Locke on measurement

Abstract

Like many virtuosi in his day, the English philosopher John Locke maintained an active interest in metrology. Yet for Locke, this was no mere hobby: questions concerning measurement were also implicated in his ongoing philosophical project to develop an account of human understanding. This paper follows Locke's treatment of four problems of measurement from the early Drafts A and B of the Essay concerning Human Understanding to the publication of this famous book and its aftermath. It traces Locke's attempt to develop a natural or universal standard for the measure of length, his attempts to grapple with the measurement of duration, as well as the problems of determining comparative measures for secondary qualities, and the problem of discriminating small differences in the conventional measures of his day. It is argued that the salient context for Locke's treatment of these problems is the new experimental philosophy and its method of experimental natural history.

Keywords: Duration; Gry; Locke; Measurement; Natural history; Newton; Picard; Richer; Rømer; Seconds pendulum; Toinard.