James Hutton
James Hutton (1726-1797), a Scottish philosopher, chemist, and farmer, was a pioneer in the field of geology. His main contributions included the ideas that the earth was immensely old and that its features were constantly and gradually changing. He argued that many such changes were caused by heat within the earth. Hutton discussed this geological change in his book Theory of the Earth (1795). His theory that geological forces are the same now as in the past became known as uniformitarianism.
According to Hutton, rocks were constantly breaking down into soil. The soil was washed off the continents and carried into the sea by rain and rivers. Then, heat from under the earth's surface consolidated the soil into new layers of rock and eventually elevated the rock above sea level. This process led to the creation of new continents, which replaced those that had been worn away. Many thinkers of Hutton's day accepted Biblical evidence that the earth was about 6,000 years old. Hutton thought that this figure was much too low. Most theorists also believed that only rare disasters, such as earthquakes, could change the earth's appearance.
Hutton was born in Edinburgh. He studied medicine there but received his degree from Leiden University in the Netherlands. After becoming a farmer in Scotland, he became interested in geology.
Excerpt adapted from the "James Hutton" article, The World Book Encyclopedia © 1999