KANT'S CRITIQUE OF TELEOLOGY IN BIOLOGICAL EXPLANATION

48 Analytic of Teleological Judgment
the first part is relatively straightforward: a normal causal
connection, as it is usually conceived, involves a sequence of causes
and effects that has a particular direction ("downwards"), so that
the effect of a cause cannot itself in turn effect its cause.
In "art" the situation is different (3); here, there seem to be
dependencies that go in both directions. A rented house is, for
instance, the efficient cause of rental income; on the other hand, the
income is the final cause or purpose of building the house. Kant
calls this last relation the nexus finalis, although the rent itself may
not properly be called a cause, but only the representation of the rent
can be considered a cause of the construction of the house. The efficient
causes may be called real causes and the final causes, taken
as representations, may be called ideal causes to emphasize that
there are only these two kinds of causality and that final causes
presuppose an understanding that has ideas and can realize
them. 31
In (1) Kant stresses that the "things themselves" cannot have
a causal influence on their own causes; in (3) he mentions that the
representation of a thing can indeed have a causal influence upon
the causes of the thing and calls this representation an ideal cause.
However sentence (2) which is supposed to provide the derivation for
the "still not quite appropriate and determinate" notion of natural
purpose has nothing whatsoever to do with Kant's tenement house
example. When it is asserted that a causal connection is conceivable
that proceeds downwards and upwards, if one considers it not "as
our mere understanding thinks it" but instead "in terms of a concept
of reason," it is not the representation of the thing, i.e. an ideal
cause, that is being considered. On the contrary, the thing itself,
which is an effect, is supposed to be the cause of its own cause. As
far as I can see, it is exclusively real causality that is being discussed
here. If this passage is to make any sense at all, then it must
be asserting the possibility in principle that a causal connection can
proceed in two "directions" at the same time. The interpretation that
might suggest itself of Kant's metaphor of the "series" of cause and
31 The division of causes into ideal (mental) and real (physical) allows Kant to
speak of both the causa formalis and the causa finalis without distinction as ideal
causes. In the passage quoted Kant speaks of the representation of the rent (causa
finalis), not of the representation of the house itself (causa formalis). In other
examples the reverse is the case: the representation of a product of art or
artisanship (not of its use or usefulness) is called the purpose (Zweckursache).