race
is of far higher dignity than were any pre-existing beings on the earth,
it is the intellectual and moral attributes of our race, rather than the
physical, which are considered; and it is by no means clear that the
organization of man is such as would confer a decided pre-eminence upon
him, if, in place of his reasoning powers, he was merely provided with
such instincts as are possessed by the lower animals.

If this be admitted, it would not follow, even if there were sufficient
geological evidence in favor of the theory of progressive development,
that the creation of man was the last link in the same chain. For the
sudden passage from an irrational to a rational animal, is a phenomenon
of a distinct kind from the passage from the more simple to the more
perfect forms of animal organization and instinct. To pretend that such
a step, or rather leap, can be part of a regular series of changes in
the animal world, is to strain analogy beyond all reasonable bounds.

_Introduction of man, to what extent a change in the system._--But
setting aside the question of progressive development, another and a far
more difficult one may arise out of the admission that man is
comparatively of modern origin. Is not the interference of the human
species, it may be asked, such a deviation from the antecedent course of
physical events, that the knowledge of such a fact tends to destroy all
our confidence in the uniformity of the order of nature, both in regard
to time past and future? If such an innovation could take place after
the earth had been exclusively inhabited for thousands of ages by
inferior animals, why should not other changes as extraordinary and
unprecedented happen from time to time? If one new cause was permitted
to supervene, differing in kind and energy from any before in operation,
why may not others have come into action at different epochs? Or what
security have we that they may not arise hereafter? And if such be the
case, how can the experience of one period, even though we are
acquainted with all the possible effects of the then existing causes, be
a standard to which we can refer all natural phenomena of other periods?

Now these objections would be unanswerable, if adduced against one who
was contending for the absolute uniformity throughout all time of the
succession of sublunary events--if, for example, he was disposed to
indulge in the philosophical reveries of some Egyptian and Greek sects,
who repre