ine sketch of the universe
in terms of infra-organic processes.

[Sidenote: Life. Natural Selection.]

Sect. 112. But the cosmos must be made internally homogeneous in these
same terms. There awaits solution, in the first place, the serious
problem of the genesis and maintenance of life within a nature that is
originally and ultimately inorganic. The assimilation of the field of
biology and physiology to the mechanical cosmos had made little real
progress prior to the nineteenth century. Mechanical theories had,
indeed, been projected in the earliest age of philosophy, and proposed
anew in the seventeenth century.[245:14] Nevertheless, the structural
and functional teleology of the organism remained as apparently
irrefutable testimony to the inworking of some principle other than that
of mechanical necessity. Indeed, the only fruitful method applicable to
organic phenomena was that which explained them in terms of purposive
adaptation. And it was its provision for a mechanical interpretation of
this very principle that gave to the Darwinian _law of natural
selection_, promulgated in 1859 in the "Origin of Species," so profound
a significance for naturalism. It threatened to reduce the last
stronghold of teleology, and completely to dispense with the intelligent
Author of nature.

Darwin's hypothesis sought to explain the origin of animal species by
survival under competitive conditions of existence through the
possession of a structure suited to the environment. Only the most
elementary organism need be presupposed, together with slight variations
in the course of subsequent generations, and both may be conceived to
arise mechanically. There will then result in surviving organisms a
gradual accumulation of such variations as promote survival under the
special conditions of the environment. Such a principle had been
suggested as early as the time of Empedocles, but it remained for Darwin
to establish it with an unanswerable array of observation and
experimentation. If any organism whatsoever endowed with the power of
generation be allowed to have somehow come to be, naturalism now
promises to account for the whole subsequent history of organic
phenomena and the origin of any known species.

[Sidenote: Mechanical Physiology.]

Sect. 113. But what of life itself? The question of the derivation of
organic from inorganic matter has proved insoluble by direct means, and
the case of naturalism must here rest upon such fa