Ted McCormick’s book is a valuable reassessment of William Petty’s intellectual legacy. Although, since it was the first and remains one of the few contemporary monographs dedicated to Cromwell’s physician and Charles II’s man in Ireland, perhaps it would be more accurate to call it a vital introduction. It takes a step back from the fragmentary reception in modern social sciences of Petty’s political arithmetic— largely based on Charles Henry Hull’s 1899 edition of his selected papers—where it is commonly associated with what we would now call econometrics. Instead of treating his work as a mere foreshadowing of the modern drive to turn economics into a quantitative science, McCormick makes the effort to reconstruct his hero’s intellectual journey in a proper historical manner. That is, he inquires as to how it might have unfolded in the mind of a driven early modern Englishman with scholarly interests, artisan’s means, and vast ambitions. The picture thus painted was, admittedly, a lot more interesting, albeit less favorable to Petty.

The first chapters provide a portrait of Petty as a young man. McCormick charts his education through Jesuit colleges in Europe to Cambridge, the acquaintances he made with Thomas Hobbs and Samuel Hartlib, and his volatile career that took him from professorship to knighthood. It is the first time that Petty’s extensive education in the leading empirical philosophies of the age, his knowledge of Harvey, Descartes, Newton, Bacon and Hobbes was so extensively documented. Even if McCormick takes away his honors as the founder of quantitative economics, he nonetheless solidifies Sir William’s fame as a brilliant thinker with practical concerns and ambition to back them up. Chapter three describes the Down Survey in preparation for the Acts of Settlement and Petty’s role in it. Chapters four through six make up the core of the argument connecting alchemical and experimental thinking with the demographic ambitions of the English as Petty would have seen them. Chapters seven and eight discuss the response to Political Arithmetic, contemporary and later.

Arguably, William Petty emerging from this volume’s pages was neither a dispassionate analyst, nor an aspiring technocrat (p. 84) simply reacting to economic indicators. The project of political arithmetic now appears to be an early and somewhat grim attempt at large-scale social engineering (p. 206, 258). The plans and methods upon which Petty mused for years involved such antics as forcibly relocating over 800 000 Irishmen—a number suspiciously close to his own estimate of the Catholic population of Ireland (p. 188)—to English cities, coercively regulating populations of different professionals to fit the Crown’s trade and colonial agendas, and turn entire countries into cattle farms (p. 256). The steps he was ready to take went far beyond the utopian genre of the time. The utopian works of his contemporaries left the details of who, what and how to be organically determined. Petty’s experimental program revolved around bending wills and physically moving bodies for the benefit of the state.

I have but two qualms about this work worth mentioning. First, McCormick’s insistence on conceptually connecting all of Petty’s interests to reconcile them into a consistent, wide-ranging research program feels unnecessary. He suggests that the alchemical metaphor employed in the report was also a description of the proposed means (p. 203). Indeed, Petty insisted on using the phrase “to transmute the Irish into English” (p. 212). but the logic behind it is far from alchemical, with his propositions of state-sponsored intermarrying (p. 201). Even when he explicitly invokes terminology normally reserved for such work, his conclusions are more in line with old-fashioned Galenic medicine concerned with the influence of the environment on one’s constitution (p. 168). McCormick addresses some of these worries in chapter 6 where he makes the alchemy-policy relation explicit. However, he admits that the best way Petty could have conceived to make an Irishman English was to take him to England—or to change Ireland to be like England. I would posit that an alchemist would have desired a more portable solution.

Second, the foray into 19th century socialist thought that McCormick made in the last chapter would have worked better as a separate article. Attached to a book steeped in 17th century confessional strife and early modern knowledge-making traditions we now label as science, it rings rather hollow. If the main objective of the book was to reconstruct what political arithmetic was to Petty and his compatriots, the study of its reception in Germany 200 years later does not obviously connect to previous chapters.

This monograph is a wake-up call to anyone still attached to the vision of science as a noble, disinterested endeavor occasionally misused by madmen and tyrants. A mere half generation after Francis Bacon’s call for a more experimental knowledge, influential researchers celebrated by the Crown had already been contemplating rational ways to go about an ethnic cleansing. Ted McCormick stumbled upon William Petty he probably would have never intended to find— one that should be a warning to social scientists, not an inspiration.