Hermetic. Any doctrine or writing connected with the esoteric teachings of Hermes, who, whether as the Egyptian Thoth or the Greek Hermes, was the God of Wisdom with the Ancients, and, according to Plato, “discovered numbers, geometry, astronomy and letters”. Though mostly considered as spurious, nevertheless the Hermetic writings were highly prized by St. Augustine, Lactantius, Cyril and others. In the words of Mr. J. Bonwick, “ They are more or less touched up by the Platonic philosophers among the early Christians (such as Origen and Clemens Alexandrinus) who sought to substantiate their Christian arguments by appeals to these heathen and revered writings, though they could not resist the temptation of making them say a little too much. Though represented by some clever and interested writers as teaching pure monotheism, the Hermetic or Trismegistic books are, nevertheless, purely pantheistic. The Deity referred to in them is defined by Paul as that in which “we live, and move and have our being”—notwithstanding the “in Him” of the translators.
Source: H.P.Blavatsky - The Theosophical Glossary