Charles Lyell and Uniformitarianism

Charles Lyell and Uniformitarianism
The geologist Sir Charles Lyell (1797 to 1875; Figure 6-3) established in his Principles of Geology (1830 to 1833) the principle of uniformitarianism. Uniformitarianism encompasses two important principles that guide the scientific study of the history of nature: (1) that the laws of physics and chemistry remain the same throughout the history of the earth, and (2) that past geological events occurred by natural processes similar to those observed today. Lyell showed that natural forces, acting over long periods of time, could explain the formation of fossil-bearing rocks. Lyell’s geological studies led him to conclude that the earth’s age must be measured in millions of years. These principles were important for discrediting miraculous and supernatural explanations of the history of nature and replacing them with scientific explanations. Lyell also stressed the gradual nature of geological changes that occur through time, and he argued further that such changes have no inherent tendency to occur in any particular direction. Both of these claims left important marks on Darwin’s evolutionary theory.