Research

“Aristotle on Needs, Justice, and Exchange” (published in Ancient Philosophy, 2025). –– Just exchange requires that the exchanged products be equal, which in turn requires that there be some “measure” (or metric) in terms of which we can calculate such equality. That measure, according to Aristotle, is need (chreia). His reason for thinking this is that need is the motive of exchange: people exchange in order to have their own needs met. But it is obscure how Aristotle can move from thinking that need is the motive of exchange to thinking that need is the measure of exchange. In this article, I argue that the key is to appreciate the political dimension of Aristotle’s treatment of exchange. In the light of that dimension, I argue that (1) whatever promotes the common benefit of the polis is just, (2) exchange promotes the common benefit of the polis, and (3) equal need-meeting is necessary to exchange––from which it is a short step to the conclusion that need is the measure of just exchange.

“Equalizing the Producers in Nicomachean Ethics 5.5″ (forthcoming in Phronesis; pre-proof version available here). –– Aristotle tells us in Nicomachean Ethics 5.5 that a just exchange involves equality. By this, Aristotle means not only that the products must be equal, but also that the exchangers themselves must be “equalized.” But the nature of this equalization is unclear and has puzzled commentators. In this article, I throw light on that unclarity, providing fresh reasons for thinking that, in a just exchange, (1) the exchangers are to be regarded as numerical equals (against the arguments of Gabriel Danzig) and that (2) the exchangers must be equalized in terms of what they give.

“Kant’s Theory of Money in the Metaphysics of Morals“ (in progress; email for a draft). –– When discussing contract in the Metaphysics of Morals, Kant embarks on a digression into the nature of money. But the “real definition” of money that he gives is perplexing: money is “the universal means by which men exchange their industriousness [Fleiß] with one another.” Three questions arise. (1) What does Kant mean by Fleiß? (2) Why does Kant invoke that concept in his real definition of money? (3) Since a real definition of X shows the possibility of X, how does Kant’s real definition show the possibility of money? In answer to these questions, I contend that Fleiß is roughly equivalent to free labor; that money is the means for exchanging Fleiß because exchange is regulated by the Fleiß involved in the production of money and goods; and that Kant’s real definition is money is offered only as a “preliminary” real definition (the explanation of the possibility of money occurs only later, in Kant’s account of the origin of money).