chapter  8
18 Pages

‘A Proportionable Mixture’: William Petty, Political Arithmetic, and the Transmutation of the Irish

ByTed McCormick

Sir William Petty’s chief role in Irish history is easily summarised: following Cromwell’s reconquest of Ireland, Petty designed and oversaw the ‘Down Survey’ of 1654-6, enabling the massive expropriation of Catholic-owned land in the Cromwellian settlement, which, modified somewhat after the restoration and again after the final defeat of James II, laid in turn the foundations for the eighteenthcentury ‘Protestant Ascendancy’.2 That Petty became a planter and improver in his own right – paid for the survey in land, he built up large estates in Kerry – is of incidental interest.3 So too is his part in bringing the scientific revolution to Ireland, bridging, as he did, the worlds of the Hartlib Circle, the Royal Society of London and the Dublin Philosophical Society.4 Of lesser note is Petty’s perennially unsuccessful pursuit of office throughout the Restoration, his abortive tenure as an admiralty

Petty’s writings furnish useful demographic and economic information and colourful opinions, but most date from a time when his active contribution to political reality was evidently long past – indeed, his best-known works, The Political Anatomy of Ireland and Political Arithmetick, were only published after his death. His real importance to Irish history, in short, lies in the 1650s.