The nature of reality and the Forms — the distinction between the changing material world and the eternal unchanging Forms that are the true reality. The Form of the Good as the highest principle, analogous to the Sun.
The soul — its immortality, its pre-existence, its knowledge as recollection (anamnesis), its tripartite structure of reason, spirit, and appetite.
Epistemology — the degrees of knowledge from imagination through belief through mathematical reasoning to dialectical understanding. The Allegory of the Cave as the complete picture of human epistemic condition.
Cosmology — the Demiurge as craftsman of the cosmos, the World Soul, the mathematical structure of creation, the relationship between eternity and time.
Ethics — virtue as knowledge, the unity of the virtues, the question of whether virtue can be taught, the good life as the life of philosophy.
Political philosophy — the ideal city as the soul writ large, the philosopher-king, the degeneration of political forms, justice as harmony of the parts.
Love and beauty — Eros as the ascent from physical beauty through moral beauty through the beauty of knowledge to the Form of Beauty itself.
Language and naming — whether words naturally fit their referents, the limits of language for conveying ultimate truth.
Death and the afterlife — the arguments for immortality, the myth of Er, the soul's judgment and reincarnation.
"There was a time when, in company with the gods, we beheld the beatific vision and were initiated into a mystery which may truly be called most blessed, celebrated by us in our state of innocence, before we were imprisoned in this living tomb which we carry about, now that we are shut up in the body, like an oyster in his shell." - Plato, Phaedrus 250b–c
Library of Light Edition 1.0 — Last revised: June 2026