thumb|16th century European depiction of Hermes Trismegistus as an old sage and teacher
Hermes Trismegistus (from , "Hermes the Thrice-Greatest") is a legendary Hellenistic period figure that originated as a syncretic combination of the Greek god Hermes and the Egyptian god Thoth. He is the purported author of the Hermetica, a widely diverse series of ancient and medieval pseudepigraphica that laid the basis of various philosophical systems known as Hermeticism.
The wisdom attributed to this figure in antiquity combined a knowledge of both the material and the spiritual world, which rendered the writings attributed to him of great relevance to those who were interested in the interrelationship between the material and the divine.
The figure of Hermes Trismegistus can also be found in both Muslim and Baháʼí writings. In those traditions, Hermes Trismegistus has been associated with the prophet Idris (the Biblical Enoch).
Origin and identity
Hermes Trismegistus may be associated with the Greek god Hermes and the Egyptian god Thoth. Greeks in the Ptolemaic Kingdom of Egypt identified Thoth with Hermes through the . Consequently, the two gods were worshiped as one, in what had been the Temple of Thoth in Khemenu, which was known in the Hellenistic period as Hermopolis.
Hermes, the Greek god of interpretive communication, was combined with Thoth, the Egyptian god of wisdom. The Egyptian priest and polymath Imhotep had been deified long after his death, and therefore assimilated to Thoth in the classical and Hellenistic periods. The renowned scribe Amenhotep and a wise man named Teôs were coequal deities of wisdom, science, and medicine; and, thus, they were placed alongside Imhotep in shrines dedicated to Thoth–Hermes during the Ptolemaic Kingdom.
Cicero enumerates several deities referred to as "Hermes":
- "fourth Mercury (Hermes) was the son of the Nile, whose name may not be spoken by the Egyptians"
- "the fifth, who is worshiped by the people of Pheneus [in Arcadia], is said to have killed Argus Panoptes, and for this reason to have fled to Egypt, and to have given the Egyptians their laws and alphabet: It is him whom the Egyptians call Theyt"
The Hermetic literature of the Egyptians was concerned with conjuring spirits and animating statues, the newly developed practice of alchemy, and informs the oldest Hellenistic writings on Greco-Babylonian astrology. In a parallel tradition, Hermetic philosophy rationalized and systematized religious cult practices and offered the adept a means of personal ascension from the constraints of physical being. This latter tradition has led to the conflation of Hermeticism with the contemporaneously developing, but distinct, Gnosticism.
The epithet "thrice great"
Fowden asserts that the first datable occurrences of the epithet "thrice great" are in the Legatio of Athenagoras of Athens and in a fragment from Philo of Byblos, . However, in a later work, Copenhaver reports that this epithet is first found in the minutes of a meeting of the council of the Ibis cult, held in 172 BCE near Memphis in Egypt. Hart explains that the epithet is derived from an epithet of Thoth found at the Temple of Esna, "Thoth the great, the great, the great." They believed in the existence of a prisca theologia, a single, true theology that threads through all religions. It was given by God to man in antiquity and passed through a series of prophets, which included Zoroaster and Plato. In order to demonstrate the verity of the prisca theologia, Christians appropriated the Hermetic teachings for their own purposes. By this account, Hermes Trismegistus was either a contemporary of Moses, The "Hermetic tradition" consequently refers to alchemy, magic, astrology, and related subjects. By modern convention the texts are usually subdivided into two categories:
:{|
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| philosophical hermetica   || deals mainly with philosophy and cosmology
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| technical hermetica || concerns practical magic, potions, and alchemy
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The expression hermetically sealed comes from the alchemical procedure to make the Philosopher's Stone. This required a mixture of materials to be placed in a glass vessel which was sealed by melting and fusing the neck closed, a procedure known as the "Seal of Hermes". The vessel was then heated for 30–40 days.
During the Renaissance, it was accepted that Hermes Trismegistus was a contemporary of Moses. However, after Isaac Casaubon's demonstration in 1614 that the Hermetic writings must postdate the advent of Christianity, the whole of Renaissance Hermeticism collapsed. As to their actual authorship: