Although it has become increasingly evident that an adequate theory of obligation must rest on evolutionary biology and human ethology, attempts toward this end need to explore the full range of personal, cultural, and political obligations observed in our species. The "new naturalism" reveals the complexity of social behavior and the defects of reductionist models that oversimplify the foundations of human duties and rights. Ultimately, this approach suggests a return to the Aristotelian concept of "natural justice." KEY WORDS: Obligation, altruism, law, human ethology, evolutionary theory, natural justice.
I. CONTEMPORARY THEORIES OF OBLIGATIONHuman social life has biological foundations. Although few contemporary philosophers and political theorists have focused on evolutionary biology and ethology, no theory can hope to explain human duties and rights without considering the life sciences (Alexander, , 1987 Ruse, 1986). To show why "obligation" must be studied as a scientific as well as philosophic question, it is useful to consider the difficulties that have resulted from the failure to do so.In recent social and political thought, human behavior is both literally and figuratively disembodied. Consider the following example from Richard E. Flathman's Political Obligation:We will argue that having a political obligation ordinarily presupposes the existence of a rule (whether a legal rule or some other type) which forbids or requires a specified form of conduct ... To say that there is a rule is not just to say that observers have detected that a certain number of people do or avoid doing X regularly or "as a rule." It is to say that at least some people have chosen to do X because they think that there are good reasons for doing so. And to say that B's conduct is governed by a rule is to say that B is one of those who has chosen to do X because he thinks there are good reasons for doing what the rule requires. Now to say that there are good reasons for doing X is to say that X can be distinguished from Y, Z, etc., (which may be merely not-doing-X), i.e., that there are alternatives to doing X over which X is preferred. It is also to say that doing Y, Z, etc., is potentially attractive to B such that there is a point to adducing reasons for doing X rather than Y or Z. In short, the existence of rules and rule-guided conduct presupposes the possibility of a tension in the thought of individuals, and hence in their society, between reasons for and reasons against accepting and choosing to conform to obligation rules. Moreover, the fact that reasoning and Biology and Philosophy 4 (1989) 17-32.