The burgeoning science of ethics has produced a trend toward pessimism. Ordinary moral judgment and motivation, we’re told, are profoundly influenced by arbitrary factors and ultimately driven by unreasoned feelings or emotions-fertile ground for sweeping debunking arguments. This book counters the current orthodoxy on its own terms by carefully engaging with the empirical literature. The resulting view, optimistic rationalism, maintains that reason plays a pervasive role in our moral minds and that ordinary moral reasoning is not particularly flawed or in need of serious repair. The science does suggest that moral knowledge and virtue don’t come easily, as we are susceptible to some unsavory influences that lead to rationalizing bad behavior. Reason can be corrupted in ethics just as in other domains, but the science warrants cautious optimism, not a special skepticism about morality in particular. Rationality in ethics is possible not just despite, but in virtue of, the psychological and evolutionary mechanisms that shape moral cognition.