Many people believe, with Dostoyevsky's Ivan Karamazov, that if
ethical precepts were not grounded in God's commands, then
anything would be permitted. From Plato on, however, the
philosophical tradition has frequently questioned the idea of a
religious foundation for ethics. Despite this, philosophers have
yearned for a different source of absolute ethical authority,
substituting the dictates of reason for any divine imperative,
seeking, with Kant, the "moral law within." Over a century ago,
Darwin outlined a different way of thinking about ethics, and we
are now able to articulate more fully the hints he offered.
Ethics emerges as a human phenomenon, permanently unfinished. To
adopt this perspective provides a different perspective on many
questions that now confront us. Fifty thousand years ago, our
ancestors lived, as chimpanzees still do, in groups of about
thirty members, mixed by age and sex. To live in this way was
itself a social achievement, one that required psychological
capacities that are rare i