in apprehending A B as a
real or objective succession we presuppose that they are elements in a
causal order of succession. Yet in support of his contention he points
only to the quite different fact that where we apprehend a succession
A B, we think of the _perception_ of A and the _perception_ of B as
elements in a necessary but subjective succession.

Before we attempt to consider the facts with which Kant is dealing, we
must refer to a feature in Kant's account to which no allusion has
been made. We should on the whole expect from the passage quoted that,
in the case where we regard two perceptions A B as necessarily
successive and therefore as constituting an objective succession, the
necessity of succession consists in the fact that A is the cause of B.
This, however, is apparently not Kant's view; on the contrary, he
seems to hold that, in thinking of A B as an objective succession, we
presuppose not that A causes B, but only that the state of affairs
which precedes B, and which therefore includes A, contains a cause of
B, the coexistence or identity of this cause with A rendering the
particular succession A B necessary. "Thus [if I perceive that
something happens] it arises that there comes to be an order among our
representations in which the present (so far as it has taken place)
points to some preceding state as a correlate, _though a still
undetermined correlate_,[41] of this event which is given, and this
correlate relates to the event by determining the event as its
consequence, and connects the event with itself necessarily in the
series of time."[42]

[41] The italics are mine.

[42] B. 244, M. 148. Cf. B. 243, M. 148 (first half) and B.
239, M. 145 (second paragraph). The same implication is to
be found in his formulation of the rule involved in the
perception of an event, e. g. "In conformity with such a
rule, there must exist in that which in general precedes an
event, the condition of a rule, according to which this event
follows always and necessarily." Here the condition of a rule
is the necessary antecedent of the event, whatever it may be.

The fact is that Kant is in a difficulty which he feels obscurely
himself. He seems driven to this view for two reasons. If he were to
maintain that A was necessarily the cause of B, he would be
maintaining that all observed sequences are causal, i. e. that in them
the antecedent and consequent are always cause and effe