Ever since Aristotle, the philosophy of science has had two clearly delineated components: (a) conceptual foundations and (b) methodology. These rather closely correspond to what one might call the metaphysical and the epistemic bases of scientific knowledge. Both branches of philosophy of science have co-existed for a long time. If anything, methodology has usually tended to predominate over foundations.

Recently, however, methodology has come onto hard times and, since the 1960s especially, it has come in for considerable abuse. Some of that abuse is doubtless well-deserved. Much of traditional methodology made assumptions about the nature of scientific inference which simply cannot be sustained.