comparison with which the adaptations of means to ends in a watch are
but miserable and rudimentary attempts at mechanism. No one can know so
well as the modern biologist in what an immeasurable degree the
mechanisms which occur in such profusion in nature surpass, in every
form of excellence, the highest triumphs of human invention. Hence at
first sight it does unquestionably appear that we could have no stronger
or better evidence of purpose than is thus afforded. In the words of
Paley: 'arrangement, disposition of parts, subserviency of means to an
end, relation of instruments to a use, imply the presence of
intelligence and mind.'

But next the question arises, Although such things certainly [may][22]
imply the presence of mind as their explanatory cause, are we entitled
to assume that there can be in nature no other cause competent to
produce these effects? This is a question which never seems to have
occurred to Paley, Bell, Chalmers, or indeed to any of the natural
theologians up to the time of Darwin. This, I think, is a remarkable
fact, because the question is one which, as a mere matter of logical
form, appears to lie so much upon the surface. But nevertheless the fact
remains that natural theologians, so far as I know without exception,
were satisfied to assume as an axiom that mechanism could have no cause
other than that of a designing mind; and therefore their work was
restricted to tracing out in detail the number and the excellency of the
mechanisms which were to be met with in nature. It is, however, obvious
that the mere accumulation of such cases can have no real, or logical,
effect upon the argument. The mechanisms which we encounter in nature
are so amazing in their perfections, that the attentive study of any one
of them would (as Paley in his illustration virtually, though not
expressly, contends) be sufficient to carry the whole position, if the
assumption be conceded that mechanism can only be due to mind. Therefore