bination, and the work of the understanding must be considered
to consist in recognizing that the manifold has been thereby combined
and unified through the conception. We are therefore obliged to accept
one of two alternatives. _Either_ the understanding merely renders the
mind conscious of the procedure of a faculty different from itself,
viz. the imagination, in which case the important role in knowledge,
viz. the effecting of the synthesis according to a principle, is
played by a faculty different from the understanding; _or_ the
imagination is the understanding working unreflectively, and the
subsequent process of bringing the synthesis to a conception is merely
a process by which the understanding becomes conscious of its own
procedure. Moreover, it is the latter alternative which we must accept
as more in accordance with the general tenor of Kant's thought. For
the synthesis of the imagination is essentially the outcome of
activity or spontaneity, and, as such, it belongs to the understanding
rather than to the sensibility; in fact we find Kant in one place
actually saying that 'it is one and the same spontaneity which at one
time under the name of imagination, at another time under that of
understanding, introduces connexion into the manifold of
perception'.[15] Further, it should be noted that since the
imagination must be the understanding working unreflectively, and
since it must be that which introduces unity into the manifold, there
is some justification for his use of language which implies that the
understanding is the source of the unity, though it will not be so in
the sense in which the passage under discussion might at first sight
lead us to suppose.

[12] The italics are mine.

[13] The italics are mine.

[14] Cf. the description of the imagination as 'blind'.

[15] B. 162 note, M. 99 note. Cf. B. 152, M. 93. Similarly at
one point in the passage under discussion (B. 102 fin., M. 62
med.) the synthesis is expressly attributed to the
spontaneity of thought.

We can now turn to the argument of the _Transcendental Deduction_
itself. Kant introduces it in effect by raising the question, 'How is
it that, beginning with the isolated data of sense, we come to acquire
knowledge?' His aim is to show (1) that knowledge requires the
performance of certain operations by the mind upon the manifold of
sense; (2) that this process is a condition not merely of knowledge,
but also o