Petty, Sir William, 1623–87, English statistician and physician. He was a founder of the Royal Society and was physician general to the army of Ireland in 1652. Petty's survey of the Irish estates appropriated by Oliver Cromwell, begun in 1654 and carried out in 13 months, was the first attempt at scientific surveying on a large scale. He won favor with Charles II, was knighted (1662), and became surveyor general of Ireland. In 1673, Petty's detailed map of Ireland was completed. It is as a political economist, however, that Petty is remembered. He disapproved of the ban on bullion export, favored an Irish-British union, and contended that labor determines price. His important writings include A Treatise on Taxes and Contributions (1662) and The Political Anatomy of Ireland (1691).

Bibliography

See biography by E. Fitzmaurice (1895, repr. 1973).

Petty, Sir William

(born May 26, 1623, Romsey, Hampshire, Eng.—died Dec. 16, 1687, London) British political economist and statistician. He gave up a life at sea to study medicine, and taught anatomy at the University of Oxford. He founded mines, ironworks, and fisheries in Ireland. He was also responsible for several inventions and was a founder of the Royal Society. Petty was an originator of political arithmetic, which he defined as the art of reasoning by figures upon things relating to government. In his best-known work, Treatise of Taxes and Contributions (1662), he favoured giving free rein to the forces of individual self-interest but declared the maintenance of a high level of employment to be a duty of the state. He also argued that the labour necessary for production was the main determinant of exchange value.