Around 1800 in places like Manchester and Leeds early industrialists were manipulating bobbins, rotating belts, moving parts of every size and shape, for the purpose of increasing the speed of their weaving or spinning. In so doing they were discovering and applying the principle that speed, absence of friction, and vibration translated into economic change, that is, into greater profits. They had come to realize that the economy was not governed simply by natural forces but also by human artifice. They knew that technological intervention could directly alter profits, that too large a steam engine could spell economic disaster just as surely as could one that was too small to accomplish the factory's work.

None of these insights from the factory floor, we are told by Margaret Schabas, had anything to do with the profound changes that occurred in economic theory between roughly 1750 and 1850. Her book rests firmly in the tradition of intellectual history that used to be called Ideengeschichte. Change occurs because great minds think better thoughts, and in this instance it was the Victorians led by John Stuart Mill who developed a new understanding of the economy, depicting it in terms of human agency, “social institutions, man-made through and through” (153). Unaided and possibly even, we are led to believe, unaware of factories and their technologies, in their hands the very notion of the economy “went from being a natural entity to being a social one” (153). Whereas Adam Smith and enlightened thinkers in general—largely for reasons of Christian piety—had seen political economy as governed by the laws of nature and hence knowable scientifically, the next two generations of thinkers retained the mantle of science, while viewing the economic as an entity devised by human manipulation that could in turn yield to human control. This thesis is most simply illustrated by price theory. For eighteenth-century thinkers “a natural price was determined by natural costs, which were determined by cycles of the harvest and population” (155). Today we are told “price theory steers a different course, emphasizing the role of demand and utility and the deliberations of a firm toward the end of maximizing profits” (155).

Overall, the thesis of there having been this sort of sea change in economic thinking over a century or more seems true enough. But the explanatory mechanisms for why this change occurred seem strangely lacking. To sustain the argument a certain amount of stereotyping is required. The Enlightenment becomes a God-fearing age, and the argument from design is offered as the essence of its piety without for a second realizing that the Boyle lectures (the locus classicus of the argument) were deeply polemical texts aimed at an army of radical pantheists, deists, skeptics, and libertines who were imagined to be in the pews as well as the coffeehouses. It is not surprising that when we get to the nineteenth century their materialist heirs, Charles Darwin and Karl Marx, are relegated to minor roles by comparison to Thomas Malthus, Mill, Alfred Marshall, David Ricardo, even Richard Jones, Philip Henry Wicksteed, and William Whewell.

This is not a book for readers who have a less than firm grasp on the dozens of economic theorists, both British and French, who occupy its pages. It also presumes a fairly detailed knowledge of scientific thought in the period because where the economic theorists find new and compelling ideas is largely in the science of their day. Smith, it is argued, got his treatment of labor and sympathy from his understanding of subtle fluids, and he “depicted the stuff of labor (imagine a subtle or imponderable fluid) implanting itself in objects and being stored there for later extraction” (89). The treatment of Smith reveals the best that can be achieved by the tradition of the history of ideas to which the book so firmly belongs. The worst comes out in sentences that will leave most readers mystified: “When physicists learn about the Fisher equation, which attempts to mimic the Boyle-Charles law in thermodynamics, they are struck by the misuse of the term velocity” (157). One other habit of thought makes this book not simply difficult, or perhaps eccentric, but curiously academic, as if intended for an audience of perhaps no more than a hundred or so specialists. So very many sentences, on nearly every page, begin as follows, “as Chandra Mukerji has argued,” “as Williams observed,” “there were brilliant studies of Enlightenment physics by … Gillispie, … Schofield, … Hankins,” “what Emma Rothschild aptly calls,” “as Dennis O’Brien points out,” “Mirowski has ably demonstrated,” “for Gary Becker, they are the result,” “Maxine Berg has argued,” and so on. These are all wonderful scholars, but this distracting style of writing renders them on the same level with thinkers such as Locke, Keynes, Foucault, Quesnay, and Smith. The reviewer is left asking, where were the editors when this manuscript flew over the transept? There are some wonderful insights into individual thinkers, fresh readings of Smith, Malthus, Marshall and even Keynes, but the reader has to work really hard to achieve a level of satisfaction that can be reasonably expected from a book by a good university press. This is an extremely learned author who could have been better served by her editors. This is a book to be assigned not as a whole but in sections depending upon the thinker whose thought needs explicating. Its learning is best on display in small doses.