Aleister Crowley, Austin Osman Spare, Dion Fortune and the German occultist Eugen Grosche were among the first Western adepts to teach the use of the psychosexual energies whose snake-like Ophidian Current permeates the most ancient secret knowledge of Africa and the Far East. This work presents an exhaustive analysis of Crowley's system of sexual magic and the strange rites which he practised and advocated for the purpose of promoting the Law of freedom with its formula of love under will.