Aleister Crowley, known variously as the Laird of Boleskine, The Great Beast 666 and ‘the wickedest man who ever lived’, is probably one of the most unjustly maligned figures in the history of the occult. It is true that Crowley had sadistic tendencies in his childhood – he once executed a cat in a number of ways to prove that it was really dead – and suffered undoubtedly from megalomania as shown by his efforts to surpass all rivals in the occult order of the Golden Dawn. But he was also a magician of considerable style and originality, and some of his concepts may well prove eventually to be significant in the history of psychology. As early as 1929, Crowley published in Paris, his work Magick in Theory and Practice, one part of which was devoted to a systematic tabling of subconscious imagery in the mind.