inquiry。 But a deduction of the pure a priori conceptions of course
never can be made in this way； seeing that； in regard to their
future employment； which must be entirely independent of experience；
they must have a far different certificate of birth to show from
that of a descent from experience。 This attempted physiological
derivation； which cannot properly be called deduction； because it
relates merely to a quaestio facti； I shall entitle an explanation
of the possession of a pure cognition。 It is therefore manifest that
there can only be a transcendental deduction of these conceptions
and by no means an empirical one； also； that all attempts at an
empirical deduction； in regard to pure a priori conceptions； are vain；
and can only be made by one who does not understand the altogether
peculiar nature of these cognitions。
But although it is admitted that the only possible deduction of pure
a priori cognition is a transcendental deduction； it is not； for
that reason； perfectly manifest that such a deduction is absolutely
necessary。 We have already traced to their sources the conceptions
of space and time； by means of a transcendental deduction； and we have
explained and determined their objective validity a priori。
Geometry； nevertheless； advances steadily and securely in the province
of pure a priori cognitions； without needing to ask from philosophy
any certificate as to the pure and legitimate origin of its
fundamental conception of space。 But the use of the conception in this
science extends only to the external world of sense； the pure form
of the intuition of which is space； and in this world； therefore；
all geometrical cognition； because it is founded upon a priori
intuition； possesses immediate evidence； and the objects of this
cognition are given a priori （as regards their form） in intuition by
and through the cognition itself。 With the pure conceptions of
understanding； on the contrary； mences the absolute necessity of
seeking a transcendental deduction； not only of these conceptions
themselves； but likewise of space； because； inasmuch as they make
affirmations concerning objects not by means of the predicates of
intuition and sensibility； but of pure thought a priori； they apply to
objects without any of the conditions of sensibility。 Besides； not
being founded on experience； they are not presented with any object in
a priori intuition upon which； antecedently to experience； they
might base their synthesis。 Hence results； not only doubt as to the
objective validity and proper limits of their use； but that even our
conception of space is rendered equivocal； inasmuch as we are very
ready with the aid of the categories； to carry the use of this
conception beyond the conditions of sensuous intuition… and； for
this reason； we have already found a transcendental deduction of it
needful。 The reader； then； must be quite convinced of the absolute
necessity of a transcendental deduction； before taking a single step
in the field of pure reason； because otherwise he goes to work
blindly； and after he has wondered about in all directions； returns to
the state of utter ignorance from which he started。 He ought；
moreover； clearly to recognize beforehand the unavoidable difficulties
in his undertaking； so that he may not afterwards plain of the
obscurity in which the subject itself is deeply involved； or bee
too soon impatient of the obstacles in his path； because we have a
choice of only two things… either at once to give up all pretensions
to knowledge beyond the limits of possible experience； or to bring
this critical investigation to pletion。
We have been able； with very little trouble； to make it
prehensible how the conceptions of space and time； although a
priori cognitions； must necessarily apply to external objects； and
render a synthetical cognition of these possible； independently of all
experience。 For inasmuch as only by means of such pure form of
sensibility an object can appear to us； that is； be an object of
empirical intuition； space and time are pure intuitions； which contain
a priori the condition of the possibility of objects as phenomena； and
an a priori synthesis in these intuitions possesses objective
validity。
On the other hand； the categories of the understanding do not
represent the conditions under which objects are given to us in
intuition； objects can consequently appear to us without necessarily
connecting themselves with these； and consequently without any
necessity binding on the understanding to contain a priori the
conditions of these objects。 Thus we find ourselves involved in a
difficulty which did not present itself in the sphere of
sensibility； that is to say； we cannot discover how the subjective
conditions of thought can have objective validity； in other words； can
bee conditions of the possibility of all cognition of objects；
for phenomena may certainly be given to us in intuition without any
help from the functions of the understanding。 Let us take； for
example； the conception of cause； which indicates a peculiar kind of
synthesis； namely； that with something； A； something entirely
different； B； is connected according to a law。 It is not a priori
manifest why phenomena should contain anything of this kind （we are of
course debarred from appealing for proof to experience； for the
objective validity of this conception must be demonstrated a
priori）； and it hence remains doubtful a priori； whether such a
conception be not quite void and without any corresponding object
among phenomena。 For that objects of sensuous intuition must
correspond to the formal conditions of sensibility existing a priori
in the mind is quite evident； from the fact that without these they
could not be objects for us； but that they must also correspond to the
conditions which understanding requires for the synthetical unity of
thought is an assertion； the grounds for which are not so easily to be
discovered。 For phenomena might be so constituted as not to correspond
to the conditions of the unity of thought； and all things might lie in
such confusion that； for example； nothing could be met with in the
sphere of phenomena to suggest a law of synthesis； and so correspond
to the conception of cause and effect； so that this conception would
be quite void； null； and without significance。 Phenomena would
nevertheless continue to present objects to our intuition； for mere
intuition does not in any respect stand in need of the functions of
thought。
If we thought to free ourselves from the labour of these
investigations by saying： 〃Experience is constantly offering us
examples of the relation of cause and effect in phenomena； and
presents us with abundant opportunity of abstracting the conception of
cause； and so at the same time of corroborating the objective validity
of this conception〃； we should in this case be overlooking the fact；
that the conception of cause cannot arise in this way at all； that； on
the contrary； it must either have an a priori basis in the；
understanding； or be rejected as a mere chimera。 For this conception
demands that something； A； should be of such a nature that something
else； B； should follow from it necessarily； and according to an
absolutely universal law。 We may certainly collect from phenomena a
law； according to which this or that usually happens； but the
element of necessity is not to be found in it。 Hence it is evident
that to the synthesis of cause and effect belongs a dignity； which
is utterly wanting in any empirical synthesis； for it is no mere
mechanical synthesis； by means of addition； but a dynamical one；
that is to say； the effect is not to be cogitated as merely annexed to
the cause； but as posited by and through the cause； and resulting from
it。 The strict universality of this law never can be a
characteristic of empirical laws； which obtain through induction
only a parative universality； that is； an extended range of
practical application。 But the pure conceptions of the understanding
would entirely lose all their peculiar character； if we treated them
merely as the productions of experience。
Transition to the Transcendental Deduction of the
Categories。 SS 10
There are only two possible ways in which synthetical representation
and its objects can coincide with and relate necessarily to each
other； and； as it were； meet together。 Either the object alone makes
the representation possible； or the representation alone makes the
object possible。 In the former case； the relation between them is only
empirical； and an a priori representation is impossible。 And this is
the case with phenomena； as regards that in them which is referable to
mere sensation。 In the latter case… although representation alone （for
of its causality； by means of the will； we do not here speak） does not
produce the object as to its existence； it must nevertheless be a
priori determinative in regard to the object； if it is only by means
of the representation that we can cognize anything as an object。 Now
there are only two conditions of the possibility of a cognition of
objects； firstly； intuition； by means of which the object； though only
as phenomenon； is given； secondly； conception； by means of which the
object which corresponds to this intuition is thought。 But it is
evident from what has been said on aesthetic that the first condition；
under which alone objects can be intuited； must in fact exist； as a
formal basis for them； a priori in the mind。 With this formal
condition of sensibility； therefore； all phenomena necessarily
correspond； because it is only through it that they can be phenomena
at all； that is； can be empirically intuited and given。 Now the
question is whether there do not exist； a priori in the mind；
conceptions of understanding also； as conditions under which alone
something； if not intuited； is yet thought as object。 If this question
be answered in the affirmative； it follows that all empirical
cognition of objects is necessarily conformable to such conceptions；
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