Proclus 412 AD – 485 AD

Proclus Lycius was a Greek Neoplatonist philosopher and the last great head of the Platonic Academy at Athens. He systematized the Neoplatonic tradition inherited from Plotinus and Iamblichus, producing detailed commentaries on Plato's dialogues and a metaphysical treatise, the Elements of Theology, that proceeds in the manner of geometric proof. Proclus articulated a hierarchy descending from the One through the henads, the divine intellects, and the souls, down to the material world. His thought shaped Christian, Islamic, and Renaissance Platonism.

Proclus was born in 412 in Constantinople to a wealthy Lycian family. He was educated at Xanthus and at Alexandria in grammar, rhetoric, and philosophy, and around 430 went to Athens, where he joined the Platonic school under Plutarch of Athens and the headship soon passed to Syrianus. Around 437 he himself became head, or 'diadochus', of the Academy, a position he held for the remainder of his long career.

His enormous output includes the Elements of Theology, the Platonic Theology, lengthy commentaries on the Timaeus, Parmenides, Republic, Alcibiades I, and Cratylus of Plato, a commentary on the first book of Euclid's Elements, and treatises on providence, fate, and the existence of evils. He also composed hymns to the gods of traditional Greek religion at a moment when public paganism was being suppressed.

Proclus gave Neoplatonism its most systematic form, organizing reality into precise triadic series descending from the One and providing the technical vocabulary that would pass, through Pseudo-Dionysius the Areopagite and the Liber de Causis, into the heart of medieval Christian theology and Renaissance Platonism. He died in Athens in 485.