This article develops an argument in defense of the claim that Aquinas holds that there are some kinds of activities which can be performed only by persons. In particular, it is argued that Aquinas holds that only persons can engage in the activities proper to a rational nature, e.g., the activities of intellect and will. Next, the article turns to discuss two implications of this thesis concerning Aquinas’s concept of a person. First, the thesis can be used to resolve a prominent scholarly debate concerning Aquinas’s views on the possibility of human persons surviving their bodily deaths. Second, it also points to a problem with a leading interpretation of Aquinas’ account of the Christian doctrine of the Incarnation. Finally, the article concludes by discussing how a correct interpretation of Aquinas’s views on these matters is related to a broader scholarly debate concerning the history of the Western concept of a person.