"Hermeticism" is the outlook associated with the Hermetic writings, a literature in Greek that developed in the early centuries after Christ under the name "Hermes Trismegistus." Much of it is concerned with astrology, alchemy, and other occult sciences, but there is also a philosophical Hermetic literature. The treatise known as the Asclepius and the collection of treatises grouped as the Corpus Hermeticum are the most important of the philosophical Hermetica, though some other fragments are preserved in the anthology of Stobaeus. These writings are probably to be dated between 100 and 300 CE. They are an amalgam of Greek philosophy, particularly Platonic, with other elements from the heterogeneous late antique culture. The Pimander, the first treatise in the Corpus Hermeticum, has obvious affinities with Genesis, suggesting an influence of Hellenistic Judaism. There may also be Persian influences, and the possibility of some contact with Christianity cannot be excluded. The ascription...