Full Idea
To regard properties as sets of individuals, and relations as sets of ordered individuals, is to make a nonsense of the whole idea of discovering a new property or relationship. Sets are defined or constructed, not discovered.
Gist of Idea
Properties and relations are discovered, so they can't be mere sets of individuals
Source
Brian Ellis (The Metaphysics of Scientific Realism [2009], 2)
Book Reference
Ellis,Brian: 'The Metaphysics of Scientific Realism' [Acument 2009], p.44
A Reaction
This bizarre view of properties (as sets) drives me crazy, until it dawns on you that they are just using the word 'property' in a different way, probably coextensively with 'predicate', in order to make the logic work.