 Together with an essentially Platonic notion of the soul, Augustine inherits the classical problems of Platonic soul-body dualism. How can soul fulfil its task of “governing” the body (cf. De quantitate animae 22) if it is incorporeal itself? And how are corporeal and psychic aspects related to each other in phenomena that involve both body and soul, especially if, like passions and desires, these are morally relevant? These problems are further complicated by the Platonic axiom that incorporeal entities, being ontologically prior to corporeal ones, cannot be causally affected by them. Augustine’s solution is indebted to Plotinus’ strategy of making the relation of the soul to the bodily affections an essentially cognitive one (O’Daly 1987, 84–87; Hölscher 1986, ch. 2.2.1; Nash 1969, 39–59; Bermon 2001: 239–281). With Plotinus, he insists that sense perception is not an affection which the soul passively undergoes (as Stoic materialism would have it, where sensory perception was interpreted as a kind of imprint in the soul) but its active awareness of affections undergone by the body (De quantitate animae 41; 48; De Genesi ad litteram 7.14.20; Plotinus, Enneads I.4.2.3–4; Brittain 2002: 274–282). In De quantitate animae, the framework of this theory is the general argument that the relation of soul to body must be conceived of not in terms of space but of “power” (see above). In De musica (6.11), this is developed into the idea that sense perception is the soul’s awareness of modifications of its own formative and vivifying activities that result from its reacting to the external impulses undergone by the body. In addition to the usual five senses, Augustine identifies a sensory faculty that relates the data of the senses to each other and judges them aesthetically (but not morally; De musica 6.5; 19); in De libero arbitrio (2.8–13) he calls this the “inner sense” (on the Aristotelian background cf. O’Daly 1987: 102–105).