori,>1 I am not at present
  concerned with them, save to remark that in that case care
  must be taken that the proof has the apodeictic certainty of a
  demonstration. For to set out to show no more than that the
  reality of such ideas is <1probable>1 is as absurd as to think of
  proving a proposition of geometry merely as a probability.
  Reason, when employed apart from all experience, can know
  propositions entirely <1a priori,>1 and as necessary, or it can know
  nothing at all. Its judgments, therefore, are never opinions;
  either it must abstain from all judgment, or must affirm with
  apodeictic certainty. Opinions and probable judgments as to
  belongs to things can be propounded only in explana-
  tion of what is actually given, or as consequences that follow-
  in accordance with empirical laws from what underlies the
  actually given. They are therefore concerned only with the
  series of the objects of experience. Outside this field, to form
  <1opinions>1 is merely to play with thoughts. For we should then
  have to presuppose yet another opinion---the opinion that we
  may perhaps arrive at the truth by a road that is uncertain.
00047
But although, in dealing with the merely speculative ques-
tions of pure reason, hypotheses are not available for the
purposes of basing propositions upon them, they are yet entirely
permissible for the purposes of defending propositions; that is
to say, they may not be employed in any dogmatic, but only in
polemical fashion. By the defence of propositions I do not
mean the addition of fresh grounds for their assertion, but
merely the nullifying of the sophistical arguments by which
our opponent professes to invalidate this assertion. Now all
synthetic propositions of pure reason have this peculiarity, that
while in asserting the reality of this or that idea we can never
have knowledge sufficient to give certainty to our proposition,
our opponent is just as little able to assert the opposite. This
equality of fortune [in the ventures] of human reason does not,
in speculative modes of knowledge, favour either of the two
parties, and it is consequently the fitting battle-ground for
their never-ending feuds. But as will be shown, reason has, in
respect of its <1practical employment,>1 the right to postulate what
in the field of mere speculation it can have no kind of right
to assume without sufficient proof. For while all such assump-
tions do violence to [the principle of] completeness of specu-
lation, that is a principle with which the practical interest is
not at all concerned. In the practical sphere reason has rights
of possession, of which it does not require to offer proof, and of
which, in fact, it could not supply proof. The burden of proof B 805
accordingly rests upon the opponent. But since the latter knows
just as little of the object under question, in trying to prove its
non-existence, as does the former in maintaining its reality,
it is evident that the former, who is asserting something as a
practically necessary supposition, is at an advantage <1(melior>1
<1est conditio possidentis).>1 For he is at liberty to employ, as it
were in self-defence, on behalf of his own good cause, the very
same weapons that his opponent employs against that cause,
that is, hypotheses. These are not intended to strengthen the
proof of his position, but only to show that the opposing party
has much too little understanding of the matter in dispute
to allow of his flattering himself that he has the advantage
in respect of speculative insight.
  Hypotheses are therefore, in the domain of pure reason,
permissible only as weapons of war, and only for the purpose
00048
of defending a right, not in order to establish it. But the oppos-
ing party we must always look for in ourselves. For specula-
tive reason in its transcendental employment is <1in itself>1
dialectical; the objections which we have to fear lie in our-
selves. We must seek them out, just as we would do in the
case of claims that, while old, have never become superannu-
ated, in order that by annulling them we may establish a
permanent peace. External quiescence is merely specious.
The root of these disturbances, which lies deep in the nature
B 778 of human reason, must be removed. But how can we do so,
A 806 unless we give it freedom, nay, nourishment, to send out
  shoots so that it may discover itself to our eyes, and that it
  may then be entirely destroyed? We must, therefore, bethink
  ourselves of objections which have never yet occurred to any
  opponent, and indeed lend him our weapons, and grant him
  the most favourable position which he could possibly desire.
  We have nothing to fear in all this, but much to hope for;
  namely, that we may gain for ourselves a possession which
  can never again be contested.
  Thus for our complete equipment we require among other
  things the hypotheses of pure reason. For although they are
  but leaden weapons, since they are not steeled by any law of ex-
  perience, they are yet as effective as those which our opponents
  can employ against us. If, therefore, having assumed (in some
  non-speculative connection) the nature of the soul to be im-
  material and not subject to any corporeal change, we are met
  by the difficulty that nevertheless experience seems to prove
  that the exaltation and the derangement of our mental powers
  are alike in being merely diverse modifications of our organs,
  we can weaken the force of this proof by postulating that our
  body may be nothing more than a fundamental appearance
  which in this our present state (in this life) serves as a condition
  of our whole faculty of sensibility, and therewith of all our
  thought, and that separation from the body may therefore
  be regarded as the end of this sensible employment of our
  faculty of knowledge and the beginning of its intellectual
A 779 employment. Thus regarded, the body would not be the cause
  of thought, but merely a restri tive condition of it, and there-
  fore, while indeed furthering the sensible and animal life, it
  would lecause of this very fact have to be sonsidered a hind-
00049
rance to the pure and spiritual life. The dependence of the
animal and sensible upon the bodily constitution would then
in nowise prove the dependence of our entire life upon the
state of our organs. We might go yet further, and discover
quite new objections, which either have never been suggested
or have never been sufficiently developed.
  Generation, in man as in non-rational creatures, is de-
pendent upon opportunity, often indeed upon sufficiency of
food, upon the moods and caprices of rulers, nay, even upon
vice. And this makes it very difficult to suppose that a creature
whose life has its first beginning in circumstances so trivial
and so entirely dependent upon our own choice, should have
an existence that extends to all eternity. As regards the con-
tinuance (here on earth) of the species as a whole, this diffi-
culty is negligible, since accident in the individual case is still
subject to a general law, but as regards each individual it
certainly seems highly questionable to expect so potent an
effect from causes so insignificant. But to meet these objec-
tions we can propound a transcendental hypothesis, namely,
that all life is, strictly speaking, intelligible only, is not sub-
jectto changes of time, and neither begins in birth nor ends B 808
in death; that this life is an appearance only, that is, a sen-
sible representation of the purely spiritual life, and that the
whole sensible world is a mere picture which in our present
mode of knowledge hovers before us, and like a dream has
in itself no objective reality; that if we could intuit our-
selves and things <1as they are,>1 we should see ourselves in
a world of spiritual beings, our sole and true community
with which has not begun through birth and will not cease
through bodily death---both birth and death being mere
appearances.
  Now of all this we have not the least knowledge. We plead
it only in hypothetical fashion, to meet the attack; we are not
actually asserting it. For it is not even an idea of reason, but
is a concept <1devised>1 merely for the purposes of self-defence.
None the less we are here proceeding in entire conformity
with reason. Our opponent falsely represents the absence of
empirical conditions as itself amounting to proof of the total
00050
impossibility of our belief, and is therefore proceeding on
the assumption that he has exhausted all the possibilities.
What we are doing is merely to show that it is just as little
possible for him to comprehend the whole field of possible
things through mere laws of experience as it is for us to reach,
outside experience, any conclusions justifiable for our reason.
Anyone who employs such hypothetical means of defence
A 781 against the rash and presumptuous negations of his opponent
  must not be considered to intend the adoption of these opinions
  as his own; he abandons them, as soon as he has disposed
  of the dogmatic pretensions of his opponent. For though
  a merely negative attitude to the assertions of others may
  seem very modest and moderate, to proceed to represent
  the objections to an assertion as proofs of the counter-asser-
  tion is to make claims no less presumptuous and visionary
  than if the positive position and its affirmations had been
  adopted.
  It is evident, therefore, that in the speculative employment
  of reason hypotheses, regarded as opinions, have no validity
  in themselves, but only relatively to the transcendent pre-
  tensions of the opposite party. For to make principles of pos-
  sible experience conditions of the possibility of things  in general
  is just as transcendent a procedure as to assert the objective
  reality of [transcendent] concepts, the objects of which can-
  not be found anywhere save outside the limits of all possible
  experience. What pure reason judges <1assertorically,>1 must
  (like everything that reason knows) be necessary; otherwise
  nothing at all is asserted Accordingly, pure reason does
  not, in point of fact, contain any opinions whatsoever. The
  hypotheses, above referred to, are merely <1problematic>1 judg-
  ments, which at least cannot be refuted, although they do
B 810 not indeed allow of any proof. They are therefore nothing
  but private opinions. Nevertheless, we cannot properly dis-
  pense with them as weapons against the misgivings which
  are apt to occur; they are necessary even to secure our inner
  tranquillity. We must preserve to them this character, care-
  fully guarding against the assumption of their independent
  authority or absolute validity, since otherwise they would
  drown reason in fictions and delusions.
00051
  CHAPTER I
  Section 4
THE DISCIPLlNE OF PURE REASON IN REGARD TO ITS
  PROOFS,
  What distinguishes the proofs of transcendental synthetic
propositions from all other proofs which yield an <1a priori>1
synthetic knowledge is that, in the case of the former, reason
may not apply itself, by means of its concepts, directly to the
object, but must first establish the objective validity of the
concepts and the possibility of their <1a priori>1 synthesis. This
rule is not made necessary merely by considerations of prud-
ence, but is essential to the very possibility of the proofs them-
selves. If I am to pass <1apriori>1 beyond the concept of an object,
I can do so only with the help of some special guidance,
supplied from outside this concept. In mathematics it is <1a>1
<1priori>1 intuition which guides my synthesis; and thereby all
our conclusions can be drawn immediately from pure intuition.  A 783
In transcendental knowledge, so long as we are concerned
only with concepts of the understanding, our guide is the
possibility of experience. Such proof does not show that the
given concept (for instance, of that which happens) leads
<1directly>1 to another concept (that of a cause); for such a transi-
tion would be a <1saltus>1 which could not be justified. The proof
proceeds by showing that experience itself, and therefore the
object of experience, would be impossible without a connec-
tion of this kind. Accordingly, the proof must also at the
same time show the possibility of arriving synthetically
and <1a priori>1 at some knowledge of things which was not
contained in the concepts of them. Unless this requirement
be met, the proofs, like streams which break their banks,
run wildly at random, whithersoever the current of hidden
association may chance to lead them. The semblance of con-
viction which rests upon subjective causes of association,
and which is regarded as insight into a natural affinity, can-
not balance the misgivings to which so hazardous a course
must rightly give rise. On this account, all attempts to prove
the principle of sufficient reason have, by the universal ad-
00052
mission of those concerned, been fruitless; and prior to our
own transcendental criticism it was considered better, since
that principle could not be surrendered, boldly to appeal to
the common sense of mankind---an expedient which always
A871  is a sign that the cause of reason is in desperate straits---
  rather than to attempt new dogmatic proofs.
  But if the proposition to be proved is an assertion of pure
  reason, and if I am therefore proposing to pass beyond my em-
  pirical concepts by means of mere ideas, justification of such a
  step in synthesis (supposing it to be possible) is all the more
  necessary as a precondition of any attemptto provethe proposi-
  tion itself. However plausible the alleged proof of the simple
  nature of our thinaing substance, derived from the unity of
  apperception, may be, it is faced by the unavoidable difficulty,
  that since the [notion of] absolute simplicity is not a concept
  which can be immediately related to a perception, but, as an
  idea, would have to be inferred, there can be no understanding
  how the bare consciousness (which is, or at least can be,
  contained <1in all thought),>1 though it is indeed so far a simple
  representation, should conduct us to the consciousness and the
  knowledge of <1a thing in which>1 thought alone can be contained.
