If time is the factor of all progress by a necessary law, this necessity
must be everywhere the same. Have the elements of matter all the same
age? If so, why have some followed the law of progress, and others not?
Why has this mud and this coal remained mud and coal, age after age,
while these other molecules have risen, in the hierarchy of the
universe, to the dignity of life? Why have these mollusks remained
mollusks throughout the succession of their generations, while others,
happily transformed, have gradually mounted the steps of the ladder up
to man? Whence comes this aristocracy of nature? Are the beings which we
call inferior only the cadets of the universe, and are they too in their
turn to mount all the steps of the ladder? Must we admit that there is
going on the continual production, not only of living cellules which are
beginning new series of generations, but also of new matter, which,
setting out from the most rudimentary condition, is beginning the
evolution which is to raise it into life? They do not venture to put
forth theses of this nature, and, in order to account for the diversity
of things, recourse is had to circumstances. The diversity of
circumstances explains the diversity of developments. But whence can
come the variety of circumstances in a world where all is produced in
the way of fatal necessity, and without the intervention of a will and
an intelligence? This is the remark of Newton. Study carefully the
systems of materialism: their authors declare that to have recourse to
God in order to account for the universe is a puerile conception
unworthy of science, because all explanation must be referred to fixed
and immutable laws; and then you will be for ever surprising them in the
very act of the adoration of _circumstances_. Convenient deities these,
which they summon to their aid in cases which they find embarrassing.

But we will not insist on these preliminary considerations. We have
allowed, for argument's sake, that all organized beings have proceeded