David Gauthier distinguishes maximizing given the actions others do from maximizing given the happiness others get, and maintains that universal conformities to the first rule coincide with equilibria in utility spaces of possible interactions, whereas universal conformities to the second coincide with optima. In Part One of the present paper some of his views concerning these matters of technical detail are tested under a variety of interpretations, and against a range of situations including most prominently situations in which actions of (...) agents are interdependent. Several limitations and needed qualifications are discovered. (shrink)