  If I represent to myself the power of a body in motion, it is
  so far for me absolute unity, and my representation of it is
  simple; and I can therefore express this representation by the
  motion of a point---for the volume of the body is not here a
  relevant consideration, and can be thought, without diminution
  of the moving power, as small as we please, and therefore even
A 785 as existing in a point. But I may not therefore conclude that
  if nothing be given to me but the moving power of a body, the
  body can be thought as simple substance---merely because its
  representation abstracts from the magnitude of its volume
  and is consequently simple. The simple arrived at by abstrac-
  tion is entirely different from the simple as an object; though
  the "I', taken in abstraction, can contain <1in itself>1 no manifold,
  in its other meaning, as signifying the soul itself, it can be a
  highly complex concept, as containing <1under itself,>1 and as
  denoting, what is very composite. I thus detect in these
  arguments a paralogism  But in order to be armed against this
00053
paralogism (for without some forewarning we should not
entertain any suspicion in regard to the proof), it is indis-
pensably necessary to have constantly at hand a criterion of
the possibility of those synthetic propositions which are in-
tended to prove more than experience yields. This criterion
consists in the requirement that proof should not proceed
directly to the desired predicate but only by means of a prin-
ciple that will demonstrate the possibility of extending our
given concept in an <1a priori>1 manner to ideas, and of
realising the latter. If this precaution be always observed, if
before attempting any proof, we discreetly take thought as to
how, and with what ground for hope, we may expect such an
extension through pure reason, and whence, in such a case,
this insight, which is not developed from concepts, and B 787
also cannot be anticipated in reference to any possible ex-
perience, is yet to be derived, we can by so doing spare our-
selves much difficult and yet fruitless labour, not expecting
from reason what obviously exceeds its power---or rather, since
reason, when obsessed by passionate desire for the speculative
enlargement of its domain, is not easily to be restrained, by
subjecting it to the discipline of self-control.
  The first rule is, therefore, not to attempt any tran-
scendental proofs until we have considered, with a view to
obtaining justification for them, from what source we propose
to derive the principles on which the proofs are to be based,
and with what right we may expect success in our inferences.
If they are principles of the understanding (for instance, that of
causality), it is useless to attempt, by means of them, to attain
to ideas of pure reason; such principles are valid only for
objects of possible experience. If they are principles of pure
reason, it is again labour lost. Reason has indeed principles
of its own; but regarded as objective principles, they are one
and all dialectical, and can have no validity save as regulative
principles for its employment in experience, with a view to
making experience systematically coherent. But if such pro-
fessed proofs are propounded, we must meet their deceptive
power of persuasion with the <1non liquet>1 of our matured
judgment; and although we may not be able to detect the A 787
illusion involved, we are yet entirely within our rights in
demanding a deduction of the principles employed in them:
00054
and if these principles have their source in reason alone,
the demand is one which can never be met. And there is
thus no need for us to concern ourselves with the particular
nature and with the refutation of each and every ground-
less illusion; at the tribunal of a critical reason, which insists
upon laws, this entire dialectic, so inexhaustible in its artifices,
can be disposed of in bulk.
  The second peculiarity of transcendental proofs is that
only <1one>1 proof can be found for each transcendental proposi-
tion. If I am inferring not from concepts but from the intuition
which corresponds to a concept, be it a pure intuition as in
mathematics, or an empirical intuition as in natural science,
the intuition which serves as the basis of the inference supplies
me with manifold material for synthetic propositions, material
which I can connect in more than one way, so that, as it is
permissible for me to start from more than one point, I can
arrive at the same proposition by different paths.
  In the case of transcendental propositions, however, we
start always from <1one>1 concept only, and assert the synthetic
condition of the possibility of the object in accordance with
this concept. Since outside this concept there is nothing
further through which the object could be determined, there
A 871 can therefore be only one ground of proof. The proof can
  contain nothing more than the determination of an object in
  general in accordance with this one single concept. In the
  Transcendental Analytic, for instance, we derived the prin-
  ciple that everything which happens has a cause, from the
  condition under which alone a concept of happening in general
  is objectively possible---namely, by showing thatthe determina-
  tion of an event in time, and therefore the event as belonging
  to experience, would be impossible save as standing under such
  a dynamical rule. This is the sole possible ground of proof; for
  the event, in being represented, has objective validity, that is,
  truth, only in so far as an object is determined for the concept
  by means of the law of causality. Other proofs of this principle
  have, indeed, been attempted, for instance, from the con-
  tingency [of that which happens]. But on examining this
  argument, we can discover no mark of contingency save only
  the <1happening,>1 that is, the existence of the object preceded
  by its non-existence, and thus are brought back to the same
00055
ground of proof as before. Similarly, if the proposition, that
everything which thinks is simple, is to be proved, we leave
out of account the manifold of thought, and hold only to the
concept of the "I', which is simple and to which all thought
is related. The same is true of the transcendental proof of the
existence of God; it is based solely on the coincidence of the B789
concepts of the most real being and of necessary being, and
is not to be looked for anywhere else.
  This caution reduces the criticism of the assertions of
reason to very small compass. When reason is conducting
its business through concepts only, there is but one possible
proof, if, that is to say, there be any possible proof at all. If,
therefore, we observe the dogmatist coming forward with ten
proofs, we can be quite sure that he really has none. For had
he one that yielded---as must always be required in matters of
pure reason---apodeictic proof, what need would he have of
the others? His purpose can only be that of the parliamentary
advocate, who intends his various arguments for different
groups, in order to take advantage of the weakness of those
before whom he is pleading---hearers who, without entering
deeply into the matter, desire to be soon quit of it, and there-
fore seize upon whatever may first happen to attract their at-
tention, and decide accordingly.
  The third rule peculiar to pure reason, in so far as it is to
be subjected to a discipline in respect of transcendental proofs,
is that its proofs must never be <1apagogical,>1 but always <1osten->1
<1five.>1 The direct or ostensive proof, in every kind of knowledge,
is that which combines with the conviction of its truth insight
into the sources of its truth; the apagogical proof, on the other
hand, while it can indeed yield certainty, cannot enable us
to comprehend truth in its connection with the grounds of its
possibility. The latter is therefore to be regarded rather as a A790
last resort than as a mode of procedure which satisfies all the
requirements of reason. In respect of convincing power, it has,
however, this advantage over the direct proofs, that contradic-
tion always carries with it more clearness of representation than
the best connection, and so approximates to the intuitional
certainty of a demonstration.
  The real reason why apagogical proofs are employed in
00056
various sciences would seem to be this. When the grounds
from which this or that knowledge has to be derived are too
numerous or too deeply concealed, we try whether we may not
arrive at the knowledge in question through its consequences.
Now this <1modusponens,>1 that is, the inference to the truth of an
assertion from the truth of its consequences, is only permissible
when all its possible consequences are [known to be] true; for
in that case there is only one possible ground for this being
so, and that ground must also be true. But this procedure
is impracticable; to discover all possible consequences of
any given proposition exceeds our powers. None the less this
mode of reasoning is resorted to, although indeed with a cer-
tain special modification, when we endeavour to prove some-
thing merely as an hypothesis. The modification made is that
we admit the conclusion as holding according to analogy,
namely, on the ground that if all the many consequences
examined by us agree with an assumed ground, all other
possible consequences will also agree with it. But from the
B 781  nature of the argument, it is obvious that an hypothesis can
  never, on such evidence, be transformed into demonstrated
  truth. The <1modus tollens>1 of reasoning, which proceeds from
  consequences to their grounds, is not only a quite rigorous but
  also an extremely easy mode of proof. For if even a single false
  consequence can be drawn from a proposition, the proposition
  is itself false. Instead, then, as in an ostensive proof, of re-
  viewing the whole series of grounds that can lead us to the
  truth of a proposition, by means of a complete insight into its
  possibility, we require only to show that a single one of the
  consequences resulting from its opposite is false, in order to
  prove that this opposite is itself false, and that the proposition
  which we had to prove is therefore true.
  The apagogic method of proof is, however, permissible
  only in those sciences where it is impossible mistakenly to
  <1substitute>1 what is subjective in our representations for what is
  objective, that is, for the knowledge of that which is in the
  object. Where such substitution tends to occur, it must often
  happen that the opposite of a given proposition contradicts
  only the subjective conditions of thought, and not the object,
  or that the two propositions contradict each other only under
  a subjective condition which is falsely treated as being object-
00057
ive; the condition being false, both can be false, without it
being possible to infer from the falsity of the one to the truth of
the other.
  In mathematics this subreption is impossible; and it is A792
there, therefore, that apagogical proofs have their true place.
In natural science, where all our knowledge is based upon
empirical intuitions, the subreption can generally be guarded
against through repeated comparison of observations; but in
this field this mode of proof is for the most part of little im-
portance. The transcendental enterprises of pure reason,
however, are one and all carried on within the domain proper
to dialectical illusion, that is, within the domain of the sub-
jective, which in its premisses presents itself to reason, nay,
forces itself upon reason, as being objective. In this field, there-
fore, it can never be permissible, so far as synthetic propositions
are concerned, tojustify assertions by disproving their opposite.
For either this refutation is nothing but the mere representa-
tion of the conflict of the opposite opinion with the subjective
conditions under which alone anything can be conceived by
our reason, which does not in the least contribute to the dis-
proof of the thing itself-- just as, for instance, we must recog-
nise that while the unconditioned necessity of the existence of
a being is altogether inconceivable to us, and that every
speculative proof of a necessary supreme being is therefore
rightly to be opposed on <1subjective>1 grounds, we have yet no
right to deny the possibility of such a primordial being <1in>1
<1itself>1---or else both parties, those who adopt the affirmative
no less than those who adopt the negative position, have
been deceived by transcendental illusion, and base their asser-
tions upon an impossible concept of the object. In that case
we can apply the rule: <1non entis nulla sunt predicata;>1 that A793
is, all that is asserted of the object, whether affirmatively or
negatively, is erroneous, and consequently we cannot arrive
apagogically at knowledge of the truth through refutation of
the opposite. If, for instance, it be assumed that the sensible
world is given <1in itself>1 in its totality, it is <1false>1 that it must be
<1either>1 infinite in space <1or>1 finite and limited. Both contentions
are false. For appearances (as mere representations) which yet
arc to be given <1in themselves>1 (as objects) are something impos-
sible; and though the infinitude of this imaginary whole would
00058
indeed be unconditioned, it would contradict (since everything
in appearances is conditioned) the unconditioned determina-
tion of magnitude, [that is, of totality], which is presupposed
in the concept.
  The apagogic method of proof is the real deluding influ-
ence by which those who reason dogmatically have always held
their admirers. It may be compared to a champion who seeks
to uphold the honour and incontestable rights of his adopted
party by offering battle to all who would question them. Such
boasting proves nothing, however, in regard to the merits of the
issue but only in regard to the respective strength of the com-
batants, and this indeed only in respect of those who take the
offensive. The spectators, observing that each party is alter-
B 822 nately conqueror and conquered, are often led to have scep-
  tical doubts in regard to the very object of the dispute. They
  are not, however, justified in adopting such an attitude; it is
  sufficient to declare to the combatants: <1non defensoribus istis>1
  <1tempus eget.>1 Everyone must defend his position directly, by a
  legitimate proof that carries with it a transcendental deduction
  of the grounds upon which it is itself made to rest. Only when
  this has been done, are we in a position to decide how far its
  claims allow of rational justification. If an opponent relies on
  subjective grounds, it is an easy matter to refute him. The
  dogmatist cannot, however, profit by this advantage. His own
  judgments are, as a rule, no less dependent upon subjective
  influences; and he can himself in turn be similarly cornered by
  his opponent. But if both parties proceed by the direct method,
  <1either>1 they will soon discover the difficulty, nay, the impossi-
  bility, of showing ground for their assertions, and will be left
  with no resort save to appeal to some form of prescriptive
  authority; <1or>1 our criticism will easily discover the illusion to
  which their dogmatic procedure is due, compelling pure
  reason to relinquish its exaggerated pretensions in the realm
  of speculation, and to withdraw within the limits of its proper
  territory---that of practical principles.
