Abstract
In 1785 James Hutton of Edinburgh published the epoch-making book Theory of the Earth in which he proposed that present geologic processes were responsible for past changes in the surface of the earth. This concept is in contrast to the then-prevailing idea of one to several major catastrophes as the most important past geologic agents. In 1830 the English geologist Charles Lyell originated the term "uniformitarianism" to describe Hutton's views. The concept is succinctly stated as: the present is the key to the past. This uniformitarian principle has dominated geological thought in a fairly strict way for nearly two centuries while the opposite view, called "catastrophism," has been considered unacceptable.