This talk considers the issue of rights and duties in the context of social relations based on persistent exchange processes, occurring at both the micro and the macro social levels. Rights and duties that acquire a functional nature in such context are characterized in a tentative formal way. A possible connection between functional rights and duties and the issue of morality as a regulation mechanism for persistent micro social relations is investigated in a preliminary way. The relevance of functional rights and duties at the macro social level for the issue of the modularity of multiagent systems is indicated.