Abstract
This paper considers Thomas Aquinas’s claim that we can use certain habitus at will. Focusing on moral habitus, this claim is interpreted as a claim about the freedom human beings have with regard to their character traits: they can freely choose to act or not act according to their character traits. After giving a brief account of how, for Aquinas, character traits influence our actions via our emotions, the paper examines whether this freedom is of a libertarian or of a compatibilist kind. A libertarian reading is defended on the basis of certain remarks of Aquinas’s about the act of contrition.