The Stranger’s Education of Theaetetus in Plato’s Sophist

Most readings of Plato’s Sophist abstract from Theaetetus the interlocutor. This misses a crucial dimension of the conversation, namely to help Theaetetus see through the sophist’s verbal tricks. I argue that Theaetetus does not yet understand the different states of human souls, nor is his mathematical training adequate for the philosophical method of division and dialectic. This makes him mistake the purifier for the sophist. Then I show that the Stranger emphasizes certain aspects while expounding his doctrines because he intends to improve Theaetetus in these two areas. I conclude by suggesting that Plato’s creation of the character of the Stranger is meant to find an alternative way of carrying on Socrates’ legacy.