ome and securely harvests, there is an
expansive force and latitude in its tentative efforts, which lifts
us out of ourselves and transfigures our mortality. We may have a
preference for moral themes, like the Homeric sage, who had seen and
known much:--

"Cities of men
And manners, climates, councils, governments";

yet we must end by confession that

"The windy ways of men
Are but dust which rises up
And is lightly laid again,"

in comparison with the work of nature, to which science testifies,
but which has no boundaries in time or space to which science can
approximate.

There is something altogether out of the reach of science, and yet the
compass of science is practically illimitable. Hence it is that from
time to time we are startled and perplexed by theories which have no
parallel in the contracted moral world; for the generalizations of
science sweep on in ever-widening circles, and more aspiring flights,
through a limitless creation. While astronomy, with its telescope,
ranges beyond the known stars, and physiology, with its microscope, is
subdividing infinite minutiae, we may expect that our historic centuries
may be treated as inadequate counters in the history of the planet on
which we are placed. We must expect new conceptions of the nature and
relations of its denizens, as science acquires the materials for fresh
generalizations; nor have we occasion for alarms if a highly advanced
knowledge, like that of the eminent Naturalist before us, confronts us
with an hypothesis as vast as it is novel. This hypothesis may or may
not be sustainable hereafter; it may give way to something else, and
higher science may reverse what science has here built up with so much
skill and patience, but its sufficiency must be tried by the tests of
science alone, if we are to maintain our position as the heirs of Bacon
and the acquitters of Galileo. We must weigh this hypothesis strictly
in the controversy which is coming, by the only tests which are
appropriate, and by no others whatsoever.

The hypothesis to which we point, and of which the present work of Mr.
Darwin is but the preliminary outline, may be stated in his own language
as follows:--"Species originated by means of natural selection, or
through the preservation of the favoured races in the struggle for
life." To render this thesis intelligible, it is necessary to interpret
its terms. In the first place, what is a species? The question i