Israël Regardie

"The Tree of Life: A Study in Magic" by Israel Regardie (published in 1932) is widely considered one of the most comprehensive and accessible introductions to the theory and practice of Western ritual magic. Regardie, who served as Aleister Crowley's personal secretary, wrote the book to demystify occultism and provide a coherent overview of the Western Esoteric Tradition. The book utilizes the Qabalistic Tree of Life as a universal filing system to organize and understand all spiritual, magical, and mythological systems.
Regardie strips away much of the intentional secrecy and blinds used by older secret societies, arguing that magic is a natural, psychological, and spiritual science. He defines the ultimate aim of magic as "The Great Work"-the union of the individual ego with the Divine or the Higher Self (Holy Guardian Angel). The text blends the teachings of the Hermetic Order of the Golden Dawn, Alchemy, Egyptian mythology, Yoga, and Crowley's Thelema.