Abstract

The aim of this paper is to help clarify the debate about whether human morality is continuous or discontinuous with nonhuman animal behavior by contrasting partiality and impartiality as moral terms. The problem for evolutionary ethicists, who derive ethics from human evolutionary history, is that only partiality, the practice of extending care and moral consideration to one’s in-group, can be accounted for by natural selection and therefore shown to be continuous with nonhuman animal behavior. Impartiality, the ideal of applying moral standards equally to all humans, on the other hand, cannot be accounted for by natural selection. A conceptual gap, or saltatory leap, thus opens up between behaviors classified morally as partial or impartial, pointing to a conclusion of discontinuity in explaining the origin of morality. Frans de Waal’s 2006 book Primates and Philosophers, How Morality Evolved, takes up this issue, with de Waal arguing for the evolutionary position, continuity, even while upholding impartiality as the highest form of morality. His opponents are “veneer theorists,” who view morality, generally, as a uniquely human construction, required in order to overcome base and selfish desires. De Waal entertains critical responses to his discussion by several thinkers, and I consider that of Peter Singer. I also look to the neuropsychological research of Joshua Greene and Jonathan Haidt, as does de Waal, for help with the apparent evolutionary gap between partial and impartial moral beliefs but do not find a solution. Finally, I suggest other ways of rescuing the continuity thesis.