Proclus

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Proclus (412 – 17 April 485), called the Lycian for his family’s homeland and Diadochos — “the Successor” — for his office, brought the long tradition of Neoplatonism to its most thorough systematic form: the last great head of the Platonic school at Athens, and the mind that arranged nearly a thousand years of Greek thought into a single deductive order. The chair he held for almost half a century traced its lineage in principle back to Plato himself; the system he built carries everything the Hellenic tradition had truly seen — dialectic, mathematics, the gods and their rites — in one connected demonstration, descending from the One and returning.

From Xanthus to the Succession

Born in Constantinople in 412 to Patricius and Marcella, Lycians of noble family, he was taken soon after birth to their home city of Xanthus, a town sacred to Apollo (Life of Proclus §6). In Alexandria he studied rhetoric with the sophist Leonas, whose house-guest he was, and grammar under Orion, of an old Egyptian priestly line, headed like his father for the law — until, on a journey to Byzantium with Leonas, the patron goddess of his birth city appeared to him in a dream and summoned him to philosophy (§§6–9). Back in Alexandria he read Aristotle under Olympiodorus the Elder — so rapid a lecturer that few could follow, though Proclus would repeat a whole lecture from memory afterward, and Olympiodorus offered him his daughter in marriage — and mathematics under the pious Heron (§9).

He reached Athens in 430 or 431, not yet twenty; the sophist Lachares, watching him bare his feet to salute the rising moon, declared in Plato’s words that he would prove a great good or its contrary (§§10–11). The aged Plutarch of Athens, then head of the school, received him, read Aristotle’s On the Soul and Plato’s Phaedo with him, and died about two years later; Syrianus succeeded, took the young man into his own house, and led him through the curriculum Iamblichus had fixed for the schools — Aristotle first, as the lesser mysteries, then the dialogues of Plato (§§12–13). Under Syrianus he also met the Orphic and Chaldean theologies. By twenty-seven he had completed his commentary on the Timaeus. Syrianus is the one predecessor he never criticizes — his true master, so thoroughly absorbed that scholarship despairs of separating their contributions — and when Syrianus died in 437, Proclus succeeded him as diadochos and held the office until his own death in 485: almost half a century.

The Rule of a Life

The biography his pupil and successor Marinus left — Proclus, or On Happiness — is one of the fullest portraits of any ancient philosopher, and frames its subject less as a thinker than as a man perfected through the scale of the virtues — natural, ethical, political, purifying, intellectual, theurgic — the last being those by which a human being acts with the gods. He never married, declining advantageous offers (§17); prayed to the sun at rising, noon, and setting; wrote some seven hundred lines a day, lectured besides, and gave sleepless stretches of the night to composing hymns (§22). He abstained from animal food; kept the monthly rites of the Mother of the Gods and the Egyptian holy days more strictly than the Egyptians; kept open fasts and all-night vigils; and sang hymns to the gods of many nations — Marnas of Gaza, Asklepius Leontuchus of Ascalon, Thyandrites of the Arabs, Isis at Philae — holding that the philosopher must be “the hierophant of the whole world in common” (§19).

These were the festivals of gods whose public worship the Christian empire was steadily closing down; the school kept them privately, with prudence. When harassment by men Marinus names only as “a sort of vultures” made Athens untenable, Proclus withdrew to Lydia for about a year, restoring the old rites there before returning (§15). And when the statue of Athena was removed from the Parthenon, a woman of great beauty announced in a dream that he must make his house ready quickly, “because the Athenian Lady wishes to dwell with you” (§30).

He learned the Chaldean rites from Asclepigenia, daughter of Plutarch and sole heir of the discipline of Nestorius (§28); Marinus credits him with rain brought in drought and with apparitions of Hecate, and tells how he prayed at the still-standing temple of Asclepius for a gravely ill girl — a younger Asclepigenia, daughter of Archiadas — and she recovered (§29). His house, where Syrianus and Plutarch had lived before him, stood near the sanctuaries of Asclepius and Dionysus in sight of the Acropolis (§29); a late-Roman house excavated in 1955 on Dionysiou Areopagitou Street has been identified as it.

Vigorous until about seventy, he died on 17 April 485 — the dating is Marinus’s own: the 124th year from Julian’s accession, the archonship of Nicagoras the younger, “the seventeenth day of the month Munychion, or the seventeenth of April” (§36). (The 8 February birth day often printed beside 412 is a modern computation from the natal horoscope Marinus appends to the Life, not part of the ancient record.) He was buried near Mount Lycabettus in a double tomb beside Syrianus, under an epigram of his own making: “I, Proclus, am of Lycian origin; Syrianus here nourished me with his lessons, to succeed as teacher.” An eclipse of the sun had darkened Athens the year before; Marinus reads it as the coming eclipse of philosophy (§37).

