George Cheyne (physician)
George Cheyne M.D. R.C. E.d. R.S.S. (1671–1743) was a pioneering physician, early proto-psychologist, philosopher and mathematician.
Cheyne was acquainted with Sir Isaac Newton and provoked Newton to publish his Quadratures and with it, his Light & Colours. Newton later offered him financial support to publish Fluxionum methodus inversa (The Inverse Method of Fluxions), but apparently he turned down the offer. Newton refused to see him any more. 
In order to succeed in medical practice, Cheyne tried to develop a rapport with his patients by regularly visiting the local taverns where they spent time, a practice common among medical practitioners of the day. He became a popular figure of local social life, and the quantity of rich food and drink he consumed in consequence left him grossly obese and very unhealthy. He began a meatless diet, taking only milk and vegetables, and regained his health. But when he returned to a more typical diet - albeit more moderate than he had previously indulged - he regained weight and his health once again deteriorated. He went back to his vegetarian diet for the remainder of his life, recommending it for everyone suffering from obesity.
He also published a number of medical treatises, including a 1715 essay arguing that life cannot be created from non-living matter, and thus "must of necessity have existed from all eternity." He also wrote on fevers, nervous disorders, and hygiene. In 1740, he penned his last work, a study of nutrition and natural living, "The Natural Method of Cureing [sic] the Diseases of the Body, and the Disorders of the Mind." His work is often quoted by vegetarians and animal rights activists, particularly the following passage:
To see the convulsions, agonies and tortures of a poor fellow-creature, whom they cannot restore nor recompense, dying to gratify luxury and tickle callous and rank organs, must require a rocky heart, and a great degree of cruelty and ferocity. I cannot find any great difference between feeding on human flesh and feeding on animal flesh, except custom and practice.
The book was an immediate success and by 1742 was in its third edition.
Speaking from personal experience, Cheyne asserted that mental depression afflicted the brilliant rather than the dull, writing that "those of the liveliest and quickest natural Parts...whose Genius is most keen and penetrating were most prone to such disorders. Fools, weak or stupid Persons, heavy and dull Souls, are seldom troubled with Vapours or Lowness of Spirits."
- Cheyne, George, The English Malady; or, A Treatise of Nervous Diseases of All Kinds, as Spleen, Vapours, Lowness of Spirits, Hypochondriacal and Hysterical Distempers, Dublin, 1733. Facsimile ed., ed. Eric T. Carlson, M.D., 1976, Scholars' Facsimiles & Reprints, ISBN 978-0-8201-1281-7.
- George Cheyne - at upenn.edu
- George Cheyne - at Electric Scotland
- Stuart, Tristram, The Bloodless Revolution: A Cultural History of Vegetarianism from 1600 to Modern Times (W.W. Norton, 2007)