Critique of Pure Reason


P 384
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
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 categorical syllogisms, the major premiss of which is
a principle asserting the relation of a predicate to a subject. 
The second type of dialectical argument follows the analogy
of the hypothetical 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
P 385
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 objective synthesis of appearances. For in this
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. 
It certainly guards reason from the slumber of fictitious 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 euthanasia 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, cosmical concepts, partly be-
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 ideal of
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
P 386
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
Section I
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-
ing. Reason does not really generate any concept. The most
it can do is to free a concept of understanding from the
unavoidable limitations of possible experience, and so to en-
deavour to extend it beyond the limits of the empirical, though
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 the conditioned is given, the entire sum of conditions,
and consequently the absolutely unconditioned (through which
alone the conditioned has been possible) is also given. The
transcendental ideas are thus, in the first 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 second place, not all categories are fitted for such
employment, but only those in which the synthesis constitutes
a series of conditions subordinated to, not co-ordinated with,
P 387
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. 
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
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 m, n, o, in which n is given as conditioned by m, and
at the same time as being the condition of o. The series ascends
from the conditioned n to m (l, k, i, etc. ), and also descends
from the condition n to the conditioned o (p, q, r, 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
possibility does not, however, rest upon the subsequent series,
o, p, q, r. This latter series may not therefore be regarded as
given, but only as allowing of being given (dabilis). 
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 regressive synthesis; and that which advances,
on the side of the conditioned, from the first consequence to
the more distant, the progressive. The first proceeds in ante-
cedentia, the second in consequentia. The cosmological ideas
deal, therefore, with the totality of the regressive synthesis
P 388
proceeding in antecedentia, not in consequentia. 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 quanta of
all our intuition, time and space. 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 a priori distinguished as
conditions (the past) from the consequents (the future). The
transcendental idea of the absolute totality of the series of con-
ditions of any given conditioned therefore refers only to all
past 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 aggregate, not a series. 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 possibility 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 the con-
dition of the limits of the given space, the measuring 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
the conditions is not in itself distinct from that of the condi-
tioned, and that in space regressus and progressus would 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
P 389
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, i.e. matter, 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
appearances, that of substance with its accidents is not adapted
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 substantial. 
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 causality. It presents a series of causes of a given
P 390
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. 
 Fourthly, the concepts of the possible, the actual, and the
necessary do not lead to any series, save in so far as the acci-
dental 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, corresponding to the
four titles of the categories:
1. Absolute completeness
of the Composition
of the given whole of all appearances. 
2. Absolute completeness
in the Division
of a given whole in the [field of] appearance. 
3. Absolute completeness
in the Origination
of an appearance. 
4. Absolute completeness
as regards Dependence of Existence
of the changeable in the [field of] appearance. 
 There are several points which here call for notice. In the
first place, the idea of absolute totality concerns only the ex-
position of appearances, and does not therefore refer to the
pure concept, such as the understanding may form, of a total-
ity of things in general. 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. 
P 391
Secondly, what reason is really seeking in this serial, re-
gressively continued, synthesis of conditions, is solely the un-
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 unconditioned is always con-
tained in the absolute totality of the series 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 at once 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
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 unconditioned 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
totality, though what it really has in view is the unconditioned,
whether of the entire series or of a part of it. Meantime, also,
it leaves undecided whether and how this totality is attain-
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
P 392
under any other condition. On the first view, the series a parte -
priori is without limits or beginning, i.e. 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
second view, there is a first member of the series which in
respect of past time is entitled, the beginning of the world, in
respect of space, the limit of the world, in respect of the parts
of a given limited whole, the simple, in respect of causes,
absolute self-activity (freedom), in respect of the existence of
alterable things, absolute natural necessity. 
We have two expressions, world and nature, 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 alike through
composition and through division. This same world is entitled
nature when it is viewed as a dynamical whole. We are not
then concerned with the aggregation in space and time, with
a view to determining it as a magnitude, but with the unity in
the existence 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 freedom, and its
conditioned causality is called natural cause in the narrower
[adjectival] sense. The conditioned in existence in general is
termed contingent and the unconditioned necessary. 
++ 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. 
++ Nature, taken adjectivally (formaliter), 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
(materialiter), 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. 
P 393
The unconditioned necessity of appearances may be entitled natural
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 appearances, and it is exclusively
to the unconditioned in the appearances that our ideas are
directed, partly also because the term 'world', in the tran-
scendental sense, signifies the absolute totality of all existing
things, and we direct our attention solely to the completeness
of the synthesis, even though that is only attainable in the
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 cosmical concepts. In
respect of the distinction between the mathematically and the
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 transcendent concepts of nature. This distinction
has no special immediate value; its significance will appear
Section 2
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 (thesis cum antithesi) 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 and the
causes of this conflict. The transcendental antithetic is an en-
quiry into the antinomy of pure reason, its causes and out-
P 394
come. If in employing the principles of understanding we do
not merely apply our reason to objects of experience, but
venture to extend these principles beyond the limits of experi-
ence, there arise pseudo-rational 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. 
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-
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
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-rational assertions thus disclose a dialectical
battlefield in which the side permitted to open the attack is
invariably victorious, and the side constrained to act on the
defensive is always defeated. Accordingly, vigorous fighters, no
P 395
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
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
result, -- this procedure, I say, may be entitled the sceptical
method. It is altogether different from scepticism -- 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
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
P 396
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-
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. 
Moral philosophy can also present its principles, together
with their practical consequences, one and all in concreto, 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 a priori
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. 
The world has a beginning
in time, and is also limited as
regards space. 
++ The antinomies follow one another in the order of the tran-
scendental ideas above enumerated. 
P 396a
The world has no begin-
ning, and no limits in space;
it is infinite as regards both
time and space. 
P 397
If we assume that the world
has no beginning in time,
then up to every given mo-
ment an eternity has elapsed,
and there has passed away in
the world an infinite series of
successive states of things. 
Now the infinity of a series
consists in the fact that it can
never be completed through
successive synthesis. It thus
follows that it is impossible for
an infinite world-series to have
passed away, and that a be-
ginning of the world is there-
fore a necessary condition of
the world's existence. This was
the first point that called for
 As regards the second point,
let us again assume the oppo-
site, namely, that the world is
an infinite given whole of co-
existing things. Now the mag-
nitude of a quantum which is
not given in intuition as
within certain limits, can be
thought only through the
synthesis of its parts, and the
totality of such a quantum
only through a synthesis that
is brought to completion
through repeated addition of unit to unit. 
++ An indeterminate quantum can be intuited as a whole when it
is such that though enclosed within limits we do not require to con-
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. 
P 397a
 For let us assume that it
has a beginning. Since the
beginning is an existence
which is preceded by a time
in which the thing is not,
there must have been a
preceding time in which the
world was not, i.e. an empty
time. Now no coming to be
of a thing is possible in an
empty time, because no part
of such a time possesses, as
compared with any other, a
distinguishing condition of
existence rather than of non-
existence; and this applies
whether the thing is sup-
posed to arise of itself or
through some other cause. In
the world many series of
things can, indeed, begin;
but the world itself cannot
have a beginning, and is
therefore infinite in respect
of past time. 
 As regards the second
point, let us start by assum-
ing the opposite, namely, that
the world in space is finite
and limited, and consequently
exists in an empty space
which is unlimited. 
P 398
In order, there-
fore, to think, as a whole, the
world which fills all spaces,
the successive synthesis of
the parts of an infinite world
must be viewed as completed,
that is, an infinite time must
be viewed as having elapsed
in the enumeration of all co-
existing things. This, how-
ever, is impossible. An in-
finite aggregate of actual
things cannot therefore be
viewed as a given whole, nor
consequently as simultane-
ously given. The world is,
therefore, as regards exten-
sion in space, not infinite, but
is enclosed within limits. This
was the second point in
++ 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. 
