The deductive method provides the warrant for the assertion of mathematical knowledge. The grounds for claiming that mathematics (and logic) provide absolutely certain knowledge, that is truth, are therefore as follows. First of all, the basic statements used in proofs are taken to be true. Mathematical axioms are assumed to be true, for the purposes of developing that system under consideration, mathematical definitions are true by fiat, and logical axioms are accepted as true. Secondly, the logical rules of inference preserve truth, that is they allow nothing but truths to be deduced from truths. On the basis of these two facts, every statement in a deductive proof,including its conclusion, is true. Thus, since mathematical theorems are all establid
hed by means of deductive proofs, they are all certain truths. This constitutes the basis of the claim of many philosophers that mathematical truths are certain truths.