  The final argument for recognizing obligations to benefit fellow-citizens appeals to what David Miller has called ‘relational facts.’ Here the general thought is that certain relationships are constituted by reciprocal obligations: one cannot be a friend or a brother without having certain friendship-obligations or sibling-obligations, respectively. If fellow-citizenship is like these other relations, then we would seem to have special obligations to fellow-citizens. But this argument, which can be found in Cicero’s De Officiis, depends upon our intuitions that fellow-citizenship is like friendship or brotherhood and that friendship and brotherhood do come with special obligations, and both intuitions require more argument. Frequently, these arguments appeal to alleged facts about human nature or about human psychology, but these appeals generally raise still further questions.