physical beings, it declares that it can only entertain the
supposition of their existence where it finds evidence of an
environment suited to their needs, and such environment may not
everywhere exist. Science, though repelled by the antiquated
theological conception of the supreme isolation of man among created
beings, regards with complacency the probability that there are
regions in the universe where no organic life exists, stars which
shine upon no inhabited worlds, and planets which nourish no animate
creatures. The astronomical view of the universe is that it consists
of matter in every stage of evolution: some nebulous and chaotic; some
just condensing into stars (suns) of every magnitude and order; some
shaped into finished solar bodies surrounded by dependent planets;
some forming stars that perhaps have no planets, and will have none;
some constituting suns that are already aging, and will soon lose
their radiant energy and disappear; and some aggregated into masses
that long ago became inert, cold, and rayless, and that can only be
revivified by means about which we can form conjectures, but of which
we actually know nothing.

As with the stars, so with the planets, which are the satellites of
stars. All investigations unite to tell us that the planets are not
all in the same state of development. As some are large and some
small, so some are, in an evolutionary sense, young, and some old. As
they depend upon the suns around which they revolve for their light,
heat, and other forms of radiant energy, so their condition varies
with their distance from those suns. Many may never arrive at a state
suitable for the maintenance of life upon their surfaces; some which
are not at present in such a state may attain it later; and the forms
of life themselves may vary with the peculiar environment that
different planets afford. Thus we see that we are not scientifically