KANT'S CRITIQUE OF TELEOLOGY IN BIOLOGICAL EXPLANATION

18 Theory of the Organism
common species membership became more and more important,
this marginal phenomenon which revealed a weakness in the
preformation theory was ever more made the focus of attention.
3) A third reason for growing dissatisfaction with the preformation
theory lay in the fact that it was hardly to be reconciled with
atomism without unscientific ad-hoc hypotheses. Atomism posited a
limit in principle to the divisibility of matter: at some level we come
upon ultimate indivisible particles. The preformation theory presupposed
that matter could in principle be divided and structured in
infinitum. The two views were compatible only if it was assumed
that only a certain number of generations are encased — for
instance, because the world was only 6000 years old and would only
survive for another few thousand. And even in such a case the
divisibility of matter necessary for encasement is out of all proportion
to the divisibility necessary for an atomistic physics. As philosophical
atomism became more and more prevalent in physics and
social philosophy, the theory of preformation became ever more
problematical.
4) The fourth and perhaps most important reason is directly
connected to the discovery of the regenerative capabilities of the
polyp. If this small animal is cut in two, the head grows a new tail
and the tail a new head. The polyp can "reproduce" (as regeneration
was called at the time) any part that it loses, as if the parts depended
on the whole and not the whole on the parts. Mechanism assumed
that the motions of a clock depended on the properties and disposition
of the parts. If a gear is missing the machine stops working. It
is not to be expected that the loss of a part enables the machine to
perform acts (e.g. replacing the part) that an undamaged machine
does not perform. This striking and much discussed phenomenon
would however have remained an amusing and interesting
anomaly at the margins of science, had not a general concept of the
reproduction of an organic system been developed. If life is
conceived as a continual process of re-producing the initial
conditions of individual and species so that the life of an organic
system consists in its self-reproduction through nourishment,
exchange and replacement of its parts, then the regenerative
capacity of the polyp is no longer merely an anomaly; it is a
paradigmatic example of the basic phenomenon of life itself. It was
only in connection with such a theory of reproduction that the
rediscovery of the fresh water hydra (Leeuwenhoek had already