one.

In the progress of geological speculation, the same laws of thought are
displayed. We have dogmas that were more than half false, passing
current for a time as universal truths. We have evidence collected in
proof of these dogmas; by and by a colligation of facts in antagonism
with them; and eventually a consequent modification. In conformity with
this improved hypothesis, we have a better classification of facts; a
greater power of arranging and interpreting the new facts now rapidly
gathered together; and further resulting corrections of hypothesis.
Being, as we are at present, in the midst of this process, it is not
possible to give an adequate account of the development of geological
science as thus regarded: the earlier stages are alone known to us. Not
only, however, is it interesting to observe how the more advanced views
now received respecting the Earth's history, have been evolved out of
the crude views which preceded them; but we shall find it extremely
instructive to observe this. We shall see how greatly the old ideas
still sway both the general mind and the minds of geologists themselves.
We shall see how the kind of evidence that has in part abolished these
old ideas, is still daily accumulating, and threatens to make other like
revolutions. In brief, we shall see whereabouts we are in the
elaboration of a true theory of the Earth; and, seeing our whereabouts,
shall be the better able to judge, among various conflicting opinions,
which best conform to the ascertained direction of geological discovery.

It is needless here to enumerate the many speculations which were in
earlier ages propounded by acute men--speculations some of which
contained portions of truth. Falling in unfit times, these speculations
did not germinate; and hence do not concern us. We have nothing to do
with ideas, however good, out of which no science grew; but only with
those which gave origin to the existing system of Geology. We therefore
begin with Werner.

Taking for data the appearances of the Earth's crust in a narrow
district of Germany; observing the constant order of superposition of
strata, and their respective physical characters; Werner drew the
inference that strata of like characters succeeded each other in like
order over the entire surface of the Earth. And seeing, from the
laminated structure of many formations and the organic remains contained
in others, that they were sedimentary; he further inferred that