This article responds to a common criticism of Aristotelian naturalism known as the Pollyanna Problem, the objection that Aristotelian naturalism, when combined with recent empirical research, generates morally unacceptable conclusions. In developing a reply to this objection, I draw upon the conception of human nature developed by the ancient Chinese philosopher Mencius, and build up an account of ethical naturalism that provides a satisfying response to the Pollyanna Problem while also preserving what is most attractive about Aristotelian naturalism.

I have asked that this article should be reprinted in the volume dedicated to Elizabeth Anscombe because it in particular reflects throughout my great indebtedness to her. I remember, as long ago as the late 1940s confidently referring to ‘the difference between descriptive and evaluative reasoning’ in one of the many discussions that we began to have from that time on. She, genuinely puzzled, simply asked, ‘What do you mean?’.