Debunking Debunking's Debunkers: A Response to Street's Critics

In her 2006 paper, A Darwinian Dilemma for Realist Theories of Value, Sharon Street argues that evolutionary psychology, if roughly true, undermines evaluative realism as a metaethical theory. Evolutionary psychology suggests that our moral beliefs track evolutionary pressures, and not realist evaluative truths. Therefore, Street concludes, evaluative realism entails moral skepticism. The most compelling arguments against Street's evolutionary debunking of evaluative realism suggest that its implications are unacceptable. Vavova (2014, 2021) argues that, in order to work, evolutionary debunking entails global skepticism. Parfit (2017), on the other hand, argues that constructivism — Street's alternative to realism —entails nihilism. Both Vavova and Parfit argue that that in order to avoid these unacceptable implications — one epistemic, and the other ethical — evolutionary debunking must either contradict itself or fail to undermine realism. This paper will argue that evolutionary debunking can successfully respond to both of these challenges.