 Suppose we agree with Lakatos that there is room for heuristics or a logic or discovery. Still, orthodoxy could insist that discovery is one thing, justification another, and that the genesis of ideas has nothing to do with their justification. Lakatos, more radically, disputed this. First, he rejected the foundationalist or justificationist project altogether: mathematics has no foundation in logic, or set theory, or anything else. Second, he insisted that the way in which a theory grows plays an essential role in its methodological appraisal. This is as much a central theme of his philosophy of empirical science as it is of his philosophy of mathematics.