Plato’s brother Glaucon plays a leading role in the Republic, where his devil’s advocacy of tyrannical injustice prods Socrates into making a lengthy defense of the just and philosophical life. Scholars rarely ask whether Socrates had any lasting effect on Glaucon, and the few who have done so almost always suppose that he was persuaded by Socrates. In Glaucon's Fate: History, Myth, and Character in Plato’s Republic, I present evidence that Glaucon in fact went on to support, and probably died fighting for, the so-called Thirty Tyrants—the Spartan-backed oligarchy, led by his cousin Critias, that governed Athens for eight months in 404-03 and put to death roughly 1,500 Athenians. This evidence casts the Republic in a radically new light. For it means that Plato’s intelligent and courageous brother could not be saved from the corruption of Athenian politics, and from kinsmen who were leaders of a reactionary tyranny, even by the age’s most capable advocate of virtue and philosophy.
What went wrong? This question leads me to explore Socrates’ rivalry with Critias, a pro-Spartan ideologue with whom he competes for the attention of ambitious young aristocrats. The problem is complicated by the fact that Socrates professes admiration in the Republic for Callipolis, a totalitarian regime modeled on Sparta that is strikingly similar to the one implemented in Athens by the Thirty. What explains Socrates’ paradoxical behavior? What responsibility does he have for Glaucon’s fate? These are the central questions of my book. I argue that they cannot be answered without attention to the thought of Critias as presented in his surviving writings and in Plato’s Timaeus-Critias and Charmides, dialogues that are closely related to the Republic in substance and drama. My reading of these dialogues in connection with the Republic, in the context of Athenian history and Greek myth, and as dramatic literature, promises to revolutionize Plato studies.