Thomas Percival FRS FRSE FSA (1740–1804) was an English physician and author, best known for crafting perhaps the first modern code of medical ethics. He drew up a pamphlet with the code in 1794 and wrote an expanded version in 1803, 'Medical Ethics, or a Code of Institutes and Precepts, Adapted to the Professional Conduct of Physicians and Surgeons in which he coined the expression "medical ethics". and
He was born at Warrington at Lancashire, the son of Joseph and Margaret (née Orred) Percival. He lost both his parents when he was three years old, so his older sister was responsible for his early education. Once he was old enough, he was placed in a private academy in his home town. He also spent time in a free grammar-school. In 1757, he was enrolled as the first student at Warrington Academy. After achieving a good reputation in classical and theological studies, he transferred to Edinburgh in 1761 (as a Dissenter he could not attend an English University). He achieved his M.D. degree in 1765 and became a fellow to the Royal Society, through a recommendation by his friend and patron Lord Willoughby de Parham, the same year.
British health reformer and ethicist. Educated at Edinburgh and then a prominent member of the Manchester Literary and Philosophical Society, he holds an important place in the history of epidemiology for his analysis of the Bills of Mortality from 1772–6, and for his code of medical ethics. The latter was initially circulated privately as a book on jurisprudence in 1794 and as a result of solicited comments from colleagues then published in an expanded form with a change in title to Medical ethics in 1803. Percival had been asked by the Manchester Royal Infirmary to help with an internal dispute and became particularly concerned with the divisions that had arisen among the different branches of the profession — the physicians, surgeons, and apothecaries with their different backgrounds of training (university, hospital, and apprenticeship respectively). But he did not merely concern himself with intraprofessional relationships: he also laid down a code for conduct towards patients, whether rich or poor, and his ideas were rapidly taken up by the USA, Australia, and Canada — in fact, the ethical code introduced by the newly formed American Medical Association in 1847 used several passages taken directly from his book.
Occupational health and medical ethics 
Percival is also known for his early work in Occupational health. He led a group of doctors to supervise textile mills, their report influenced Robert Peel's to introduce the Health and Morals of Apprentices Act of 1802. The legislation stipulated that children could work only 12 hours per day, walls had to be washed, and visitors had to be admitted to factories so that they could make health-related suggestions.
Percival's Medical Ethics served as a key source for the American Medical Association (AMA) code, adopted in 1847. Though hyperbolic in its recognition of Percival, the AMA itself states:
The most significant contribution to Western medical ethical history subsequent to Hippocrates was made by Thomas Percival, an English physician, philosopher, and writer. In 1803, he published his Code of Medical Ethics. His personality, his interest in sociological matters, and his close association with the Manchester Infirmary led to the preparation of a scheme of professional conduct relative to hospitals and other charities from which he drafted the code that bears his name.
As one expert writes, "The Percivalian code asserted the moral authority and independence of physicians in service to others, affirmed the profession's responsibility to care for the sick, and emphasized individual honor."
Selected works 
- Essays medical and experimental: on the following subjects, viz. I. The empiric. II. The dogmatic. Or, arguments for and against the use of theory and reasoning in physick. III. Experiments and observations on astringents and bitters IV. On the uses and operation of blisters. V. On the resemblance between chyle and milk. London: for Joseph Johnson and B. Davenport, 1767 (followed by later editions)
- Essays medical and experimental [Vol. II]: on the following subjects: 1. On the Columbo root. 2. On the orchis root. 3. On the waters of Buxton and Matlock ... 4. On the medicinal uses of fixed air. 5. On the antiseptic and sweetening powers ... of factitious air. 6. On the noxious vapours of charcoal. 7. On the atrabilis. 8. On sea salt. 9. On coffee. To which are added, select histories of diseases ... London: for Joseph Johnson, 1773
- Essays, medical philosophical and experimental; By Thomas Percival, M.D. F.R.S. and A.S. Lond. F.R.S. and R.M.S. Edinb. Member of the Royal Society of Medicine at Paris ; of the Royal Society of Agriculture at Lyons ; and of the American Philosophy Soc. at Philadelphia, &c. &c. The fourth edition, revised and enlarged. 2 vols. Warrington: printed by W. Eyres, for J. Johnson, London, 1788–89
- Medical ethics; or a Code of institutes and precepts, adapted to the professional interests pf physicians and surgeons. Manchester: S. Russell, 1803 (followed by later editions)
- Codes of Ethics: Some History, Center for the Study of Ethics in the Professions at IIT
- Ivan Waddington, "The Development of Medical Ethics - A Sociological Analysis," Medical History (1975) 19#1 pp 36-51
- Waterston, Charles D; Macmillan Shearer, A (July 2006). Former Fellows of the Royal Society of Edinburgh 1783-2002: Biographical Index II. Edinburgh: The Royal Society of Edinburgh. ISBN 978-0-902198-84-5. Retrieved September 25, 2010.
- Dr Thomas Percival and the Beginnings of Industrial Legislation
- Environmental History Timeline (1795)
- Short history of medical ethics, AMA web site
- "'Bioethics: Codes, Oaths, Guidelines and Position Statements". Dalhousie University Libraries. Retrieved 2009-08-19.
Further reading 
- Brockbank, E. M. (1929) "History of Collegiate Teaching: some pioneers; Thomas Percival". In: Book of Manchester and Salford. Manchester: Falkner & Co.; pp. 30–33.