00059
THE TRANSCENDENTAL DOCTRINE OF METHOD A795
  CHAPTER II
  THE CANON OF PURE REASON
IT is humiliating to human reason that it achieves nothing in
its pure employment, and indeed stands in need of a discipline
to check its extravagances, and to guard it against the decep-
tions which arise therefrom. But, on the other hand, reason
is reassured and gains self-confidence, on finding that it itself
can and must apply this discipline, and that it is not called
upon to submit to any outside censorship; and, moreover, that
the limits which it is compelled to set to its speculative employ-
ment likewise limit the pseudo-rational pretensions of all its
opponents, and that it can secure against all attacks whatever
may remain over from its former exaggerated claims. The
greatest and perhaps the sole use of all philosophy of pure
reason is therefore only negative; since it serves not as an
organon for the extension but as a discipline for the limitation
of pure reason, and, instead of discovering truth, has only the
modest merit of guarding against error.
  There must, however, be some source of positive modes of
knowledge which belong to the domain of pure reason, and
which, it may be, give occasion to error solely owing to mis-
understanding, while yet in actual fact they form the goal to- B 796
wards which reason is directing its efforts. How else can we
account for our inextinguishable desire to find firm footing
somewhere beyond the limits of experience? Reason has a pre-
sentiment of objects which possess a great interest for it. But
when it follows the path of pure speculation, in order to ap-
proach them, they fly before it. Presumably it may look for
better fortune in the only other path which still remains open
to it, that of its <1Practical>1 employment.
00060
  I understand by a canon the sum-total of the <1a priori>1 prin-
ciples of the correct employment of certain faculties of know-
ledge. Thus general logic, in its analytic portion, is a canon
for understanding and reason in general; but only in regard
to their form; it abstracts from all content. The transcendental
analytic has similarly been shown to be the canon of the pure
<1understanding;>1 for understanding alone is capable of true syn-
thetic modes of knowledge <1a priori.>1 But when no correct em-
ployment of a faculty of knowledge is possible there is no
canon. Now all synthetic knowledge through pure <1reason>1 in
its speculative employment is, as has been shown by the proofs
given, completely impossible. There is therefore no canon of
its speculative employment; such employment is entirely dia-
lectical. All transcendental logic is, in this respect, simply a
B 872 discipline. Consequently, if there be any correct employment
  of pure reason, in which case there must be a canon of its
  employment, the canon will deal not with the speculative but
  with the <1practical employment of reason.>1 This practical em-
  ployment of reason we shall now proceed to investigate.
  THE CANON OF PURE REASON
  Section 1
  THE ULTIMATE END OF THE PURE EMPLOYMENT OF
  OUR REASON
  Reason is impelled by a tendency of its nature to go out
  beyond the field of its empirical employment, and to venture
  in a pure employment, by means of ideas alone, to the utmost
  limits of all knowledge, and not to be satisfied save through
  the completion of its course in [the apprehension of] a self-
  subsistent systematic whole. Is this endeavour the outcome
  merely of the speculative interests of reason? Must we not
  rather regard it as having its source exclusively in the prac-
  tical interests of reason?
  I shall, for the moment, leave aside all question as to the
  success which attends pure reason in its speculative exercise,
  and enquire only as to the problems the solution of which
00061
constitutes its ultimate aim, whether reached or not, and in
respect of which all other aims are to be regarded only as
means. These highest aims must, from the nature of reason, B 826
have a certain unity, in order that they may, as thus unified,
further that interest of humanity which is subordinate to no
higher interest.
  The ultimate aim to which the speculation of reason in its
transcendental employment is directed concerns three objects:
the freedom of the will, the immortality of the soul, and the
existence of God. In respect of all three the merely speculative
interest of reason is very small; and for its sake alone we should
hardly have undertaken the labour of transcendental investiga-
tion---a labour so fatiguing in its endless wrestling with in-
superable difficulties---since whatever discoveries might be
made in regard to these matters, we should not be able to make
use of them in any helpful manner <1in concreto,>1 that is, in the
study or nature.  If the will be free, this can have a bearing only
on the intelligible cause of our volition. For as regards the phe-
nomena of it's outward expressions, that is, of our actions, we
must account for them---in accordance with a maxim which
is inviolable, and which is so fundamental that without it we
should not be able to employ reason in any empirical manner
whatsoever---in the same manner as all other appearances of
nature, namely, in conformity with unchangeable laws. If,
again, we should be able to obtain insight into the spiritual
nature of the soul, and therewith of its immortality, we could
make no use of such insight in explaining either the appear-
ances of this present life or the specific nature of a future B 827
state. For our concept of an incorporeal nature is merely nega-
tive, and does not in the least extend our knowledge, yielding
no sufficient material for inferences, save only such as are
merely fictitious and cannot be sanctioned by philosophy. If,
thirdly, the existence of a supreme intelligence be proved, by
its means we might indeed render what is purposive in the
constitution and ordering of the world comprehensible in a
general sort or way, but we should not be in the least war-
ranted in deriving from it any particular arrangement or dis-
position, or in boldly inferring any such, where it is not per-
ceived. For it is a necessary rule of the speculative employment
of reason, not to pass over natural causes, and, abandoning
00062
that in regard to which we can be instructed by experience, to
deduce something which we know from something which en-
tirely transcends all our [possible] knowledge. In short, these
three propositions are for speculative reason always tran-
scendent, and allow of no immanent employment---that is,
employment in reference to objects of experience, and so in
some manner really of service to us---but are in themselves,
notwithstanding the very heavy labours which they impose
upon our reason, entirely useless.
  If, then, thes  three cardinal propositions are not in any
way necessary for <1knowledge,>1 and are yet strongly recom-
B 828 mended by our reason, their importance, properly regarded,
  must concern only the <1practical.>1
  By "the practical' I mean everything that is possible
  through freedom. When, however, the conditions of the exer-
  cise of our free will are empirical, reason can have no other
  than a regulative employment in regard to it, and can serve
  only to effect unity in its empirical laws. Thus, for instance,
  in the precepts of prudence, the whole business of reason
  consists in uniting all the ends which are prescribed to us by
  our desires in the one single end, <1happiness,>1 and in co-
  ordinating the means for attaining it. In this field, therefore,
  reason can supply none <1butpragmatic>1 laws of free action, for
  the attainment of those ends which are commended to us by
  the senses; it cannot yield us laws that are pure and deter-
  mined completely <1apriori.>1 Laws of this latter type, pure prac-
  tical laws, whose end is given through reason completely <1a>1
  <1priori,>1 and which are prescribed to us not in an empirically
  conditioned but in an absolute manner, would be products of
  pure reason. Such are the <1moral>1 laws; and these alone, there-
  fore, belong to the practical employment of reason, and allow
  of a canon.
  The whole equipment of reason, in the discipline which
  may be entitled pure philosophy, is in fact determined with
  a view to the three above-mentioned problems. These, how-
  ever, themselves in turn refer us yet further, namely, to the
  problem <1what we ought to do,>1 if the will is free, if there is
A801 a God and a future world. As this concerns our attitude to
  the supreme end, it is evident that the ultimate intention
  of nature in her wise provision for us has indeed. in the
00063
constitution of our reason, been directed to moral interests
alone.
  But we must be careful, in turning our attention to an
object which is foreign a to transcendental philosophy, that we
do not indulge in digressions to the detriment of the unity of
the system, nor on the other hand, by saying too little on this
new topic, fail in producing conviction through lack of clear-
ness. I hope to avoid both dangers, by keeping as close as
possible to the transcendental, and by leaving entirely aside
any psychological, that is, empirical, factors that may per-
chance accompany it.
  I must first remark that for the present I shall employ the
concept of freedom in this practical sense only, leaving aside
that other transcendental meaning which cannot be empiric-
ally made use of in explanation of appearances, but is itself B 802













00001
a problem for reason, as has been already shown. A will is
purely <1animal (arbitrium brutum),>1 which cannot be deter-
mined save through sensuous impulses, that <1is,pathologically.>1
A will which can be determined independently of sensuous
impulses, and therefore through motives which are repre-
sented only by reason, is entitledfreewill <1(arbitrium liberum),>1
and everything which is bound up with this will, whether as
ground or as consequence, is entitled <1practical.>1 [The fact of]
practical freedom can be proved through experience. For the
human will is not determined by that alone which stimulates,
that is, immediately affects the senses; we have the power to
overcome the impressions on our faculty of sensuous desire, by
calling up representations of what, in a more indirect manner,
is useful or injurious. But these considerations, as to what is
desirable in respect of our whole state, that is, as to what is
good and useful, are based on reason.  Reason therefore provides
a All practical concepts relate to objects of satisfaction or dis-
satisfaction, that is, of pleasure and pain, and therefore, at least
indirectly, to the objects of our feelings. But as feeling is not a faculty
whereby we represent things, but lies outside our whole faculty of
knowledge, the elements of our judgments so far as they relate to
pleasure or pain, that is, the elements of practical judgments, do not
belong to transcendental philosophy, which is exclusively concemed
with pure <1a priori>1 modes of knowledge.
00002
laws which are imperatives, that is, <1objective laws offreedom,>1
which tell us <1what ought to happen>1---although perhaps it never
does happen---therein differing from <1laws of nature,>1 which
relate only to <1that which happens.>1 These laws are therefore to
be entitled practical laws.
A 803  Whether reason is not, in the actions through which it
  prescribes laws, itself again determined by other influences,
  and whether that which, in relation to sensuous impulses, is
  entitled freedom, may not, in relation to higher and more
  remote operating causes, be nature again, is a question which
  in the practical field does not concern us, since we are de-
  manding of reason nothing but the <1rule>1 of conduct; it is a
  merely speculative question, which we can leave aside so long
  as we are considering what ought or ought not to be done.
  While we thus through experience know practical freedom to
  be one of the causes in nature, namely, to be a causality of
  reason in the determination of the will, transcendental free-
  dom demands the independence of this reason---in respect of
  its causality, in beginning a series of appearances---from all
  determining causes of the sensible world.  Transcendental
  freedom is thus, as it would seem, contrary to the law of
  nature, and therefore to all possible experience; and so re-
  mains a problem. But this problem does not come within the
  province of reason in its practical employment; and we have
  therefore in a canon of pure reason to deal with only two
  questions, which relate to the practical interest of pure reason,
  and in regard to which a canon of its employment must be
  possible---Is there a God? and, Is there a future life? The
  question of transcendental freedom is a matter for speculative
A 804
B 832 knowledge only, and when we are dealing with the practical
  we can leave it aside as being an issue with which we have
  no concern. Moreover, a quite sufficient discussion of it is to
  be found in the antinomy of pure reason.
00003
  THE CANON OF PURE REASON
  Section 2
THE IDEAL OF THE HIGHEST GOOD, AS A DETERMINING
  GROUND OF THE ULTIMATE END OF PURE REASON
  Reason, in its speculative employment, conducted us
through the field of experience, and since it could not find
complete satisfaction there, from thence to speculative
ideas, which, however, in the end brought us back to experi-
ence. In so doing the ideas fulfilled their purpose, but in a
manner which, though useful, is not in accordance with our
expectation. One other line of enquiry still remains open to
us: namely, whether pure reason may not also be met with
in the practical sphere, and whether it may not there conduct
us to ideas which reach to those highest ends of pure reason
that we have just stated, and whether, therefore, reason may
not be able to supply to us from the standpoint of its practical
interest what it altogether refuses to supply in respect of its
speculative interest.
  All the interests of my reason, speculative as well as
practical, combine in the three following questions:
  I. What can I know?    A 805
  2. What ought I to do? B 833
  3. What may I hope?
  The first question is merely speculative. We have, as I
flatter myself, exhausted all the possible answers to it, and at
last have found the answer with which reason must perforce
content itself, and with which, so long as it takes no account of
the practical, it has also good cause to be satisfied. But from
the two great ends to which the whole endeavour of pure
reason was really directed, we have remained just as far re-
moved as if through love of ease we had declined this labour
of enquiry at the very outset. So far, then, as knowledge is
concerned, this much, at least, is certain and definitively
established, that in respect of these two latter problems, know-
ledge is unattainable by us.
