Full Idea
For the nominalist, belonging to the extension of a predicate is just an inexplicable ultimate fact.
Gist of Idea
For nominalists, predicate extensions are inexplicable facts
Source
George Molnar (Powers [1998], 1.2)
Book Reference
Molnar,George: 'Powers: a study in metaphysics', ed/tr. Mumford,Stephen [OUP 2003], p.24
A Reaction
I sometimes think of myself as a nominalist, but when it is summarised in Molnar's way I back off. He seem to be offering a third way, between platonic realism and nominalism. It is physical essentialist realism, I think.