KANT'S CRITIQUE OF TELEOLOGY IN BIOLOGICAL EXPLANATION

78 Kant's Logic
Both conflicting propositions presuppose that the world as a
whole is given and therefore must have a definite magnitude. However,
the world as the totality of objects of a possible experience can
never be given as a whole to any human understanding. The world
could only then be given as a whole (although not to our understanding)
if it were a thing in itself. Thus, in so far as we debate
whether the world is finite or infinite, we presuppose that it is something
given and thus that it can have a determinate magnitude. If
the world as a whole is not given it need also not have a determinate
magnitude, either finite or infinite. The apparently analytical opposition
proves to be merely dialectical; the contradiction turns out to
be a contrary opposition, as soon as the presupposition that the
world is a thing in itself is dropped — a presupposition that
grounded the tertium non datur in the conjunction of an affirmative
and an infinite judgment.
If, however, I take away this assumption, or this transcendental illusion, and
deny that the world is a thing in itself, the contradictory opposition of the
two assertions is converted into a merely dialectical opposition. Since the
world does not exist in itself (independently of the regressive series of my
representations), it exists neither as an in itself infinite nor as an in itself
finite whole. It is only to be met with in the empirical regress of the series of
appearances, and not as something in itself at all. Hence, if this series is
always conditioned, then it is never completely given, and the world is not an
unconditioned whole, and thus also does not exist as such a whole, either of
infinite or of finite magnitude. (B*532-3)
The solution to this (the first) antinomy shows that it is "merely
dialectical, and that it is a conflict due to an illusion" (B534).
It is here that we can see the true purpose of Kant's systematic
use of the apagogical form of proof in the antinomies chapter.
The resolution of the antinomy shows that both seemingly contradictory
propositions are false, i.e. that the opposition is not contradictory
but rather contrary. But both have supposedly been proved to be
true. The solution is to be found in the form of proof: The proofs are
not proofs at all, they are refutations of the respective counterpropositions.
Only under the assumption, tertium non datur, can one
interpret the refutation of the counterproposition as a proof of the
proposition; and precisely this presupposition is shown by the contrariety
to be false. With the falsehood of the presupposition all
proofs become invalid while the refutations remain unaffected; and
since the refutations are still valid, all theses and antitheses are
thus false. If the proofs had been direct, they would continue to be