Full Idea
Quine brought classes into semantics in order to oust properties.
Clarification
'Semantics' is the study of meaning
Gist of Idea
Quine brought classes into semantics to get rid of properties
Source
report of Willard Quine (works [1961]) by Colin McGinn - Logical Properties Ch.3
Book Reference
McGinn,Colin: 'Logical Properties' [OUP 2003], p.68
A Reaction
Quine's view has always struck me as odd, as I don't see how you can decide what set something belongs to if you haven't already decided its properties. But then I take it that nature informs you of most properties, and set membership is not arbitrary.