The Corpus Hermeticum (or Hermetica) is a collection of Egyptian-Greek wisdom texts from the 2nd and 3rd centuries AD. Most of the texts are presented as dialogues in which a teacher, generally identified as Hermes Trismegistus, enlightens a disciple. The texts discuss the divine, the cosmos, mind, and nature. Some touch upon alchemy, astrology, and related concepts. These texts form the basis of Hermeticism.