Black Magic is Not a Myth in Articles by Aleister Crowley.

“A renegade priest gathers about him a congregation of sensation-hunters and religious fanatics; then only can the ceremonies of profanation be of extended black magical effect.” [via, also]

Consider also:

  1. “The ‘Black Mass’ is a totally different matter. I could not celebrate it if I wanted to, for I am not a consecrated priest of the Christian Church. The celebrant must be a priest, for the whole idea of the practice is to profane the Sacrament of the Eucharist. Therefore you must believe in the truth of the cult and the efficacy of its ritual.”
  2. “A girl played the violin during the rites. She was a good violinist, but under the influence of the ceremonies, she was more; she played sublimely, like a supreme virtuoso, in the magical invocations directed upon her.”
  3. “Black magic is not a myth. It is a totally unscientific and emotional form of magic, but it does get results–of an extremely temporary nature. The recoil upon those who practice it is terrific.”
  4. “To practice black magic you have to violate every principle of science, decency, and intelligence. You must be obsessed with an insane idea of the importance of the petty object of your wretched and selfish desires.”
  5. “I have been accused of being a ‘black magician.’ No more foolish statement was ever made about me. I despise the thing to such an extent that I can hardly believe in the existence of people so debased and idiotic as to practice it.”