Aristotle on justice in exchange: commensurability by fiat

This essay offers an interpretation of Aristotle's remarks on the commensurability of goods in Book V of the Nicomachean Ethics. It explores the term ‘by hypothesis’ (ἐξ ὑποθέσεως) which Aristotle uses to describe the institution of currency through which commensurability is established. The term implies that Aristotle conceives the origins of currency to lie in a conscious act of stipulation rather than through a spontaneous process in which currency is established via the unintended consequences of individual action. In conclusion, contemporary theories of money are considered and it is asked with which Aristotle’s conception of money aligns most closely.