The Elements of Theology

What sets Proclus apart is method. Where Plotinus had written in bursts of concentrated vision, Proclus argued in propositions. His Elements of Theology lays out the whole metaphysical universe as a chain of 211 theorems, each demonstrated from those before it, in deliberate imitation of Euclid — the very title, Stoicheiōsis, echoes Euclid’s Stoicheia. The first 112 propositions establish the grammar of reality: unity and multiplicity, cause and participation, wholes and parts, infinity, eternity. The second half deploys that grammar across the three kinds of true causes — the henads, the intellects, and the souls.

The hinge of the whole is proposition 35: “Every effect remains in its cause, proceeds from it, and reverts upon it” (trans. Dodds). Remaining, procession, reversion — monē, proodos, epistrophē — is the structure of everything that exists: beings come forth, abide in their source, and turn back, the rhythm on which his entire system turns (see emanation). Every level is mediated by triads — Being, Life, Intellect — and by the principle that what proceeds from a cause must also return to it; since Zeller, the triad has been read as the signature of his thought.

The henads are the gods. Between the imparticipable One and everything after it stand the participated unities, and these are the gods of the tradition — the whole of Greek polytheism set into the metaphysics of the One with demonstrative rigor (a doctrine credited variously to Iamblichus or to Syrianus). Where Plotinus had three primary hypostases, Proclus filled the descent with graded multitudes of gods and intermediary powers, and his Platonic Theology — the late summa of pagan Platonic theology — unfolds the procession of the divine hierarchies from the One down to the angels, daimones, and heroes. The result is the most fully articulated map of reality the pagan schools produced, and the most populous.

Signature doctrines mark the system’s reach. Evil has no principle of its own: it exists only as parhypostasis, a parasitic by-existence on the good — the teaching of his On the Existence of Evils, which was to have a long career under another name. The world is both eternal and generated, against Aristotle’s either-or. Providence leaves freedom standing because the mode of knowledge is conditioned by the knower, not the known (proposition 124) — a solution that passed through Ammonius and Boethius’s Consolation to the Latin Middle Ages.

Theurgy and the Oracles

He held, with Iamblichus before him, that thought alone cannot complete the soul’s ascent: the soul descends wholly — no summit remains above, as Plotinus had taught — and the way back is bridged by what the gods themselves established. Theurgy, Proclus writes in the Platonic Theology (I 25), is “a power higher than all human wisdom embracing the blessings of divination, the purifying powers of initiation and in a word all the operations of divine possession”: philosophy begins the ascent, and the hieratic art completes it. Damascius later recorded the school’s two tempers — Plotinus and Porphyry gave priority to philosophy; Iamblichus, Syrianus, and Proclus to the hieratic practice. He revered the Chaldean Oracles as scripture, above even the poems of Orpheus in authority; his commentary on them took more than five years (§26).

The Works

He wrote, by Marinus’s report, almost without pause; roughly two-thirds of the output is lost and much of the rest mutilated, yet what survives still fills shelves. Commentaries remain on five Platonic dialogues — Alcibiades, Cratylus, Timaeus, and Parmenides, each broken off partway, with a set of essays on the Republic. Above all he wrote on the Timaeus and the Parmenides, the two “perfect” dialogues that between them contain the whole of Platonism: the Timaeus as divine physics, nature traced to the demiurge, and the Parmenides as theology proper — the dialogue whose dialectic he read as a coded theology of the One. The Commentary on the First Book of Euclid’s Elements carries in its two prologues the fullest ancient philosophy of mathematics — geometrical figures as projections of the soul’s innate reason-principles into imagination, geometry an ascent leading the soul upward — and is a prime source for the early history of Greek geometry. Beside these stand the Elements of Physics; the Exposition of Astronomical Hypotheses; the Tria opuscula — three treatises on providence, fate, and the existence of evils — surviving complete only in William of Moerbeke’s thirteenth-century Latin; the Platonic Theology, transmitted incomplete; and seven Hymns. Fragments remain of On the Eternity of the World — eighteen arguments against the Christians, answered by Philoponus — of the Hesiod commentary, and of On the Hieratic Art, preserved through Ficino’s Latin. The lost works include commentaries on Aristotle’s Organon and Plotinus’s Enneads, On Orphic Theology, On the Harmony of Orpheus, Pythagoras and Plato with the Oracles, On Hecate, and On the Mother of the Gods. Two texts long printed under his name — the De Sphaera and a paraphrase of Ptolemy — are spurious.