P 397a
will therefore not only be
P 398a
related in space but also
related to space. Now since
the world is an absolute whole
beyond which there is no
object of intuition, and there-
fore no correlate with which
the world stands in relation,
the relation of the world
to empty space would be a
relation of it to no object. 
But such a relation, and con-
sequently the limitation of
the world by empty space, is
nothing. The world cannot,
therefore, be limited in space;
that is, it is infinite in respect
of extension. 
++ 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
P 398n
is a determination which can never be perceived, and is therefore
the predicate of a mere thought-entity. 
P 399
I. On the Thesis 
 In stating these conflicting
arguments I have not sought
to elaborate sophisms. That
is to say, I have not resorted
to the method of the special
pleader who attempts to take
advantage of an opponent's
carelessness -- freely allowing
the appeal to a misunderstood
law, in order that he may be
in a position to establish his
own unrighteous claims by
the refutation of that law. 
Each of the above proofs
arises naturally out of the
matter in dispute, and no ad-
vantage has been taken of
the openings afforded by er-
roneous conclusions arrived
at by dogmatists in either
 I might have made a
pretence of establishing the
thesis in the usual manner of
the dogmatists, by starting
from a defective concept of
the infinitude of a given mag-
nitude. I might have argued
that a magnitude is infinite
if a greater than itself, as
determined by the multipli-
city of given units which it contains, is not possible. 
P 399a
II. On the Antithesis
 The proof of the infinitude
of the given world-series and
of the world-whole, rests upon
the fact that, on the contrary
assumption, an empty time
and an empty space, must
constitute the limit of the
world. I am aware that
attempts have been made to
evade this conclusion by argu-
ing that a limit of the world
in time and space is quite
possible without our having
to make the impossible as-
sumption of an absolute
time prior to the beginning
of the world, or of an absolute
space extending beyond the
real world. With the latter
part of this doctrine, as held
by the philosophers of the
Leibnizian school, I am en-
tirely satisfied. Space is merely
the form of outer intuition;
it is not a real object which
can be outwardly intuited; it
is not a correlate of the ap-
pearances, but the form of
the appearances themselves. 
And since space is thus no
object but only the form of
possible objects, it cannot be
P 400a
regarded as something abso-
lute in itself that determines
the existence of things. 
P 400
no multiplicity is the great-
est, since one or more units
can always be added to it. 
Consequently an infinite given
magnitude, and therefore an
infinite world (infinite as re-
gards the elapsed series or as
regards extension) is impos-
sible; it must be limited in
both respects. Such is the
line that my proof might have
followed. But the above con-
cept is not adequate to what
we mean by an infinite whole. 
It does not represent how
great it is, and consequently
is not the concept of a maxi-
mum. Through it we think
only its relation to any assign-
able unit in respect to which
it is greater than all num-
ber. According as the unit
chosen is greater or smaller,
the infinite would be greater
or smaller. Infinitude, how-
ever, as it consists solely
in the relation to the given
unit, would always remain
the same. The absolute mag-
nitude of the whole would
not, therefore, be known in
this way; 
P 400a
as appearances, determine
space, that is, of all its pos-
sible predicates of magnitude
and relation they determine
this or that particular one to
belong to the real. Space, on
the other hand, viewed as a
self-subsistent something, is
nothing real in itself; and can-
not, therefore, determine the
magnitude or shape of real
things. Space, it further fol-
lows, whether full or empty,
may be limited by appear-
ances, but appearances can-
not be limited by an empty
space outside them. This is
likewise true of time. But
while all this may be granted,
it yet cannot be denied that
these two non-entities, empty
space outside the world and
empty time prior to it, have
to be assumed if we are to
assume a limit to the world
in space and in time. 
++ It will be evident that what we here desire to say is that empty
space, so far as it is limited by appearances, that is, empty space
within the world, 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
P 401
indeed, the above concept does not really deal
with it. 
The true transcendental
concept of infinitude is this,
that the successive synthesis
of units required for the enu-
meration of a quantum can
never be completed. Hence
it follows with complete cer-
tainty that an eternity of
actual successive states lead-
ing up to a given (the pre-
sent) moment cannot have
elapsed, and that the world
must therefore have a begin-
In the second part of the
thesis the difficulty involved
in a series that is infinite and
yet has elapsed does not arise,
since the manifold of a world
which is infinite in respect of
extension is given as co-exist-
ing. But if we are to think the
totality of such a multiplicity,
and yet cannot appeal to
limits that of themselves con-
stitute it a totality in intuition,
we have to account for a con-
cept which in this case cannot
proceed from the whole to
the determinate multiplicity
of the parts, but which must
demonstrate the possibility of
a whole by means of the
successive synthesis of the
++ This quantum therefore contains a quantity (of given units)
which is greater than any number -- which is the mathematical con-
cept of the infinite. 
P 400a
 The method of argument
which professes to enable us
to avoid the above conse-
quence (that of having to
P 401a
assume that if the world has
limits in time and space, the
infinite void must determine
the magnitude in which actual
things are to exist) consists
in surreptitiously substituting
for the sensible world some
intelligible world of which
we know nothing; for the
first beginning (an exist-
ence preceded by a time of
non-existence) an existence
in general which presupposes
no other condition whatso-
ever; and for the limits of
extension boundaries of the
world-whole -- thus getting
rid of time and space. But we
are here treating only of the
mudus phaenomenon and
its magnitude, and cannot
therefore abstract from the
aforesaid conditions of sensi-
bility without destroying the
very being of that world. If
the sensible world is limited,
it must necessarily lie in the
infinite void. If that void, and
consequently space in general
as a priori condition of the
possibility of appearances, be
set aside, the entire sensible
world vanishes. This world
is all that is given us in
our problem. 
P 402
 Now since this synthesis must constitute a never
to be completed series, I can-
not think a totality either
prior to the synthesis or by
means of the synthesis. For
the concept of totality is in
this case itself the representa-
tion of a completed synthesis
of the parts. And since this
completion is impossible, so
likewise is the concept of it. 
Every composite substance
in the world is made up of
simple parts, and nothing any-
where exists save the simple
or what is composed of the
Let us assume that com-
posite substances are not
made up of simple parts. If
all composition be then re-
moved in thought, no com-
posite part, and (since we
admit no simple parts) also
no simple part, that is to say,
nothing at all, will remain,
and accordingly no substance
will be given. Either, there-
fore, it is impossible to remove
in thought all composition,
or after its removal there
must remain something which
P 403
exists without composition,
that is, the simple. 
P 401a
The mundus
intelligibilis is nothing but
the general concept of a
P 402a
world in general, in which
abstraction is made from all
conditions of its intuition,
and in reference to which,
therefore, no synthetic pro-
position, either affirmative
or negative, can possibly be
No composite thing in the
world is made up of simple
parts, and there nowhere
exists in the world anything
Assume that a composite
thing (as substance) is made
up of simple parts. Since all
external relation, and there-
fore all composition of sub-
stances, is possible only in
space, a space must be made
up of as many parts as are
contained in the composite
which occupies it. Space,
however, is not made up of
simple parts, but of spaces. 
Every part of the composite
must therefore occupy a space. 
But the absolutely first parts
P 403a
of every composite are simple. 
P 403
In the for-
mer case the composite would
not be made up of substances;
composition, as applied to
substances, is only an acci-
dental relation in independ-
ence of which they must
still persist as self-subsistent
beings. Since this contradicts
our supposition, there remains
only the original supposition,
that a composite of sub-
stances in the world is made
up of simple parts. 
