Full Idea
It was a justly celebrated insight of Frege that numbers attach to the concepts under which objects fall, and not to the objects themselves.
Gist of Idea
Frege showed that numbers attach to concepts, not to objects
Source
report of Gottlob Frege (Grundlagen der Arithmetik (Foundations) [1884]) by David Wiggins - Sameness and Substance 1.6
Book Reference
Wiggins,David: 'Sameness and Substance' [Blackwell 1980], p.44
A Reaction
A combination of this idea, and Aristotle's 'Categories', give us the roots of the philosophy of David Wiggins. Frege's example of two boots (or one 'pair' of boots) is the clearest example. …But the world dictates our concepts.