1 The Virtue of Justice and the Justice of Institutions: Aquinas on Money and Just Exchange Ryan Darr Abstract Justice, according to Thomas Aquinas, is a personal virtue. Modern theorists, by contrast, generally treat justice as a virtue of social institutions. Jean Porter rightly argues that both perspectives are necessary. But how should we conceive the relationship between the virtue of justice and the justice of institutions? I address this question by drawing from Aquinas’s account of the role of the convention of money in mediating relations of just exchange. Developing Aquinas’s account, I defend two conclusions and raise one problem. The conclusions are: (1) Aquinas does presuppose the need for just institutions in just relations; (2) Aquinas highlights the importance of an underappreciated consideration: the way institutions mediate just or unjust relationships. The problem, which naturally arises from bringing together the virtue of justice and the justice of institutions, is whether and how individuals can act justly in a context of structural injustice. Ryan Darr is a Postdoctoral Research Associate in Philosophy of Religion at the University Center for Human Values, Princeton University, 304 Louis Marx Hall, Princeton, NJ 08544; rdarr@princeton.edu. Justice, like nearly every moral topic, is the subject of protracted disagreements. Yet disagreements about justice, unlike disagreements about most other moral topics, are not only about its nature and justification or its concrete application. Disagreements about justice are often also disagreements about the subject to which it is to be attributed. Though ethicists disagree, for example, about the nature, justification, and application of courage, they agree that courage is a quality of human beings. No such consensus can be found when it comes to justice. According to the dominant modern view, which is found most importantly in John Rawls’s A Theory of Justice, justice is, in Rawls’s famous phrase, “the first virtue of social institutions.” 1 For Rawls and many who have written in his wake, justice and injustice are primarily qualities of institutions. One also commonly encounters the idea that justice and injustice are qualities of states of affairs. The extreme economic inequality of contemporary society, for example, is often called unjust. In this sort of usage, justice and injustice are attributed not first to institutions but