  The second question is purely practical. As such it can
00004
indeed come within the scope of pure reason, but even so is not
transcendental but moral, and cannot, therefore, in and by
itself, form a proper subject for treatment in this Critique.
  The third question---If I do what I ought to do, what may
I then hope?---is at once practical and theoretical, in such
fashion that the practical serves only as a clue that leads us to
the answer to the theoretical question, and when this is followed
out, to the speculative question. For all <1hoping>1 is directed to
happiness, and stands in the same relation to the practical and
the law of morality as <1knowing and the law of nature>1 to the
B 806 theoretical knowledge of things. The former arrives finally
  at the conclusion that <1something is>1 (which determines the
  ultimate possible end) <1because something ought to happen;>1
  the latter, that <1something is>1 (which operates as the supreme
  cause) <1because something happens.>1
  Happiness is the satisfaction of all our desires, <1extensively,>1
  in respect of their manifoldness, <1intensively,>1 in respect of
  their degree, and <1protensively,>1 in respect of their duration.
  The practical law, derived from the motive of <1happiness,>1 I
  term pragmatic (rule of prudence), and that law, if there is
  such a law, which has no other motive than <1worthiness of>1
  <1being happy,>1 I term moral (law of morality). The former
  advises us what we have to do if we wish to achieve happiness;
  the latter dictates to us how we must behave in order to de-
  serve happiness. The former is based on empirical principles;
  for only by means of experience can I know what desires there
  are which call for satisfaction; or what those natural causes
  are which are capable of satisfying them. The latter takes no
  account of desires, and the natural means of satisfying them,
  and considers only the freedom of a rational being in general,
  and the necessary conditions under which alone this freedom
  can harmonise with a distribution of happiness that is made
  in accordance with principles. This latter law can therefore be
  based on mere ideas of pure reason, and known <1a priori.>1
B807  I assume that there really are pure moral laws which de-
  termine completely <1a priori>1 (without regard to empirical
  motives, that is, to happiness) what is and is not to be done,
  that is, which determine the employment of the freedom of a
  rational being in general; and that these laws command in an
  <1absolute>1 manner (not merely hypothetically, on the supposi-
00005
tion of other empirical ends), and are therefore in every respect
necessary. I am justified in making this assumption, in that I
can appeal not only to the proofs employed by the most en-
lightened moralists, but to the moral judgment of every man,
in so far as he makes the effort to think such a law clearly.
  Pure reason, then, contains, not indeed in its speculative
employment, but in that practical employment which is also  -
moral, principles of the <1possibility of experience,>1 namely, of
such actions as, in accordance with moral precepts, <1might>1 be
met with in the <1history>1 of mankind. For since reason com-
mands that such actions should take place, it must be possible
for them to take place. Consequently, a special kind of system-
atic unity, namely the moral, must likewise be possible.
We have indeed found that the systematic unity of nature
cannot be proved <1in accordance with speculative principles>1
<1of reason.>1 For although reason does indeed have causality in
respect of freedom in general, it does not have causality in
respect of nature as a whole; and although moral principles
of reason can indeed give rise to free actions, they cannot give
rise to laws of nature. Accordingly it is in their practical, B 806
meaning thereby their moral, employment, that the principles
of pure reason have objective reality.
  I entitle the world a <1moral world,>1 in so far as it may be in
accordance with all moral laws; and this is what by means of
the freedom of the rational being it <1can be,>1 and what according
to the necessary laws of morality it <1ought to be.>1 Owing to our
here leaving out of account all conditions (ends) and even all
the special difficulties to which morality is exposed (weakness
or depravity of human nature), this world is so far thought as
an intelligible world only. To this extent, therefore, it is a
mere idea, though at the same time a practical idea, which
really can have, as it also ought to have, an influence upon the
sensible world, to bring that world, so far as may be possible,
into conformity with the idea. The idea of a moral world has,
therefore, objective reality, not as referring to an object of an
intelligible intuition (we are quite unable to think any such
object), but as referring to the sensible world, viewed, however,
as being an object of pure reason in its practical employ-
ment, that is, as a <1corpus mysticum>1 of the rational beings in it,
so far as the free will of each being is, under moral laws, in
00006
complete systematic unity with itself and with the freedom
of every other.
  This is the answer to the first of the two questions of pure
reason that concern its practical interest:---<1Do that through>1
B 809 <1which thou becomest worthy to be happy.>1 The second question
  is:---If I so behave as not to be unworthy of happiness, may I
  hope thereby to obtain happiness? In answering this question
  we have to consider whether the principles of pure reason,
  which prescribe the law <1a priori,>1 likewise connect this hope
  necessarily with it.
  I maintain that just as the moral principles are necessary
  according to reason in its <1practical>1 employment, it is in the
  view of reason, in the field of its <1theoretical>1 employment, no
  less necessary to assume that everyone has ground to hope
  for happiness in the measure in which he has rendered himself
  by his conduct worthy of it, and that the system of morality
  is therefore inseparably---though only in the idea of pure
  reason---bound up with that of happiness.
  Now in an intelligible world, that is, in the moral world, in
  the concept of which we leave out of account all the hindrances
  to morality (the desires), such a system, in which happiness is
  bound up with and proportioned to morality, can be con-
  ceived as necessary, inasmuch as freedom, partly inspired and
  partly restricted by moral laws, would itself be the cause of
  general happiness, since rational beings, under the guidance
  of such principles, would themselves be the authors both of
  their own enduring well-being and of that of others. But such
A 810  system of self-rewarding morality is only an idea, the carry-
  ing out of which rests on the condition that <1everyone>1 does
  what he ought, that is, that all the actions of rational beings
  take place just as if they had proceeded from a supreme will
  that comprehends in itself, or under itself, all private wills.
  But since the moral law remains binding for every one in the
  use of his freedom, even although others do not act in con-
  formity with the law, neither the nature of the things of the
  world nor the causality of the actions themselves and their
  relation to morality determine how the consequences of these
  actions will be related to happiness. The alleged necessary
  connection of the hope of happiness with the necessary en-
  deavour to render the self worthy of happiness cannot there-
00007
fore be known through reason. It can be counted upon only if
a <1Supreme Reason,>1 that governs according to moral rules, be
likewise posited as underlying nature as its cause.
  The idea of such an intelligence in which the most perfect
moral will, united with supreme blessedness, is the cause of all
happiness in the world---so far as happiness stands in exact re-
lation with morality, that is, with worthiness to be happy---I
entitle the <1ideal of the supreme good.>1  It is, therefore, only in the
ideal of the supreme <1original>1 good that pure reason can find
the ground of this connection, which is necessary from the prac-
tical point of view, between the two elements of the supreme B 811
derivative good---the ground, namely, of an intelligible, that is,
moral world.  Now since we are necessarily constrained by reason
to represent ourselves as belonging to such a world, while the
senses present to us nothing but a world of appearances, we
must assume that moral world to be a consequence of our con-
duct in the world of sense (in which no such connection be-
tween worthiness and happiness is exhibited), and therefore to
be for us a future world. Thus God and a future life are two
postulates which, according to the principles of pure reason,
are inseparable from the obligation which that same reason
imposes upon us.
  Morality, by itself, constitutes a system. Happiness, how-
ever, does not do so, save in so far as it is distributed in exact
proportion to morality. But this is possible only in the intel-
ligible world, under a wise Author and Ruler. Such a Ruler,
together with life in such a world, which we must regard as a
future world, reason finds itself constrained to assume; other-
wise it would have to regard the moral laws as empty figments
of the brain, since without this postulate the necessary conse-
quence which it itself connects with these laws could not
follow. Hence also everyone regards the moral laws as <1com->1
<1mands;>1 and this the moral laws could not be if they did not
connect <1a priori>1 suitable consequences with their rules, and
thus carry with them <1promises>1 and <1threats.>1 But this again they
could not do, if they did not reside in a necessary being, as the A 812
supreme good, which alone can make such a purposive unit  B 840
possible.
  Leibniz entitled the world, in so far as we take account
only of the rational beings in it, and of their connection ac-
00008
cording to moral laws under the government of the supreme
good, <1the kingdom of grace,>1 distinguishing it from the <1king->1
<1dom of nature,>1 in which these rational beings do indeed stand
under moral laws, but expect no other consequences from
their actions than such as follow in accordance with the course
of nature in our world of sense. To view ourselves, therefore, as
in the world of grace, where all happiness awaits us, except in so
far as we ourselves limit our share in it through being unworthy
of happiness, is, from the practical standpoint, a necessary idea
of reason.
  Practical laws, in so far as they are subjective grounds of
actions, that is, subjective principles, are entitled <1maxims.>1 The
<1estimation>1 of morality, in regard to its purity and consequences,
is effected in accordance with <1ideas,>1 the <1observance>1 of its laws
in accordance with <1maxims.>1
  It is necessary that the whole course of our life be sub-
ject to moral maxims; but it is impossible that this should
happen unless reason connects with the moral law, which is a
mere idea, an operative cause which determines for such con-
duct as is in accordance with the moral law an outcome, either
A 813) in this or in another life, that is in exact conformity with our
  supreme ends. Thus without a God and without a world in-
  visible to us now but hoped for, the glorious ideas of morality
  are indeed objects of approval and admiration, but not springs
  of purpose and action. For they do not fulfil in its complete-
  ness that end which is natural to every rational being and
  which is determined <1a priori,>1 and rendered necessary, by that
  same pure reason.
  Happiness, taken by itself, is, for our reason, far from
  being the complete good. Reason does not approve happiness
  (however inclination may desire it) except in so far as it is united
  with worthiness to be happy, that is, with moral conduct.
  Morality, taken by itself, and with it, the mere <1worthiness>1 to
  be happy, is also far from being the complete good. To make
  the good complete, he who behaves in such a manner as not to
  be unworthy of happiness must be able to hope that he will
  participate in happiness. Even the reason that is free from all
  private purposes, should it put itself in the place of a being that
  had to distribute all happiness to others, cannot judge other-
  wise; for in the practical idea both elements are essentially
00009
connected, though in such a manner that it is the moral dis-
position which conditions and makes possible the participation
in happining, and not conversely the prospect of happiness
that makes possible the moral disposition. For in the latter
case the disposition would not be moral, and therefore would (A 814
not be worthy of complete happiness---happiness which in
the view of reason allows of no limitation save that which
arises from our own immoral conduct.
  Happiness, therefore, in exact proportion with the morality
of the rational beings who are thereby rendered worthy of it,
alone constitutes the supreme good of that world wherein, in
accordance with the commands of a pure but practical reason,
we are under obligation to place ourselves. This world is in-
deed an intelligible world only, since the sensible world holds
out no promise that any such systematic unity of ends can
arise from the nature of things. Nor is the reality of this unity
based on anything else than the postulate of a supreme ori-
ginal good. In a supreme good, thus conceived, self-subsistent
reason, equipped with all the sufficiency of a supreme cause,
establishes, maintains, and completes the universal order of
things, according to the most perfect design---an order which
in the world of sense is in large part concealed from us.
  This moral theology has the peculiar advantage over
speculative theology that it inevitably leads to the concept of
a <1sole, all-perfect,>1 and <1rational>1 primordial being, to which
speculative theology does not, on objective grounds, even so
much as <1point the way,>1 and as to the existence of which it is
still less capable of yielding any <1conviction.>1 For neither in
transcendental nor in natural theology, however far reason
may carry us, do we find any considerable ground for assum-
ing only some one single being which we should be justi- (A815
fied in placing prior to all natural causes, and upon which (B 843
we might make them in all respects dependent. On the
other hand, if we consider from the point of view of moral
unity, as a necessary law of the world, what the cause must
be that can alone give to this law its appropriate effect, and
so for us obligatory force, we conclude that there must be
one sole supreme will, which comprehends all these laws in
itself. For how, under different wills, should we find complete
00010
unity of ends. This Divine Being must be omnipotent, in
order that the whole of nature and its relation to morality
in the world may be subject to his will; omniscient, that
He Way know our innermost sentiments and their moral
worth; omnipresent, that He may be immediately at hand for
the satisfying of every need which the highest good demands;
eternal, that this harmony of nature and freedom may never
fail, etc.
