Evolutionary Debunking, Moral Realism and Moral Knowledge

This paper reconstructs what I take to be the central evolutionary debunking argument that underlies recent critiques of moral realism. The argument claims that given the extent of evolutionary influence on our moral faculties, and assuming the truth of moral realism, it would be a massive coincidence were our moral faculties reliable ones. Given this coincidence, any presumptive warrant enjoyed by our moral beliefs is defeated. So if moral realism is true, then we can have no warranted moral beliefs, and hence no moral knowledge. In response, I first develop what is perhaps the most natural reply on behalf of realism – namely, that many of our highly presumptively warranted moral beliefs are immune to evolutionary influence and so can be used to assess and eventually resuscitate the epistemic merits of those that have been subject to such influence. I then identify five distinct ways in which the charge of massive coincidence has been understood and defended. I argue that each interpretation is subject to serious worries. If I am right, these putative defeaters are themselves subject to defeat. Thus many of our moral beliefs continue to be highly warranted, even if moral realism is true.