Full Idea
If properties are sui generis entities, one must decide whether they are abstract or concrete.
Gist of Idea
If properties are sui generis, are they abstract or concrete?
Source
Alex Oliver (The Metaphysics of Properties [1996], §09)
Book Reference
-: 'Mind' [-], p.21
A Reaction
A nice basic question! I take the real properties to be concrete, but we abstract from them, especially from their similarities, and then become deeply confused about the ontology, because our language doesn't mark the distinctions clearly.