  But this systematic unity of ends in this world of intelli-
gences---a world which is indeed, as mere nature, a sensible
world only, but which, as a system of freedom, can be entitled
an intelligible, that is, a moral world <1(regnumgratiae)>1---leads in-
evitably also to the purposive unity of all things, which constitute
this great whole, in accordance with universal laws of nature (just
  as the former unity is in accordance with universal and neces-
  sary laws of morality), and thus unites the practical with the
  speculative reason. The world must be represented as having
  A 816)  riginated from an idea if it is to be in harmony with that em-
  ployment of reason without which we should indeed hold our-
  selves to be unworthy of reason, namely, with the moral em-
  ployment---which is founded entirely on the idea of the supreme
  good- In this way all investigation of nature tends to take the
  form of a system of ends, and in its widest extension becomes a
  physico-theology.  But this, as it has its source in the moral order,
  as a unity grounded in freedom's own essential nature, and not
  accidentally instituted through external commands, connects
  the purposiveness of nature with grounds which must be
  inseparably connected <1a priori>1 with the inner possibility of
  things, and so leads to a <1transcendental theology->1--a theology
  which takes the ideal of supreme ontological perfection as a
  principle of systematic unity. And since all things have their
  origin in the absolute necessity of the one primordial being,
  that principle connects them in accordance with universal and
  necessary laws of nature.
  What <1use>1 can we make four understanding, even in re-
  spect of experience, if we do not propose ends to ourselves?
  But the highest ends are those of morality, and these we can
  know only as they are given us by pure reason. But though
  provided with these, and employing them as a clue, we cannot
  make use of the knowledge of nature in any serviceable manner
00011
in the building up of knowledge, unless nature has itself
shown unity of design. For without this unity we should our-
selves have no reason, inasmuch as there would be no school
for reason, and no fertilisation through objects such as might
afford materials for the necessary concepts. But the former
purposive unity is necessary, and founded on the will's own
essential nature, and this latter unity [of design in nature]
which contains the condition of its application <1in concreto,>1
must be so likewise. And thus the transcendental enlargement
of our knowledge, as secured through reason, is not to be
regarded as the cause, but merely as the effect of the practical
purposiveness which pure reason imposes upon us.
  Accordingly we find, in the history of human reason, that
until the moral concepts were sufficiently purified and deter-
mined, and until the systematic unity of their ends was under-
stood in accordance with these concepts and from necessary
principles, the knowledge of nature, and even a quite con-
siderable development of reason in many other sciences, could
give rise only to crude and incoherent concepts of the Deity,
or as sometimes happened resulted in an astonishing in-
difference in regard to all such matters. A greater preoccupa-
tion with moral ideas, which was rendered necessary by the
extraordinarily pure moral law of our religion, made reason
more acutely aware of its object, through the interest which it
was compelled to take in it. And this came about, independ-
ently of any influence exercised by more extended views of
nature or by correct and reliable transcendental insight (for
that has always been lacking). It was the moral  ideas that gave  A 818
rise to that concept of the Divine Being which we now hold
to be correct---and we so regard it not because speculative
reason convinces us of its correctness, but because it com-
pletely harmonises with the moral principles of reason. Thus it
is always only to pure reason, though only in its practical
employment, that we must finally ascribe the merit of having
connected with our highest interest a knowledge which reason
can think only, and cannot establish, and of having thereby
shown it to be, not indeed a demonstrated dogma, but a
postulate which is absolutely necessary in view of what are
reason's own most essential ends.
00012
  But when practical reason has reached this goal, namely,
the concept of a sole primordial being as the supreme good,
it must not presume to think that it has raised itself above all
empirical conditions of its application, and has attained to an
immediate knowledge of new objects, and can therefore I start
from this concept, and can deduce from it the moral laws
themselves. For it is these very laws that have led us, in virtue
of their <1inner>1 practical necessity, to the postulate of a self-
sufficient cause, or of a wise Ruler of the world, in order that
through such agency effect may be given to them. We may
not, therefore, in reversal of such procedure, regard them as
accidental and as derived from the mere will of the Ruler,
A  19) especially as we have no conception of such a will, except as
  formed in accordance with these laws. So far, then, as prac-
  tical reason has the right to serve as our guide, we shall not
  look upon actions as obligatory because they are the commands
  of God, but shall regard them as divine commands because
  we have an inward obligation to them. We shall study freedom
  according to the purposive unity that is determined in accord-
  ance with the principles of reason, and shall believe ourselves
  to be acting in conformity with the divine will in so far only
  as we hold sacred the moral law which reason teaches us from
  the nature of the actions themselves; and we shall believe that
  we can serve that will only by furthering what is best in the
  world, alike in ourselves and in others. Moral theology is thus
  of immanent use only. It enables us to fulfil our vocation in
  this present world by showing us how to adapt ourselves to the
  system of all ends, and by warning us against the fanaticism,
  and indeed the impiety, of abandoning the guidance of a
  morally legislative reason in the right conduct of our lives, in
  order to derive guidance directly from the idea of the Supreme
  Being. For we should then be making a transcendent em-
  ployment of moral theology; and that, like a transcendent use
  of pure speculation, must pervert and frustrate the ultimate
  ends of reason.
00013
THE CANON OF PURE REASON  B 208
  Section 3
OPINING, KNOWING, AND BELIEVING
The holding of a thing to be true is an occurrence in our
understanding which, though it may rest on objective grounds,
also requires subjective causes in the mind of the individual
who makes thejudgment. If the judgment is valid for everyone,
provided only he is in possession of reason, its ground is ob-
jectively sufficient, and the holding of it to be true is entitled
<1conviction>1.  If it has its ground only in the special character of
the subject, it is entitled <1persuasion.>1
  Persuasion is a mere illusion, because the ground of the
judgment, which lies solely in the subject, is regarded as objec-
tive. Such a judgment has only private validity, and the hold-
ing of it to be true does not allow of being communicated.
But truth depends upon agreement with the object, and in re-
spect of it the judgments of each and every understanding
must therefore be in agreement with each other <1(consentientia>1
<1uni tertio, consentiunt inter se).>1 The touchstone whereby we
decide whether our holding a thing to be true is conviction
or mere persuasion is therefore external, namely, the possi-
bility of communicating it and of finding it to be valid for all
human reason. For there is then at least a presumption that
the ground of the agreement of all judgments with each other,  A 821
notwithstanding the differing characters of individuals rests  B 849
upon the common ground, namely, upon the object, and that
it is for this reason that they are all in agreement with the
object---the truth of the judgment being thereby proved.
  So long, therefore, as the subjectviews the judgment merely
as an appearance of his mind, persuasion cannot be subject-
ively distinguished from conviction. The experiment, how-
ever, whereby we test upon the understanding of others
whether those grounds of the judgment which are valid for us
have the same effect on the reason of others as on our own, is
a means, although only a subjective means, not indeed of pro-
ducing conviction, but of detecting any merely private validity
00014
in the judgment, that is, anything in it which is mere per-
suasion.
  If, in addition, we can specify the subjective <1causes>1 of the
judgment, which we have taken as being its objective <1grounds,>1
and can thus explain the deceptive judgment as an event in
our mind, and can do so without having to take account of the
character of the object, we expose the illusion and are no longer
deceived by it, although always still in some degree liable to
come under its influence, in so far as the subjective cause of
the illusion is inherent in our nature.
  I cannot <1assert>1 anything, that is, declare it to be a judg-
ment necessarily valid for everyone, save as it gives rise to
  B 8822) conviction. Persuasion I can hold to on my own account, if it
  so pleases me, but I cannot, and ought not, to profess to
  impose it as binding on anyone but myself.
  The holding of a thing to be true, or the subjective validity
  of the judgment, in its relation to conviction (which is at the
  same time objectively valid), has the following three degrees:1
  <1opining, believing,>1 and <1knowing. Opining>1 is such holding of a
  judgment as is consciously insufficient, not only objectively,
  but also subjectively. If our holding of the judgment be only
  subjectively sufficient, and is at the same time taken as being
  objectively insufficient, we have what is termed <1believing.>1
  Lastly, when the holding of a thing to be true is sufficient
  both subjectively and objectively, it is <1knowledge.>1 The sub-
  jective sufficiency is termed <1conviction>1 (for myself), the
  objective sufficiency is termed <1certainty>1 (for everyone).
  There is no call for me to spend further time on the ex-
  planation of such easily understood terms.
  I must never presume to <1opine,>1 without <1knowing at least>1
  <1something>1 by means of which the judgment, in itself merely
  problematic, secures connection with truth, a connection
  which, although not complete, is yet more than arbitrary
  fiction. Moreover, the law of such a connection must be cer-
  tain. For if, in respect of this law also, I have nothing but
  opinion, it is all merely a play of the imagination, without the
  least relation to truth. Again, <1opining>1 is not in any way per-
  missible in judging by means of pure reason. For since such
  B 88231) judging is not based on grounds of experience, but being in
00015
every case necessary has all to be arrived at <1a priori,>1 the prin-
ciple of the connection requires universality and necessity, and
therefore complete certainty; otherwise we should have no
guidance as to truth. Hence it is absurd to have an opinion
in pure mathematics; either we must know, or we must
abstain from all acts of judgment. It is so likewise in the case
of the principles of morality, since we must not venture upon
an action on the mere opinion that it is <1allowed,>1 but must
know it to be so.
  In the transcendental employment of reason, on the other
hand, while opining is doubtless too weak a term to be ap-
plicable, the term knowing is too strong. In the merely specu-
lative sphere we cannot therefore make any judgments what-
soever. For the subjective grounds upon which we may hold
something to be true, such as those which are able to produce
belief, are not permissible in speculative questions, inasmuch
as they do not hold independently of all empirical support,
and do not allow of being communicated in equal measure to
others.
  But it is only from a <1practicalpoint of view>1 that the theo-
retically insufficient holding of a thing to be true can be
termed believing. This practical point of view is either in
reference to <1skill>1 or in reference to <1morality,>1 the former being
concerned with optional and contingent ends, the latter with
ends that are absolutely necessary.
  Once an end is accepted, the conditions of its attainment
are hypothetically necessary. This necessity is subjectively,
but still only comparatively, sufficient, if I anow of no other B 824
conditions under which the end can be attained. On the other
hand, it is sufficient, absolutely and for everyone, if I know
with certainty that no one can have knowledge of any other
conditions which lead to the proposed end. In the former case
my assumption and the holding of certain conditions to be
true is a merely contingent belief; in the latter case it is a
necessary belief.1 The physician must do something for a
patient in danger, but does not know the nature of his illness.
He observes the symptoms, and if he can find no more liaely
alternative, judges it to be a case of phthisis.  Now even in his
own estimation his belief is contingent only; another observer
00016
might perhaps come to a sounder conclusion. Such contingent
belief, which yet forms the ground for the actual employment
of means to certain actions, I entitle <1pragmatic belief.>1
  The usual touchstone, whether that which someone asserts
is merely his persuasion---or at least his subjective conviction,
that is, his firm belief---is <1betting.>1 It often happens that some-
one propounds his views with such positive and uncompromis-
ing assurance that he seems to have entirely set aside all
thought of possible error. A bet disconcerts him. Sometimes
it turns out that he has a conviction which can be estimated at
a value of one ducat, but not of ten. For he is very willing to
venture one ducat, but when it is a question of ten he becomes
B 85 ) aware, as he had not previously been, that it may very well be
" that he is in error. If, in a given case, we represent ourselves
  as staking the happiness of our whole life, the triumphant
  tone of our judgment is greatly abated; we become extremely
  diffident, and discover for the first time that our belief does not
  reach so far. Thus pragmatic belief always exists in some
  specific degree, which, according to differences in the interests
  at stake, may be large or may be small.
