This paper is concerned with the relationship between the metaphysical doctrine of realism about the external world and semantic realism, as characterised by Michael Dummett. I argue that Dummett's conception of the relationship is flawed, and that Crispin Wright's account of the relationship, although designed to avoid the problems which beset Dummett's, nevertheless fails for similar reasons. I then aim to show that despite the fact that Dummett and Wright both fail to give a plausible account of the relationship between semantic realism and the metaphysical doctrine of realism, the semantic issue and the metaphysical issue are importantly related. I outline the precise sense in which the evaluation of semantic realism is relevant to the evaluation of realism about the external world, a sense overlooked by opponents of Dummett, such as Simon Blackburn and Michael Devitt. I finish with some brief remarks on metaphysics, semantics, and the nature of philosophy, and suggest that Dummett's arguments against semantic realism can retain their relevance to metaphysical debate even if we reject Dummett's idea that the theory of meaning is thefoundation of all philosophy.