5 Some readers may feel that assertion requires justification. What valid warrant can there be for mathematical knowledge other than demonstration or proof? Clearly it is necessary to find other grounds for asserting that mathematical statements are true. The principal accounts of truth are the correspondence theory of truth, the coherence theory of truth (Woozley, 1949). The pragmatic theory of truth (Dewey, 1938) and truth as convention (Quine, 1936; Quimton, 1963). We can first dismiss the coherence and pragmatic theories of truth as irrelevant here, since there do not claim that truth can be warranted absolutely. The correspondence theory can be interpreted either empirically or non-empirically, to say that basic mathematical truths describe true states of affairs either in the world or in some abstract realm. But then the truths of mathematics are justified empirically or intuitively, respectively, and neither grounds serve as warrants for certain knowledge.