ded the marked predominance of positive researches wherein no
account was taken of the "pride of man." There can be no doubt that
Darwin has done much to familiarise us with this attitude. Take for
instance the first part of _The Descent of Man_: it is an accumulation
of typical facts, all tending to diminish the distance between us and
our brothers, the lower animals. One might say that the naturalist had
here taken as his motto, "Whosoever shall exalt himself shall be
abased; and he that shall humble himself shall be exalted." Homologous
structures, the survival in man of certain organs of animals, the
rudiments in the animal of certain human faculties, a multitude of
facts of this sort, led Darwin to the conclusion that there is no
ground for supposing that the "king of the universe" is exempt from
universal laws. Thus belief in the _imperium in imperio_ has been, as
it were, whittled away by the progress of the naturalistic spirit,
itself continually strengthened by the conquests of the natural
sciences. The tendency may, indeed, drag the social sciences into
overstrained analogies, such, for instance, as the assimilation of
societies to organisms. But it will, at least, have had the merit of
helping sociology to shake off the pre-conception that the groups
formed by men are artificial, and that history is completely at the
mercy of chance. Some years before the appearance of _The Origin of
Species_, August Comte had pointed out the importance, as regards the
unification of positive knowledge, of the conviction that the social
world, the last refuge of spiritualism, is itself subject to
determinism. It cannot be doubted that the movement of thought which
Darwin's discoveries promoted contributed to the spread of this
conviction, by breaking down the traditional barrier which cut man off
from Nature.

But Nature, according to modern naturalists, is no immutable thing: it
is rather perpetual movement, continual progression. Their discoveries
batter a breach directly into the Aristotelian notion of species; they
refuse to see in the animal world a collection of immutable types,
distinct from all eternity, and corresponding, as Cuvier said, to so
many particular thoughts of the Creator. Darwin especially
congratulated himself upon having been able to deal this doctrine the
_coup de grace_: immutability is, he says, his chief enemy; and he is
concerned to show--therein following up Lyell's work--that everything
in the o