since； if they are not presupposed； it is impossible that anything can
be an object of experience。 Now all experience contains； besides the
intuition of the senses through which an object is given； a conception
also of an object that is given in intuition。 Accordingly； conceptions
of objects in general must lie as a priori conditions at the
foundation of all empirical cognition； and consequently； the objective
validity of the categories； as a priori conceptions； will rest upon
this； that experience （as far as regards the form of thought） is
possible only by their means。 For in that case they apply
necessarily and a priori to objects of experience； because only
through them can an object of experience be thought。
The whole aim of the transcendental deduction of all a priori
conceptions is to show that these conceptions are a priori
conditions of the possibility of all experience。 Conceptions which
afford us the objective foundation of the possibility of experience
are for that very reason necessary。 But the analysis of the
experiences in which they are met with is not deduction； but only an
illustration of them； because from experience they could never
derive the attribute of necessity。 Without their original
applicability and relation to all possible experience； in which all
objects of cognition present themselves； the relation of the
categories to objects； of whatever nature； would be quite
inprehensible。
The celebrated Locke； for want of due reflection on these points；
and because he met with pure conceptions of the understanding in
experience； sought also to deduce them from experience； and yet
proceeded so inconsequently as to attempt； with their aid； to arrive
it cognitions which lie far beyond the limits of all experience。 David
Hume perceived that； to render this possible； it was necessary that
the conceptions should have an a priori origin。 But as he could not
explain how it was possible that conceptions which are not connected
with each other in the understanding must nevertheless be thought as
necessarily connected in the object… and it never occurred to him that
the understanding itself might； perhaps； by means of these
conceptions； be the author of the experience in which its objects were
presented to it… he was forced to drive these conceptions from
experience； that is； from a subjective necessity arising from repeated
association of experiences erroneously considered to be objective…
in one word； from habit。 But he proceeded with perfect consequence and
declared it to be impossible； with such conceptions and the principles
arising from them； to overstep the limits of experience。 The empirical
derivation； however； which both of these philosophers attributed to
these conceptions； cannot possibly be reconciled with the fact that we
do possess scientific a priori cognitions； namely； those of pure
mathematics and general physics。
The former of these two celebrated men opened a wide door to
extravagance… （for if reason has once undoubted right on its side；
it will not allow itself to be confined to set limits； by vague
remendations of moderation）； the latter gave himself up entirely to
scepticism… a natural consequence； after having discovered； as he
thought； that the faculty of cognition was not trustworthy。 We now
intend to make a trial whether it be not possible safely to conduct
reason between these two rocks； to assign her determinate limits；
and yet leave open for her the entire sphere of her legitimate
activity。
I shall merely premise an explanation of what the categories are。
They are conceptions of an object in general； by means of which its
intuition is contemplated as determined in relation to one of the
logical functions of judgement。 The following will make this plain。
The function of the categorical judgement is that of the relation of
subject to predicate； for example； in the proposition： 〃All bodies are
divisible。〃 But in regard to the merely logical use of the
understanding； it still remains undetermined to which Of these two
conceptions belongs the function Of subject and to which that of
predicate。 For we could also say： 〃Some divisible is a body。〃 But
the category of substance； when the conception of a body is brought
under it； determines that； and its empirical intuition in experience
must be contemplated always as subject and never as mere predicate。
And so with all the other categories。
SECTION II Transcendental Deduction of the pure Conceptions of
the Understanding。 SS 11
Of the Possibility of a Conjunction of the manifold representations
given by Sense。
The manifold content in our representations can be given in an
intuition which is merely sensuous… in other words； is nothing but
susceptibility； and the form of this intuition can exist a priori in
our faculty of representation； without being anything else but the
mode in which the subject is affected。 But the conjunction
（conjunctio） of a manifold in intuition never can be given us by the
senses； it cannot therefore be contained in the pure form of