If follows, as an immediate
consequence, that the things
in the world are all, without
exception, simple beings; that
composition is merely an
external state of these beings;
and that although we can
never so isolate these ele-
mentary substances as to
take them out of this state
of composition, reason must
think them as the primary
subjects of all composition,
and therefore, as simple be-
ings, prior to all composition. 
P 403a
The simple therefore occupies
a space. Now since every-
thing real, which occupies a
space, contains in itself a
manifold of constituents ex-
ternal to one another, and is
therefore composite; and since
a real composite is not made
up of accidents (for accidents
could not exist outside one
another, in the absence of
substance) but of substances,
it follows that the simple
would be a composite of
substances -- which is self-
The second proposition of
the antithesis, that nowhere
in the world does there exist
anything simple, is intended
to mean only this, that the
existence of the absolutely
simple cannot be established
by any experience or percep-
tion, either outer or inner;
and that the absolutely simple
is therefore a mere idea, the
objective reality of which can
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
P 404a
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. 
P 405
I. On the Thesis 
When I speak of a whole
as necessarily made up of
simple parts I am referring
only to a substantial whole
that is composite in the strict
sense of the term 'composite',
that is, to that accidental
unity of the manifold which,
given as separate (at least in
thought), is brought into a
mutual connection, and there-
by constitutes a unity. Space
should properly be called not
compositum but totum, since
its parts are possible only in
the whole, not the whole
through the parts. It might,
indeed, be called a composi-
tum ideale, but not reale. 
This, however, is a mere
subtlety. Since space is not
a composite made up of
substances (nor even of
real accidents), if I remove
all compositeness from it,
nothing remains, not even the
point. For a point is possible
only as the limit of a space,
and so of a composite. Space
and time do not, therefore,
consist of simple parts. What
belongs only to the state of a
substance, even though it has
a magnitude, e.g. alteration,
does not consist of the simple; 
P 405a
II. On the Antithesis
Against the doctrine of the
infinite divisibility of matter,
the proof of which is purely
mathematical, objections have
been raised by the monadists. 
These objections, however, at
once lay the monadists open to
suspicion. For however evi-
dent mathematical proofs
may be, they decline to recog-
nise that the proofs are based
upon insight into the constitu-
tion of space, in so far as space
is in actual fact the formal
condition of the possibility of
all matter. They regard them
merely as inferences from ab-
stract but arbitrary concepts,
and so as not being applicable
to real things. How can it be
possible to invent a different
kind of intuition from that
given in the original intuition
of space, and how can the a -
priori determinations of space
fail to be directly applicable
to what is only possible in so
far as it fills this space! Were
we to give heed to them,
then beside the mathematical
point, which, while simple,
is not a part but only the
limit of a space, we should
have to conceive physical
points as being likewise
P 406a
P 406
that is to say, a certain degree
of alteration does not come
about through the accretion
of many simple alterations. 
Our inference from the com-
posite to the simple applies
only to self-subsisting things. 
Accidents of the state [of a
thing] are not self-subsisting. 
Thus the proof of the neces-
sity of the simple, as the con-
stitutive parts of the sub-
stantially composite, can easily
be upset (and therewith the
thesis as a whole), if it be
extended too far and in the
absence of a limiting qualifi-
cation be made to apply to
everything composite -- as has
frequently happened. 
Moreover I am here speak-
ing only of the simple in so
far as it is necessarily given
in the composite -- the latter
being resolvable into the
simple, as its constituent
parts. The word monas, in the
strict sense in which it is em-
ployed by Leibniz, should refer
only to the simple which is
immediately given as simple
substance e.g. in self-con-
sciousness), and not to an
element of the composite. 
This latter is better entitled
atomus. As I am seeking
to prove the [existence of]
simple substances only as
elements in the composite, I
P 407
might entitle the thesis of
the second antinomy, tran-
scendental atomistic. 
P 406a
and yet as having the
distinguishing characteristic
of being able, as parts of
space, to fill space through
their mere aggregation. With-
out repeating the many fa-
miliar and conclusive refuta-
tions of this absurdity -- it
being quite futile to attempt
to reason away by sophistical
manipulation of purely dis-
cursive concepts the evident
demonstrated truth of mathe-
matics -- I make only one ob-
servation, that when philo-
sophy here plays tricks with
mathematics, it does so be-
cause it forgets that in this
discussion we are concerned
only with appearances and
their condition. Here it is
not sufficient to find for the
pure concept of the com-
posite formed by the under-
standing the concept of the
simple; what has to be found
is an intuition of the simple
for the intuition of the com-
posite (matter). But by the
laws of sensibility, and there-
fore in objects of the senses,
this is quite impossible. 
Though it may be true that
when a whole, made up of
substances, is thought by the
pure understanding alone, we
must, prior to all composi-
tion of it, have the simple, 
P 407
But as
this word has long been ap-
propriated to signify a parti-
cular mode of explaining
bodily appearances (mole-
culae), and therefore pre-
supposes empirical concepts,
the thesis may more suitably
be entitled the dialectical
principle of monadology. 
P 406a
 this does not hold of the
P 407a
totum substantiale phaeno-
menon which, as empirical
intuition in space, carries
with it the necessary char-
acteristic that no part of it
is simple, because no part of
space is simple. The monad-
ists have, indeed, been suffi-
ciently acute to seek escape
from this difficulty by refusing
to treat space as a condition
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-
The second dialectical as-
sertion has this peculiarity,
that over against it stands
a dogmatic assertion which
is the only one of all the
pseudo-rational assertions that
undertakes to afford mani-
fest evidence, in an empirical
P 408a
object, of the reality of that
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-consciousness
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 outwardly, as
P 409a
an object of intuition, it must
exhibit [some sort of] com-
positeness in its appearance; 
P 409
Causality in accordance
with laws of nature is not the
only causality from which the
appearances of the world can
one and all be derived. To
explain these appearances it
is necessary to assume that
there is also another causality,
that of freedom. 
Let us assume that there
is no other causality than that
in accordance with laws of
nature. This being so, every-
thing which takes place pre-
supposes a preceding state
upon which it inevitably fol-
lows according to a rule. But
the preceding state must it-
self be something which has
taken place (having come to
be in a time in which it
previously was not); 
P 409a
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] external to one an-
There is no freedom; every-
thing in the world takes place
solely in accordance with
laws of nature. 
Assume that there is free-
dom in the transcendental
sense, as a special kind of
causality in accordance with
which the events in the
world can have come about,
namely, a power of absolutely
beginning a state, and there-
fore also of absolutely begin-
ning a series of consequences
of that state;
P 410
for if it had always existed, its con-
sequence also would have
always existed, and would
not have only just arisen. 
The causality of the cause
through which something
takes place is itself, therefore,
something that has taken
place, which again presup-
poses, in accordance with
the law of nature, a pre-
ceding state and its causality,
and this in similar manner a
still earlier state, and so on. 
If, therefore, everything takes
place solely in accordance
with laws of nature, there
will always be only a relative
and never a first beginning,
and consequently no com-
pleteness of the series on the
side of the causes that arise
the one from the other. But
the law of nature is just this,
that nothing takes place with-
out a cause sufficiently deter-
mined a priori. The proposi-
tion that no causality is pos-
sible save in accordance with
laws of nature, when taken
in unlimited universality, is
therefore self-contradictory;
and this cannot, therefore,
be regarded as the sole kind
of causality. 
P 409a
 it then follows
that not only will a series
have its absolute beginning
P 410a
in this spontaneity, but that
the very determination of
this spontaneity to originate
the series, that is to say,
the causality itself, will have
an absolute beginning; there
will be no antecedent through
which this act, in taking
place, is determined in ac-
cordance with fixed laws. 
