ABSTRACT
This chapter explains the sense in which Aristotle considers numbers to be 'ones' and describes one of the more problematic aspects of his conception of mathematics. When mathematical attributes such as numbers are defined in terms of the physical objects possessing those attributes they clearly have sensible matter as their matter. As far as the question of individuation is concerned, noetic numbers have two features which serve to distinguish them from sensible numbers: they are potential and they are equivocal, whereas sensible numbers are actual and univocal. As far as the question of the unity of numbers is concerned, the Platonist view is that noetic numbers derive their unity from their genus. They are the kinds of things they are in virtue of the genus to which they belong, and it is in virtue of their belonging to this genus that they can be identified and individuated.
