Full Idea
We cannot really be talking about the things whence an abstraction-like entity is abstracted if there are no such things.
Gist of Idea
We can't account for an abstraction as 'from' something if the something doesn't exist
Source
David Lewis (On the Plurality of Worlds [1986], 3.3)
Book Reference
Lewis,David: 'On the Plurality of Worlds' [Blackwell 2001], p.173
A Reaction
Sounds like a killer blow, but I don't think so. I can't think of a concept which doesn't have a possible basis in reality, assuming that it might be a complex assemblage of abstracted components.