intellectual
_processes_ as was the rest of the universe--or that, if they were, still
they yielded better evidence of having been due to these processes than
does the rest of the universe. And it is easy to perceive that his error
arose from his pre-formed belief in special creation. So long as a man
regards every living organism which he sees as the lineal descendant of a
precisely similar organism originally struck out by the immediate fiat of
Deity, so long is he justified in holding his axiom, "Contrivance must have
had a contriver." For "adaptation" then becomes to our minds the synonym of
"contrivance"--it being utterly inconceivable that the numberless
adaptations found in any living organism could have resulted in any other
way than by intelligent contrivance, at the time when this organism was in
the first instance _suddenly_ introduced into its complex conditions of
life. Still, as an argument, this is of course merely reasoning in a
circle: we adopt a hypothesis which presupposes the existence of a Deity as
the first step in the proof of his existence. I do not say that Paley
committed this error expressly, but merely that if it had not been for his
pre-formed conviction as to the truth of the special-creation theory, he
would probably not have written his "Natural Theology."

Sec. 26. Thus let us take a case of his own choosing, and the one which is
adduced by him as typical of "the application of the argument." "I know of
no better method of introducing so large a subject than that of comparing a
single thing with a single thing; an eye, for example, with a telescope. As
far as the examination of the instrument goes, there is precisely the same
proof that the eye was made for vision as there is that the telescope was
made for assisting it. They are both made upon the same principles, both
being adjusted to the laws by which the transmission and refraction of rays
of light are regulated. I speak not of the origin of the laws themselves;
but these laws being fixed, the construction in both cases is adapted to
them. For instance: these laws require, in order to produce the same
effect, that the rays of light, in passing through water into the eye,
should be refracted by a more convex surface than when it passes out of air
into the eye. Accordingly we find that the eye of a fish, in that part of
it called the crystalline lens, is much rounder than the eye of terrestrial
animals. What plainer manifestation of des