lation but those of the intellect. He reasons back to a
beginning of the present state of things; he admits the possibility of an
end.

I have said that the three schools of geological speculation which I have
termed Catastrophism, Uniformitarianism, and Evolutionism, are commonly
supposed to be antagonistic to one another; and I presume it will have
become obvious that in my belief, the last is destined to swallow up the
other two. But it is proper to remark that each of the latter has kept
alive the tradition of precious truths.

CATASTROPHISM has insisted upon the existence of a practically unlimited
bank of force, on which the theorist might draw; and it has cherished the
idea of the development of the earth from a state in which its form, and
the forces which it exerted, were very different from those we now know.
That such difference of form and power once existed is a necessary part
of the doctrine of evolution.

UNIFORMITARIANISM, on the other hand, has with equal justice insisted
upon a practically unlimited bank of time, ready to discount any quantity
of hypothetical paper. It has kept before our eyes the power of the
infinitely little, time being granted, and has compelled us to exhaust
known causes, before flying to the unknown.

To my mind there appears to be no sort of necessary theoretical
antagonism between Catastrophism and Uniformitarianism. On the contrary,
it is very conceivable that catastrophes may be part and parcel of
uniformity. Let me illustrate my case by analogy. The working of a clock
is a model of uniform action; good time-keeping means uniformity of
action. But the striking of the clock is essentially a catastrophe; the
hammer might be made to blow up a barrel of gunpowder, or turn on a
deluge of water; and, by proper arrangement, the clock, instead of
marking the hours, might strike at all sorts of irregular periods, never
twice alike, in the intervals, force, or number of its blows.
Nevertheless, all these irregular, and apparently lawless, catastrophes
would be the result of an absolutely uniformitarian action; and we might
have two schools of clock-theorists, one studying the hammer and the
other the pendulum.

Still less is there any necessary antagonists between either of these
doctrines and that of Evolution, which embraces all that is sound in both
Catastrophism and Uniformitarianism, while it rejects the arbitrary
assumptions of the one and the, as arbitrary, limitations of t