Honors Program


Document Type


Date of this Version

Winter 3-2020


Hilton, A. (2020). Justice in exchange: The difficulty of establishing commensurability in Aristotle’s Nichomachean Ethics. The University of Nebraska-Lincoln.


Copyright Asher Hilton 2020


In Chapter 5 of Book V of the Nichomachean Ethics, an analysis of justice in exchange leads Aristotle to conclude that differing things can only be made commensurate in a practical sense. The passage sets up a relationship between association, exchange, equality, and commensurability in market exchange and leaves Aristotle with differing notions of commensurability. Aristotle considers demand (a need for resources) to be a means of resolving the tension; however, this possibility is subject to objections. Aristotle’s analysis of association for exchange is problematic, as is his exchange-equality relationship; examples from economic game theory illustrate the objections to Aristotle’s analysis. Finally, the dependence of equality on commensurability proves to be problematic due to Aristotle’s own distinction between strict and practical commensurability. Therefore, Aristotle’s analysis in the passage is subject to two observations. The first is that demand does not provide commensurability. The second is that the relationship of association, exchange, equality and commensurability must be reconsidered in order to avoid objections.