274c & following, is Socrates’ denunciation of depending on the written word: reading encourages you to think you know things, when you don’t; relying on texts leads to a feeble memory; writing fails to fit the message to its audience; texts are frozen and can’t answer questions. Writing is an amusement and an aide-memoire – not serious philosophy.
And now, on to the Parmenides.
If it didn’t mean wishing away the parable of the cave, I might wish Plato had never written The Republic: such an ugly book, full of Socrates at his worst: it put me off Plato, and in fact philosophy, for decades. I’m glad that I have lived long enough to meet this Socrates who prays to Pan by the riverside: asking for his daily bread, and to be made beautiful inside. A different man entirely.