o an image.

'It follows, then, that the affinity or connectedness of the data of
sense presupposed by the _re_production which is presupposed in
knowledge, is actually produced by the _pro_ductive faculty of
imagination, which, in combining the data into a sensuous image,
gives them the unity required.'

If, as it seems necessary to believe, this be the correct
interpretation of the passage,[18] Kant is here trying to carry out
to the full his doctrine that _all_ unity or connectedness comes from
the mind's activity. He is maintaining that the imagination, acting
_pro_ductively on the data of sense and thereby combining them into an
image, gives the data a connectedness which the understanding can
subsequently recognize. But to maintain this is, of course, only to
throw the problem one stage further back. If reproduction, in order to
enter into knowledge, implies a manifold which has such connexion that
it is capable of being reproduced according to rules, so the
production of sense-elements into a coherent image in turn implies
sense-elements capable of being so combined. The act of combination
cannot confer upon them or introduce into them a unity which they do
not already possess.

[18] If the preceding interpretation (pp. 223-4) be thought
the correct one, it must be admitted that Kant's vindication
of the affinity breaks down for the reason given, p. 220.

The fact is that this step in Kant's argument exhibits the final
breakdown of his view that all unity or connectedness or relatedness
is conferred upon the data of sense by the activity of the mind.
Consequently, this forms a convenient point at which to consider what
seems to be the fundamental mistake of this view. The mistake stated
in its most general form appears to be that, misled by his theory of
perception, he regards 'terms' as given by things in themselves
acting on the sensibility, and 'relations' as introduced by the
understanding,[19] whereas the fact is that in the sense in which terms
can be said to be given, relations can and must also be said to be
given.

[19] The understanding being taken to include the
imagination, as being the faculty of _spontaneity_ in
distinction from the _passive_ sensibility.

To realize that this is the case, we need only consider Kant's
favourite instance of knowledge, the apprehension of a straight line.
According to him, this presupposes that there is given to us a
manifold, which--w