Full Idea
I would define categorical properties as those whose identities depend only on the kinds of structures they represent.
Gist of Idea
Categorical properties depend only on the structures they represent
Source
Brian Ellis (The Metaphysics of Scientific Realism [2009], 3 n8)
Book Reference
Ellis,Brian: 'The Metaphysics of Scientific Realism' [Acument 2009], p.70
A Reaction
Aha. So categorical properties would be much more perspicaciously labelled as 'structural' properties. Why does philosophical terminology make it all more difficult than it needs to be?