Petty, Sir William

Sir William Petty (1623–1687), scientist and statistician, first came to public notice in Ireland in the 1650s. He was set on the path of scientific inquiry after having been taught mathematics by Jesuits in Normandy. Back in England, he was influenced by a group of reformers around Samuel Hartlib, a Protestant refugee from central Europe eager for social and educational changes. In 1651 the new regime first made Petty professor of anatomy at the University of Oxford and then in 1652, physician to the army in Ireland. He soon took over the survey of lands confiscated by the English state between 1649 and 1653. The result, the Down Survey, although not without flaws, provided the basis for the Cromwellian land settlement. Besides benefiting many military and Protestant civilians, the land redistribution also enriched Petty: He received £9,000 and substantial estates with annual rentals approaching £6,000 by the 1680s.

The Dublin administration, appreciative of his skills, made him clerk to the council and after 1655 secretary to the effective ruler of the island, Henry Cromwell, the younger son of Oliver Cromwell. Petty shared Cromwell's wish to move toward civilian instead of military government; this provoked radicals and soldiers to attack him in the Westminster Parliament of 1659, of which he was a member. He readily submitted to the restored Charles II, hopeful of high employment, but what he received—a knighthood in 1661, a place on the Irish privy council and its council of trade, and the judgeship of the Irish admiralty court in 1676—hardly matched his high estimate of his own abilities. He directed his energies into science and technology. A founder-member of the Royal Society of London, he was intermittently active in its affairs. He also pioneered, with John Graunt, the analysis of mortality rates in London and Dublin, and extrapolated both trends and population totals. His interest in quantification (although his figures were not always accurate) led to more sustained treatments of the natural and human geography of Ireland. On his own estates, especially in remote Kerry, he sought to demonstrate the merits of a methodical approach in exploiting iron ore, water power, timber, and the sea. The results failed to live up to his extravagant hopes.

Embittered by what he saw as his own neglect, Petty could be intemperate. In private he delighted friends with his irreverence. He wrote, sometimes obsessively and repetitively, about the politics, economy, and society of Ireland and England. Much was utopian or merely outrageous: He happily contemplated the enforced exchange of peoples from the two kingdoms. He was excessively optimistic that his unsentimental ideas about Ireland would recommend him to the Catholic James II, but a deluge of proposals failed to return Petty to the influence that he had briefly enjoyed between 1655 and 1659. He left behind a body of writings, many focused on Ireland, that showed him to be an unusually disciplined analyst. He also prepared the first county maps of Ireland, published in 1685 as Hiberniae Delineatio. The scope of Petty's interests and the scale of his achievements were fully apparent after his death: His Political Arithmetic was published in 1690, his Political Anatomy in 1691. The publication of all of his significant works has still to be completed. His writings, if sometimes repetitive and impractical, provide abundant details of the physical and human geography of seventeenth-century Ireland and England. They also show Petty's formidable intellectual prowess, especially as the originator of the statistical method known as political arithmetic.

SEE ALSO Agriculture: 1500 to 1690; Boyle, Robert; Cromwellian Conquest; Dublin Philosophical Society; Restoration Ireland

Bibliography

Barnard, T. C. "Sir William Petty, Irish Landowner." In History and Imagination: Essays in Honor of H. R. Trevor-Roper, edited by Hugh Lloyd-Jones, Valerie Pearl, and Blair Worden. 1981.

Fitzmaurice, Lord E. The Life of Sir William Petty, 1623–1687. 1895.

Harris, Frances. "Ireland as a Laboratory: The Archive of Sir William Petty." In Archives of the Scientific Revolution: The Formation and Exchange of Ideas in Seventeenth-Century Europe, edited by Michael Hunter. 1998.

Hull, Charles Henry, ed. The Economic Writings of Sir WilliamPetty. 2 vols. 1899.

Larcom, Sir Thomas, ed. The History of the Survey of Ireland,Commonly Called the Down Survey, by Dr. William Petty,A.D. 1655–6. 1851.

Petty-Fitzmaurice, H. W. E., marquess of Lansdowne, ed. ThePetty Papers. 2 vols. 1927.

Petty-Fitzmaurice, H. W. E., marquess of Lansdowne, ed. ThePetty-Southwell Correspondence, 1676–1687. 1928.

Petty Papers. ADD MSS 72850–72908. British Library.

Toby Barnard

Petty, Sir William (1623–87). Born in Romsey (Hants), his education took him to the Jesuit College, Caen, and later to Leiden, Utrecht, Amsterdam, Oxford, and London, where his studies focused upon medicine. With doctorates in both physics and medicine, he became professor of medicine, then anatomy, at Oxford University (1648), taking a chair in music in 1651 at Gresham College, London, and at the same time acting as medical officer to the English army in Ireland. In this latter connection he undertook a topographical survey of land in Ireland later assigned to Cromwell's soldiers (as well as to himself). Hence his work covered many subject areas. His best-known and most influential publications were Political Arithmetic (1678) and Treatise of Taxes and Contributions (1662), two texts in economics. They both placed emphasis upon the use of economic statistics in determining economic policy. Two years before his death he became adviser to James II.

John R. Presley