Anamnesis

Anamnesis is Plato's doctrine that what we call learning is really remembering. In the Meno, faced with the paradox that one cannot inquire into what one does not know (for how would one recognize the answer?), Socrates draws correct geometrical conclusions from an untaught slave boy merely by questioning him, and argues that the boy must have had the knowledge within all along, needing only to be prompted to recover it.

The soul's prior life

In the Phaedo the theory grounds the immortality of the soul: to recollect, the soul must have existed and known before it entered the body. What it recollects are the Forms — Equality, Beauty, the Good — which it beheld in its disembodied state. Sensible things, by always falling short of the Forms, serve as reminders that awaken the latent memory; we judge two things 'equal but imperfectly so' only because we already carry Equality itself within us.

The myth of the Phaedrus

The Phaedrus paints the doctrine in myth: souls once journeyed in the train of the gods around the rim of heaven and glimpsed the Forms in their fullness before falling into bodies, and earthly beauty now stirs that lost vision and regrows the soul's wings. Anamnesis thus makes knowledge a kind of homecoming, and binds Plato's epistemology to his teaching on the soul and rebirth.