The Long Afterlife

His influence outran his world. Around the year 500 a Christian author writing as Dionysius the Areopagite — Paul’s Athenian convert — carried the Proclean architecture into the heart of Christian mysticism, at times nearly verbatim and never by name: the clearest case is the evil-doctrine of On the Existence of Evils, absorbed into On the Divine Names, whence it governed Christian discussion of evil into the nineteenth century. The disguise held until the late nineteenth century, when scholars demonstrated the dependence on Proclus; Dodds compressed the result into a sentence — Proclus went “conquering Europe in the guise of an early Christian.” The corpus’s later career runs through Christian Neoplatonism.

A second channel ran through Arabic. In the ninth century the Elements of Theology was digested into the Kitāb al-Īḍāḥ fī l-khayr al-maḥḍ, “the Explanation of the Pure Good,” in the orbit of Islamic Neoplatonism; between 1167 and 1187 Gerard of Cremona turned the digest into Latin as the Liber de causis, and the universities read it as Aristotle’s own theology, the completion of the Metaphysics. The mask came off in 1268, when William of Moerbeke translated the Elements itself and Thomas Aquinas, comparing the two, identified the Liber’s true source in his commentary on it.

Byzantium never lost the Greek. Michael Psellus studied Proclus intensively in the eleventh century and preserved fragments of lost works; his pupil Ioane Petritsi translated the Elements into Georgian with a commentary; in the twelfth century Nicholas of Methone wrote a formal Refutation (Anaptyxis) of the Elements, probably left unfinished — the last fourteen theorems unrefuted — proof the work was still read; George Pachymeres completed the Parmenides commentary around 1300; and Cardinal Bessarion collected the manuscripts (the channel runs on under Byzantine Platonism). From that world the texts passed west: Nicolaus Cusanus studied Proclus in translation even before Marsilio Ficino, and Ficino composed, in imitation of Proclus, a Christian Platonic Theology on the immortality of the soul — the very title an homage, at the springhead of Renaissance Neoplatonism. In England Thomas Taylor translated the whole of Proclus and attempted to reconstruct the lost seventh book of the Platonic Theology; in France Victor Cousin aimed at a complete edition; and Hegel, lecturing on the history of philosophy, judged that “in Proclus we have the culminating point of the Neo-Platonic philosophy.”

Through these channels a pagan systematizer shaped Christian and Islamic metaphysics for a millennium. Whether that systematizing was the work of a great organizer or of an original mind is a question scholarship still weighs: Marinus’s own chapter on his master’s innovations lists only minor items, and the older reading of Proclus as the consummate compiler retains its force, while much recent work finds in him a rigorous and inventive thinker — the one who made of Neoplatonism a science. Within his own lifetime the school he led was nearing its end; it was closed by imperial order in 529, a little over forty years after his death, with Damascius, not Proclus, as its literal last diadochos.

Editions and Studies

The primary biographical source is Marinus’s Life of Proclus, available in Kenneth Sylvan Guthrie’s 1925 English translation at https://www.tertullian.org/fathers/marinus_01_life_of_proclus.htm. The reference treatment of the philosophy is Christoph Helmig and Carlos Steel’s “Proclus” in the Stanford Encyclopedia of Philosophy (2011, revised 2020), https://plato.stanford.edu/entries/proclus/. E. R. Dodds’s Proclus: The Elements of Theology (Clarendon Press, 1933; second edition 1963) remains the critical edition and translation on which the proposition count and the standard English renderings rest, and H. D. Saffrey and L. G. Westerink’s six-volume Budé edition of the Théologie platonicienne (Les Belles Lettres, 1968–1997) is the citation standard for the late summa. Radek Chlup’s Proclus: An Introduction (Cambridge University Press, 2012), https://doi.org/10.1017/CBO9781139028042, is the standard one-volume modern study and a leading voice of the re-evaluation of Proclus as thinker rather than compiler; Pieter d’Hoine and Marije Martijn’s collaborative All From One: A Guide to Proclus (Oxford University Press, 2017), https://doi.org/10.1093/acprof:oso/9780199640331.003.0001, maps the present state of the field. Lucas Siorvanes’s Proclus: Neo-Platonic Philosophy and Science (Edinburgh University Press, 1996), https://doi.org/10.1515/9781474472654, is strongest on the physics and astronomy; Glenn R. Morrow’s A Commentary on the First Book of Euclid’s Elements (Princeton University Press, 1970), https://doi.org/10.1515/9780691214672, is the standard English of the Euclid commentary; and R. M. van den Berg’s Proclus’ Hymns: Essays, Translations, Commentary (Brill, 2001), https://doi.org/10.1163/9789047401032, edits and interprets the seven surviving hymns — the devotional face of a system that ends, as it begins, in prayer.

→ In the library: The Dialogues of Plato (Jowett, 1892) · The Chaldæan Oracles (Mead, 1908)

→ Related: Neoplatonism · Plato · Iamblichus · The One · Nous · Emanation · Theurgy · Chaldean Oracles Tradition · Pseudo Dionysius The Areopagite · Damascius