on, it
might, perhaps, be contended, that the agency of man did not constitute
an anomalous deviation from the previously established order of things.
It might then have been said, that the earth's becoming at a particular
period the residence of human beings, was an era in the moral, not in
the physical world--that our study and contemplation of the earth, and
the laws which govern its animate productions, ought no more to be
considered in the light of a disturbance or deviation from the system,
than the discovery of the satellites of Jupiter should be regarded as a
physical event affecting those heavenly bodies. Their influence in
advancing the progress of science among men, and in aiding navigation
and commerce, was accompanied by no reciprocal action of the human mind
upon the economy of nature in those distant planets; and so the earth
might be conceived to have become, at a certain period, a place of moral
discipline and intellectual improvement to man, without the slightest
derangement of a previously existing order of change in its animate and
inanimate productions.

The distinctness, however, of the human from all other species,
considered merely as an efficient cause in the physical world, is real;
for we stand in a relation to contemporary species of animals and plants
widely different from that which other irrational animals can ever be
supposed to have held to each other. We modify their instincts, relative
numbers, and geographical distribution, in a manner superior in degree,
and in some respects very different in kind from that in which any other
species can affect the rest. Besides, the progressive movement of each
successive generation of men causes the human species to differ more
from itself in power at two distant periods, than any one species of the
higher order of animals differs from another. The establishment,
therefore, by geological evidence, of the first intervention of such a
peculiar and unprecedented agency, long after other parts of the animate
and inanimate world existed, affords ground for concluding that the
experience during thousands of ages of all the events which may happen
on this globe, would not enable a philosopher to speculate with
confidence concerning future contingencies.

If, then, an intelligent being, after observing the order of events for
an indefinite series of ages, had witnessed at last so wonderful an
innovation as this, to what extent would his belief in the regu