But every beginning of action
presupposes a state of the
not yet acting cause; and a
dynamical beginning of the
action, if it is also a first be-
ginning, presupposes a state
which has no causal con-
nection with the preceding
state of the cause, that is to
say, in nowise follows from
it. Transcendental freedom
thus stands opposed to the
law of causality; and the kind
of connection which it as-
sumes as holding between the
successive states of the active
causes renders all unity of
experience impossible. It is
not to be met with in any
experience, and is therefore
an empty thought-entity. 
In nature alone, therefore,
[not in freedom], must we
seek for the connection and
order of cosmical events. 
Freedom (independence) from
the laws of nature is no doubt
a liberation from compulsion,
but also from the guidance
P 411a
of all rules. 
P 410
 We must, then, assume a
causality through which some-
thing takes place, the cause
of which is not itself
P 411
determined, in accordance with
necessary laws, by another
cause antecedent to it, that is
to say, an absolute spontaneity
of the cause, whereby a series
of appearances, which pro-
ceeds in accordance with laws
of nature, begins of itself. 
This is transcendental free-
dom, without which, even in
the [ordinary] course of na-
ture, the series of appearances
on the side of the causes can
never be complete. 
P 411a
For it is not
permissible to say that the
laws of freedom enter into
the causality exhibited in the
course of nature, and so take
the place of natural laws. 
If freedom were determined
in accordance with laws,
it would not be freedom;
it would simply be nature
under another name. Nature
and transcendental freedom
differ as do conformity to
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. 
P 412
I. On the Thesis
The transcendental idea of
freedom does not by any
means constitute the whole
content of the psychological
concept of that name, which
is mainly empirical. The tran-
scendental idea stands only
for the absolute spontaneity
of an action, as the proper
ground of its imputability. 
This, however, is, for philo-
sophy, the real stumbling-
block; for there are insur-
mountable difficulties in the
way of admitting any such
type of unconditioned caus-
ality. What has always so
greatly embarrassed specula-
tive reason in dealing with
the question of the freedom
of the will, is its strictly
transcendental aspect. The
problem, properly viewed, is
solely this: whether we must
admit a power of spontane-
ously beginning a series of
successive things or states. 
How such a power is possible
is not a question which re-
quires to be answered in this
case, any more than in regard
to causality in accordance
with the laws of nature. For,
[as we have found], we have
to remain satisfied with the
P 413
a priori knowledge that this
latter type of causality must be
P 412a
II. On the Antithesis
The defender of an om-
nipotent nature (transcend-
ental physiocracy), in main-
taining his position against
the pseudo-rational argu-
ments offered in support of the
counter-doctrine of freedom,
would argue as follows. If
you do not, as regards time,
admit anything as being
mathematically first in the
world, there is no necessity,
as regards causality, for seek-
ing something that is dynamic-
ally first. What authority
have you for inventing an
absolutely first state of the
world, and therefore an abso-
lute beginning of the ever-
flowing series of appearances,
and so of procuring a resting-
place for your imagination
by setting bounds to limitless
nature? Since the substances
in the world have always
existed -- at least the unity of
experience renders necessary
such a supposition -- there is
no difficulty in assuming that
change of their states, that is,
a series of their alterations, has
likewise always existed, and
therefore that a first begin-
ning, whether mathematical
or dynamical, is not to be looked for. 
P 413
we are not in the
least able to comprehend how
it can be possible that through
one existence the existence
of another is determined, and
for this reason must be guided
by experience alone. The
necessity of a first beginning,
due to freedom, of a series of
appearances we have demon-
strated only in so far as it
is required to make an origin
of the world conceivable; for
all the later following states
can be taken as resulting ac-
cording to purely natural
laws. But since the power
of spontaneously beginning
a series in time is thereby
proved (though not under-
stood), it is now also per-
missible for us to admit
within the course of the
world different series as cap-
able in their causality of
beginning of themselves, and
so to attribute to their sub-
stances a power of acting
from freedom. And we must
not allow ourselves to be
prevented from drawing this
conclusion by a misapprehen-
sion, namely that, as a series
occurring in the world can
have only a relatively first
beginning, being always pre-
ceded in the world by some
other state of things, no
P 414
absolute first beginning of a
series is possible during the
course of the world. 
P 413a
The possibility of
such an infinite derivation,
without a first member to
which all the rest is merely a
sequel, cannot indeed, in re-
spect of its possibility, be ren-
dered comprehensible. But
if for this reason you refuse
to recognise this enigma in
nature, you will find yourself
compelled to reject many
fundamental synthetic pro-
perties and forces, which as
little admit of comprehension. 
The possibility even of altera-
tion itself would have to be
denied. For were you not
assured by experience that
alteration actually occurs,
you would never be able to
excogitate a priori the pos-
sibility of such a ceaseless
sequence of being and not-
Even if a transcendental
power of freedom be allowed,
as supplying a beginning of
happenings in the world, this
power would in any case have
to be outside the world
(though any such assump-
tion that over and above the
sum of all possible intuitions
there exists an object which
cannot be given in any pos-
sible perception, is still a very
bold one). But to ascribe to
substances in the world itself
such a power, can never be
P 414
For the
absolutely first beginning of
which we are here speaking
is not a beginning in time,
but in causality. If, for in-
stance, I at this moment
arise from my chair, in com-
plete freedom, without being
necessarily determined thereto
by the influence of natural
causes, a new series, with all
its natural consequences in
infinitum, has its absolute
beginning in this event, al-
though as regards time this
event is only the continuation
of a preceding series. For this
resolution and act of mine do
not form part of the succession
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. 
P 414a
 for, should this be done, that connection of
appearances determining one
another with necessity ac-
cording to universal laws,
which we entitle nature, and
with it the criterion of em-
pirical truth, whereby experi-
ence is distinguished from
dreaming, would almost en-
tirely disappear. Side by side
with such a lawless faculty
of freedom, nature [as an
ordered system] is hardly
thinkable; the influences of
the former would so un-
ceasingly alter the laws of
the latter that the appear-
ances which in their natural
course are regular and uni-
form would be reduced to
disorder and incoherence. 
P 414
 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
P 415
philosophers of antiquity, with the
sole exception of the Epi-
curean School, felt them-
selves obliged, when explain-
ing cosmical movements, to
assume a prime mover, 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. 
There belongs to the world,
either as its part or as its
cause, a being that is abso-
lutely necessary. 
The sensible world, as the
sum-total of all appearances,
contains a series of alterations. 
For without such a series even
the representation of serial
time, as a condition of the
possibility of the sensible
world, would not be given us. 
++ 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. 
P 415a
An absolutely necessary
being nowhere exists in the
world, nor does it exist out-
side the world as its cause. 
If we assume that the
world itself is necessary, or
that a necessary being exists
in it, there are then two alter-
natives. Either there is a be-
ginning in the series of alter-
ations which is absolutely
necessary, and therefore with-
out a cause, or the series it-
self is without any beginning,
and although contingent and
P 416a
conditioned in all its parts,
none the less, as a whole, is
absolutely necessary and un-
P 415
But every alteration stands
under its condition, which pre-
cedes it in time and renders
P 416
it necessary. Now every con-
ditioned that is given pre-
supposes, in respect of its
existence, a complete series of
conditions up to the uncon-
ditioned, which alone is abso-
lutely necessary. Alteration
thus existing as a consequence
of the absolutely necessary,
the existence of something
absolutely necessary must
be granted. But this neces-
sary existence itself belongs
to the sensible world. For if
it existed outside that world,
the series of alterations in the
world would derive its begin-
ning from a necessary cause
which would not itself belong
to the sensible world. This,
however, is impossible. For
since the beginning of a series
in time can be determined
only by that which precedes
it in time, the highest condi-
tion of the beginning of a
series of changes must exist
in the time when the series
as yet was not (for a begin-
ning is an existence preceded
by a time in which the thing
that begins did not yet exist). 
