Full Idea
There is an old explanation of the utility of mathematics. Mathematics describes the structural features of our world, features which are manifested in the behaviour of all the world's inhabitants.
Gist of Idea
The old view is that mathematics is useful in the world because it describes the world
Source
Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.1)
Book Reference
Kitcher,Philip: 'The Nature of Mathematical Knowledge' [OUP 1984], p.105
A Reaction
He only cites Russell in modern times as sympathising with this view, but Kitcher gives it some backing. I think the view is totally correct. The digression produced by Cantorian infinities has misled us.