KANT'S CRITIQUE OF TELEOLOGY IN BIOLOGICAL EXPLANATION

Teleological Maxims 51
this kind of efficient causality forces us to employ certain ideas or
representations as cognitive means. 34
Teleological Maxims
In the last three sections of the Analytic (§§66-68) Kant makes
a virtue of necessity. Since in the case of inner purposiveness, we
have to make use of teleological expressions, that is, since in science
we cannot get by without them, we ought then to squeeze as much
out of these principles as we can — but only as heuristic maxims.
Thus, even in instances where we do not need to employ teleological
principles, we should feel free to use them to help pick up the traces
of mechanism. For instance, when examining a natural purpose
that one can only conceive as embodying a means-and-end relation,
one ought to consider all parts of it as possible only according to the
concept of purpose, even such parts as could otherwise be explained
in a purely mechanistic fashion such as bones, hair and skin etc.
That is, even the parts that one could explain according to empirical
laws should also be considered from a functional point of view (§66).
Furthermore, nature as a whole should be judged as a system of
relative purposes without of course establishing a hierarchy of such
purposes and enthroning one of them as the ultimate purpose of
nature. In modern terms, one should consider things in their ecological
connections — whether they are "purposive" for other things
and whether other things are "purposive" for them. It is thus possible
and perhaps useful to consider nature not just as a system of
causal laws but also as a system of purposive relations (§67).
Finally, Kant emphasizes (§68) that in spite of its usefulness
teleology is not an intrinsic principle of natural science but rather is
"borrowed" from outside. Teleological principles are only regulative
and themselves have no explanatory value, even though they may
help us to find explanations. Explanations are mechanistic: in an
experiment the phenomenon to be explained is produced according
to known empirical laws: "for we have complete insight only into
what we can ourselves make and accomplish according to concepts"
(B309; CJ, 264).
34 This point especially is emphasized by Jacob, Logic of Life, pp. 88-89.