P 416a
The former
alternative, however, conflicts
with the dynamical law of the
determination of all appear-
ances in time; and the latter
alternative contradicts itself,
since the existence of a series
cannot be necessary if no
single member of it is neces-
If, on the other hand, we
assume that an absolutely
necessary cause of the world
exists outside the world, then
this cause, as the highest
member in the series of the
causes of changes in the
world, must begin the exist-
ence of the latter and their
series. Now this cause must
itself begin to act, and its
causality would therefore be
in time, and so would be-
long to the sum of appear-
ances, that is, to the world. It
follows that it itself, the cause,
would not be outside the
world -- which contradicts our
++ The word 'begin' is taken in two senses; first as active, signify-
ing that as cause it begins (infit) a series of states which is its effect;
secondly as passive, signifying the causality which begins to operate
(fit) in the cause itself. I reason here from the former to the latter
P 416
Accordingly the causality
of the necessary cause of
P 417
alterations, and therefore the
cause itself, must belong to
time and so to appearance --
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. 
I. On the Thesis
In proving the existence of
a necessary being I ought
not, in this connection, to
employ any but the cosmo-
logical argument, that,
namely, which ascends from
the conditioned in the [field
of] appearance to the un-
conditioned in concept, this
latter being regarded as the
necessary condition of the
absolute totality of the series. 
To seek proof of this from the
mere idea of a supreme being
belongs to another principle
of reason, and will have to
be treated separately. 
The pure cosmological
proof, in demonstrating the
existence of a necessary being,
P 418
has to leave unsettled whether
this being is the world itself
or a thing distinct from it. 
P 416a
Therefore neither
in the world, nor outside the
world (though in causal
P 417a
connection with it), does there
exist any absolutely necessary
II. On the Antithesis
The difficulties in the way
of asserting the existence of
an absolutely necessary high-
est cause, which we suppose
ourselves to meet as we
ascend in the series of appear-
ances, cannot be such as
arise in connection with mere
concepts of the necessary
existence of a thing in general. 
The difficulties are not, there-
fore, ontological, but must
concern the causal connection
of a series of appearances for
which a condition has to be
assumed that is itself un-
conditioned, and so must be
cosmological, and relate to
empirical laws. 
P 418
To establish the latter view,
we should require principles
which are no longer cosmo-
logical and do not continue in
the series of appearances. For
we should have to employ
concepts of contingent beings
in general (viewed as objects
of the understanding alone)
and a principle which will
enable us to connect these,
by means of mere concepts,
with a necessary being. But
all this belongs to a tran-
scendent philosophy; and
that we are not yet in a
position to discuss. 
If we begin our proof
cosmologically, resting it upon
the series of appearances and
the regress therein according
to empirical laws of causality,
we must not afterwards sud-
denly deviate from this mode
of argument, passing over to
something that is not a mem-
ber of the series. Anything
taken as condition must be
viewed precisely in the same
manner in which we viewed
the relation of the condi-
tioned to its condition in the
series which is supposed to
carry us by continuous ad-
vance to the supreme condi-
P 417
It must be
shown that regress in the
P 418a
series of causes (in the
sensible world) can never
terminate in an empirically
unconditioned condition, and
that the cosmological argu-
ment from the contingency
of states of the world, as
evidenced by their alterations,
does not support the assump-
tion of a first and absolutely
originative cause of the series. 
A strange situation is dis-
closed in this antinomy. 
From the same ground on
which, in the thesis, the ex-
istence of an original being
was inferred, its non-exist-
ence is inferred in the anti-
thesis, and this with equal
stringency. We were first
assured that a necessary being
exists because the whole of
past time comprehends the
series of all conditions and
therefore also the uncondi-
tioned (that is, the necessary);
we are now assured that there
is no necessary being, and
precisely for the reason that
the whole of past time com-
prehends the series of all
conditions (which therefore
are one and all themselves
conditioned). The explana-
tion is this. The former argu-
ment takes account only of
the absolute totality of the
series of conditions deter-
mining each other in time,
P 419a
and so reaches what is un-
conditioned and necessary. 
P 419
If, then, this relation is sensible and falls within the
province of the possible em-
pirical employment of under-
standing, the highest condi-
tion or cause can bring the
regress to a close only in
accordance with the laws of
sensibility, and therefore only
in so far as it itself belongs
to the temporal series. The
necessary being must there-
fore be regarded as the highest
member of the cosmical series. 
Nevertheless certain think-
ers have allowed themselves
the liberty of making such a
saltus (metabasis eis allo
genos. From the alterations
in the world they have in-
ferred their empirical con-
tingency, that is, their de-
pendence on empirically de-
termining causes, and so have
obtained an ascending series
of empirical conditions. And
so far they were entirely in
the right. But since they
could not find in such a
series any first beginning, or
any highest member, they
passed suddenly from the
empirical concept of con-
tingency, and laid hold upon
the pure category, which then
gave rise to a strictly intelli-
gible series the completeness
of which rested on the exist-
ence of an absolutely neces-
sary cause. 
P 419a
The latter argument, on the
other hand, takes into con-
sideration the contingency of
everything which is deter-
mined in the temporal series
(everything being preceded
by a time in which the condi-
tion must itself again be
determined as conditioned),
and from this point of view
everything unconditioned and
all absolute necessity com-
pletely vanish. Nevertheless,
the method of argument in
both cases is entirely in con-
formity even with ordinary
human reason, which fre-
quently falls into conflict with
itself through considering its
object from two different
points of view. M. de Mairan
regarded the controversy be-
tween two famous astrono-
mers, which arose from a
similar difficulty in regard to
choice of standpoint, as a
sufficiently remarkable phe-
nomenon to justify his writing
a special treatise upon it. The
one had argued that the
moon revolves on its own
axis, because it always turns
the same side towards the
earth. The other drew the
opposite conclusion that the
moon does not revolve on its
own axis, because it always
P 420a
turns the same side towards
the earth. 
P 420
Since this cause was not bound down to any
sensible conditions, it was
freed from the temporal con-
dition which would require
that its causality should itself
have a beginning. But such
procedure is entirely illegiti-
mate, as may be gathered
from what follows. 
In the strict meaning of the
category, the contingent is
so named because its contra-
dictory opposite is possible. 
Now we cannot argue from
empirical contingency to in-
telligible contingency. When
anything is altered, the op-
posite of its state is actual
at another time, and is there-
fore possible. This present
state is not, however, the
contradictory opposite of the
preceding state. To obtain
such a contradictory opposite
we require to conceive, that
in the same time in which the
preceding state was, its op-
posite could have existed in
its place, and this can never
be inferred from [the fact of]
the alteration. A body which
was in motion (= A) comes
to rest (= non-A). Now from
the fact that a state opposite
to the state A follows upon
the state A, we cannot argue
that the contradictory op-
posite of A is possible, and
that A is therefore con-
P 420a
Both inferences
were correct, according to the
point of view which each
chose in observing the moon's
P 421
To prove such a conclusion, it would have to
be shown that in place of the
motion, and at the time at
which it occurred, there could
have been rest. All that we
know is that rest was real in
the time that followed upon
the motion, and was therefore
likewise possible. Motion at
one time and rest at another
time are not related as contra-
dictory opposites. Accord-
ingly the succession of op-
posite determinations, that is,
alteration, in no way estab-
lishes contingency of the type
represented in the concepts of
pure understanding; and can-
not therefore carry us to the
existence of a necessary being,
similarly conceived in purely
intelligible terms. Alteration
proves only empirical con-
tingency; that is, that the
new state, in the absence of
a cause which belongs to the
preceding time, could never
of itself have taken place. 
