When the term rational' is used in formal economic theory, a strict definition is implicit. This strict definition cannot accommodate the complexities of our everyday ideas of what is rational. The concept of rationality that is embedded in our language is not a morally neutral one. It has always been believed possible to argue rationally about the worthiness of goals, the legitimacy of claim to rights, the existence of obligations or duties. Outside the discussions of the social sciences, argument concerning the rationality of a choice or action is never a purely technical, value-free...