James Hutton (3 June 1726 OS (14 June 1726 NS) Edinburgh, Scotland — 26 March 1797) was a Scottish geologist, naturalist, chemist and experimental farmer. He is considered the father of modern geology. His theories of geology and geologic time, also called deep time, came to be included in theories which were called plutonism and uniformitarianism.

Educated at the Royal High School, and trained as both a lawyer and medical doctor, Hutton found himself attracted to the nascent science of geology. While working as a "gentleman farmer" in Berwickshire during his thirties and forties, he hit on a variety of ideas to explain the rock formations he saw around him. Studying at the University of Edinburgh in the throes of the Scottish Enlightenment, he fell in with several first-class minds in the sciences including John Playfair and Joseph Black. He was also a close friend of philosopher David Hume and economist Adam Smith.

At Glen Tilt in the Cairngorm mountains in the Scottish Highlands, Hutton found granite penetrating metamorphic schists, in a way which indicated that the granite had been molten at the time. This showed to him that granite formed from cooling of molten rock, not precipitation out of water as others at the time believed, and that the granite must be younger than the schists.

He went on to find a similar penetration of volcanic rock through sedimentary rock near the centre of Edinburgh, at Salisbury Crags, adjoining Arthur's Seat: this is now known as Hutton's Section. He found other examples on the Isle of Arran and in Galloway.

In 1787 Hutton noted what is now known as the Hutton Unconformity at Inchbonny, Jedburgh, in layers of sedimentary rock. As shown in the illustrations here to the right, layers of grey shale in the lower layers of the cliff face are tilted almost vertically, immediately above which are horizontal layers of red sandstone. He found a similar formation at Siccar Point on the Berwickshire coast in 1788.

Hutton reasoned that there must have been several cycles, each involving deposition on the seabed, uplift with tilting and erosion then undersea again for further layers to be deposited, and there could have been many cycles before over an extremely long history. In a 1788 paper he presented at the Royal Society of Edinburgh, Hutton remarked, "we find no vestige of a beginning, no prospect of an end." (This memorable line was quoted in the 1989 song “No Control” by songwriter and professor Greg Graffin.)

Hutton brought James Hall and John Playfair to see the strata in 1788. Playfair later commented about the experience, "the mind seemed to grow giddy by looking so far into the abyss of time."

An abstract of Hutton's Theory (Concerning the System of the Earth, its Duration, and Stability) was first read at meetings of the Royal Society of Edinburgh on 7 March 1785 and 4 April 1785. It was published in full (entitled Theory of the Earth or an Investigation of the Laws observable in the Composition, Dissolution, and Restoration of Land upon the Globe) in Volume 1 of the Society's Transactions in 1788.

Following criticism, especially Richard Kirwan's, who thought him atheist and not logical, among other things, Hutton published a two volume version of his theory in 1795, consisting of the 1788 version of his theory (with slight additions) along with a lot of material drawn from shorter papers Hutton already had to hand on various subjects such as the origin of granite. It included a review of alternative theories, such as those of Thomas Burnet and Georges-Louis Leclerc, Comte de Buffon.

The whole was entitled An Investigation of the Principles of Knowledge and of the Progress of Reason, from Sense to Science and Philosophy when the third volume was completed in 1794. Its 2,138 pages prompted Playfair to remark that “The great size of the book, and the obscurity which may justly be objected to many parts of it, have probably prevented it from being received as it deserves.”

His new theories placed him into opposition with the then-popular Neptunist theories of Abraham Gottlob Werner, that all rocks had precipitated out of a single enormous flood. Hutton proposed that the interior of the Earth was hot, and that this heat was the engine which drove the creation of new rock: land was eroded by air and water and deposited as layers in the sea; heat then consolidated the sediment into stone, and uplifted it into new lands. This theory was dubbed "Plutonist" in contrast to the flood-oriented theory.

As well as combatting the Neptunists, he also opened up the concept of deep time for scientific purposes, in opposition to Catastrophism. Rather than accepting that the earth was no more than a few thousand years old, he maintained that the Earth must be much older (indeed, he went rather overboard and asserted that the Earth was infinitely old). His main line of argument was that the tremendous displacements and changes he was seeing did not happen in a short period of time by means of catastrophe, but that processes still happening on the Earth in the present day had caused them. As these processes were very gradual, the Earth needed to be ancient, in order to allow time for the changes. Before long, scientific inquiries provoked by his claims had pushed back the age of the earth into the millions of years – still too short when compared with what is known in the 21st century, but a distinct improvement.

