Moral Intuitionism Meets Empirical Psychology

G. E. Moore’s diatribe against the naturalistic fallacy in 1903 set the stage for most of twentieth-century moral philosophy. The main protagonists over the next sixty years were intuitionists and emotivists, both of whom were convinced by Moore that empirical science is irrelevant to moral philosophy and common moral beliefs. Even in the 1970s and 1980s, when a wider array of moral theories entered the scene and applied ethics became popular, few moral philosophers paid much attention to developments in biology and psychology. This isolation must end. Moral philosophers cannot continue to ignore developments in psychology, brain science, and biology. Of course, philosophers need to be careful when they draw lessons from empirical research. As Moore and his followers argued, we should not jump straight from descriptive premises in psychology or biology to positive moral conclusions or normative conclusions in moral epistemology. That would be a fallacy.2 Nonetheless, psychology can still affect moral philosophy in indirect ways. That is what I want to illustrate here. I will trace an indirect path from empirical premises to a normative conclusion