Socrates acts as a philosophical midwife to the young mathematician Theaetetus, helping him labor to deliver a definition of knowledge. They test the theories that knowledge is perception, true judgment, or true judgment with an account, ultimately finding all of them wanting. The dialogue is a brilliant exercise in epistemology, filled with memorable metaphors like the wax tablet of memory and the aviary of birds. It demonstrates the rigor of the Socratic method, valuing the clearing away of false beliefs as much as the discovery of positive truths.