Such is the condition pre-
scribed by the law of causal-
ity. This cause, even if it be
viewed as absolutely neces-
sary, must be such as can be
thus met with in time, and
must belong to the series of
P 422
Section 3
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 a priori 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
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
P 423
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
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
reign 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
P 424
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
a principle of pure empiricism, 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 dogmatism
of pure reason. 
In the determination of the cosmological ideas, we find on
the side of dogmatism, that is, of the thesis:
First, a certain practical interest 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 speculative interest on the side of
P 425
the thesis. When the transcendental ideas are postulated and
employed in the manner prescribed by the thesis, the entire
chain of conditions and the derivation of the conditioned can
be grasped completely a priori. 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 popularity;
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
the side of empiricism, that is, of the antithesis: 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, moral ideas and principles lose all
validity, and share in the fate of the transcendental ideas
which served as their theoretical support. 
But secondly, in compensation, empiricism yields advan-
tages to the speculative interest of reason, which are very
P 426
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
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 think and to
invent 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 in concreto (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,
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. 
P 427
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 presuppositions and faith on behalf of our practical
interest; only they could never be permitted to assume the
title and dignity of science and rational insight. Knowledge,
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 contrast between the teaching of Epicurus and that of
Plato is of this nature. 
++ 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; 
P 428
 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
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
so scholastically correct a manner as those with special train-
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; 
++ 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
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 [i.e. 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 ignore these dogmatic propositions [that there is a limit and
beginning to the world, a Divine Cause, etc. ], can justly be accused
of wishing to deny them. 
P 429
whereas 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
knows what its fears or hopes incite it to assume or to believe. 
Thus empiricism 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
P 430
complete edifice of knowledge is, on such assumptions, alto-
gether impossible. Thus the architectonic interest of reason --
the demand not for empirical but for pure a priori 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 free; 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 nature. 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-
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. 
Section 4
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-
less there are sciences the very nature of which requires that
every question arising within their domain should be com-
P 431
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 right and what is wrong, since this con-
cerns our obligation, and we have no obligation to that which
we cannot know. In the explanation of natural appearances,
on the other hand, much must remain uncertain and many
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
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
P 432
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
is unknown to us, though not therefore impossible. 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-
ence, being no longer empirical. Since we are here dealing
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
asking what is the constitution of any object in itself, nor
as regards possible experience are we enquiring what can
be given in concreto 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
++ Although to the question, what is the constitution of a tran-
scendental object, no answer can be given stating what it is, we can
yet reply that the question itself is nothing, 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 given
as object, and in which none of the categories (and it is to them
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. 
P 433
It is not so extraordinary as at first seems the case, that a
science should be in a position to demand and expect none but
assured answers to all the questions within its domain (quae-
stiones domesticae), 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
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 treating 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,
P 434
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
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
seek in our idea itself. For so long as we obstinately persist
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 in concreto. For that purpose, in
addition to this exhaustive intuition, we should require what
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
P 435
possible perceptions we always remain involved in conditions,
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
way, when taken together in an absolute whole, is not itself
a perception. Yet it is just the explanation of this very
whole that is demanded in the transcendental problems of
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. 
P 436
Section 5
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. 
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 too large or too small for any con-
cept of the understanding, 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
P 437
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: --
First, that the world has no beginning: it is then too large
for our concept, which, consisting as it does in a successive
regress, can never reach the whole eternity that has elapsed. 
Or suppose that the world has a beginning, it will then, in the
necessary empirical regress, be too small for the concept of
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 small 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 infinite
and unlimited, it is too large for any possible empirical con-
cept. If it is finite 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 empirical synthesis it is always necessary that
the unconditioned be an empirical concept. Consequently, a
limited world is too small for our concept. 
Secondly, if every appearance in space (matter) consists of
infinitely many parts, the regress in the division will always
be too great for our concept; while if the division of space is
to stop at any member of the division (the simple), the regress
will be too small for the idea of the unconditioned. For this
member always still allows of a regress to further parts con-
tained in it. 
Thirdly, if we suppose that nothing happens in the world
save in accordance with the laws of nature, 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 a parte priori without end. 
P 438
Nature, as working always through efficient causes, is thus
too large 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 freedom, 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 small for
our necessary empirical concept. 
Fourthly, if we admit an absolutely necessary being
(whether it be the world itself, or something in the world, or
the cause of the world), we set it in a time infinitely 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
 If, again, we hold that everything belonging to the world
(whether as conditioned or as condition) is contingent, any
and every given existence is too small 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
P 439
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
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. 
Section 6
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
in which they are represented, as extended beings, or as series of
alterations, have no independent existence outside our thoughts. 
This doctrine I entitle transcendental idealism. The realist, in
the transcendental meaning of this term, treats these modifica-
tions of our sensibility as self-subsistent things, that is, treats
mere representations as things in themselves. 
++ I have also, elsewhere, sometimes entitled it formal idealism,
to distinguish it from material idealism, that is, from the usual type
of idealism which doubts or denies the existence of outer things
P 439
It would be unjust to ascribe to us that long-decried
P 440
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-
 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
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 things; 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
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 never given in them-
selves, but only in experience, and have no existence outside it. 
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
P 441
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
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
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 objects. The non-sensible cause
of these 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
is given in itself prior to all experience. But the appearances,
P 442
while conforming to it, are not given in themselves, but only in
this experience, being mere representations, which as percep-
tions can mark out a real object only in 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
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
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
P 443
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
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
to guard us against a deceptive error which is bound to arise
if we misinterpret our empirical concepts. 
Section 7
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
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
all its conditions is set us as a task. 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
P 444
series. The above proposition is thus analytic, and has nothing
to fear from a transcendental criticism. It is a logical postulate
of reason, that through the understanding we follow up and
extend as far as possible that connection of a concept with its
conditions which directly results from the concept itself. 
Further, if the conditioned as well as its condition are
things in themselves, then upon the former being given, the
regress to the latter is not only set as a task, but therewith
already really given. And since this holds of all members of
the series, the complete series of the conditions, and therefore
the unconditioned, is given therewith, or rather is presupposed
in view of the fact that the conditioned, which is only possible
through the complete series, is given. The synthesis of the
conditioned with its condition is here a synthesis of the mere
understanding, which represents things as they are, without
considering whether and how we can obtain knowledge of
them. If, however, what we are dealing with are appearances
-- as mere representations appearances cannot be given save
in so far as I attain knowledge of them, or rather attain them
in themselves, for they are nothing but empirical modes of
knowledge -- I cannot say, in the same sense of the terms, that
if the conditioned is given, all its conditions (as appearances)
are likewise given, and therefore cannot in any way infer the
absolute totality of the series of its conditions. The appear-
ances are in their apprehension themselves nothing but an
empirical synthesis in space and time, and are given only in
this synthesis. It does not, therefore, follow, that if the con-
ditioned, in the [field of] appearance, is given, the synthesis
which constitutes its empirical condition is given therewith
and is presupposed. This synthesis first occurs in the regress,
and never exists without it. What we can say is that a regress
to the conditions, that is, a continued empirical synthesis, on
the side of the conditions, is enjoined or set as a task, and that
in this regress there can be no lack of given conditions. 
These considerations make it clear that the major premiss
of the cosmological inference takes the conditioned in the
transcendental sense of a pure category, while the minor pre-
miss takes it in the empirical sense of a concept of the under-
standing applied to mere appearances. The argument thus
commits that dialectical fallacy which is entitled sophisma
P 445
figurae dictionis. This fallacy is not, however, an artificial
one; a quite natural illusion of our common reason leads
us, when anything is given as conditioned, thus to assume in
the major premiss, as it were without thought or question, its
conditions and their series. This assumption is indeed simply
the logical requirement that we should have adequate pre-
misses for any given conclusion. Also, there is no reference to a
time-order in the connection of the conditioned with its con-
dition; they are presupposed as given together with it. Further,
it is no less natural, in the minor premiss, to regard appear-
ances both as things in themselves and as objects given to the
pure understanding, than to proceed as we have done in the
major, in which we have [similarly] abstracted from all those
conditions of intuition under which alone objects can be given. 
