“Do people help others because they think they will get pleasure from doing so (hedonism), or because they have an ultimate desire to help another (true altruism)? Sober and Wilson argue that evolutionary biology can shed light on this problem. They do not say that human traits that evolved by individual selection are hedonistic and those that evolved by group selection are truly altruistic. Their argument is more subtle than that…[This book] will stimulate thought about important questions.”