Abstract

It is sometimes alleged that “the reliability challenge” to moral realism is equally compelling against mathematical realism. This allegation is of interest. The reliability challenge to moral realism is increasingly taken to be the most serious challenge to moral realism. However, the specific considerations that are said to motivate it – such as considerations of rational dubitability and evolutionary influence – are widely held not to motivate an analogous challenge to mathematical realism. If it turned out that, in fact, they do, then one might have to choose between moral realism and mathematical realism.<br><br>Nevertheless, the relevant allegation has never been clarified, let alone evaluated. In this paper, I clarify and evaluate it. I argue that the allegation is plausible, but depends on theses in the philosophy of mathematics that are widely doubted. One upshot of the discussion is that mathematical realism faces challenges that have not been widely appreciated. Another is that the reliability challenge to moral realism may not be the most interesting epistemological challenge to moral realism.