very much hotter than it is at present. There has been a time,
therefore, in which the igneous forces of the earth, to which we
owe the phenomena of earthquakes and volcanoes, must have been
far more intensely active than we can conceive of from anything
that we can see at the present day. By the same hypothesis, the
sun is a cooling body, and must at one time have possessed a
much higher temperature than it has at present. But increased
heat of the sun would seriously alter the existing conditions
affecting the evaporation and precipitation of moisture on our
earth; and hence the aqueous forces may also have acted at one
time more powerfully than they do now. The fundamental principle
of catastrophism is, therefore, not wholly vicious; and we have
reason to think that there must have been periods--very remote,
it is true, and perhaps unrecorded in the history of the earth--in
which the known physical forces may have acted with an intensity
much greater than direct observation would lead us to imagine.
And this may be believed, altogether irrespective of those great
secular changes by which hot or cold epochs are produced, and
which can hardly be called "catastrophistic," as they are produced
gradually, and are liable to recur at definite intervals.

Admitting, then, that there _is_ a truth at the bottom of the once
current doctrines of catastrophism, still it remains certain that
the history of the earth has been one of _law_ in all past time,
as it is now. Nor need we shrink back affrighted at the vastness
of the conception--the vaster for its very vagueness--that we
are thus compelled to form as to the duration of _geological
time_. As we grope our way backward through the dark labyrinth
of the ages, epoch succeeds to epoch, and period to period, each
looming more gigantic in its outlines and more shadowy in its