Proclus

Proclus Lycaeus (412–485 CE) was the last great systematizer of the Neoplatonic tradition and head (diadochus) of the Platonic Academy at Athens. Born in Constantinople and educated at Alexandria and then Athens under Syrianus, he led the Academy for decades, producing voluminous commentaries on Plato, hymns to the gods, and the rigorous Elements of Theology, a chain of 211 propositions with deductive proofs laying out the entire structure of reality.

He was both a tireless scholar and a devout practitioner of pagan religious rites in an increasingly Christian empire. For the mind-power lineage, Proclus carried Neoplatonism to its most elaborate and architectonic form.

He refined the emanation scheme of Plotinus and Iamblichus into a fully articulated hierarchy descending from the ineffable One, governed by his signature triadic law of remaining, procession, and reversion: every effect remains in its cause, proceeds from it, and returns to it.

Between the One and the realm of Intellect he placed the henads—supreme unities or gods, transcendent complements of the One through which its unity is distributed to all things. And he gave a central place to theurgy, ritual practice that draws on the henads’ power to elevate the soul to the divine, holding that such sacred action reaches higher than discursive thought alone.

This grand layered cosmos and the doctrine of return-to-the-source passed, through Pseudo-Dionysius, deep into Christian mysticism and the later esoteric inheritance.