James Hutton (1726–1797), a Scottish farmer and naturalist, is known as the founder of modern geology. He was a great observer of the world around him.

More importantly, he made carefully reasoned geological arguments. Hutton came to believe that the Earth was perpetually being formed; for example, molten material is forced up into mountains, eroded, and then eroded sediments are washed away. He recognized that the history of the Earth could be determined by understanding how processes such as erosion and sedimentation work in the present day. His ideas and approach to studying the Earth established geology as a proper science.

In the late eighteenth century, when Hutton was carefully examining the rocks, it was generally believed that Earth had come into creation only around six thousand years earlier (on October 22, 4004 B.C., to be precise, according to the seventeenth century scholarly analysis of the Bible by Archbishop James Ussher of Ireland), and that fossils were the remains of animals that had perished during the Biblical flood. As for the structure of the Earth, “natural philosophers” agreed that much bedrock consisted of long, parallel layers which occurred at various angles, and that sediments deposited by water were compressed to form stone. Hutton perceived that this sedimentation takes place so slowly that even the oldest rocks are made up of, in his words, “materials furnished from the ruins of former continents.” The reverse process occurs when rock exposed to the atmosphere erodes and decays. He called this coupling of destruction and renewal the “great geological cycle,” and realized that it had been completed innumerable times.

Hutton came to his chosen field by quite a roundabout route. Born in Edinburgh in 1726, he studied medicine and chemistry at the Universities of Edinburgh, Paris, and Leiden, in the Netherlands, and then spent fourteen years running two small family farms. It was farming that gave rise to Hutton’s obsession with how the land could hold its own against the destructive forces of wind and weather he saw at work around him. Hutton began to devote his scientific knowledge, his philosophical turn of mind, and his extraordinary powers of observation to a subject that had only recently acquired a name: geology.