Full Idea
If Callias is a white man, then whiteness belongs in a way to Callias, or to man, in as much as Callias, to whom it is accidental here to be a man, is white.
Gist of Idea
Whiteness can only belong to man because an individual like Callias happens to be white
Source
Aristotle (Metaphysics [c.324 BCE], 1030b20)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.183
A Reaction
The point here is that 'white' can only belong to 'man' because some individual man happens to be white.