Moralists tend to have a low opinion of self interest. It is seen as force that has to be controlled or transcended. This essay tries to get beyond the bifurcation of human motivations into self-interest (which is seen as vicious or non-moral) and concern for others (which is virtuous). It argues that there are some surprising affinities between self-interest and morality. Notably the principal force that checks self-interest is self-interest itself. Consequently, self-interest often coincides with and reinforces the commands of morality and promotes civility and consideration for others. Therefore it provides us with resources for constructing a more humane and civil society.