The Ideas
Prisca theologia
Prisca theologia ("ancient theology") is the Renaissance idea that God gave one true theology to remote antiquity, handed down through a chain of sages, Hermes Trismegistus near its head, and flowing into Plato and Christianity. It rested on a wrong chronology, demolished philologically by Isaac Casaubon in 1614.
In 1463 Cosimo de’ Medici told Marsilio Ficino to pause translating Plato and translate Hermes first. That decision only makes sense inside one big idea: prisca theologia, the “ancient theology”.
The idea
God, the theory ran, gave a single true theology to remote antiquity, transmitted through a genealogy of sages, in the chain of Ficino’s Platonic Theology (XVII.1): Zoroaster, Hermes Trismegistus, Orpheus, Aglaophemus, Pythagoras, Plato. Since Hermes was believed older than Plato and near-contemporary with Moses, the Corpus Hermeticum seemed to anticipate Genesis and the Gospel of John. The claim had patristic cover: Lactantius treated Hermes as an ancient gentile prophet of Christ; Augustine accepted his antiquity while condemning the idolatry of the Asclepius. Crucially, the Renaissance version was an attempt to prove Christianity’s truth, not an alternative to it.
The demolition
In 1614 Isaac Casaubon showed on philological grounds, post-classical Greek vocabulary, anachronisms, echoes of Plato and Christian idiom, that the Corpus is a product of the early Roman imperial era, not primeval Egypt. It is a landmark of historical criticism. It did not, however, kill Hermes: post-1614 Hermetic currents flourished, and Athanasius Kircher simply ignored the redating.
Who built the chain
The order of the sages was never fixed. Gemistos Plethon, the Byzantine philosopher who came to Florence for the council of 1438-39, put Zoroaster at the head of his line, and his lectures left a mark on the Florentine circle. Ficino gave the chain in different orders in different works, and in his preface to the Pimander Zoroaster is missing altogether; D.P. Walker’s The Ancient Theology (1972) follows the variants. Pico della Mirandola, in 1486, added Kabbalah to the sources of the one wisdom. In 1540 Agostino Steuco gave the related idea its lasting name in De perenni philosophia.
The chain, text by text
Each row is one text: when it was written and first printed, who stands at the head, in what order the sages follow, and where the passage can be checked.
| Text | Written / first printed | At the head | Order in this text | Source |
|---|---|---|---|---|
| Gemistos Plethon, Book of Laws (Nomoi) I.2 | Written before Plethon’s death (SEP gives 1452). A few years after becoming patriarch in 1454, Gennadios Scholarios ordered every copy destroyed; the surviving fragments, some unpublished until then, were collected in print by C. Alexandre, Paris 1858 | Zoroaster, the oldest lawgiver and sage known by report | Zoroaster; Eumolpus, Minos, Lycurgus, Iphitus, Numa; the Brahmins, the Magi, the Curetes; the priests of Dodona, Polyidus, Tiresias, Chiron; the Seven Sages; Pythagoras and Plato, followed by Parmenides, Timaeus, Plutarch, Plotinus, Porphyry, Iamblichus. Hermes is not on the list | Plethon, Traité des lois, ed. Alexandre (1858), pp. 30-33 (scan); dates: SEP, “Byzantine Philosophy” (2018) |
| Marsilio Ficino, Argumentum (preface) to his Latin Pimander | Commissioned by Cosimo in 1463 and finished within a few months, while Cosimo was still alive, as Ficino recalled in his 1492 preface to Plotinus (Creuzer, vol. I, p. xvii); first printed Treviso, Gerardus de Lisa, 18 December 1471 | Mercurius (Hermes) Trismegistus, “the first author of theology” | Mercurius, Orpheus, Aglaophemus, Pythagoras, Philolaus, Plato: six theologians. Zoroaster is absent | SEP, “Marsilio Ficino” (2024), citing Opera omnia (Basel 1576), p. 1836; Bodleian record of the 1471 edition; text read in the Venice 1481 printing |
| Ficino, Platonic Theology XVII.1 | Written 1469-1474; printed in Florence by Antonio Miscomini, 7 November 1482 (copy) | Zoroaster, head of the Magi | Zoroaster, Mercurius Trismegistus, Orpheus, Aglaophemus, Pythagoras, Plato. After Plato his interpreters split into six Academies: three Attic (the Old under Xenocrates, the Middle under Arcesilaus, the New under Carneades) and three foreign (the Egyptian under Ammonius, the Roman under Plotinus, the Lycian under Proclus) | Ficino, Platonic Theology, vol. 6, ed. M.J.B. Allen and J. Hankins (I Tatti, 2006); Latin read in Opera (Basel 1561), p. 386, scan; dates: SEP (2024) |
