A Greco-Egyptian wisdom tradition and the seed vault of Western esotericism.
Documented
The misdating that launched a revival
In 1463 Cosimo de' Medici had the Corpus Hermeticum translated before Plato, believing it older. In 1614 Isaac Casaubon proved the texts were post-classical by their vocabulary. The prestige collapsed; the influence never did.
Assessment: Fully documented. One philological argument in 1614 quietly ended the Renaissance's favorite ancient authority.
Stories
The thrice-greatest scribe
The tradition's own story: Hermes Trismegistus, a fusion of Greek Hermes and Egyptian Thoth, wrote the foundation texts of all hidden knowledge, and every esoteric order descends from his pupils.
Assessment: The fusion deity is documented in Hellenistic religion. The authorship is pseudepigraphy, standard practice for the era. The story of the sage outlasted the proof that he never existed.
Interesting claims
As above, so below as literal physics
The Emerald Tablet's maxim is read by modern occultists not as metaphor but as a description of real correspondences between cosmic and human structure, a unified field theory in fourteen lines.
Assessment: The Tablet's text is documented, its translation history is documented, and its physics is not. It remains the single most quoted sentence in Western esotericism, which is itself a fact worth archiving.
Sources and further reading
Copenhaver, Hermetica: Corpus Hermeticum (1992 translation)
Casaubon, De rebus sacris (1614), the dating argument
Yates, Giordano Bruno and the Hermetic Tradition (1964)