Reason monolithism: A Darwinian dilemma for “relaxed” realism

Abstract Street formulated a Darwinian Dilemma for realist theories of value. Much criticism of her formulation of the dilemma targets the second horn, posed by the scientifically implausible assumption of a tracking relation between our attitudes and evaluative truth. This paper shows how a recent wave of metaethical realism, most prominently defended by Scanlon, succeeds without a tracking relation and thus avoids the Darwinian Dilemma in Street's formulation. However, Scanlon's approach, which builds on the concept of a reason relation and defends a metaphysically pluralist, domain‐specific conception of truth, runs into another version of the Darwinian Dilemma. The problem is not that Scanlon's realism assumes a tracking relation but that it assumes what I call reason monolithism – the idea that there is one possible expression of the faculty of reason and that this cognitive faculty could not be otherwise, which is scientifically implausible on similar grounds.