objective reality； because we have no intuition to which the
synthetical unity of apperception； which alone the categories contain；
could be applied； for the purpose of determining an object。 Our
sensuous and empirical intuition can alone give them significance
and meaning。
If； then； we suppose an object of a non…sensuous intuition to be
given we can in that case represent it by all those predicates which
are implied in the presupposition that nothing appertaining to
sensuous intuition belongs to it； for example； that it is not
extended； or in space； that its duration is not time； that in it no
change （the effect of the determinations in time） is to be met with；
and so on。 But it is no proper knowledge if I merely indicate what the
intuition of the object is not； without being able to say what is
contained in it； for I have not shown the possibility of an object
to which my pure conception of understanding could be applicable；
because I have not been able to furnish any intuition corresponding to
it； but am only able to say that our intuition is not valid for it。
But the most important point is this； that to a something of this kind
not one category can be found applicable。 Take； for example； the
conception of substance； that is； something that can exist as subject；
but never as mere predicate； in regard to this conception I am quite
ignorant whether there can really be anything to correspond to such
a determination of thought； if empirical intuition did not afford me
the occasion for its application。 But of this more in the sequel。
Of the Application of the Categories to Objects of the
Senses in general。 SS 20
The pure conceptions of the understanding apply to objects of
intuition in general； through the understanding alone； whether the
intuition be our own or some other； provided only it be sensuous；
but are； for this very reason； mere forms of thought； by means of
which alone no determined object can be cognized。 The synthesis or
conjunction of the manifold in these conceptions relates； we have
said； only to the unity of apperception； and is for this reason the
ground of the possibility of a priori cognition； in so far as this
cognition is dependent on the understanding。 This synthesis is；
therefore； not merely transcendental； but also purely intellectual。
But because a certain form of sensuous intuition exists in the mind
a priori which rests on the receptivity of the representative
faculty （sensibility）； the understanding； as a spontaneity； is able to
determine the internal sense by means of the diversity of given
representations； conformably to the synthetical unity of apperception；
and thus to cogitate the synthetical unity of the apperception of
the manifold of sensuous intuition a priori； as the condition to which
must necessarily be submitted all objects of human intuition。 And in
this manner the categories as mere forms of thought receive
objective reality； that is； application to objects which are given
to us in intuition； but that only as phenomena； for it is only of
phenomena that we are capable of a priori intuition。
This synthesis of the manifold of sensuous intuition； which is
possible and necessary a priori； may be called figurative （synthesis
speciosa）； in contradistinction to that which is cogitated in the mere
category in regard to the manifold of an intuition in general； and
is called connection or conjunction of the understanding （synthesis
intellectualis）。 Both are transcendental； not merely because they
themselves precede a priori all experience； but also because they form
the basis for the possibility of other cognition a priori。
But the figurative synthesis； when it has relation only to the
originally synthetical unity of apperception； that is to the
transcendental unity cogitated in the categories； must； to be
distinguished from the purely intellectual conjunction； be entitled
the transcendental synthesis of imagination。 Imagination is the
faculty of representing an object even without its presence in
intuition。 Now； as all our intuition is sensuous； imagination； by
reason of the subjective condition under which alone it can give a
corresponding intuition to the conceptions of the understanding；
belongs to sensibility。 But in so far as the synthesis of the
imagination is an act of spontaneity； which is determinative； and not；
like sense； merely determinable； and which is consequently able to
determine sense a priori； according to its form； conformably to the
unity of apperception； in so far is the imagination a faculty of
determining sensibility a priori； and its synthesis of intuitions
according to the categories must be the transcendental synthesis of
the imagination。 It is an operation of the understanding on
sensibility； and the first application of the understanding to objects
of possible intuition； and at the same time the basis for the exercise
of the other functions of that faculty。 As figurative； it is
distinguished from the merely intellectual synthesis； which is
produced by the understanding alone； without the aid of imagination。
Now； in so far as imagination is spontaneity； I sometimes call it also
the productive imagination； and distinguish it from the
reproductive； the synthesis of which is subject entirely to
empirical laws； those of association； namely； and which； therefore；
contributes nothing to the explanation of the possibility of a
priori cognition； and for this reason belongs not to transcendental
philosophy； but to psychology。
We have now arrived at the proper place for explaining the paradox
which must have struck every one in our exposition of the internal
sense （SS 6）； namely… how this sense represents us to our own
consciousness； only as we appear to ourselves； not as we are in
ourselves； because； to wit； we intuite ourselves only as we are
inwardly affected。 Now this appears to be contradictory； inasmuch as
we thus stand in a passive relation to ourselves； and therefore in the
systems of psychology； the internal sense is monly held to be one
with the faculty of apperception； while we； on the contrary； carefully
distinguish them。
That which determines the internal sense is the understanding； and
its original power of conjoining the manifold of intuition； that is；
of bringing this under an apperception （upon which rests the
possibility of the understanding itself）。 Now； as the human
understanding is not in itself a faculty of intuition； and is unable
to exercise such a power； in order to conjoin； as it were； the
manifold of its own intuition； the synthesis of understanding is；
considered per se； nothing but the unity of action； of which； as such；
it is self…conscious； even apart from sensibility； by which； moreover；
it is able to determine our internal sense in respect of the
manifold which may be presented to it according to the form of
sensuous intuition。 Thus； under the name of a transcendental synthesis
of imagination； the understanding exercises an activity upon the
passive subject； whose faculty it is； and so we are right in saying
that the internal sense is affected thereby。 Apperception and its
synthetical unity are by no means one and the same with the internal
sense。 The former； as the source of all our synthetical conjunction；
applies； under the name of the categories； to the manifold of
intuition in general； prior to all sensuous intuition of objects。
The internal sense； on the contrary； contains merely the form of
intuition； but without any synthetical conjunction of the manifold
therein； and consequently does not contain any determined intuition；
which is possible only through consciousness of the determination of
the manifold by the transcendental act of the imagination （synthetical
influence of the understanding on the internal sense）； which I have
named figurative synthesis。
This we can indeed always perceive in ourselves。 We cannot
cogitate a geometrical line without drawing it in thought； nor a
circle without describing it； nor represent the three dimensions of
space without drawing three lines from the same point perpendicular to
one another。 We cannot even cogitate time； unless； in drawing a
straight line （which is to serve as the external figurative
representation of time）； we fix our attention on the act of the
synthesis of the manifold； whereby we determine successively the
internal sense； and thus attend also to the succession of this
determination。 Motion as an act of the subject （not as a determination
of an object）；* consequently the synthesis of the manifold in space；
if we make abstraction of space and attend merely to the act by
which we determine the internal sense according to its form； is that
which produces the conception of succession。 The understanding；
therefore； does by no means find in the internal sense any such
synthesis of the manifold； but produces it； in that it affects this
sense。 At the same time； how 〃I who think〃 is distinct from the 〃I〃
which intuites itself （other modes of intuition being cogitable as
at least possible）； and yet one and the same with this latter as the
same subject； how； therefore； I am able to say： 〃I； as an intelligence
and thinking sub