The prose of Principles of Knowledge was so obscure, in fact, that it also impeded the acceptance of Hutton's geological theories. Restatements of his geological ideas (though not his thoughts on evolution) by John Playfair in 1802 and then Charles Lyell in the 1830s removed this hindrance. If anything, Hutton's ideas were eventually accepted too well. At least some of the initial resistance to modern scientific ideas like plate tectonics and asteroid strikes causing mass extinctions can be attributed to too-strict adherence to uniformitarianism.

It was not merely the earth to which Hutton directed his attention. He had long studied the changes of the atmosphere. The same volume in which his Theory of the Earth appeared contained also a Theory of Rain. He contended that the amount of moisture which the air can retain in solution increases with temperature, and, therefore, that on the mixture of two masses of air of different temperatures a portion of the moisture must be condensed and appear in visible form. He investigated the available data regarding rainfall and climate in different regions of the globe, and came to the conclusion that the rainfall is regulated by the humidity of the air on the one hand, and mixing of different air currents in the higher atmosphere on the other.

Hutton also advocated uniformitarianism for living creatures too – evolution, in a sense – and even suggested natural selection as a possible mechanism affecting them:

:"...if an organised body is not in the situation and circumstances best adapted to its sustenance and propagation, then, in conceiving an indefinite variety among the individuals of that species, we must be assured, that, on the one hand, those which depart most from the best adapted constitution, will be the most liable to perish, while, on the other hand, those organised bodies, which most approach to the best constitution for the present circumstances, will be best adapted to continue, in preserving themselves and multiplying the individuals of their race." – Investigation of the Principles of Knowledge, volume 2.

Hutton gave the example that where dogs survived through "swiftness of foot and quickness of sight... the most defective in respect of those necessary qualities, would be the most subject to perish, and that those who employed them in greatest perfection... would be those who would remain, to preserve themselves, and to continue the race". Equally, if an acute sense of smell was "more necessary to the sustenance of the animal... the same principle [would] change the qualities of the animal, and.. produce a race of well scented hounds, instead of those who catch their prey by swiftness". The same "principle of variation" would influence "every species of plant, whether growing in a forest or a meadow".

He came to his ideas as the result of experiments in plant and animal breeding, some of which he outlined in an unpublished manuscript, the Elements of Agriculture. He distinguished between heritable variation as the result of breeding, and non-heritable variations caused by environmental differences such as soil and climate.

Hutton saw his "principle of variation" as explaining the development of varieties, but rejected the idea of evolution originating species as a "romantic fantasy". As a deist, to him this mechanism allowed species to form varieties better adapted to particular conditions and was evidence of benevolent design in nature. Hutton's ideas on geology were clarified in Charles Lyell's books, which Charles Darwin read with enthusiasm during his voyage on the Beagle, and it remained to Darwin to independently develop the idea of natural selection to explain The Origin of Species and bring it to the forefront of public consciousness at the same time as providing the voluminous evidence necessary to win over the scientific community to the theory.

* An Investigation of the Principles of Knowledge and of the Progress of Reason, from Sense to Science and Philosophy 1794 * Theory of the Earth 1795 * Elements of Agriculture 1797

;Biographies<nowiki>:</nowiki> * Jack Repcheck: The Man Who Found Time: James Hutton and the Discovery of the Earth's Antiquity. London and Cambridge, Massachusetts: Simon & Schuster (2003). ISBN 0743231899 (UK), ISBN 073820692X (US).

* Stephen Baxter: Ages in Chaos: James Hutton and the Discovery of Deep Time. New York: Tor Books (Forge imprint), 2004. ISBN 0-76531-238-7. Published in the UK as Revolutions in the Earth: James Hutton and the True Age of the World. London: Weidenfeld & Nicolson, 2003. ISBN 0-29782-975-0.

*Geology of Scotland *Climate of Scotland *Nicholas Steno *Shen Kuo

*Biography of James Hutton (From: Encyclopaedia Britannica, 11th Ed., 1910-1911) *James Hutton and Uniformitarianism (scroll down) *James Hutton's memorial in Greyfriars Kirkyard, Edinburgh *First Publication of Theory of the Earth *Glossary Definition and examples of unconformity * *