BODY AND PRACTICE IN KANT

282
THE RELATIONAL CATEGORIES
I see a ship driven downstream. My perception of its position
downstream follows the perception of its position upstream, and it is
impossible that in the apprehension of this appearance the ship
should first be perceived downstream and afterwards upstream. The
order in the sequence of the perceptions in apprehension is therefore
here determined, and the apprehension is bound to it. (A 192/ B 237)
What is it in this example that makes it possible for us to transcend the
subjective order of apprehension? Kant is quite clear that it is the
category of causality. By means of this category, you decide that the
situation in which the ship was higher up the river is the cause leading to
the situation in which the ship has moved to a lower point of the river.
Let us call the first situation A and the second B. By deciding that A is
the cause of B, it follows that B cannot precede A. It also follows that it is
impossible to apprehend B before A.
This is the case whenever we observe that something happens. Kant
here seems to be thinking that the concept of something happening
implies the concept of an objective time order, which is why he can claim
that the rule of causality is necessarily present in all contexts in which
something is happening.
But this rule is always to be found in the perception of that which
happens, and it makes the order of perceptions that follow one
another (in the apprehension of this appearance) necessary. (A193/B
238)
How do we know that one event is the cause of another? According to
Hume we can never know this in an absolute sense. As our idea of
causality is based on induction, it lacks the universal and necessary
character found in a priori principles. Kant agrees with Hume that if the
concept of causality was founded merely on induction, then the principle
that everything that happens has a cause would be merely empirical, and
thus accidental (A 196/ B 241). However, Kant claims that there is more
to causality than this and that it is possible to prove that causality is a
necessary condition of objective time determination. According to this
proof, objective time determination is possible only given the necessary
connection between cause and effect.
The argument has here the structure of a transcendental proof.
Starting out from something thought to be evident, that is, the fact that
we experience the world as a series of events taking place in an
irreversible time order, Kant then proceeds to argue that this fact can
only be explained by assuming that this time order already stands under