Yet in so doing we have overlooked an important distinction
between the concepts. The synthesis of the conditioned with
its conditions (and the whole series of the latter) does not in
the major premiss carry with it any limitation through time
or any concept of succession. The empirical synthesis, on the
other hand, that is, the series of the conditions in appearance,
as subsumed in the minor premiss, is necessarily successive,
the members of the series being given only as following upon
one another in time; and I have therefore, in this case, no right
to assume the absolute totality of the synthesis and of the
series thereby represented. In the major premiss all the mem-
bers of the series are given in themselves, without any condi-
tion of time, but in this minor premiss they are possible only
through the successive regress, which is given only in the
process in which it is actually carried out. 
When this error has thus been shown to be involved in the
argument upon which both parties alike base their cosmo-
unable to offer any sufficient title in support of their claims. 
But the quarrel is not thereby ended -- as if one or both of the
parties had been proved to be wrong in the actual doctrines
they assert, that is, in the conclusions of their arguments. For
although they have failed to support their contentions by valid
grounds of proof, nothing seems to be clearer than that since
one of them asserts that the world has a beginning and the
other that it has no beginning and is from eternity, one of the
P 446
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
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
there is no other thing, nothing outside it, with which it could
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. 
P 447
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 (vel suaveolens vel
non suaveolens), 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 (per disparata), 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 contradictory
If, therefore, we say that the world is either infinite in
extension or is not infinite (non est infinitus), 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
(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
may, however, likewise be false; the world may not be given
as a thing in itself, nor as being in its magnitude either infinite
or finite. I beg permission to entitle this kind of opposition
dialectical, and that of contradictories analytical. 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
P 448
rather this accompanying transcendental illusion, and deny
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
in itself neither as an infinite whole nor as a finite 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
necessary existence. These series can never be regarded as
being in themselves in their totality either finite or infinite. 
Being series of subordinated representations, 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
applying to appearances 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
P 449
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
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. 
Section 8
Since no maximum of the series of conditions in a sensible
world, regarded as a thing in itself, is given through the cos-
mological principle of totality, but can only be set as a task
that calls for regress in the series of conditions, the principle
of pure reason has to be amended in these terms; and it
P 450
then preserves its validity, not indeed as the axiom that we
think the totality as actually in the object, but as a problem 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 rule, pre-
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 constitutive 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 rule, postulating what we ought to do in the
regress, but not anticipating what is present in the object as
it is in itself, prior to all regress. Accordingly I entitle it a
regulative 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),
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
P 451
pure reason, we must observe, first, that it cannot tell us what
the object is, but only how the empirical regress is to be carried
out 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 progressus in
infinitum. Philosophers, whose task it is to examine concepts,
refuse to accept this expression as legitimate, substituting for
it the phrase progressus in indefinitum. 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 (progressus in in-
definitum) would be mere subtlety. When we say, ' Draw a line',
it sounds indeed more correct to add in indefinitum than in
infinitum. Whereas the latter means that you must not cease
producing it -- which is not what is intended -- the former means
only, produce it as far as you please; and if we are referring
only to what it is in our power to do, this expression is quite
P 452
correct, for we can always make the line longer, without end. 
So is it in all cases in which we speak only of the progress, that
is, of the advance 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
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 (datum), but only as something con-
ditioned, that allows of being given (dabile), 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 in
infinitum, or only that it is indeterminately far extended (in
indefinitum)?  Can we, for instance, ascend from the men now
living, through the series of their ancestors, in infinitum; 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 in infinitum; 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 (in
indefinitum). Accordingly, the division of a body, that is, of a
portion of matter given between certain limits, must be said to
proceed in infinitum. 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
of this part is the part of the part, and so on, and since in
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 in infinitum. On
P 453
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 in infinitum, 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 in infinitum or in
indefinitum, 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 possible to proceed back in
the series of its inner conditions in infinitum. When the whole
is not given, but has first to be given through empirical regress,
we can only say that the search for still higher conditions of the
series is possible in infinitum. 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 find further members of the series; in
the other case, since no experience is absolutely limited, the
necessity is that we enquire for them. For either we have no
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 limits must be distinct from that which is
P 454
thereby limited), 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. 
Section 9
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
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 in itself 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 for the continuation 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 dialec-
tical will thus be converted into a doctrinal principle. In fact,
if this principle can be upheld as determining, in accordance
P 455
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
determined a priori the objects in themselves. For only in pro-
portion as the principle is effective in directing the widest
possible empirical employment of the understanding, can it
exercise, in respect of the objects of experience, any influence
in extending and correcting our knowledge. 
Solution of the Cosmological Idea of the Totality of the
Composition of the Appearances of a Cosmic Whole 
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 no experience of an absolute
limit, that is, no experience of any condition as being one
that empirically 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-
ditions which must themselves again be regarded as empiric-
ally conditioned, contains the rule in terminis, 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 (in indefinitum). 
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
P 456
for a given perception arise at all. Now we have the cosmic
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 doing 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 in infinitum. 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
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 regressus in indefini-
tum, which, as it determines no magnitude in the object,
is clearly enough distinguishable from the regressus in infini-
++ 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. 
P 457
I cannot say, therefore, that the world is infinite 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 infinity; that would be to
presuppose that the world has infinite magnitude. I also can-
not say that the regress is finite; 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
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
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. 
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 in indefinitum. 
++ 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. 
P 458
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
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,
e.g. 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
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 in the world are conditionally
limited, the world itself is neither conditionally nor uncon-
ditionally limited. 
Similarly, since the world can never be given as complete,
and since even the series of conditions for that which is given
as conditioned cannot, as a cosmic series, be given as complete,
the concept of the magnitude of the world is given only through
the regress and not in a collective intuition prior to it. But the
regress consists only in the determining of the magnitude, and
does not give any determinate 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. 
P 459
Solution of the Cosmological Idea of the Totality of
Division of a Whole given in Intuition 
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 (subdivisio or decompositio)
is a regress in the series of these conditions. The absolute
totality of this series would be given only if the regress could
reach simple 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 in infinitum. For the conditions (the parts)
are themselves contained in the conditioned, and since this
is given complete in an intuition that is enclosed between
limits the parts are one and all given together with the con-
ditioned. The regress may not, therefore, be entitled merely
a regress in indefinitum. 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 it is made up of infinitely
many parts. For although all parts are contained in the intuition
of the whole, the whole division 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 aggregate. But the
whole series of the division is not so contained, for it is a
successive infinite and never whole, 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
naturally follows, namely, to an outer appearance enclosed
P 460
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 substance, 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] appearance. 
For this latter is not an absolute subject, but only an abiding
image 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 in infinitum 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 quantum discretum. 
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 in infinitum, 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
P 461
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
conceived as organised in infinitum the whole is represented
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 quantum continuum; it is inseparable from the
occupation of space, which is indeed its ground. To view any-
thing as being a quantum discretum, is to take 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 possibility 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. 
Concluding Note on the Solution of the Mathematical - trans-
cendental Ideas, and Preliminary Observation on the Solution of
the Dynamical - transcendental Ideas. 
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
P 462
condition is always a member of a series along with the con-
ditioned, and so is homogeneous 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
least the 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
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 mathematical, the other two a
dynamical 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 dynamical 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 dismissed as
resting, on both sides, on false presuppositions. But since in
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 extension 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
P 463
these respects all homogeneous. But the concept of the under-
standing, which underlies these ideas, may contain either a
synthesis solely of the homogeneous (which is presupposed
alike in the composition and in the division of every magni-
tude), or a synthesis of the heterogeneous. 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 sensible 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
purely intelligible, and as such outside the series, can be
allowed. In this way reason obtains satisfaction and the
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 non-sensible. We
are thus able to obtain satisfaction for understanding on
the one hand and for reason on the other. 
