This chapter begins with an account of the three conceptions of rulers mentioned in the title, i.e., the Thrasymachean ruler, Altruistic ruler and Socratic ruler. It then describes a dispute over the implication of the following two claims that are central to Socrates' refutation of Thrasymachus' account of justice. (E) No expert in so far as he is an expert – i.e., no expert qua expert – seeks his own benefit; every expert qua expert seeks the benefit of the object that his expertise rules over and cares for (R) No ruler in so far as he is a ruler – i.e., no ruler qua ruler – seeks his own...

This chapter begins with an account of the three conceptions of rulers mentioned in the title, i.e., the Thrasymachean ruler, Altruistic ruler and Socratic ruler. It then describes a dispute over the implication of the following two claims that are central to Socrates' refutation of Thrasymachus' account of justice. (E) No expert in so far as he is an expert – i.e., no expert qua expert – seeks his own benefit; every expert qua expert seeks the benefit of the object that his expertise rules over and cares for (R) No ruler in so far as he is a ruler – i.e., no ruler qua ruler – seeks his own benefit; every ruler qua ruler seeks the benefit of his subject. By showing how Socrates defends (E) and (R), the chapter illustrates that neither (E) nor (R) poses any real threat to psychological egoism. To begin with, there is no evidence that Socrates' defence embraces the possibility of either an altruistic expert or an altruistic ruler. Second, there is evidence in Socrates' defence that he upholds psychological egoism – even for those who are virtuous. Third, there is evidence in Socrates' defence that he entertains the possibility of a Socratic ruler who pursues the goal of the coherent science of happiness as a means to his own happiness.