KANT'S CRITIQUE OF TELEOLOGY IN BIOLOGICAL EXPLANATION

Analysis of Purpose 43
ness in order to explain them at all. Such objects of experience can
only be comprehended as law governed and causally determined
under certain conditions, namely, that the concept or representation
of the object guided the efficient causes of the object in its production.
Or as Kant puts it:
Only in one case does experience lead our power of judgment to the
concept of a purposiveness that is both objective and material, i.e., to the
concept of a purpose of nature, namely, when we have to judge a relation of
cause to effect which is such that we can see it as law-governed only if we
regard the cause's action as based on the idea of the effect, with this idea as
the underlying condition under which the cause itself can produce that
effect. (B278; CJ, 244)
Although in such a case we can comprehend the lawful character of
the process only if we assume that an idea of the result guides the
process, we do not assume that there really exists an understanding
that has the idea. This idea is a cognitive tool of ours, it is not an
intention actually supposed to be realized by any understanding
agent.
Relative purposiveness includes the usefulness of one thing
for another. Kant speaks of the "utility" of a thing for humans and
its "benefit" for other living creatures. Any thing that can serve as a
means for some other thing may be said to be relatively purposive,
whereby the "other thing" in Kant's examples is always an organism.
Kant lists a number of such relatively purposive natural
relationships, such as the benefit of sandy soil for spruce trees or of
rivers for plants. He points out however that the relative purposiveness
of a thing depends on the purpose-character of the creature for
which it is beneficial. Only if we were to assume that the existence of
certain things were a purpose of nature, would we have to consider
"those natural things that are indispensable for this" as natural
purposes (B282; CJ, 246). But we have no empirical or logical
reasons to believe that any particular thing or kind of thing ought to
exist; this applies to humans as well.
The relative purposiveness of one thing for another never justifies
the inference that the purposive thing can only be thought to be
possible in this connection. The relative purposiveness of one thing
for another is never a necessary component of the explanation of the
thing's origin. "For even if there were none of that natural utility,
we would find that natural causes are fully adequate to make things
come out this way" (B284; CJ, 247). The origin of the sandy soil so
beneficial for the spruce trees can be completely explained without