This page created 7-8-02 by Sara Donaldson
Last revised 8-1-02
© 2002, Nowell Donovan
Maintained by Sara Donaldson

The Geological thought of Professor Prestwich

In designing his textbook, Professor Prestwich faced an interesting dichotomy. Two basic philosophies competed in his geological world, at a time when the relatively young science was still struggling to come to terms with the liberating consequences of the concept of “deep time.” Thus, in his Introduction he notes:
“The fundamental question of time and force has given rise to two schools [of thought], one of which adopts uniformity of action in all time, -- while the other considers that the physical forces were more active and energetic in geological periods than at present.

“On the Continent and in America the latter view prevails, but in this country the theory of uniformity has been more generally held and taught.”

His views are a moderate balance between an extreme view of “uniformitarianism”, holding to incremental change of such slowness as to be essentially undetectable, and a wholehearted reliance on special events or “catastrophes.” In essence the argument is a geological equivalent to the “steady state” versus “big bang” debate in the recent history of Physics:

“The eloquence and ability with which Uniformitarianism has been advocated, furthered by the palpable objections to the extreme views held by some eminent geologists of the other school, led in England to its very wide acceptance. But it must be borne in mind that uniformitarian doctrines have probably been carried further by his followers than by their distinguished advocate, Sir Charles Lyell, and also that the doctrine on Non-uniformity must not be confounded with a blind reliance on catastrophes; nor does it, as might be supposed from the tone of some of its opponents, involve any questions respecting uniformity of law, but only those respecting uniformity of action.

“I myself have long been led to conclude that the phenomena of Geology, so far from showing uniformity of action in all time, present an unceasing series of changes dependent upon the circumstances of the time; and that, while the laws of Chemistry and Physics are unchangeable and as permanent as the material universe itself, the exhibition of the consequences of those laws in their operation on the earth has been, as new conditions and new combinations successively arose in the course of its long geological history, one of constant variation in degree and intensity of action.”

The conclusions that he reaches in the final paragraph are essentially those that underpin modern geological thought. My own thought is that we interpret “through time by analogy drawn from the present.” Some processes operate at lightning speed, others are incredibly slow: all interact in some way - there are no closed systems. It’s a pity that “uniformitarianism” is such an ugly word!