George Gemistos Plethon

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At Mistra, the fortress-town terraced down a spur of Mount Taygetos above the plain of Sparta, an old judge kept a school. The Despotate of the Morea — the last substantial Byzantine holding in the Peloponnese, ruled by princes of the Palaiologan house while the empire shrank to little more than Constantinople and its hinterland — had become, in its final decades, the most concentrated site of Greek learning anywhere. Into this twilight Georgios Gemistos was born around 1355, and there he taught Plato to a generation of pupils who would carry Greek philosophy across the sea. He took, late in life, a second name that announced his allegiance: Plethon, meaning the full or the abundant, chosen because its sound shadowed that of Plato. To be named like the master was the whole of his program in a single word.

Plethon was a layman, never a cleric — a magistrate and counselor in the Despotate, advising the despots Theodore and Constantine on the governance of the Morea, drafting memoranda on taxation, land, and the reform of the army. The philosophy he professed was therefore not the discreet Platonism of the cloister but the conviction of a man at the center of public affairs that the order of the cosmos and the order of the state were one continuous fabric, and that both had gone wrong, and that Plato held the design by which both might be set right.

The standing of the world

What Plethon recovered at Mistra was not a literary Plato but a metaphysical one, read through the whole apparatus of late-antique Neoplatonism — through Proclus above all, the last great systematizer of the pagan schools, whose architecture of descending divine orders Plethon treated as the true exposition of Platonic doctrine. At the summit stands a single source, the first god, beyond determination; from it the orders of being proceed in a graded descent, each level the image and the cause of the one below. This is the contemplative spine of the tradition that runs back through Proclus to Iamblichus and Plotinus to Plato himself, and Plethon held it not as antiquarian learning but as the literal truth of how things stand.

His cosmos is governed throughout by necessity. Plethon was a thoroughgoing determinist: every event is fixed in the chain of causes that proceeds from the first god, and freedom consists not in escaping that order but in understanding it and consenting to it. The soul is immortal and divine, kin to the gods, destined to circuit through embodiments; the heavens are everlasting; the structure of reality is eternal and will not pass away. These are precisely the propositions that Byzantine orthodoxy had condemned in the eleventh-century Platonists — the eternity of the world, the transmigration of souls, the reality of the Platonic Ideas as substantial beings. Plethon held them all, and held them as the deposit of the most ancient wisdom of mankind.

The ancient theology and the Magi of Zoroaster

For Plethon the truth was old — older than Plato, older than Greece. He constructed a genealogy of revelation that ran from Zoroaster and the Magi of Persia at the head, down through a line of sages — Eumolpus, the priests of the mysteries, Pythagoras — to Plato, in whom the ancient doctrine reached its philosophical perfection. This is the scheme that Renaissance Italy would come to call the prisca theologia, the ancient theology — a single stream of divine wisdom carried by a succession of inspired teachers; Plethon’s version of it placed Zoroaster, not Hermes Trismegistus, at the fountainhead, and so gave the Renaissance one of the two great genealogies through which it would read its own recovered antiquity.

The text on which this Persian priority rested was the body of Greek hexameters known as the Chaldean Oracles. In late antiquity these verses had been ascribed to Julian the Theurgist and treated by the Neoplatonists as revealed scripture; they survived into the Byzantine world chiefly through the commentary of the eleventh-century scholar Michael Psellos, who had epitomized Proclus’s lost exegesis of them. Plethon took this inheritance and remade it. He produced a recension — a reordered text of the Oracles he entitled The Magical Sayings of the Magi of Zoroaster — stripping away the Christian and antiquarian frame in which Psellos had set them and reattributing the whole to Zoroaster and his Magi. To it he added a Brief Explanation, a running commentary that read the verses as a coherent Platonic theology. The attribution was his own construction and historically mistaken: the Oracles are a product of Greek philosophical religion under the Roman Empire, not of any Persian priesthood. But the construction was consequential. It was this Plethonian text — Zoroaster’s Oracles, ordered and expounded — that crossed into Italy and lodged in the imagination of the Florentine Platonists.

The council and the quarrel

In 1438 the Byzantine state played its last diplomatic card. Emperor John VIII Palaiologos led a great delegation to Italy to negotiate the union of the Eastern and Western churches, hoping that reunion would buy military aid against the advancing Ottomans. Plethon, by then in his eighties and the most venerable scholar of the Greek world, traveled with the embassy as a lay member — not to argue doctrine, for he was no theologian of the schools, but as a learned authority whose presence lent the delegation weight. The council sat first at Ferrara, then moved to Florence; the union was at last proclaimed in the cathedral of Florence in July 1439, its decree read out by Plethon’s brilliant pupil Bessarion. It would be repudiated almost everywhere in the East as soon as the delegates returned home.

