What Is Magick, really?

Magick, in the context of Aleister Crowley's Thelema, is a term used to show and differentiate the occult from performance magic and is defined as "the Science and Art of causing Change to occur in conformity with Will", including both "mundane" acts of will as well as ritual magic. Crowley wrote that "it is theoretically possible to cause in any object any change of which that object is capable by nature".