 The highest level of reflexivity, however, is found in the will, because only the will is capable of moving itself to action. In order to be free, the will has to be able to move itself in such a way that it can also refrain from moving itself. It has this ability because it is related to itself as a mover to a moved thing: “Insofar as the will is free, it has another kind of reflexivity upon itself which the intellect lacks: for, the will is turned toward itself not only as to an object, but also as a mover to a moved thing” (Summa II q. 51, p. 115). In fact, the reflexivity of the intellect is based on the will’s ability to direct other powers of the soul. (Summa II q. 57, pp. 364–66; ibid., q. 58, pp. 421–23.) Usually human beings are able to control themselves by their will, and this ability is what makes them persons. Reflexivity of the will plays a crucial role in the process, as we can see from a passage in which Olivi explains how sleep affects the psychological processes of the soul: