Abstract

This paper presents John Buridan’s nominalist ontology of habits, as the acquired qualities of innate powers aiding or hampering their operations, against the background of a more traditional interpretation of Aristotle’s doctrine to be found in Boethius, Albert the Great, Thomas Aquinas, and Cajetan. The paper argues that considerations of his late question commentary on Aristotle’s Nicomachean Ethics may have forced Buridan to rethink some of his earlier arguments for his parsimonious nominalist ontology of powers endorsed in such earlier works as his Questions on Aristotle’s Categories and De anima. The lesson to be drawn from this investigation seems to be that upon working out the details of a nominalist programme in such fields as moral psychology and ethics, the requisite refinements sooner or later will involve such modifications of an originally “radical” programme that would bring it closer to what used to be the “mainstream” view. Even so, this much seems enough further down the line to change significantly how issues are framed relative to the “mainstream” view as well.