| Ficino, preface (Prooemium) to his Latin Plotinus, addressed to Lorenzo de’ Medici | Printed with the translation, Florence, Antonio Miscomini, 7 May 1492 | Zoroaster among the Persians and Mercurius among the Egyptians, side by side and in agreement | Zoroaster and Mercurius; Orpheus and Aglaophemus among the Thracians; Pythagoras among the Greeks and Italians; Plato, with whom this philosophy is completed in Athens; then Plotinus, who at last stripped this theology of its veils. The same preface recalls Cosimo hearing Plethon in Florence at the time of the council | Plotinus, Opera omnia, ed. F. Creuzer (Oxford 1835), vol. I, pp. xvii-xviii (scan); colophon of the 1492 edition quoted in the same volume, p. xxxviii (scan) |
| Giovanni Pico della Mirandola, the 900 Conclusions and the speech written to introduce them, later called the Oration on the Dignity of Man | Conclusions printed Rome, Eucharius Silber, end of 1486; the speech written in 1486, first printed Bologna 1496, after its author’s death | Moses: Kabbalah as an oral Torah confided to him and passed on in secret | Moses, then Esdras and other sages, a hidden line Pico held holier than the pagan wisdom traced to Zoroaster and Hermes; among the gentiles he preferred Chaldean prophets and Orphic bards to the Egyptian Hermes | SEP, “Giovanni Pico della Mirandola” (Copenhaver, 2024) |
| Agostino Steuco, De perenni philosophia I.1, on the succession of doctrine from the beginning of the world, and I.3 | Printed Lyon, Sebastian Gryphius, 1540 | The first man, Adam: his knowledge passed through Methuselah and Noah to Abraham | In ch. 3, peoples first: the Chaldeans, then Hebrews, Egyptians, Phoenicians, Greeks, Romans. The Magi lead Chaldean theology and Mercurius Trismegistus the Egyptian; among the Greeks Orpheus, then Homer and Hesiod, then Thales, Pythagoras, Anaxagoras, Empedocles, Parmenides, Plato; last, though somewhat unlike those before them, Aristotle and Theophrastus | Steuco, De perenni philosophia (Lyon 1540), book I, ch. 1 (scan) and ch. 3, p. 7 (scan) |
| Isaac Casaubon, De rebus sacris et ecclesiasticis exercitationes XVI, Exercitatio I, section X | Printed London, 1614 | No one: the book under Hermes’ name drops out of the line | No order. Casaubon calls the book that had circulated for some centuries under Mercurius Trismegistus’ name (the treatises now called the Corpus Hermeticum) semichristiani merum figmentum (p. 75), “the mere fiction of a semi-Christian”, written to make Christian doctrine look known to the sages of remotest antiquity. He begins his dissection with the first treatise, the Poimandres. Who Hermes was and when he lived, he leaves aside here | Casaubon, Exercitationes (London 1614), I.10, p. 75 (scan); study: A. Grafton, “Protestant versus Prophet”, Journal of the Warburg and Courtauld Institutes 46 (1983), pp. 78-93 |
| Ralph Cudworth, The True Intellectual System of the Universe, book I, chs. 1 and 4 | Printed London, Richard Royston, 1678 | For atomist physics, Moschus the Phoenician, possibly Moses (a conjecture Cudworth takes from Arcerius and Selden); for Egypt, Thoth, called Hermes by the Greeks, and a second Hermes “Trismegist” | Moschus; then Pythagoras, who met Moschus’ successors at Sidon; then Empedocles and other Pythagoreans. In Cudworth’s account, old Egyptian philosophy reached Greece through Pythagoras; Casaubon had detected forgery in “two or three at most” of the Hermetic books, not in all of them, and the Asclepius was no Christian forgery | Cudworth, True Intellectual System (London 1678), pp. 12-14 (scan) and pp. 319-331 (scan); SEP, “Ralph Cudworth” (Hutton, 2025) |
Ficino’s own words for the single school (secta) of ancient theology that his six theologians form, from the Argumentum as printed in Venice in 1481: exordia sumens a Mercurio: a Diuo Platone penitus absoluta, “taking its beginning from Mercurius, brought to full completion by the divine Plato” (Lucas Dominici, 1481, scan; the passage is at p. 1836 of the Basel 1576 Opera omnia).
