KANT'S CRITIQUE OF TELEOLOGY IN BIOLOGICAL EXPLANATION

Decline of Preformation 15
On the basis of this deistic teleology the preformation theory
was able to conceive of the actually given species forms as necessary
and contingent at the same time. They were necessary in the sense
that they functioned in a purely mechanical manner. They were
contingent in the sense that their form was underdetermined by the
mere laws of matter in motion. There are many other possible combinations
of the particles which would nonetheless be compatible
with the properties of those particles and might even be capable of
living once produced. But these do not belong to the forms that were
selected at the construction of the world system, and they are
(presumably) too complicated to be likely to arise of their own accord.
Every really given organism is causally fully determined on the assumption
of an original preformation; and the encasement of the
germs sees to it that the original organization is maintained without
any extraordinary intervention by God.
Decline of the Preformation Theory
In the fifth decade of the 18th century a fundamental change
in theories and explanations of the organism began, which led
towards the end of the century to vitalism. It was no longer the
quantitative complexity of the organism that occupied the foreground;
rather the difference between organic and unorganic was
seen to be of a qualitative kind, often expressed in the form of a
double organization: the particles of matter were taken to be organized
into organic parts or molecules and then these already
organic parts were taken to be organized into organisms. The fall of
the classical mechanistic explanation is clearly marked by the
commotion surrounding Abraham Trembly's discovery of the fresh
water hydra (polyp) around 1740, which served as occasion and
point of departure for a number of new theories. The fact that the
preformation theory, which had for sixty years been the paradigm of
scientific explanation in organic nature, could be toppled so quickly
and completely is due to the fact that the theoretical prerequisites
had been slowly accumulating in the course of the 18th century and
all that was needed was an empirical stimulus — and perhaps a
generational change among scientists. However, even after 1740, a
number of important scientists continued to be committed to the pre-