Evolution and moral realism

We are moral apes, a difference between humans and our relatives that has received significant recent attention in the evolutionary literature. Evolutionary accounts of morality have often been recruited in support of error theory: moral language is truth-apt, but substantive moral claims are never true (or never warranted). In this article, we: (i) locate evolutionary error theory within the broader framework of the relationship between folk conceptions of a domain and our best scientific conception of that same domain; (ii) within that broader framework, argue that error theory and vindication are two ends of a continuum, and that in the light of our best science, many folk conceptual structures are neither hopelessly wrong nor fully vindicated; and (iii) argue that while there is no full vindication of morality, no seamless reduction of normative facts to natural facts, nevertheless one important strand in the evolutionary history of moral thinking does support reductive naturalism-moral facts are facts about cooperation, and the conditions and practices that support or undermine it. In making our case for (iii), we first respond to the important error theoretic argument that the appeal to moral facts is explanatorily redundant, and second, we make a positive case that true moral beliefs are a 'fuel for success', a map by which we steer, flexibly, in a variety of social interactions. The vindication, we stress, is at most partial: moral cognition is a complex mosaic, with a complex genealogy, and selection for truth-tracking is only one thread in that genealogy.