  But in many cases, when we are dealing with an object
  about which nothing can be done by us, and in regard to which
  our judgment is therefore purely theoretical, we can conceive
  and picture to ourselves an attitude for which we regard
  ourselves as having sufficient grounds, while yet there is no
  existing means of arriving at certainty in the matter. Thus
  even in purely theoretical judgments there is an <1analogon>1
  <1of practical>1 judgments, to the mental entertaining of which
  the term <1"belief'>1 is appropriate, and which we may entitle
  <1doctrinal belief.>1 I should be ready to stake my all on the con-
  tention---were it possible by means of any experience to settle
  the question---that at least one of the planets which we see is
  inhabited. Hence I say that it is not merely opinion, but a
  strong belief, on the correctness of which I should be prepared
  to run great risks, that other worlds are inhabited.
  B 8  )  Now we must admit that the doctrine of the existence of
  God belongs to doctrinal belief. For as regards theoretical
  knowledge of the world, I can <1cite>1 nothing which necessarily
  presupposes this thought as the condition of my explanations
00017
yet does so without my being in a position to give a specu-
lative account of it.
  But the merely doctrinal belief is somewhat lacking in
stability; we often lose hold of it, owing to the speculative
B 8826) difficulties which we encounter, although in the end we
  always inevitably return to it.
  It is quite otherwise with <1moral belief.>1 For here it is abso-
  lutely necessary that something must happen, namely, that I
  must in all points conform to the moral law. The end is here
  irrefragably established, and according to such insight as I
  can have, there is only one possible condition under which this
  end can connect with all other ends, and thereby have prac-
  tical validity, namely, that there be a God and a future world.
  I also know with complete certainty that no one can be ac-
  quainted with any other conditions which lead to the same
  unity of ends under the moral law. Since, therefore, the moral
  precept is at the same time my maxim (reason prescribing that
  it should be so), I inevitably believe in the existence of God
  and in a future life, and I am certain that nothing can shake
  this belief, since my moral principles would thereby be them-
  selves overthrown, and I cannot disclaim them without be-
  coming abhorrent in my own eyes.
  Thus even after reason has failed in all its ambitious at-
  tempts to pass beyond the limits of all experience, there is
  still enough left to satisfy us, so far as our practical stand-
  point is concerned. No one, indeed, will be able to boast
B 8 97) that he <1knows>1 that there is a God, and a future life; if he
  knows this, he is the very man for whom I have long [and
  vainly] sought. All knowledge, if it concerns an object of
  mere reason, can be communicated; and I might therefore
  hope that under his instruction my own knowledge would be
  extended in this wonderful fashion. No, my conviction is not
  <1logical,>1 but <1moral>1 certainty; and since it rests on subjective
  grounds (of the moral sentiment), I must not even say, <1"It is>1
  morally certain that there is a God, etc.', but "I <1am>1 morally
  certain, etc.' In other words, belief in a God and in another
  world is so interwoven with my moral sentiment that as there
  is little danger of my losing the latter, there is equally little
  cause for fear that the former can ever be taken from me.
00018
The only point that may seem questionable is the basing
of this rational belief on the assumption of moral sentiments.
If we leave these aside, and take a man who is completely
indifferent with regard to moral laws, the question propounded
by reason then becomes merely a problem for speculation,
and can, indeed, be supported by strong grounds of analogy,
but not by such as must compel the most stubborn scepticism
to give way.a But in these questions no man is free from all (B 83o8
interest. For although, through lack of good sentiments, he
may be cut off from moral interest, still even in this case
enough remains to make him <1fear>1 the existence of a God
and a future life. Nothing more is required for this than that
he at least cannot pretend that there is any <1certainty>1 that
there is <1no>1 such being and <1no>1 such life. Since that would have
to be proved by mere reason, and therefore apodeictically, he
would have to prove the impossibility of both, which assuredly
no one can reasonably undertake to do. This may therefore
serve as <1negative>1 belief, which may not, indeed, give rise to
morality and good sentiments, but may still give rise to an
analogon of these, namely, a powerful check upon the out-
break of evil sentiments.
in opening up prospects beyond the limits of experience?
Nothing more than two articles of belief? Surely the common
understanding could have achieved as much, without appeal- (B 8831
ing to philosophers for counsel in the matter
  I shall not here dwell upon the service which philosophy
has done to human reason through the laborious efforts of its
criticism, granting even that in the end it should turn out to
be merely negative; something more will be said on this point
in the next section. But I may at once reply: Do you really
  a  The human mind (as, I likewise believe, must necessarily be the
case with every rational being) takes a natural interest in morality, (  30
although this interest is not undivided and practically preponderant.
If we confirm and increase this interest, we shall find reason very
teachable and in itself more enlightened as regards the uniting of the
speculative with the practical interest. But if we do not take care that we first make men good, at
least make some measure good, we shall never
make honest believers of them.
00019
should transcend the common understanding, and should only
be revealed to you by philosophers? Precisely what you find
fault with is the best confirmation of the correctness of the
above assertions. For we have thereby revealed to us, what
could not at the start have been foreseen, namely, that in
matters which concern all men without distinction nature is
not guilty of any partial distribution of her gifts, and that in
regard to the essential ends of human nature the highest
philosophy cannot advance further than is possible under the
guidance which nature has bestowed even upon the most
ordinary understanding.
00020
THE TRANSCENDENTAL DOCTRINE OF METHOD (B 8632
  CHAPTER III
  THE ARCHITECTONIC OF PURE REASON
BY an architectonic I understand the art of constructing sys-
tems. As systematic unity is what first raises ordinary know-
ledge to the rank of science, that is, makes a system out of a
mere aggregate of knowledge, architectonic is the doctrine of
the scientific in our knowledge, and therefore necessarily
forms part of the doctrine of method.
  In accordance with reason's legislative prescriptions, our
diverse modes of knowledge must not be permitted to be a
mere rhapsody, but must form a system. Only so can they
further the essential ends of reason. By a system I understand
the unity of the manifold modes of knowledge under one idea.
This idea is the concept provided by reason---of the form of a
whole---in so far as the concept determines <1a priori>1 not only
the scope of its manifold content, but also the positions which
the parts occupy relatively to one another. The scientific con-
cept of reason contains, therefore, the end and the form of that
whole which is congruent with this requirement. The unity of
the end to which all the parts relate and in the idea of which
they all stand in relation to one another, makes it possible for
us to determine from our anowledge of the other parts whether
any part be missing, and to prevent any arbitrary addition, or (B 886331
in respect of its completeness any indeterminateness that does
not conform to the limits which are thus determined <1a priori.>1
The whole is thus an organised unity <1(articulatio),>1 and not an
aggregate <1(coacervatio).>1 It may grow from within <1(per intus->1
<1susceptionem),>1 but not by external addition <1(per appositionem).>1
It is thus like an animal body, the growth of which is not by
00021
the addition of a new member, but by the rendering of each
member, without change of proportion, stronger and more
effective for its purposes.
  The idea requires for its realisation a <1schema,>1 that is, a
constituent manifold and an order of its parts, both of which
must be determined <1a priori>1 from the principle defined by its
end. The schema, which is not devised in accordance with an
idea, that is, in terms of the ultimate aim of reason, but em-
pirically in accordance with purposes that are contingently
occasioned (the number of which cannot be foreseen) yields
<1technical>1 unity; whereas the schema which originates from an
idea (in which reason propounds the ends <1a priori,>1 and does
not wait for them to be empirically given) serves as the basis
of <1architectonic>1 unity. Now that which we call science, the
schema of which must contain the outline <1(monogramma)>1 and
B 8634 the division of the whole into parts, in conformity with the
  idea, that is, <1apriori,>1 and in so doing must distinguish it with
  certainty and according to principles from all other wholes, is
  not formed in technical fashion, in view of the similarity of
  its manifold constituents or of the contingent use of our know-
  ledge <1in concreto>1 for all sorts of optional external ends, but in
  architectonic fashion, in view of the affinity of its parts and of
  their derivation from a single supreme and inner end, through
  which the whole is first made possible.
  No one attempts to establish a science unless he has an
  idea upon which to base it. But in the working out of the
  science the schema, nay even the definition which, at the start,
  he first gave of the science, is very seldom adequate to his idea.
  For this idea lies hidden in reason, like a germ in which the
  parts are still undeveloped and barely recognisable even under
  microscopic observation. Consequently, since sciences are de-
  vised from the point of view of a certain universal interest,
  we must not explain and determine them according to the
  description which their founder gives of them, but in con-
  formity with the idea which, out of the natural unity of the
  parts that we have assembled, we find to be grounded in
  reason itself. For we shall then find that its founder, and often
  even his latest successors, are groping for an idea which they
  have never succeeded in making clear to themselves, and that
00022
consequently they have not been in a position to determine the
proper content, the articulation (systematic unity), and limits
of the science.
  It is unfortunate that only after we have spent much time
in the collection of materials in somewhat random fashion at
the suggestion of an idea lying hidden in our minds, and after
we have, indeed, over a long period assembled the materials in
a merely technical manner, does it first become possible for (A 835
us to discern the idea in a clearer light, and to devise a whole
architectonically in accordance with the ends of reason.
Systems seem to be formed in the manner of lowly organisms 1
through a <1generatio aequivoca>1 from the mere confluence of
assembled concepts, at first imperfect, and only gradually
attaining to completeness, although they one and all have had
their schema, as the original germ, in the sheer self-develop-
ment of reason. Hence, not only is each system articulated in
accordance with an idea, but they are one and all organically
united in a system of human knowledge, as members of one
whole, and so as admitting of an architectonic of all human
knowledge, which, at the present time, in view of the great
amount of material that has been collected, or which can be
obtained from the ruins of ancient systems, is not only pos-
sible, but would not indeed be difficult. We shall content our-
selves here with the completion of our task, namely, merely to
outline the <1architectonic>1 of all knowledge arising from <1pure>1
<1reason;>1 and in doing so we shall begin from the point at which
the common root of our faculty of knowledge divides and
throws out two stems, one of which is <1reason.>1 By reason I here
understand the whole higher faculty of knowledge, and am
therefore contrasting the rational with the empirical.
  If I abstract From all the content of knowledge, objectively
regarded, then all knowledge, subjectively regarded, is either (B 8
historical or rational. Historical knowledge is <1cognitio ex datis;>1
rational knowledge is <1cognitio ex principiis.>1 However a mode
of knowledge may originally be given, it is still, in relation to
the individual who possesses it, simply historical, if he knows
only so much of it as has been given to him from outside (and
this in the form in which it has been given to him), whether
through immediate experience or narration, or (as in the case
00023
of general knowledge) through instruction. Anyone, therefore,
who has <1learnt>1 (in the strict sense of that term) a system of
philosophy, such as that of Wolff, although he may have all
its principles, explanations, and proofs, together with the
formal divisions of the whole body of doctrine, in his head,
and, so to speak, at his fingers' ends, has no more than a
complete <1historical>1 knowledge of the Wolffian philosophy.
He knows and judges only what has been given him. If we
dispute a definition, he does not know whence to obtain
another. He has formed his mind on another's, and the imi-
tative faculty is not itself productive. In other words, his
  knowledge has not in him arisen <1out>1 of reason, and although,
  objectively considered, it is indeed knowledge due to reason,
  it is yet, in its subjective character, merely historical. He has
  grasped and kept; that is, he has learnt well, and is merely
  a plaster-cast of a living man. Modes of rational knowledge
  which are rational objectively (that is, which can have their
  first origin solely in human reason) can be so entitled sub-
  jectively also, only when they have been derived from uni-
  B 8637) versal sources of reason, that is, from principles---the sources
  from which there can also arise criticism, nay, even the rejec-
  tion of what has been learnt.