Plethon’s own contribution to the council’s business was slight; his contribution to the history of thought was immense, and he made it almost by accident. Falling ill during the proceedings, and finding the Florentines confused about the relation of Plato to Aristotle, he composed a short, combative treatise — On the Differences of Aristotle from Plato, the De differentiis — to set them straight. Its argument was that Aristotle had been overrated by the Latin scholastics at Plato’s expense, and that on the questions that mattered most Aristotle was simply inferior: his god was a first mover and nothing more, where Plato’s god is the maker of all intelligible and separate substance and so the true cause of the universe; Aristotle denied the divine Ideas and providence over particulars; Aristotle had no doctrine of the soul’s immortality worthy of the name.

The treatise opened a quarrel that would run for the rest of the century. It was answered, sharply, by Plethon’s old antagonist George Gennadios Scholarios, the leading Aristotelian of the Greek world and a future patriarch, who wrote a Defense of Aristotle; Plethon replied again; into the dispute came George of Trebizond, who would eventually accuse Plethon of a vast pagan and Islamizing conspiracy against Christendom, and Theodore Gaza, and at last Bessarion himself, whose Against the Calumniator of Plato gave the debate its most measured and durable statement. The Plato–Aristotle controversy was thus the first great intellectual export of the dying Byzantine world to the living Latin one, and Plethon had struck its opening note from a sickbed in Florence.

The second Plato

The deeper effect of Plethon’s months in Florence was made not on paper but on the imagination of his hosts. He lectured, informally, to the humanists of the city on Plato and on the doctrines of the later Platonists, and the impression he left was extraordinary. He spoke of a Plato unknown to the Latin schools — a Plato of divine emanation, of the soul’s ascent, of an ancient wisdom older than Athens — and the Florentines, by the report that came down to them, were so taken with him that they called him a second Plato, Plato come again.

The line that carries this story is itself a problem. Two generations later Marsilio Ficino — the translator who would give Latin Europe its Plato, its Plotinus, and its Corpus Hermeticum — wrote, in the preface to his translation of Plotinus, that the great Cosimo de’ Medici had conceived the idea of a Platonic academy in Florence when he heard Plethon discourse at the council, and that Ficino’s own life’s work was the fruit Cosimo had planted. This founding-legend made Plethon the literal seed of the Florentine Renaissance revival of Platonism, and it has been repeated ever since. The historian James Hankins has shown that it will not bear the documentary weight placed on it: there is no independent evidence that Cosimo and Plethon ever met or conversed, the language barrier would have stood between them, and the Platonic academy Ficino is supposed to have headed was an informal teaching circle that left no statutes and no membership rolls and was never, in its own day, called by that name. Ficino’s preface, on this reading, is not a chronicle but a piece of self-authorizing genealogy — a translator giving his work a noble lineage. What survives the deflation is real enough: Plethon did lecture at Florence, the recension of the Oracles he carried did reach the Florentine Platonists, and the figure of the white-bearded Greek sage who had spoken of Plato as living truth did lodge itself in the Florentine memory deeply enough that a fresco of the Procession of the Magi, painted in the Medici palace within a generation, is generally taken to include his face.

The Book of Laws

Behind the public scholar there was a more radical man, and the evidence of him is a book that almost entirely no longer exists. In the last years of his life Plethon composed the Nomoi, the Book of Laws — a vast work, modeled on Plato’s own Laws, that set out not merely a philosophy but a religion. It was a complete reformed Hellenic cult: a restored polytheism in which the Olympian gods returned, but returned transfigured into metaphysical principles. Zeus is the first god, the One, the source beyond being; Poseidon is the second principle, the world of the intelligible Ideas; the lesser gods are the orders of being descending from them, the celestial and supercelestial powers, down to the daemons and the soul of the world. The pantheon of myth is read, name by name, as the structure of the Neoplatonic cosmos. To this metaphysics Plethon joined a liturgy — a calendar of festivals, a body of hymns and prayers addressed to the gods, rules of ritual life — and an ethics of consent to the iron order of fate. The whole is governed by the same determinism as his cosmology: the gods do not suspend necessity, they are its articulation, and to worship them rightly is to align the soul with the way things inexorably are.

