Aristotle maintains that defining "intelligence" (nous) requires first defining its activity, “understanding” or “insight” (noēsis) which requires first having considered its objects, intelligible beings (noēta). This chapter is about the nature of these objects: what about them makes them intelligible? My principal proposals are that what makes them intelligible is that they are "separate" and "unmixed," and that because, insofar as they are intelligible, they are, in their essence, "activity."’ I am aware this makes it sound as though Aristotle takes intelligibility to consist in some kind of intelligence. But in fact this is a result he is committed to, by the doctrines that intelligence is intelligible and that there is something that intelligible objects "all are in common"; for the alternative, as he himself says, is to suppose that intelligence "will have something mixed-in, which makes it intelligible just like the rest." The challenge, then, is not to steer clear of this result, but to make sense of it. My proposal is that the key to this lies in realizing that and why Aristotle thinks of intelligibility as a creature of intelligence.