  All knowledge arising out of reason is derived either from
  concepts or from the construction of concepts. The former is
  called philosophical, the latter mathematical. I have already
  treated of the fundamental difference between these two modes
  of knowledge in the first chapter [of this Transcendental Doc-
  trine of Method]. Knowledge [as we have just noted] can be
  objectively philosophical, and yet subjectively historical, as is
  the case with most novices, and with all those who have never
  looked beyond their School, and who remain novices all their
  lives. But it is noteworthy that mathematical knowledge, in its
  subjective character, and precisely as it has been learned, can
  also be regarded as knowledge arising out of reason, and that
  there is therefore in regard to mathematical knowledge no such
  distinction as we have drawn in the case of philosophical know-
  ledge. This is due to the fact that the sources of knowledge,
  from which alone the teacher can derive his knowledge, lie no-
  where but in the essential and genuine principles of reason, and
  consequently cannot be acquired by the novice from any other
00024
source, and cannot be disputed; and this, in turn, is owing to
the fact that the employment of reason is here <1in concreto>1 only,
although likewise <1a priori,>1 namely, in intuition which is pure,
and which precisely on that account is infallible, excluding
all illusion and error. Mathematics, therefore, alone of all the
sciences <1(a priori)>1 arising from reason, can be learned; philo-
sophy can never be learned, save only in historical fashion;
as regards what concerns reason, we can at most learn to
<1philosophise.>1
  <1Philosophy>1 is the system of all philosophical knowledge (A 838
If we are to understand by it the archetype for the estimation
of all attempts at philosophising, and if this archetype is to
serve for the estimation of each subjective philosophy, the struc-
ture of which is often so diverse and liable to alteration, it must
be taken objectively. Thus regarded, philosophy is a mere idea
of a possible science which nowhere exists <1in concreto,>1 but to
which, by many different paths, we endeavour to approximate,
until the one true path, overgrown by the products of sen-
sibility, has at last been discovered, and the image, hitherto
so abortive, has achieved likeness to the archetype, so far as
this is granted to [mortal] man. Till then we cannot learn
philosophy; for where is it, who is in possession of it, and how
shall we recognise it? We can only learn to philosophise, that
is, to exercise the talent of reason, in accordance with its
universal principles, on certain actually existing attempts at
philosophy, always, however, reserving the right of reason to
investigate, to confirm, or to reject these principles in their
very sources.
  Hitherto the concept of philosophy has been a merely schol-
astic concept---a concept of a system of knowledge which is
sought solely in its character as a science, and which has there-
fore in view only the systematic unity appropriate to science,
and consequently no more thanthe <1logical>1 perfection of know-
ledge. But there is likewise another concept of philosophy, a
<1conceptus cosniicus,>1 which has always formed the real basis of
the term "philosophy', especially when it has been as it were
personified and its archetype represented in the ideal <1philo->1 (B 8639
<1sopher.>1 On this view, philosophy is the science of the relation
of all knowledge to the essential ends of human reason
00025
<1(teleologia rationis humanae),>1 and the philosopher is not an
artificer in the field of reason, but himself the lawgiver of
human reason.  In this sense of the term it would be very
vainglorious to entitle oneself a philosopher, and to pretend
to have equalled the pattern which exists in the idea alone.
  The mathematician, the natural philosopher, and the
logician, however successful the two former may have been in
their advances in the field of rational knowledge, and the two
latter more especially in philosophical knowledge, are yet only
artificers in the field of reason. There is a teacher, [conceived]
in the ideal, who sets them their tasks, and employs them as
instruments, to further the essential ends of human reason.
Him alone we must call philosopher; but as he nowhere exists,
while the idea of his legislation is to be found in that reason
with which every human being is endowed, we shall keep
entirely to the latter, determining more precisely what philo-
sophy prescribes as regards systematic unity, in accordance
A 540) with this cosmical concept,a from the standpoint of its essential
  ends.
  Essential ends are not as such the highest ends; in view
  of the demand of reason for complete systematic unity, only
  one of them can be so described. Essential ends are therefore
  either the ultimate end or subordinate ends which are neces-
  sarily connected with the former as means. The former is no
  other than the whole vocation of man, and the philosophy
  which deals with it is entitled moral philosophy. On account
  of this superiority which moral philosophy has over all other
  occupations of reason, the ancients in their use of the term
  "philosopher' always meant, more especially, the <1moralist;>1 and
  even at the present day we are led by a certain analogy to
  entitle anyone a philosopher who appears to exhibit self-control
  under the guidance of reason, however limited his knowledge
  may be.
  The legislation of human reason (philosophy) has two
  objects, nature and freedom, and therefore contains not only
  a By "cosmical concept' <1[Weltbegriff]>1 is here meant the concept
  which relates to that in which everyone necessarily has an interest;
  and accordingly if a science is to be regarded merely as one of the
  disciplines designed in view of certain optionally chosen ends, I must
  determine it in conformity with <1scholastic concepts.>1
00026
the law of nature, but also the moral law, presenting them
at first in two distinct systems, but ultimately in one single
philosophical system. The philosophy of nature deals with all
<1that is,>1 the philosophy of morals with that which <1ought to be.>1
  All philosophy is either knowledge arising out of pure
reason, or knowledge obtained by reason from empirical
principles. The former is termed pure, the latter empirical
philosophy.
  The philosophy of pure reason is either a <1propaedeutic>1 (B 869
(preparation), which investigates the faculty of reason in
respect of all its pure <1a priori>1 knowledge, and is entitled
the science which exhibits in systematic connection the whose'
arising out of pure reason, and which is entitled <1metaphysics->1
The title "metaphysics' may also, however, be given to the
whole of pure philosophy, inclusive of criticism, and so as com-
prehending the investigation of all that can ever be known
<1a priori>1 as well as the exposition of that which constitutes a
system of the pure philosophical modes of knowledge of this
type---in distinction, therefore, from all empirical and from
all mathematical employment of reason.
  Metaphysics is divided into that of the <1speculative>1 and that
of the <1practical>1 employment of pure reason, and is there-
fore either <1metaphysics of nature>1 or <1metaphysics of morals.>1
The former contains all the principles of pure reason that
are derived from mere concepts (therefore excluding mathe-
matics), and employed in the <1theoretical>1 knowledge of all
things; the latter, the principles which in <1a priori>1 fashion
determine and make necessary <1all our actions.>1 Now morality
is the only code of laws applying to our actions which can
be derived completely <1a priori>1 from principles. Accordingly,
the metaphysics of morals is really pure moral philosophy,
with no underlying basis of anthropology or of other empirical (A 842
conditions. The term "metaphysics', in its <1strict>1 sense, is com-
monly reserved for the metaphysics of speculative reason.
But as pure moral philosophy really forms part of this special
00027
branch of human and philosophical knowledge derived from
pure reason, we shall retain for it the title "metaphysics'. We
are not, however, at present concerned with it, and may there-
fore leave it aside.
  It is of the utmost importance to <1isolate>1 the various modes
of knowledge according as they differ in kind and in origin,
and to secure that they be not confounded owing to the fact
that usually, in our employment of them, they are combined.
What the chemist does in the analysis of substances, and
the mathematician in his special disciplines, is in still greater
degree incumbent upon the philosopher, that he may be able
to determine with certainty the part which belongs to each
special kind of knowledge in the diversified employment of the
  understanding and its special value and influence. Human
  reason, since it first began to think, or ratherto reflect, has never
  been able to dispense with a metaphysics; but also has never
  been able to obtain it in a form sufficiently free from all foreign
  elements. The idea of such a science is as old as speculative
  human reason; and what rational being does not speculate,
  either in scholastic or in popular fashion? It must be admitted,
  843) however, that the two elements of our knowledge---that
  which is in our power completely <1a priori,>1 and that which is
  obtainable only <1a posteriori>1 from experience---have never been
  very clearly distinguished, not even by professional thinkers,
  and that they have therefore failed to bring about the delimita-
  tion of a special kind of knowledge, and thereby the true idea
  of the science which has preoccupied human reason so long and
  so greatly. When metaphysics was declared to be the science
  of the first principles of human knowledge, the intention was
  not to mark out a quite special kind of knowledge, but only
  a certain precedence in resp ct of generality, which was not
  sufficient to distinguish such knowledge from the empirical.
  For among empirical principles we can distinguish some that
  are more general, and so higher in rank than others; but
  where in such a series of subordinated members---a series in
  which we do not distinguish what is completely <1a priori>1 from
  what is known only <1a posteriori>1---are we to draw the line
  which distinguishes the highest or <1first>1 members from the
  lower subordinate members? What should we say, if in the
00028
reckoning of time we could distinguish the epochs of the
world only by dividing them into the first centuries and those
that follow? We should ask: Does the fifth, the tenth century,
etc., belong with the first centuries? So in like manner I ask:
Does the concept of the extended belong to metaphysics?
You answer, Yes. Then, that of body too? Yes. And that of (B  44
fluid body? You now become perplexed; for at this rate every-
thing will belong to metaphysics. It is evident, therefore, that
the mere degree of subordination (of the particular under
the general) cannot determine the limits of a science; in the  -
case under consideration, only complete difference of kind and
of origin will suffice. But the fundamental idea of metaphysics
was obscured on yet another side, owing to its exhibiting, as
<1a priori>1 knowledge, a certain similarity to mathematics.
Certainly they are related, in so far as they both have an
<1a priori>1 origin; but when we bear in mind the difference
between philosophical and mathematical knowledge, namely,
that the one is derived from concepts, whereas in the other
we arrive at <1a priori>1 judgments only through the construction
which has indeed always been in a manner felt but could
never be defined by means of any clear criteria. Thus it
has come about that since philosophers failed in the task of
developing even the idea of their science, they could have
no determinate end or secure guidance in the elaboration
of it, and, accordingly, in this arbitrarily conceived enter-
prise, ignorant as they were of the path to be taken, they have
always been at odds with one another as regards the dis-
coveries which each claimed to have made on his own separate
path, with the result that their science has been brought into
contempt, first among outsiders, and finally even among
themselves.
  All pure <1a priori>1 knowledge, owing to the special faculty (B 8
of knowledge in which alone it can originate, has in itself a
peculiar unity; and metaphysics is the philosophy which has
as its task the statement of that knowledge in this systematic
unity. Its speculative part, which has especially appropriated
this name, namely, what we entitle <1metaphysics of nature,>1 and
which considers everything in so far as <1it is>1 (not that which
00029
ought to be) by means of <1a priori>1 concepts, is divided in the
following manner.
  Metaphysics, in the narrower meaning of the term, con-
sists of <1transcendental philosophy>1 and <1physiology>1 of pure
reason. The former treats only of the understanding and of
reason, in a system of concepts and principles which relate to
objects in general but take no account of objects that <1may be>1
<1given (Ontologia);>1 the latter treats of <1nature,>1 that is, of the
sum <1of given>1 objects (whether given to the senses, or, if we will,
to some other kind of intuition) and is <1therefore physiology>1---
although only <1rationalis.>1 The employment of reason in this
rational study of nature is either physical or hyperphysical,
or, in more adequate terms, is either <1immanent>1 or <1transcen->1
<1dent.>1 The former is concerned with such knowledge of nature
as can be applied in experience <1(in concreto),>1 the latter with
that connection of objects of experience which transcends
846) all experience. This <1transcendent>1 physiology has as its object
  either an <1inner>1 connection or an <1outer>1 connection, both, how-
  ever, transcending possible experience. As dealing with an
  inner connection it is the physiology of nature as a whole,
  that is, the <1transcendental knowledge of the world;>1 as dealing
  with an outer connection, it is the physiology of the relation
  of nature as a whole to a being above nature, that is to say,
  it is the <1transcendental knowledge of God.>1
  Immanent physiology, on the other hand, views nature as
  the sum of all objects of the senses, and therefore just as it is
  given us, but solely in accordance with <1a priori>1 conditions,
  under which alone it can ever be given us. There are only two
  kinds of such objects.  Those of the outer senses, and so
  their sum, <1corporeal nature.>1 The object of inner sense,
  the soul, and in accordance with our fundamental concepts of
  it, <1thinking nature.>1 The metaphysics of corporeal nature is
  entitled physics; and as it must contain only the principles of
  an <1a priori>1 knowledge of it, <1rational physics.>1 The metaphysics
  of thinking nature is entitled <1psychology,>1 and on the same
  ground is to be understood as being only the <1rational know->1
  <1ledge>1 of it.
