 The third Aristotelian work on which Richard Kilvington commented during his regency in the Arts Faculty was the Nicomachean Ethics. His commentary on the second and tenth books of the Ethics takes a form of ten questions, which deal only with selected issues that were the subjects of Kilvington’s lectures at Oxford: e.g., creating and destroying moral virtue, free acts of volition, the behavior of honest people and the delight taken in their actions (or conversely, the punishment of those who act evilly), and questions concerning particular virtues such as courage, generosity, magnanimity, justice, and prudence. As Michałowska has shown, Kilvington uses terminist logic and mathematical physics to solve ethical problems (see Michałowska 2011a, 2016). Michałowska also shows that, just as he did in his questions on the Physics, Kilvington follows Ockham’s minimalist ontology by treating ethical qualities—i.e., vices and virtues, cognition and wisdom, good and evil—as volition-like objects, calling them res. Being real things and not merely mental concepts, they can be measured by addition, subtraction, and division into parts, for they undergo change via increase or decrease and so have varying degrees of intensity. Such changes—e.g., undergoing punishment for an evil act—cannot be instantaneous and must happen in time. Each change is the result of an acting power overcoming resistance. In the case of moral acts, the changes do not produce any external effects but internal modifications in terms of the intensity of virtues and vices. When a vice acts upon a virtue, it causes its continuous change, and so someone’s courage can vary in intensity. Virtues and vices are opposed in Kilvington’s physical theory, so it is impossible for someone to be vicious and virtuous at the same time, although it is possible for them to be generous at one time, miserly at another.