Undiscovered Scotland

 

James Hutton lived from 3 June 1726 to 26 March 1797. He is considered by many to be the father of modern geology. He also promoted the concept of "deep time" which called into question the Biblical account of creation; and foreshadowed Darwin's views on natural selection by a century. The wider picture in Scotland at the time is set out in our Historical Timeline.

Hutton was born in Edinburgh and educated at the Royal High School. He went on to study medicine and law at the Universities of Edinburgh, Paris, and Leiden. After graduation he moved on to run two small family farms in Berwickshire. It was as a farmer in his thirties and forties that Hutton began to draw conclusions from his observations of the world around him, and from the erosive forces of wind and weather on the landscape. This led him into a more academic approach to a subject that, at the time, had only very recently gained a name: geology.

Returning to his studies at the University of Edinburgh at the height of the Scottish Enlightenment, Hutton became close friends with a number of eminent scientists of the day including John Playfair and Joseph Black, he also came to know the philosopher David Hume and the economist Adam Smith.

Hutton's key insight was to lead him to propose a revolutionary theory for the formation of the earth. At the time the prevailing view was Neptunist, that all rocks had precipitated out of a single enormous flood. Underpinning the existing theory was the belief that the world was only about six thousand years old, being formed on 22 October 4004 B.C., according to an analysis produced in the 1600s by James Ussher. the Archbishop of Armagh.

In looking at the world around him, Hutton found a series of examples of rock formations that could not be explained by the prevailing theory. At Glen Tilt in the Cairngorms, Hutton found granite penetrating metamorphic schists, in a way which indicated that the granite had been molten at the time. He found similar penetrations of volcanic rock through sedimentary rock in Edinburgh, at Salisbury Crags: now known as Hutton's Section. And he found further examples on the Isle of Arran and in Galloway. Hutton concluded that the Neptunist view must be be wrong, and proposed instead a Plutonist theory, in which the interior of the Earth was hot, and that this heat was the engine which drove the creation of new rock.

Hutton's theories went further. He had observed what became known as Hutton's Unconformity in layers of sedimentary rocks at Siccar Point on the Berwickshire coast. Here, the lower part of the cliff showed layers of grey shale tilted to lie almost vertically, then immediately above this the upper part of the cliff shows near horizontal layers of red sandstone. Hutton reasoned that this must have been caused by a cyclic process, involving deposition on the seabed, uplift with tilting and erosion. And he thought there could have been many such cycles over an extremely long history, measured, he said, in millions of years rather than thousands of years.

His theories led Hutton to propose the principle of uniformitarianism, in which the forces that shaped the world are still under way in the world we see today around us. His extension of this view to living creatures brought him to something very close to the principle of natural selection, a century before Darwin arrived at the same idea.

Hutton never married, and at the time of his death in 1797 he was living with his three sisters. His geological theories gradually gained influence during the latter part of his life, though Hutton's obscure written style meant that recognition of his full importance had to wait for interpretations of his work by more accessible writers after his death, especially John Playfair's Illustrations of the Huttonian Theory of the Earth, published in 1802. By the mid 1800s, Hutton's view of geology formed part of the bedrock of scientific orthodoxy