Hermeticism, or Hermetism, is a philosophical and religious tradition rooted in the teachings attributed to Hermes Trismegistus, a syncretic figure combining elements of the Greek god Hermes and the Egyptian god Thoth. This system encompasses a wide range of esoteric knowledge, including aspects of alchemy, astrology, and theurgy, and has significantly influenced various mystical and occult traditions throughout history. The writings attributed to Hermes Trismegistus, often referred to as the Hermetica, were produced over a period spanning many centuries (c. 300 BCE – 1200 CE) and may be very different in content and scope.
One particular form of Hermetic teaching is the religio-philosophical system found in a specific subgroup of Hermetic writings known as the 'religio-philosophical' Hermetica. The most famous of these are the Corpus Hermeticum, a collection of seventeen Greek treatises written between approximately 100 and 300 CE, and the Asclepius, a treatise from the same period, mainly surviving in a Latin translation. This specific historical form of Hermetic philosophy is sometimes more narrowly referred to as Hermetism, to distinguish it from other philosophies inspired by Hermetic writings of different periods and natures.