Whether people are evil is not a popular topic among contemporary moral theorists. Nonetheless, assumptions about whether humans are generally good or evil play widespread and unnoticed roles in moral theorizing. In this paper, I show some of the ways that moral optimism – the view that humans are generally good – affects contemporary ethical theory. I start with recent work by Gilbert Harman and John Doris, in which empirical psychology plays important roles in ethical reflection. Wherever empirical work is taken to have normative implications, the issue of whether people are fundamentally good contributes to thinking about how empirical studies relate to normative conclusions. I then turn to Barbara Herman's work to show how optimism informs discussions of central issues in contemporary moral philosophy. I end with Kant's “moral pessimism.”

Throughout, I primarily contrast moral optimism with moral pessimism. Moral optimists need believe neither that people are omniscient nor that they always do the best thing, but only that the main failings of most people are not primarily moral, but have to do with ignorance or incompetence or social conditions or (non-culpable) negligence or lack of self-control.