In Book 1 of in the Republic, Thrasymachus violently disagreed with the outcome of Socrates' discussion with Polemarchus about justice. He claims that "injustice, if it is on a large enough scale, is stronger, freer, and more masterly than justice'" (344c). The character is well-known for the assertion, "Justice is the advantage of the stronger." Socrates counters by forcing him to admit that there is some standard of wise rule — Thrasymachus does claim to be able to teach such a thing — and then arguing that this suggests a standard of justice beyond the advantage of the stronger. The rest of the dialogue is occasioned by Glaucon's dissatisfaction with Socrates' refutation.

Nothing about Thrasymachus is known outside of his presence in the Republic. There is a man by the same name mentioned in Aristotle's Politics (V.5.4) who overthrew the democracy at Cyme, but nothing is known of this event, nor can it be said with any degree of certainty that they are the same man.

Thrasymachus' importance thus derives entirely from his being a character in Plato's dialogue. He is noted for his unabashed, even reckless, defense of injustice and for his famous blush at the end of Book 1, after Socrates has tamed him. The meaning of this blush, like that of Socrates' statement in Book 6 that he and Thrasymachus "have just become friends, though we weren't even enemies before" (498c), is a source of some dispute.

In Leo Strauss's interpretation, Thrasymachus and his definition of justice represent the city and its laws, and thus are in a sense opposed to Socrates and to philosophy in general. As an intellectual, however, Thrasymachus shared enough with the philosopher to potentially act to protect philosophy in the city.

Links

• Stanford Encyclopedia of Philosopht entry on Callicles and Thrasymachus