William Stanley Jevons (1835 – 1882) is no stranger to historians of 19th-century economics. Jevons's contributions to economics have been widely discussed including, but not limited to, a systematic overview of his economic writings (Peart, 1996), his use of mathematics (Schabas, 1990), to what extent he influenced neoclassical economists (Winch, 1972), and commentary on `Jevons's Paradox' (Alcott, 2005). His central contribution lies in the great influence he had on future economists in being among the first to employ mathematical reasoning, specifically the methods of differential and integral calculus, to economic concepts. As Margaret Schabas writes: “[H]e was the first to argue systematically that the true science of economics called for mathematics, and he persisted in promoting this cause throughout his career” (1989, pp. 61 – 62). While many have written on Jevons's views in philosophy of science more generally, this paper focuses on elucidating Jevons's remark in The Theory of Political Economy where he says “I do not hesitate to say...that Economics might be gradually erected into an exact science” (Jevons, 1871, p. 21). While Schabas (1984) argues Jevons did not actually think of economics as an exact science, concluding her paper with the comment that “an algebraic analysis of the quantitative relationships of the economy would actually serve to clarify the approximate nature of such knowledge” (p. 146 – emphasis added), I seek to elucidate what Jevons might have meant by economics as an exact science.
