History of Political Economy 32.4 (2000) 711-731
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The Significance of John Locke’s Medical Studies for His Economic Thought
William O. Coleman
John Locke (1632–1704) was both a medical practitioner and an economic theorist. This article seeks to measure the significance of this conjunction. Did his medical studies stimulate his economic thought? Did his medical researches and economic theories share a common stimulus? Or were they completely irrelevant to each other? Locke’s biographers have favored the last possibility: in their view Locke’s medical studies stand disconnected from his important life’s work.1 This essay, however, entertains the opposite thesis and will present and weigh evidence suggesting a connection between Locke’s medical and economic work. It argues, specifically, that his economic liberalism may have received some inspiration from his Hippocratism in medicine.
It also suggests that a case can be made that Locke’s medical researches and his economic theories shared a common stimulus. The program of “Puritan utilitarianism” may account for both Locke’s interest in medicine and his interest in economics.
Thus the intellectual biography conducted in this essay supports the general thesis that an extensive intellectual context stimulated the development of his economic ideas. [End Page 711]
Locke the Economist
Locke’s renown among historians of economic thought rests on Some Considerations Concerning the Lowering of Interest, and Raising the Value of Money ( 1991), Further Considerations Concerning Raising the Value of Money ( 1991), and the chapter “On Property” in the Two Treatises of Government ( 1988, bk. 2, chap. 4).
The economic ideas that he expresses in these writings might be summarized as follows. Locke believed national wealth to be the outcome of thrift and labor.2 Locke’s stress on labor as a source of wealth has been interpreted as amounting to a labor theory of value.3 In truth, Locke did not have a labor theory of value: to his mind market value was determined by the “proportion” between “quantity” (supply) and “vent” (demand), where vent depended upon “necessity or usefulness” (Locke  1991, 244).4 In keeping with these principles, Locke held that the “value of money” was determined by the plenitude or scarcity of money. This implied that the purchasing power of money fell with the amount of money in circulation.5 It implied, too, that the interest rate (which Locke saw as the hire price of money) would also fall with the supply of money.6 So although an orthodox quantity theorist with respect to prices, Locke allowed that money was nonneutral with respect to the interest rate. The final landmark in Locke’s thinking was his “metallism”: to John Locke money was no more or less than a precious metal (silver, in the case of England in the 1690s).
May Locke be simply categorized as either a mercantilist or a classical economist? He has been described as a mercantilist (Leigh 1974, 215); he has been interpreted as an early classical economist (Vaughn 1980). [End Page 712] He has also been analyzed as a transitionary figure linking mercantilism to classicism (Keynes 1936, 343).
Plainly, Locke is not a textbook characterization of a classical economist. Specifically, Locke rejected the neutrality of interest with respect to the money supply. Further, he was, on occasion, prepared to recommend tariffs (Guest 1992). More generally, his watchful, undeceived, pessimistic temperament is a considerable distance from the tranquil and optimistic outlook common (although not universal) in the classical economists. Locke never extolled the market; he could never extol anything—apart from his own watchful, undeceived, and pessimistic philosophy.
Nevertheless, Locke’s views of value and wealth are broadly those of the classical economists. If he deviated from the textbook characterization of a classical economist, so did most classical economists. Even the nonneutrality of money is not the anomaly it may seem, since he coupled that nonneutrality with a denial that the state could manipulate that nonneutrality to control the rate of interest.7 Indeed, the thrust of both his two principal works (Some Considerations and...