sensuous intuition； for it is a spontaneous act of the faculty of
representation。 And as we must； to distinguish it from sensibility；
entitle this faculty understanding； so all conjunction whether
conscious or unconscious； be it of the manifold in intuition； sensuous
or non…sensuous； or of several conceptions… is an act of the
understanding。 To this act we shall give the general appellation of
synthesis； thereby to indicate； at the same time； that we cannot
represent anything as conjoined in the object without having
previously conjoined it ourselves。 Of all mental notions； that of
conjunction is the only one which cannot be given through objects； but
can be originated only by the subject itself； because it is an act
of its purely spontaneous activity。 The reader will easily enough
perceive that the possibility of conjunction must be grounded in the
very nature of this act； and that it must be equally valid for all
conjunction； and that analysis； which appears to be its contrary；
must； nevertheless； always presuppose it； for where the
understanding has not previously conjoined； it cannot dissect or
analyse； because only as conjoined by it； must that which is to be
analysed have been given to our faculty of representation。
But the conception of conjunction includes； besides the conception
of the manifold and of the synthesis of it； that of the unity of it
also。 Conjunction is the representation of the synthetical unity of
the manifold。* This idea of unity； therefore； cannot arise out of that
of conjunction； much rather does that idea； by bining itself with
the representation of the manifold； render the conception of
conjunction possible。 This unity； which a priori precedes all
conceptions of conjunction； is not the category of unity （SS 6）； for
all the categories are based upon logical functions of judgement；
and in these functions we already have conjunction； and consequently
unity of given conceptions。 It is therefore evident that the
category of unity presupposes conjunction。 We must therefore look
still higher for this unity （as qualitative； SS 8）； in that； namely；
which contains the ground of the unity of diverse conceptions in
judgements； the ground； consequently； of the possibility of the
existence of the understanding； even in regard to its logical use。
*Whether the representations are in themselves identical； and
consequently whether one can be thought analytically by means of and
through the other； is a question which we need not at present
consider。 Our Consciousness of the one； when we speak of the manifold；
is always distinguishable from our consciousness of the other； and
it is only respecting the synthesis of this （possible） consciousness
that we here treat。
Of the Originally Synthetical Unity of Apperception。 SS 12
The 〃I think〃 must acpany all my representations； for otherwise
something would be represented in me which could not be thought； in
other words； the representation would either be impossible； or at
least be； in relation to me； nothing。 That representation which can be
given previously to all thought is called intuition。 All the diversity
or manifold content of intuition； has； therefore； a necessary relation
to the 'I think；〃 in the subject in which this diversity is found。 But
this representation； 〃I think；〃 is an act of spontaneity； that is to
say； it cannot be regarded as belonging to mere sensibility。 I call it
pure apperception； in order to distinguish it from empirical； or
primitive apperception； because it is self…consciousness which； whilst
it gives birth to the representation〃 I think；〃 must necessarily be
capable of acpanying all our representations。 It is in all acts
of consciousness one and the same； and unacpanied by it； no
representation can exist for me。 The unity of this apperception I call
the transcendental unity of self…consciousness； in order to indicate
the possibility of a priori cognition arising from it。 For the
manifold representations which are given in an intuition would not all
of them be my representations； if they did not all belong to one
self…consciousness； that is； as my representations （even although I am
not conscious of them as such）； they must conform to the condition
under which alone they can exist together in a mon
self…consciousness； because otherwise they would not all without
exception belong to me。 From this primitive conjunction follow many
important results。
For example； this universal identity of the apperception of the
manifold given in intuition contains a synthesis of representations
and is possible only by means of the consciousness of this
synthesis。 For the empirical consciousness which acpanies different
representations is in itself fragmentary and disunited； and without
relation to the identity of the subject。 This relation； then； does not
exist because I acpany every representation with consciousness； but
because I join one representation to another； and am conscious of
the synthesis of them。 Consequently； only because I can connect a
variety of given representations in one consciousness； is it
possibl