120 THE STRUCTURE OF EVOLUTIONARY THEORY
- Darwin often uses Paley's logic, sometimes against his predecessor. Paley,
for example, dismisses arguments about "tendencies to order" or "principles of
design" as empty verbiage, explaining nothing; a true cause must be identified,
namely God himself. Darwin makes the same point, but cites evolution as the true
cause, while branding statements about creation ex nihilo as empty verbiage. Paley
writes (p. 76): "A principle of order is the word: but what is meant by a principle of
order, as different from an intelligent Creator, has not been explained either by
definition or example: and, without such explanation, it should seem to be a mere
substitution of words for reasons, names for causes." - Paley discusses many themes of later and central importance to Darwin. He
criticizes the major evolutionary conjectures of his day, including Buff on "interior
molds," and the idea of use and disuse. (Since I doubt that he had read Lamarck's
earliest evolutionary work by 1802, Paley probably derived this aspect of
Lamarck's theory from its status as folk wisdom in general culture.) Paley also
states the following crisp epitome of the very argument from Malthus that so struck
Darwin. (I am not claiming that this passage provided a covert source for Darwin's
central insight. Darwin, after all, had also read Malthus.) "The order of generation
proceeds by something like a geometrical progression. The increase of provision,
under circumstances even the most advantageous, can only assume the form on an
arithmetic series. Whence it follows, that the population will always overtake the
provision, will pass beyond the line of plenty, and will continue to increase till
checked by the difficulty of procuring subsistence" (p. 540).
This influence, and this desire to overturn Paley, persisted throughout
Darwin's career. Ghiselin (1969), for example, regards Darwin's orchid book as a
conscious satire on Paley's terminology and argument. Darwin called this work
(1862), his next book after the Origin of Species, "On the various contrivances by
which British and foreign orchids are fertilized by insects." Paley used the word
"contrivance," as my previous quotations show, to designate an organic design
obviously well-made by an intelligent designer. But Darwin argues that orchids
must be explained as contraptions, not contrivances. Their vaunted adaptations are
jury-rigged from ordinary parts of flowers, and must have evolved from such an
ancestral source; the major adaptive features of orchids have not been expressly
and uniquely designed for their current functions.
Now suppose, as a problem in abstract perversity, that one made a pledge to
subvert Paley in the most radical way possible. What would one claim? I can
imagine two basic refutations. One might label Paley's primary observation as
simply wrong—by arguing that exquisite adaptation is relatively rare, and that the
world is replete with error, imperfection, misery and caprice. If God made such a
world, then we might want to reassess our decision to worship him. An upsetting
argument indeed, but Darwin chose an even more radical alternative.
With even more perversity, one might judge Paley's observation as undoubtedly
correct. Nature features exquisite adaptation at overwhelming relative