Whether the Laws was a literary construction, a thought-experiment in god-as-principle pushed to its limit, or the actual creed of a man who had quietly ceased to be a Christian, is the question on which everything about Plethon finally turns — and it cannot be answered from the book, because the book was destroyed. Plethon died at Mistra; the traditional date is 1452, though John Monfasani has argued for 1454, which would mean the old philosopher lived to learn of the fall of Constantinople in 1453, the event his whole reforming project had been meant to forestall. After his death the manuscript of the Nomoi came into the hands of Scholarios, who had become, as Gennadios II, the first ecumenical patriarch under Ottoman rule. He read it, judged it a manifesto of apostasy and idolatry, and had it burned — keeping, by his own account, only enough of the table of contents and a few chapters to document the heresy he had condemned. What survives of the Laws is therefore a ruin: the fragments preserved by the man who destroyed it, gathered and edited centuries later. The reformed religion of the Hellenes exists now chiefly as the shape of the hole left where its scripture was.

The scholarship and the texts

The recovery of Plethon is unusually dependent on a single act of preservation by an enemy, and the modern study of him is built around the surviving wreckage of the Nomoi together with the works that escaped the fire — the De differentiis, the recension of the Oracles, the political memoranda, the funeral orations he composed for the despotic house.

The foundational modern edition of the fragments of the Laws is that of Charles Alexandre, Pléthon: Traité des lois (Paris: Firmin Didot, 1858), which prints the surviving Greek with a French translation by Augustin Pellissier and appends the Greek of Plethon’s recension and exposition of the Chaldean Oracles; it remains in the public domain and is the point from which the textual study of Plethon’s religion begins. The standard critical edition of the Oracles in Plethon’s recension is now Brigitte Tambrun-Krasker, Oracles chaldaïques: Recension de Georges Gémiste Pléthon (Athens, Paris, and Brussels, 1995). The genealogy of Plethon’s Persian attribution — how the Chaldean verses became the oracles of Zoroaster’s Magi, and how that move descended from the Byzantine reception of Psellos — is traced by Dylan Burns in “The Chaldean Oracles of Zoroaster, Hekate’s Couch, and Platonic Orientalism in Psellos and Plethon” (Aries 6, 2006).

The dispute over what Plethon actually was is the live center of the field, and it should not be flattened. Niketas Siniossoglou, in Radical Platonism in Byzantium: Illumination and Utopia in Gemistos Plethon (Cambridge, 2011), reads him as a genuine pagan apostate — the man in whom the latent anti-Christian tendencies of Byzantine humanism reached their fulfillment, whose utopianism and whose polytheism are two faces of one revolt against the Christian order. Against this, Vojtěch Hladký, in The Philosophy of Gemistos Plethon: Platonism in Late Byzantium, between Hellenism and Orthodoxy (Ashgate, 2014) — reviewed in the Bryn Mawr Classical Review — and John Monfasani in a series of studies read him as a recognizably philosophical figure whose theology is best understood as a Platonic exercise rather than a covert cult, and who cannot simply be lifted out of the Christian world he lived and died in. The two readings are, as the scholars themselves have conceded in print, methodologically irreconcilable; the review literature around Siniossoglou’s book has made the disagreement, rather than its resolution, the durable result. The hostile testimony of George of Trebizond — who painted Plethon as the prophet of a coming universal paganism — belongs to this debate as evidence to be weighed, not as established biography. The earlier framework of James Hankins, Plato in the Italian Renaissance (Leiden, 1990), supplies the indispensable check on the Florentine legend that grew up around the man.

Mistra to Rimini

There is a coda that the determinist would perhaps have appreciated. The Despotate of the Morea fell to the Ottomans in 1460; Mistra emptied; the school was scattered. Six years later Sigismondo Pandolfo Malatesta, the soldier-lord of Rimini, campaigning in the Peloponnese, had Plethon’s bones disinterred and carried back across the Adriatic. He had them set in a sarcophagus on the outer flank of the Tempio Malatestiano, the strange humanist church he was building over an older friary in his own city — the philosopher of the Hellenic gods given a tomb in a Christian temple turned into a monument to earthly fame. The inscription Malatesta set over him names him simply prince of philosophers of his time. Plethon had taught that the soul, immortal and divine, runs its appointed circuit through the eternal order and returns; his body, at least, completed an unappointed one, from the last Greek school under Taygetos to a marble niche in Italy, arriving in the West almost exactly as the West was beginning to read the Plato he had carried there.

→ Related: Byzantine Platonism · Plato · Aristotle · Marsilio Ficino · Bessarion · Chaldean Oracles Tradition · Zoroaster · Renaissance Neoplatonism · Prisca Theologia · Neoplatonism · Hermes Trismegistus