Full Idea
In traditional abstraction, the colour green merely has the intrinsic property of being green, other properties of things being abstracted away. But why should that be regarded as a type? It must be because the property is common to the instances.
Gist of Idea
If green is abstracted from a thing, it is only seen as a type if it is common to many things
Source
Kit Fine (Cantorian Abstraction: Recon. and Defence [1998], §5)
Book Reference
-: 'Journal of Philosophy' [-], p.19
A Reaction
A nice question which shows that the much-derided single act of abstraction is not sufficient to arrive at a concept, so that abstraction is a more complex matter (perhaps even a rational one) than simple empiricists believe.