Charles Lyell and Charles Darwin were the first to argue against catastrophism. They argued a slow, gradual change known as Uniformitarianism, a theory of geological processes that states changes in the earth’s surface that occurred in past geologic time are referable to the same causes as changes now being produced on the surface. The basic concept was first developed by Scottish geologist James Hutton (1726-1797) in his Theory of the Earth (1788) and was further expanded on by John Playfair in his Illustrations of the Huttonian Theory (1964).
Lyell wrote Principles of Geology (1860) that synthesized four basic components of geology: the first is that natural laws are constant in time and space; second, the processes forming the earth now should be used to study how the earth was formed in the past; the third is that geological change is slow and steady; lastly, the earth has been relatively unchanged since its beginnings. Lyell argued that the earth is millions of years old, not thousands, and therefore, there was no need for cataclysms. Darwin was able to demonstrate how species were not fixed but modified over time, lending further evidence to the theory of Uniformitarianism.