This chapter explicates the concept of realism, and distinguishes it from related concepts with which it is often conflated. It shows that, properly conceived, realism has no ontological implications, and that influential epistemological objections to moral and mathematical realism fallaciously assume otherwise. One upshot of the discussion is that it is no response to Paul Benacerraf’s epistemological challenge to claim that there are no special mathematical entities with which to “get in touch.” The chapter concludes with a distinction between realism and objectivity, a distinction which is central to Chapter 6. It uses the Parallel Postulate, understood as a claim of pure geometry, as a paradigm of a claim that fails to be objective, even if mathematical realism is true. Conversely, it explains how realism about claims of a kind may be false even though they are objective in a sense in which the Parallel Postulate is not.
Debunking, supervenience, and Hume’s Principle
