pothesis--that the heavenly bodies
were formed by the slow contraction of heated nebulous masses, is
indicated by so many facts that it seems scarcely possible to doubt it
except on the theory that the laws of nature were, at some former time,
different from those which we now see in operation. Granting the
evolutionary hypothesis, every star has its lifetime. We can even lay
down the law by which it passes from infancy to old age. All stars do
not have the same length of life; the rule is that the larger the star,
or the greater the mass of matter which composes it, the longer will it
endure. Up to the present time, science can do nothing more than point
out these indications of a beginning, and their inevitable consequence,
that there is to be an end to the light and heat of every heavenly
body. But no cautious thinker can treat such a subject with the ease of
ordinary demonstration. The investigator may even be excused if he
stands dumb with awe before the creation of his own intellect. Our
accurate records of the operations of nature extend through only two or
three centuries, and do not reach a satisfactory standard until within
a single century. The experience of the individual is limited to a few
years, and beyond this period he must depend upon the records of his
ancestors. All his knowledge of the laws of nature is derived from this
very limited experience. How can he essay to describe what may have
been going on hundreds of millions of years in the past? Can he dare to
say that nature was the same then as now?

It is a fundamental principle of the theory of evolution, as developed
by its greatest recent expounder, that matter itself is eternal, and
that all the changes which have taken place in the universe, so far as
made up of matter, are in the nature of transformations of this eternal
substance. But we doubt whether any physical philosopher of the present
day would be satisfied to accept any demonstration of the eternity of
matter. All he would admit is that, so far as his observation goes, no
change in the quantity of matter can be produced by the action of any
known cause. It seems to be equally uncreatable and indestructible. But
he would, at the same time, admit that his experience no more sufficed
to settle the question than the observation of an animal for a single
day would settle the question of the duration of its life, or prove
that it had neither beginning nor end. He would probably admit that
e