7 Matthew J. Advent Usury and Interest Journal of Markets & Morality Volume 27, Number 1: 7–30 Copyright © 2024 Matthew J. Advent PhD Candidate in Philosophy, The Catholic University of America There has been a recent increase in Catholic authors concerned about usury. However, these authors generally misunderstand later Thomistic teaching on this subject. This article uses the writings of Saint Alphonsus Liguori, Cardinal Juan de Lugo, and Cardinal Jozef-Ernest van Roey to explain how later Thomists approach extrinsic titles (particularly lucrum cessans) and explain how this tradition was able to develop Aquinas’s usury theory in a way that allowed a universal right to charge interest on a loan given the proper intention. Finally, it deals with several recent objections to this and finds them lacking. 1 Introduction In recent years there has been an uptick among Catholic intellectuals seriously concerned about usury. Indeed, in the last several years a number of works on the subject have appeared in prominent Catholic intellectual journals and in books published by Catholic presses. 2 Whatever the merits of these works, they all primarily focus directly on Aquinas and engage with the tradition of usury analysis in later Thomists only indirectly, if at all. 3 This leads to persistent misunderstandings of later Scholastic teaching on usury and can lead to the impression that at some point Thomists, and Catholics more generally, simply forgot Aquinas’s understanding of usury as a sin. 4 This, however, could not be further from the truth. When we look at later Thomistic discussions of lending, we see thoughtful debates about how Thomas’s teaching applies in different circumstances. These Usury and Interest Forgotten Contributions to the Thomistic Tradition