While only in his late twenties, Manly Palmer Hall published his The Secret Teachings of All Ages – An Encyclopedia Outline of Masonic, Hermetic, Qabbalistic and Rosicrucian Symbolic Philosophy in 1928. It was a remarkable effort for such a young man, and The Secret Teachings of All Ages remains a remarkable book.
“The most dangerous form of black magic is the scientific perversion of occult power for the gratification of personal desire. Its less complex and more universal form is human selfishness, for selfishness is the fundamental cause of all worldly evil. A man will barter his eternal soul for temporal power, and down through the ages a mysterious process has been evolved which actually enables him to make this exchange. In its various branches the black art includes nearly all forms of ceremonial magic, necromancy, witchcraft, sorcery, and vampirism. Under the same general heading are also included mesmerism and hypnotism, except when used solely for medical purposes, and even then there is an element of risk for all concerned.”
Pasted from <http://www.sacred-texts.com/eso/sta/sta24.htm> THE SECRET TEACHINGS OF ALL AGESby Manly P. HallAt <http://www.sacred-texts.com/eso/sta/>