Nothing could be more mistaken than the view that magick is based upon a misapprehension of the nature of the physical world in relation to human intellect.  As a social equilibrator it is essential that the magician have a comprehensive knowledge of the various planes whose interaction results in a comprehensive reality.  The primary function of the magician is the understanding and control of the basic forces of life and death as they manifest in change.  Thus it is necessary that the magician be free of the limitation of any particular point of view.  He will thus understand and utilize the scientific method, but he will also comprehend this as one force in the network of forces which constitute his field of culture.
-“Purpose and Object of Magick” in On Magick.

Nothing is of its nature evil, and nothing is of its nature good.  Evil is only excess, good is simply balance.  All things are subject to abuse, all things are susceptible to beneficial use.  And balance does not consist in denial, or excess of indulgence.