  The whole system of metaphysics thus consists of four
  main parts: (1) ontology; (2) rational physiology; (3) rational
  cosmology; (4) rational theology. The second part, namely,
00030
  (A 847
the doctrine of nature as developed by pure reason, contains (B 875
two divisions <1physica rationalisa>1 and <1psychologia rationalis.>1
  The originative idea of a philosophy of pure reason itself
prescribes this division, which is therefore <1architectonic,>1 in
accordance with the essential ends of reason, and not merely
<1technical,>1 in accordance with accidentally observed simil-
arities, and so instituted as it were at haphazard. Accordingly
the division is also unchangeable and of legislative authority.
There are, however, some points which may well seem doubt-
ful, and may weaken our conviction as to the legitimacy of
its claims.
  First of all, how can I expect to have knowledge <1a priori>1
(and therefore a metaphysics) of objects in so far as they are
given to our senses, that is, given in an <1a posteriori>1 manner?
And how is it possible to know the nature of things and
to arrive at a rational physiology according to principle  (A 848
<1apriori?>1 The answer is this: we take nothing more from experi-
ence than is required to <1give>1 us an object of outer or of inner
sense. The object of outer sense we obtain through the mere
concept of matter (impenetrable, lifeless extension), the object
of inner sense through the concept of a thinking being (in the
empirical inner representation, "I think'). As to the rest, in the
whole metaphysical treatment of these objects, we must en-
tirely dispense with all empirical principles which profess to
add to these concepts any other more special experience, with
a view to our passing further judgments upon the objects.
  Secondly, how are we to regard <1empirical psychology,>1
  a I must not be taken as meaning thereby what is commonly
called <1physica generalis;>1 the latter is rather mathematics than phil-
osophy of nature. The metaphysics of nature is quite distinct from
mathematics. It is very far from enlarging our knowledge in the
  atics, but still is very important as yield-
ing a criticism of the pure knowledge of understanding in its
application to nature. For lack of it, even mathematicians, holding
to certain common concepts, which though common are yet in
fact metaphysical, have unconsciously encumbered their doctrine
of nature with hypotheses which vanish upon criticism of the prin-
ciples involved, without, however, doing the least injury to the
employment of mathematics-employment which is quite indis-
pensable in this field.
00031
which has always claimed its place in metaphysics, and from
which in our times such great things have been expected for
the advancement of metaphysics, the hope of succeeding by
<1apriori>1 methods having been abandoned. I answer that it be-
longs where the proper (empirical) doctrine of nature belongs,
namely, by the side of <1applied>1 philosophy, the <1a priori>1 prin-
ciples of which are contained in pure philosophy; it is therefore
so far connected with applied philosophy, though not to be
  confounded with it. Empirical psychology is thus completely
  banished from the domain of metaphysics; it is indeed already
  completely excluded by the very idea of the latter science. In
  conformity, however, with scholastic usage we must allow it
  some sort of a place (although as an episode only) in meta-
  A 849)  hysics and this from economical motives, because it is not yet
  so rich as to be able to form a subject of study by itself, and yet
  is too important to be entirely excluded and forced to settle
  elsewhere, in a neighbourhood that might well prove much
  less congenial than that of metaphysics. Though it is but a
  stranger it has long been accepted as a member of the house-
  hold, and we allow it to stay for some time longer, until it is in
  a position to set up an establishment of its own in a complete
  anthropology, the pendant to the empirical doctrine of nature.
  Such, then, in general, is the idea of metaphysics. At first
  more was expected from metaphysics than could reasonably be
  demanded, and for some time it diverted itself with pleasant
  anticipations. But these hopes having proved deceptive, it
  has now fallen into general disrepute. The argument of our
  Critique, taken as a whole, must have sufficiently convinced
  the readerthat although metaphysics cannot be the foundation
  of religion, it must always continue to be a bulwark of it, and
  that human reason, being by its very nature dialectical, can
  never dispense with such a science, which curbs it, and by a
  scientific and completely convincing self-knowledge, prevents
  the devastations of which a lawless speculative reason would
  otherwise quite inevitably be guilty in the field of morals as
  well as in that of religion. We can therefore be sure that how-
  B 878 ever cold or contemptuously critical may be the attitude off
  A 850  those who judge a science not by its nature but by its acci-
  dental effects, we shall always return to metaphysics as to a be-
  loved one with whom we have had a quarrel. For here we are
00032
concerned with essential ends---ends with which metaphysics
must ceaselessly occupy itself, either in striving for genuine
insight into them, or in refuting those who profess already to
have attained it.
  Metaphysics, alike of nature and of morals, and especially
that criticism of our adventurous and self-reliant reason which
serves as an introduction or propaedeutic to metaphysics,
alone properly constitutes what may be entitled philosophy,
in the strict sense of the term. Its sole preoccupation is wisdom;
and it seeks it by the path of science, which, once it has been
trodden, can never be overgrown, and permits of no wander-
ing. Mathematics, natural science, even our empirical know-
ledge, have a high value as means, for the most part, to con-
tingent ends, but also, in the ultimate outcome, to ends that
are necessary and essential to humanity. This latter service,
however, they can discharge only as they are aided by a know-
ledge through reason from pure concepts, which, however we
may choose to entitle it, is really nothing but metaphysics.
  For the same reason metaphysics is also the full and com-
plete development1 of human reason. Quite apart from its
influence, as science, in connection with certain specific ends  (A 851
it is an indispensable discipline. For in dealing with reason it
treats of those elements and highest maxims which must form
the basis of the very <1possibility>1 of some sciences, and of the
<1use>1 of all. That, as mere speculation, it serves rather to prevent
errors than to extend knowledge, does not detract from its
value. On the contrary this gives it dignity and authority,
through that censorship which secures general order and har-
mony, and indeed the well-being of the scientific common-
wealth, preventing those who labour courageously and fruit-
fully on its behalf from losing sight of the supreme end, the
happiness of all mankind.
00033
  CHAPTER IV
  THE HISTORY OF PURE REASON
  THIS title stands here only in order to indicate one remaining
  division of the system, which future workers must complete.
  I content myself with casting a cursory glance, from a purely
  transcendental point of view, namely, that of the nature of
  pure reason, on the works of those who have laboured in this
  field---a glance which reveals [many stately] structures, but in
  ruins only.
  It is a very notable fact, although it could not have been
  otherwise, that in the infancy of philosophy men began where
  we should incline to end, namely, with the knowledge of God,
  occupying themselves with the hope, or rather indeed with
  the specific nature, of another world. However gross the
  religious concepts generated by the ancient practices which
  still persisted in each community from an earlier more
  barbarous state, this did not prevent the more enlightened
  members from devoting themselves to free investigation of
  these matters; and they easily discerned that there could be
  no better ground1 or more dependable way of pleasing the in-
  visible power that governs the world, and so of being happy
  8853) in another world at least, than by living the good life. Ac-
  cordingly theology and morals were the two motives, or rather
  the two points of reference, in all those abstract enquiries of
  reason to which men came to devote themselves. It was chiefly,
  however, the former that step by step committed the purely
  speculative reason to those labours which afterwards became
  so renowned under the name of metaphysics.
00034
I shall not here attempt to distinguish the periods of his-
tory in which this or that change in metaphysics came about,
but shall only give a cursory sketch of the various ideas which
gave rise to the chief revolutions [in metaphysical theory].
And here I find that there are three issues in regard to
which the most noteworthy changes have taken place in the
course of the resulting controversies.
  1.  <1In respect of the object>1 of all our "knowledge through
reason', some have been mere <1sensualists,>1 others mere <1intel->1
<1lectualists. Epicurus>1 may be regarded as the outstanding
philosopher among the former, and <1Plato>1 among the latter.
The distinction between the two schools, subtle as it is,
dates from the earliest times; and the two positions have
ever since been maintained in unbroken continuity. Those
of the former school maintained that reality is to be found
solely in the objects of the senses, and that all else is fiction;
those of the latter school, on the other hand, declared that
in the senses there is nothing but illusion, and that only (B 8854
the understanding knows what is true. The former did not
indeed deny reality to the concepts of the understanding; but
this reality was for them merely <1logical,>1 whereas for the others
it was <1mystical.>1 The former conceded <1intellectual concepts,>1 but
admitted sensible objects only. The latter required that true
objects should be <1purely intelligible,>1 and maintained that by
means of the pure understanding we have an <1intuition>1 that
is unaccompanied by the senses---the senses, in their view,
serving only to confuse the understanding.
  2. <1In respect of the origin>1 of the modes of "knowledge
through pure reason', the question is as to whether they are
derived from experience, or whether in independence of ex-
perience they have their origin in reason. <1Aristotle>1 may be
regarded as the chief of the <1empiricists,>1 and <1Plato>1 as the
chief of the <1noologists. Locke,>1 who in modern times followed
Aristotle, and <1Leibniz,>1 who followed Plato (although in con-
siderable disagreement with his mystical system), have not
been able to bring this conflict to any definitive conclusion.
However we may regard Epicurus, he was at least much more
inasmuch as he never sought to pass by inference beyond the
limits of experience. This is especially true as regards Locke,
00035
who, after having derived all concepts and principles from
experience, goes so far in the use of them as to assert that we
A 855) can prove the existence of God and the immortality of the
  soul with the same conclusiveness as any mathematical pro-
  position---though both lie entirely outside the limits of
  possible experience.
  3. <1In respect of method.>1---If anything is to receive the
  title of method, it must be a procedure in accordance with
  principles. We may divide the methods now prevailing in this
  field of enquiry into the <1naturalistic>1 and the <1scientific.>1 The
  <1naturalist>1 of pure reason adopts as his principle that through
  common reason, without science, that is, through what he
  calls sound reason, he is able, in regard to those most sublime
  questions which form the problem of metaphysics, to achieve
  more than is possible through speculation. Thus he is virtu-
  ally asserting that we can determine the size and distance of
  the moon with greater certainty by the naked eye than by
  mathematical devices. This is mere misology, reduced to
  principles; and what is most absurd of all, the neglect of all
  artificial means is eulogised as a special <1method>1 of extending
  our knowledge. For as regards those who are naturalists from
  <1lack>1 of more insight, they cannot rightly be blamed. They
  follow common reason, without boasting of their ignorance
  as a method which contains the secret how we are to fetch
  truth from the deep well of Democritus. <1Quod sapio, satis>1
  <1est mihi, non ego curo, esse quod A rcesilas aerumnosique>1
B 884) <1Solonesa>1 is the motto with which they may lead a cheerful
  and praiseworthy life, not troubling themselves about science,
  nor by their interference bringing it into confusion.
  As regards those who adopt a <1scientific>1 method, they have
  the choice of proceeding either <1dogmatically>1 or <1sceptically;>1
  but in any case they are under obligation to proceed <1system->1
  <1atically.>1 I may cite the celebrated Wolff as a representative
  of the former mode of procedure, and David Hume as a repre-
  sentative of the latter, and may then, conformably with my
  present purpose, leave all others unnamed. The <1critical>1 path
  alone is still open. If the reader has had the courtesy and
  patience to accompany me along this path, he may now judge
  for himself whether, if he cares to lend his aid in making this
  a Persius <1[Sat.>1 iii 78-79].
00036
path into a high-road, it may not be possible to achieve be-
fore the end of the present century what many centuries have
not been able to accomplish; namely, to secure for human
reason complete satisfaction in regard to that with which it
has all along so eagerly occupied itself, though hitherto
in vain.