After 1614: the same idea without the dates
Casaubon broke the chronology, not the hope behind it. The conviction that one truth stands behind all religions returned in the 20th century as perennialism, popularised by Aldous Huxley’s The Perennial Philosophy (1945), and as the Traditionalism of René Guénon. Both keep the shared truth and drop the line of named ancient sages. Historians treat the whole family as an idea with a history, not a finding.
Traps
Keep two terms apart: prisca theologia locates truth in the deep past, degenerating over time; the related philosophia perennis holds truth to be always and everywhere available. Popular writing conflates them constantly. And any site claiming the Corpus Hermeticum is “5,000 years old” is repeating a Renaissance error refuted in 1614, though the honest nuance is that the late texts do preserve older, genuinely Egyptian traditions.
Why it matters
Prisca theologia explains why Hermeticism mattered so enormously to the Renaissance, and why its history is a story about chronology. One dating error powered two centuries of Christian Hermetism; one philological fact-check founded modern source criticism.
Fair questions
Who coined the term philosophia perennis?
Agostino Steuco, in De perenni philosophia (1540). It names the related idea that one truth is available in every age, as opposed to prisca theologia, which places the pure truth at the beginning.
Is prisca theologia still believed today?
In a new form. Perennialism (Aldous Huxley, The Perennial Philosophy, 1945) and the Traditionalism of René Guénon keep one truth behind all religions without the Renaissance chronology. Historians treat it as an idea with a history, not a finding.
What is the best book on prisca theologia?
D.P. Walker, The Ancient Theology (1972), for the Renaissance sources; Frances Yates, Giordano Bruno and the Hermetic Tradition (1964), for the story, read with the corrections later scholars made to it.
What does prisca theologia mean?
Latin for 'ancient theology': the idea that God gave one true theology to remote antiquity, passed down through sages, Zoroaster, Hermes, Orpheus, Pythagoras, Plato in Ficino's chain, and harmonizing with Christianity.
How is it different from philosophia perennis?
Prisca theologia locates truth in the deep past, degenerating over time; philosophia perennis holds truth is always available everywhere. The Renaissance worked with the first; modern perennialism recycles the second, they are often conflated.
Who disproved the antiquity of Hermes?
Isaac Casaubon, in 1614, using philological evidence, post-classical vocabulary and anachronisms, dated the Corpus Hermeticum to the early Roman imperial era. Many occult writers simply ignored him.
Sources & further reading
- Copenhaver, Hermetica (1992), introduction.
- Ebeling, The Secret History of Hermes Trismegistus (2007).
- D.P. Walker, The Ancient Theology (1972).
- Agostino Steuco, De perenni philosophia (1540).
- Aldous Huxley, The Perennial Philosophy (1945).
- Gemistos Plethon, Traité des lois, ed. C. Alexandre (Paris 1858), I.2, pp. 30-33.
- Marsilio Ficino, Argumentum to the Pimander (Treviso 1471; text read in the Venice 1481 printing).
- Marsilio Ficino, Platonic Theology, vol. 6: Books XVII-XVIII, ed. M.J.B. Allen and J. Hankins (2006).
- Marsilio Ficino, preface to his Latin Plotinus (Florence 1492), in Plotinus, Opera omnia, ed. F. Creuzer (Oxford 1835), vol. I.
- C.S. Celenza, “Marsilio Ficino”, Stanford Encyclopedia of Philosophy (rev. 2024).
- B. Copenhaver, “Giovanni Pico della Mirandola”, Stanford Encyclopedia of Philosophy (rev. 2024).
- K. Ierodiakonou and B. Bydén, “Byzantine Philosophy”, Stanford Encyclopedia of Philosophy (rev. 2018).
- Isaac Casaubon, De rebus sacris et ecclesiasticis exercitationes XVI (London 1614), I.10.
- A. Grafton, “Protestant versus Prophet: Isaac Casaubon on Hermes Trismegistus”, Journal of the Warburg and Courtauld Institutes 46 (1983), pp. 78-93.
- Ralph Cudworth, The True Intellectual System of the Universe (London 1678).
- S. Hutton, “Ralph Cudworth”, Stanford Encyclopedia of Philosophy (rev. 2025).
- Stanford Encyclopedia of Philosophy: Marsilio Ficino.