For 30 years Michael Dummett has been arguing that metaphysics has a logical basis. One early statement of that view is found in 1973 in his first book on Frege: the dispute between realism and idealism, he says there, is the fundamental metaphysical issue, and it should be resolvable if we can determine the general form which a theory of meaning should take — that is to say, if we can determine what the central concept of the theory of meaning should be.¹ By the theory of meaning Dummett meant, he said, what is usually called "philosophical logic'. As he conceives it, the theory would provide a model of what we know in knowing a language, in understanding the expressions of a language (FPL, pp. 669–70). Thus the theory of meaning is "the fundamental part of philosophy which underlies all others' (FPL, p. 669). Dummett spells out this conception of philosophy as part of an argument for the importance of Frege in the history of philosophy. Descartes supposedly misled us into thinking that epistemology was the foundation of all philosophy, but Frege's greatness is that he enables us to see that it is the theory of meaning that properly has that position (ibid.).