Full Idea
Our much loved mathematical knowledge rests on two supports: inexorable deductive logic (the stuff of proof), and the set theoretic axioms.
Gist of Idea
Mathematics rests on the logic of proofs, and on the set theoretic axioms
Source
Penelope Maddy (Naturalism in Mathematics [1997], I Intro)
Book Reference
Maddy,Penelope: 'Naturalism in Mathematics' [OUP 2000], p.1