Full Idea
The radical individuality of essential properties of origin makes them unsuitable for inclusion in an Aristotelian essence.
Gist of Idea
Essential properties of origin are too radically individual for an Aristotelian essence
Source
Charlotte Witt (Substance and Essence in Aristotle [1989], 6.2)
Book Reference
Witt,Charlotte: 'Substance and Essence in Aristotle' [Cornell 1994], p.191
A Reaction
Nevertheless, Aristotle believes in individual essences, though these seem to be fixed by definitions, which are composed of combinations of universals. The uniqueness is of the whole definition, not of its parts.