The foreword to the Goetia sets out to explain some of the terminology involved and what exactly is meant by each of the spirits. To start, it is explained that the original Greek word, daimon, was derived by Plato from the Greek word knowing.
Aleister Crowley was a 20th century English occultist and ceremonial magician who founded the Thelema movement. Crowley’s curiosity about magick and the occult started in his youth when he became a member of the Hermetic Order of the Golden Dawn. Shortly after, he made contact with his Holy Guardian Angel, Aiwass, who would guide him toward starting his own esoteric group, the A.A. Crowley claimed that Aiwass dictated to him a divine text, The Book of the Law, and anointed him as a prophet to spread the teachings about living in accordance with one’s True Will. Read articles about Aleister Crowley below.
Magick is the Science and Art of causing Change to occur in conformity with Will.