KANT'S CRITIQUE OF TELEOLOGY IN BIOLOGICAL EXPLANATION

Necessary Maxims 157
I ought always to reflect on these events and forms in terms of the principle
of the mere mechanism of nature, and hence ought to investigate this principle
as far as I can, because unless we presuppose it in our investigation [of
nature] we can have no cognition of nature at all in the proper sense of the
term. (B315; CJ, 268)
Our knowledge of nature is mechanistic according to Kant; explanation
for us is per se mechanistic explanation. As we saw earlier,
Kant took the position at the end of the Analytic that we only have
"insight" into that which we can in principle produce, at least in
thought. And even in the announcement of the antinomy itself, he
indicated the nature of the necessity of the antinomy when he said:
"These maxims are necessary ... reflective judgment needs such
concepts whenever it seeks so much as to get to know nature in
terms of its empirical laws" (§69, B312; CJ, 266). In the last section
of the Dialectics Kant wrote:
Reason is tremendously concerned not to abandon the mechanism nature
[employs] in its products, and not to pass over it in explaining them, since
without mechanism we cannot gain insight into the nature of things (§78,
B354; CJ, 295)
Finally, we read in the Doctrine of Method, that without "the principle
of natural mechanism ... there can be no natural science at
all" (§80, B368; CJ, 304).
The negative form of all these assertions is significant: Kant
maintains that we must judge all material things to be possible
according to the mere mechanism of nature, because we cannot
explain them otherwise. As incorrigible reductionists we cannot
accept an explanation that is not mechanistic. Thus the necessity
for the mechanistic judgment of natural things consists in the fact
that we have no alternative to mechanistic explanation. It should
not be forgotten that the maxim of mechanism (R1) is merely
regulative. It makes no prescriptions for nature, only for us: we
must consider natural things as if they could be explained
mechanistically.
In order to justify the necessity of (both parts of) the second
maxim (R2) we can, on the other hand, refer back to the Analytic or
to §75 where the argument is recapitulated. The necessity of this
maxim is hypothetical and becomes real on the occasion of a "particular
experience": If there is something that we have to consider
as a natural purpose, then we cannot judge it merely mechanistically
and must also consider it teleologically. A natural purpose is