Lyell, Charles

Nineteenth-century Scottish natural philosopher who laid the foundations for the modern sciences of geology and evolutionary biology. His book Principles of Geology had an enormous influence on other scientists in the nineteenth century, especially Charles Darwin. He was the founder of the doctrine of uniformitarianism, which holds that all processes on the Earth are the same today as they have been in the past. Geologists often use the slogan “the present is the key to the past” to summarize Lyell's ideas.