Theaetetus
A student of the mathematician Theodorus, whom Theodorus praises when speaking with Socrates. Socrates is intrigued by Theodorus’ description of him, and asks him to come speak with him. Theaetetus, upon meeting Socrates, is asked what “knowledge” is. He says he does not know, but is eager to continue speaking with Socrates to try to figure it out.
Socrates
A philosopher and friend of Theodorus. Socrates asks Theaetetus what “knowledge” is, and Theaetetus says he does not know how to answer that question. Socrates assures him that he is there to help him figure it out, comparing himself to a midwife. Instead of helping deliver babies, however, Socrates’ job is to help people give birth to thought. As such, he guides Theaetetus through the conversation as Theaetetus tries to figure out what it means to have knowledge.
Euclid of Megara
Euclid of Megara opens the dialogue by speaking with his friend Terpsion about a dialogue he has between Socrates and Theaetetus. The dialogue, he says, is from when Theaetetus was young. Euclid of Megara’s conversation with Terpsion acts as a frame for the dialogue itself.
Terpsion
A friend of Euclid of Megara, who reads the dialogue between Socrates and Theaetetus with Euclid of Megara.
