“Illuminism: A pseudoscientific movement of mystics and visionaries in the 18th century which influenced literature in the 19th century. At first inspired by Christian doctrines, illuminists sought to live according to the Gospel and to regenerate their souls by direct contact with the divine. They also, however, believed in spiritism, magnetism, alchemy, and magic and professed to invoke the invisible and the arcane. Among the more famous illuminists were Swedenborg, who conversed with the dead; Lavater a believer in black magic , who thought to contact God by magnetism; Claude de Saint Martin (“the unknown philosopher”), who sought to hasten the coming of Christ by meditation and prayer; Mesmer (see MESMERISM); the Comte de Saint-Germain, who pretended to be several hundred years old and to possess the elixir of eternal life; Franz Joseph Gall, who founded the pseudoscience of phrenology, the study of the relationship of skull shape to character traits; and the famous “Count” Alessandro di Cagliostro, a charlatan who performed feats of magic and alchemy, founded a secret Masonic sect, and narrowly escaped death at the hands of the Inquisition. A reaction against 18-century rational philosophies, illuminism under many names (e.g. millenarianism, syncretism, neopaganism, pythagorism, theosophy, etc.) influenced some writers of the romantic period. It revived a sense of religious exaltation and created, or recreated, a need for the infinite merged with a sense of the inner life.”
Excerpted from: Murphy, Bruce, ed. Benet’s Reader’s Encyclopedia, Fourth Edition. New York: Harper Collins, 1996.