The general name of Gnostics has been employed to designate several sects that sprung up in the eastern parts of the Roman empire about the time of the advent of Christianity; although it supposed that their principle doctrines had been taught centuries before in many of the cities of Asia Minor. The word Gnosticism is derived from the Greek Gnosis or knowledge, and was a term used in the earliest daysof philosophy to signify the science of divine things, or as Matter says, "superior or celestial knowledge." He thinks the word was first used by the Jewish philosophers of the famous school of Alexandria. The favorite opinion of scholars is that the sect of Gnostics arose among the philosophers who were the converts of Paul and other Apostles, who sought to mingle the notions of the Jewish Egyptian school, the speculations of the Kabbalists, and the Grecian and Asiatic doctrines with the simpler teaching of the new religion which they had embraced. They believed that the writings of the Apostles enunciated only the articles of vulgar faith; but that there were esoteric traditions which had been translated from generation to generation in mysteries, to which they gave the name of Gnosticism or Gnosis. King says (Gnostics, p. 7,) that they drew the materials out of which they constructed their system from two religions, viz., the Zendavesta and its modifications in the Kabbala, and the reformed Brahmanical religion, as taught by the Buddhist missionaries,
Notwithstanding the large area of country over which this system of mystical philosophy extended, and the number of different sects that adopted it, the same fundamental doctrine was everywhere held by the chiefs of Gnosticism. This was, that the visible creation was not the work of the Suprme Deity, but of the Demiurgus, a simple emanation, and several degrees removed from the Godhead. To the latter, indeed, styled by them "the unknown Father," they attributed the creation of the unknown intellectual world, the Eons and Angels, while they made the creation of the world of matter the work of the Demiurgus.
Gnosticism abounded in symbols and legends, in talismans and amulets, many of which were adopted into the popular superstitions of the Mediaeval ages. It is, too, interesting to the student of masonic antiquities because of its remote connection with that Order, some of whose symbols have been indirectly traced to Gnostic origin. The Druses of Mount Lebanon were supposed to be a sect of Gnostics; and the constant intercourse which was maintained during the Crusades between Europe and Syria produced an effect upon the Western nations through the influence of the pilgrims and warriors.
Towards the Mancheans, the most prominent offshoot of Gnosticism, the Templars excercised a tolerant spirit very inconsistent with the professed objects of their original foundation, wich led to the charge that they were affected by the dogmas of Manicheism.
The strange ceremonies observed in the initiation into various secret societies that existed in the Lower Empire are said to have been modelled on the Gnostic rites of the Mithraic Cave.
The architects and stone-masons of the Middle Ages borrowed many of the principles of ornamentation, by which they decorated the ecclesiastical edifices which they constructed, from the abtruse symbols of the Gnostics.
So, too, we find Gnostic symbols in the Hermetic Philosophyand in the system of Rosicrucianism; and lastly many of the symbols still used by Fremasonry - such, for instance, as the triangle within a circle, the letter G, and the pentacle of Solomon - have been traced to a Gnostic source.
An Encyclopedia of Freemasonry: By Albert Mackey, M.D. 1894