Hermeticism is a set of philosophical and religious beliefs based primarily upon the writings attributed to Hermes Trismegistus, who is put forth as a wise sage and Egyptian priest, and who is commonly seen as synonymous with the Egyptian god Thoth. These beliefs have influenced Western magic traditions and held great influence during the Renaissance. In Islam, the Hermetic cult was accepted in 830 CE as being the Sabians mentioned in the Qur'an. The term Hermetic is from medieval Latin hermeticus, in English attested since the 17th century as the adjective to Hermeticism (as in "Hermetic writers", Isaac Newton 1676) The synonymous Hermetical also occurs in the 17th century. Hermes Trismegistus (Greek: Ἑρμῆς ὁ Τρισμέγιστος, "thrice-great Hermes"; Latin: Mercurius ter Maximus) is the syncretism of the Greek god Hermes and the Egyptian god Thoth. In Hellenistic Egypt, the Egyptian god Thoth was given as epithet the Greek name of Hermes. He has also been identified with Enoch. Other similar syncretized gods include Serapis and Hermanubis. In the readings from Edgar Cayce, Hermes or Thoth was an engineer from the submerging Atlantis and he built or designed or directed the construction of the Pyramids of Egypt.
The Hermetic Order of the Golden Dawn was a magical order of the late 19th and early 20th centuries, practicing a form of theurgy and spiritual development . It was possibly the single greatest influence on twentieth century western occultism. Concepts of magic and ritual that became core elements of many other traditions, including Wicca, Thelema, and other forms of magical spirituality popular today, are drawn from the Golden Dawn tradition.
Hermes Trismegistus might also be explained in Euhemerist fashion as a man who was the son of the god, and in the Kabbalistic tradition that was inherited by the Renaissance, it could be imagined that such a personage had been contemporary with Moses, communicating to a line of adepts a parallel wisdom, from Zoroaster to Plato. A historian, however, would leave such speculation to the history of alchemy and the nineteenth-century history of occultism. Both Thoth and Hermes were gods of writing and of magic in their respective cultures. Thus, the Greek god of interpretive communication was combined with the Egyptian god of wisdom as a patron of astrology and alchemy. In addition, both gods were psychopomps; guiding souls to the afterlife.
The majority of Greeks, and later Romans, did not accept Hermes Trismegistus in the place of Hermes. The two gods remained distinct from one another. Cicero noted several individuals referred to as "Hermes"
- The fifth, who is worshipped by the people of Pheneus, is said to have killed Argus, and for this reason to have fled to Egypt, and to have given the Egyptians their laws and alphabet: he it is whom the Egyptians call Theyn Thoth.
The Hermetic Literature added to the Egyptian concerns with conjuring spirits and animating statues that inform the oldest texts, Hellenistic writings of Greco-Babylonian astrology and the newly developed practice of alchemy. In a parallel tradition, Hermetic philosophy rationalized and systematized religious cult practices and offered the adept a method of personal ascension from the constraints of physical being, which has led to confusion of Hermeticism with Gnosticism, which was developing contemporaneously.
As a divine fountain of writing, Hermes Trismegistus was credited with tens of thousands of writings of high standing, reputed to be of immense antiquity. Plato's Timaeus and Critias state that in the temple of Neith at Sais, there were secret halls containing historical records which had been kept for 9,000 years. Clement of Alexandria was under the impression that the Egyptians had forty-two sacred writings by Hermes, encapsulating all the training of Egyptian priests. Siegfried Morenz has suggested (Egyptian Religion) "The reference to Thoth's authorship...is based on ancient tradition; the figure forty-two probably stems from the number of Egyptian nomes, and thus conveys the notion of completeness." The Neo-Platonic writers took up Clement's "forty-two essential texts".
The Hermetic Literature, the Hermetica, is a category of papyri containing spells and induction procedures. In the dialogue called the Asclepius (after the Greek god of healing) the art of imprisoning the souls of demons or of angels in statues with the help of herbs, gems and odors, is described, such that the statue could speak and prophesy. In other papyri, there are other recipes for constructing such images and animating them, such as when images are to be fashioned hollow so as to enclose a magic name inscribed on gold leaf.