++ Understanding does not admit among appearances any condi-
tion which can itself be empirically unconditioned. But if for some
conditioned in the [field of] appearance we can conceive an intellig-
ible 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
empirically unconditioned, without prejudice to the continuity of the
empirical regress. 
P 464
The dialectical arguments, which in one or other way sought unconditioned
totality in mere appearances, fall to the ground, and the pro-
positions of reason, when thus given this more correct inter-
pretation, may both alike be true. 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. 
Solution of the Cosmological Idea of Totality in the
Derivation of Cosmical Events from their Causes 
When we are dealing with what happens there are only two
kinds of causality conceivable by us; the causality is either
according to nature or arises from freedom. 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 come into being, and that in
accordance with the principle of the understanding it must
in its turn itself require a cause. 
 By freedom, on the other hand, in its cosmological mean-
ing, I understand the power of beginning a state spontane-
ously. 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 itself happens 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
P 465
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 transcendental 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
coercion through sensuous impulses. For a will is sensuous, in
so far as it is pathologically affected, i.e. by sensuous motives;
it is animal (arbitrium brutum), if it can be pathologically
necessitated. The human will is certainly an arbitrium sensi-
tivum, not, however, brutum but liberum. For sensibility does
not necessitate its action. There is in man a power of self-
determination, independently of any coercion through sensuous
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 ought 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 entirely of itself. 
Here then, as always happens when reason, in venturing
beyond the limits of possible experience, comes into conflict
with itself the problem is not really physiological but trans-
cendental. 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
P 466
this solution, a task which transcendental philosophy cannot
decline, I must define somewhat more accurately the 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 only the dynami-
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 either
from nature or 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 absolute reality of appearances here mani-
fests its injurious influence, to the confounding of reason. For
if appearances are things 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
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-
P 467
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. 
Possibility of Causality through Freedom, in Harmony with the
Universal Law of Natural Necessity. 
Whatever in an object of the senses is not itself appearance,
I entitle intelligible. 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 causality of this being
can be regarded from two points of view. Regarded as the
causality of a thing in itself, it is intelligible in its action; re-
garded as the causality of an appearance in the world of sense,
it is sensible in its effects. 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
P 468
object, besides the quality in terms of which it appears, a
causality which is not appearance, although its effect is to be
met with in appearance. Every efficient cause must have a
character, 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 empirical character, 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
intelligible character, 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 action would begin or cease, and it would not, there-
fore, have to conform to the law of the determination of all that
is alterable in time, namely, that everything which happens
must have its cause in the appearances 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 thought 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
P 469
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
In its intelligible character (though we can only have a
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
noumenon, nothing happens 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 in this
active being itself; but we may yet quite correctly say that the
active being of itself 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. 
Explanation of the Cosmological Idea of Freedom in its con-
nection with Universal Natural Necessity. 
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 action of
P 470
the cause, is antecedent in time to the effect which has ensued
upon it, it cannot itself have always existed, but must have
happened, and among the appearances 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 nature 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,
to distinguish it from all objects of possible experience, and so
to make of it a mere thought-entity, a phantom of the brain. 
This would seem to imply the existence of a chain of causes
which in the regress to their conditions allows of no absolute tot-
ality. 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 in the 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
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-
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 original 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
P 471
rather be, that while for every effect in the [field of] appear-
ance a connection with its cause in accordance with the
laws 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
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 action of these causes in the [field of] appearance is in con-
formity with all the laws of empirical causality. In this way
the acting subject, as causa phaenomenon, 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
noumenon 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
P 472
unknown to us. This intelligible ground does not have to be
considered in empirical enquiries; it concerns only thought
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
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 impera-
tives which in all matters of conduct we impose as rules upon
our active powers. 'Ought' expresses a kind of necessity and of
connection with grounds which is found nowhere else in the
P 473
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 ought to be other than what in all these
time-relations it actually is. When we have the course of
nature alone in view, 'ought' 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 'ought' 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
appearance. The action to which the 'ought' 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 will, they
can never give rise to the 'ought', but only to a willing which,
while very far from being necessary, is always conditioned; and
the 'ought' 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,
it must none the less exhibit an empirical character. For every
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
P 474
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-
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 observing, 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 to explain their coming into being, but reason in so
far as it is itself the cause producing them -- if, that is to say,
we compare them with [the standards of] reason in its practical
bearing, we find a rule and order altogether different from the
order of nature. For it may be that all that has happened in the
course of nature, and in accordance with its empirical grounds
must inevitably have happened, ought not to have happened. 
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
P 475
determined by empirical causes, but because they were deter-
mined by grounds of reason. 
Granted, then, that reason may be asserted to have caus-
ality in respect of appearance, its action can still be said to
be free, even although its empirical character (as a mode of
sense) is completely and necessarily determined in all its
detail. This empirical character is itself determined in the in-
telligible character (as a mode of thought). 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. The action, in so far as it can be ascribed to a mode
of thought as its cause, does not follow therefrom in accord-
ance with empirical laws; that is to say, it is not preceded
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, arise or begin to be at a certain time. For in
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 through
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. 
++ 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 (merito fortunae), can
never be determined; and upon it therefore no perfectly just judg-
ments can be passed. 
P 476
For here the condition is outside 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
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
in the series 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-
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 before and after; 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. 
P 477
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-
mined, we none the less blame the agent, not indeed on account
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
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
P 478
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 deter-
mining, not determinable. We may not, therefore, ask why
reason has not determined itself differently, but only why it
has not through its causality determined the appearances 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. 
 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 space 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
P 479
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 reality
of freedom as one of the faculties which contain the cause of
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 possibility of
freedom. For in this also we should not have succeeded, since
we cannot from mere concepts a priori 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 not incompatible with nature. 
Solution of the Cosmological Idea of the Totality of the De-
pendence of Appearances as regards their Existence in
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 necessary being. We are concerned here, not
with unconditioned causality, but with the unconditioned
existence of substance itself. The series which we have in
P 480
view is, therefore, really a series of concepts, not a series
of intuitions in which one intuition is the condition of the
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
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. 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
member, not even as the highest member of it, nor would it
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
P 481
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 (substantia phaenomenon) con-
ceived to belong to the series of conditions, and only its
causality 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 ens extramundanum), and as
purely intelligible. In no other way can it be secured against
the law which renders all appearances contingent and de-
The regulative principle of reason, 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
that is free from all empirical conditions and itself contains
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 transcendent, adopting grounds of explanation that are
incapable of any representation in concreto, 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 impossible, 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
P 482
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, both may be true. Such
an absolutely necessary being, as conceived by the under-
standing, may be in itself impossible, but this can in no wise
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 the empirical series, no matter what member it may be, we
are never justified in making a leap out beyond the context
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 things, but not with
mere representations 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 intelli-
gible 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-
tingency. That, indeed, is all that we had to do in order to
remove the apparent antinomy; and it can be done in this way
only. If for everything conditioned in its existence the con-
dition 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
P 483
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 not 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
contingency of appearances, that is to say, with the never-
ending regress in the series of empirical conditions. 
Concluding Note on the whole Antinomy of Pure Reason. 
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 cosmological. 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 transcendent. 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 a priori 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-
P 484
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
reasons that could establish the possibility of such an object,
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 look 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 viewed
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 are 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
very first step which we take beyond the world of sense
obliges us, in seeking for such new knowledge, to begin with
an enquiry into absolutely necessary being, and to derive from
the concepts of it the concepts of all things in so far as they
are purely intelligible. This we propose to do in the next