HERMES TRISMEGISTOS. Identified with Hermes in the Histories of Herodotos (fifth century BCE), the Egyptian god Thoth was sometimes called aa aa ur (or paa paa paa). In the Egypt of the Ptolemies at the beginning of the second century BCE, this epithet was rendered approximately as megistos kai megistos theos, megas Hermēs ("greatest and greatest god, great Hermes") or, more succinctly, as Hermes Trismegistos ("thrice greatest Hermes"; Mahé, 1978–1982, vol. 1, p. 1; vol. 2, p. 469).

Because this meaning soon became obscured, the title was reinterpreted in various ways. According to the eighth-century historian George Syncellus, who in part is confirmed by Augustine (354–430 CE), Manethon (third century BCE) supposedly taught that trismegistos is the surname of the second Hermes, son of Agathodemon (the Hellenized name of the god Khnum or Kneph) and the father of Tat (another version of Thoth), who is said to have transcribed the teachings...