The aim of this long essay is to explain why the philosopher-ruler of Plato's Republic descends “with regret” or having been “compelled” from his contemplation of the Forms to rule the state. It offers a new, optimistic interpretation of his goal in so descending, namely to try to make everyone into a philosopher. After a brief introductory section, I turn to the argument of the Republic to show both that the philosopher's understanding of the Good causes him to try to maximize the amount of good in the cosmos, and that, since every rational person is capable, in virtue of his rational soul, of becoming a philosopher, this amounts to adopting the aforementioned goal. In the third section, I argue that the source of his regret cannot be that he sacrifices his own happiness in descending. Here the vehicle is a consideration of the “Plotinian” reading of the Republic, whose conclusion is that once he has achieved knowledge of the Forms, the philosopher can neither increase his happiness by further study, nor lose his happiness. Hence, if he is true to his goal, he has to try to improve the lot of others. In the next section, I argue that the Timaeus' account of the Demiurge's construction of the cosmos helps us to understand both the nature of the ruler's attempts to make everyone a philosopher and why he also understands that he will inevitably fail. Here the key idea is to link the Timaeus' account of Necessity or the Wandering Cause with the circumstances facing the philosopher in ruling the state. In the conclusion, I sketch how this account of the philosopher's reason for descending suggests that the best or ideal city in the Republic is not the tripartite kallipolis, but is rather a version of the City of Pigs.