ually had recourse for the explanation of
these changes to the supposition of sundry violent and
extraordinary catastrophes, cataclysms, or general revolutions
having occurred in the physical state of the earth's surface.

As the idea imparted by the term Cataclysm, Catastrophe, or
Revolution, is extremely vague, and may comprehend any thing you
choose to imagine, it answers for the time very well as an
explanation; that is, it stops further inquiry. But it has also
the disadvantage of effectually stopping the advance of science,
by involving it in obscurity and confusion.

If, however, in lieu of forming guesses as to what may have been
the possible causes and nature of these changes, we pursue that,
which I conceive the only legitimate path of geological inquiry,
and begin by examining the laws of nature which are actually in
force, we cannot but perceive that numerous physical phenomena
are going on at this moment on the surface of the globe, by
which various changes are produced in its constitution and
external characters; changes extremely analogous to those of
earlier date, whose nature is the main object of geological
inquiry.

These processes are principally,

I. The Atmospheric phenomena.

II. The laws of the circulation and residence of Water on the
exterior of the globe.

III. The action of Volcanos and Earthquakes.

The changes effected before our eyes, by the operation of these
causes, in the constitution of the crust of the earth are
chiefly--

I. The Destruction of Rocks.

II. The Reproduction of others.

III. Changes of Level.

IV. The Production of New Rocks from the interior of the globe
upon its surface.

Changes which in their general characters bear so strong an
analogy to those which are suspected to have occurred in the
earlier ages of the world's history, that, until the processes
which give rise to them have been maturely studied under every
shape, and then applied with strict impartiality to explain the
appearances in question; and until, after a long investigation,
and with the most liberal allowances for all possible
variations, and an unlimited series of ages, they have been
found wholly inadequate to the purpose, it would be the height
of absurdity to have recourse to any gratuitous and unexampled
hypoth