Keynes, Meltzer and Involuntary Unemployment: The Intensional and Extensional Logic of Definitions

Abstract

Critics often argue as if logical points were involved in definitions where in fact none such are present. Provided definitions are used consistently in a given context, each set will lead to perfectly accurate Fundamental Equations. . . . Moreover, there is a further point which critics are still more liable to overlook ? and one of very great practical importance to anyone who essays to write an intricate work on economics. A definition can often be vague within fairly wide limits and capable of several interpretations differing slightly from one another, and still be perfectly serviceable and free from serious risk of leading either the author or the reader into error, provided that any of the alternative definitions will do so long as it is used consistently within a given context. . . . (J.M. Keynes, 1979, p. 36)