In my third year at Cambridge, I devoted myself consciously to the Great Work, understanding thereby the Work of becoming a Spiritual Being, free from the constraints, accidents, and deceptions of material existence.
I found myself at a loss for a name to designate my work, just as H. P. Blavatsky some years earlier. "Theosophy", "Spiritualism", "Occultism", "Mysticism", all involved undesirable connotations.
I chose therefore the name.
"MAGICK"
as essentially the most sublime, and actually the most discredited, of all the available terms.
I swore to rehabilitate
MAGICK,
to identify it with my own career; and to compel mankind to respect, love, and trust that which they scorned, hated and feared. I have kept my Word.

Introduction. - Magick Book IV : Liber ABA - Part III : Magick in Theory and Practice (1929)