THE THEORY AND PRACTICE OF BLACK MAGIC
"Some understanding of the intricate theory and practice of ceremonial magic may be derived from a brief consideration of its underlying premises.
First. The visible universe has an invisible counterpart, the higher planes of which are peopled by good and beautiful spirits; the lower planes, dark and foreboding, are the habitation of evil spirits and demons under the leadership of the Fallen Angel and his ten Princes.
Second. By means of the secret processes of ceremonial magic it is possible to contact these invisible creatures and gain their help in some human undertaking. Good spirits willingly lend their assistance to any worthy enterprise, but the evil spirits serve only those who live to pervert and destroy.
Third. It is possible to make contracts with spirits whereby the magician becomes for a stipulated time the master of an elemental being.
Fourth. True black magic is performed with the aid of a demoniacal spirit, who serves the sorcerer for the length of his earthly life, with the understanding that after death the magician shall become the servant of his own demon. For this reason a black magician will go to inconceivable ends to prolong his physical life, since there is nothing for him beyond the grave.
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.
Though the demonism of the Middle Ages seems to have disappeared, there is abundant evidence that in many forms of modern thought--especially the so-called 'prosperity' psychology, 'willpower-building' metaphysics, and systems of 'high-pressure' salesmanship--
The practice of magic--either white or black--depends upon the ability of the adept to control the universal life force--that which Eliphas Levi calls the great magical agent or the astral light. By the manipulation of this fluidic essence the phenomena of transcendentalism are produced. The famous hermaphroditic Goat of Mendes was a composite creature formulated to symbolize this astral light. It is identical with Baphomet the mystic pantheos of those disciples of ceremonial magic, the Templars, who probably obtained it from the Arabians.
Black magic has merely passed through a metamorphosis, and although its name be changed its nature remains the same.
A well-known magician of the Middle Ages was Dr. Johannes Faustus, more commonly known as Dr. Faust. By a study of magical writings he was enabled to bind to his service an elemental who served him for many years in various capacities. Strange legends are told concerning the magical powers possessed by Dr. Faust. Upon one occasion the philosopher, being apparently in a playful mood, threw his mantle over a number of eggs in a market-woman's basket, causing them to hatch instantly. At another time, having fallen overboard from a small boat, he was picked up and returned to the craft with his clothes still dry. But, like nearly all other magicians, Dr. Faust came at length to disaster; he was found one morning with a knife in his back, and it was commonly believed that his familiar spirit had murdered him. Although Goethe's Dr. Faust is generally regarded as merely a fictional character, this old magician actually lived during the sixteenth century. Dr. Faust wrote a book describing his experiences with spirits, a section of which is reprinted below. (Dr. Faust must not be confused with Johann Fust, the printer.) "
Source:
CEREMONIAL MAGIC AND SORCERY -
http://www.sacred-texts.com/eso/sta/sta24.htm