possible because the
things concerned, i. e. phenomena, must conform to the sensibility and
the understanding, i. e. to the mind's perceiving and thinking nature.
But both the problem and the answer, so stated, give no clue to the
particular _a priori_ judgements thus rendered possible nor to the
nature of the sensibility and the understanding in virtue of which we
make them. It has been seen, however, that the judgements in question
fall into two classes, those of mathematics and those which form the
presuppositions of physics. And it is Kant's aim to relate these
classes to the sensibility and the understanding respectively. His
view is that mathematical judgements, which, as such, deal with
spatial and temporal relations, are essentially bound up with our
perceptive nature, i. e. with our sensibility, and that the principles
underlying physics are the expression of our thinking nature, i. e. of
our understanding. Hence if the vindication of this relation between
our knowing faculties and the judgements to which they are held to
give rise is approached from the side of our faculties, it must be
shown that our sensitive nature is such as to give rise to
mathematical judgements, and that our understanding or thinking nature
is such as to originate the principles underlying physics. Again, if
the account of this relation is to be adequate, it must be shown to be
exhaustive, i. e. it must be shown that the sensibility and the
understanding give rise to no other judgements. Otherwise there may be
other _a priori_ judgements bound up with the sensibility and the
understanding which the inquiry will have ignored. Kant, therefore, by
his distinction between the sensibility and the understanding, sets
himself another problem, which does not come into sight in the first
formulation of the general question 'How are _a priori_ synthetic
judgements possible?' He has to determine what _a priori_ judgements
are related to the sensibility and to the understanding respectively.
At the same time the distinction gives rise to a division within the
main problem. His chief aim is to discover how it is that _a priori_
judgements are universally applicable. But, as Kant conceives
the issue, the problem requires different treatment according
as the judgements in question are related to the sensibility or
to the understanding. Hence arises the distinction between the
_Transcendental Aesthetic_ and the _Transcendental Analytic_, the
former dea