This chapter continues the investigation of the phenomenon that Aristotle describes as ‘perceiving that we see and hear’ by analysing the much discussed passage from the beginning of De Anima III.2 in which Aristotle seems to maintain that we perceive that we see by sight, without even mentioning the possibility that we do so by a higher-order capacity. This appears to be in flat contradiction with what he says in De Somno et Vigilia 2, discussed in the preceding chapter. It is argued that the De Anima III.2 is an aporetic passage in which Aristotle replies to a challenge posed by Plato in the Charmides. It is important to note that Aristotle meets the challenge on Plato's own terms, which is why he does not introduce any higher-order capacities. Because this passage is dialectical, we should not take its conclusion to be Aristotle's considered view. In the course of his argument Aristotle mentions that it is by sight that we perceive darkness. However, it is argued that sight as such cannot achieve the perception of darkness. What is required is a higher-order capacity which registers inactivity of the sense of sight. Since the awareness of the activity of an individual sense is the work of the common sense, it is natural to suppose that awareness of an individual sense's inactivity is the work of the common sense. So the common sense provides us with the awareness of both the activity and inactivity of the individual senses. This monitoring function of the common sense is comparable with certain modern conceptions of consciousness.
Keywords: Aristotle, Plato, Charmides, De Anima, De Somno et Vigilia, perception, darkness, awareness, activity, inactivity, consciousness