Full Idea
What makes it the case that, if we call the account of something a 'definition', that thing is a unity? If 'two-footed animal' is the account of man, and a definition, why, then, is 'man' a single thing and not a plurality (viz. animal and two-footed)?
Gist of Idea
If we define 'man' as 'two-footed animal', why does that make man a unity?
Source
Aristotle (Metaphysics [c.324 BCE], 1037b10)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.212
A Reaction
The obvious answer, I would have thought, is that we can think of man as a unity or as a plurality, depending on which aspect we are interested in. I see no problem with this. Nature offers us unities, but we ultimately select them.