The magical name of Violet Mary Firth, Dion Fortune (Deo Non Fortuna, which means “by God and not by luck”) figured prominently in the Golden Dawn and the Theosophical movement. From the early part of her life, she expressed a keen interest in psychology and was influenced by Freud, Alfred Adler, and Jung, but she felt a special affinity for Jung's theory of archetypes and his investigation into mythic images and symbols.

She wrote several books, the best known being Applied Magic, The Esoteric Philosophy of Love and Marriage, The Mystical Qabala, and Psychic Self-Defence. She also authored novels that contained magical themes and information. In her writings, Fortune discussed a divine “Inner Light” that resembled a higher manifestation of Freud's libido. In her second book, she discussed the connection between sex and the life force, and she recommended dedicating this energy to a god form. In both her fiction and nonfiction works, Fortune expressed a knowledge of sex magic. Her books, however, upset MacGregor Mathers's wife Moina, who expelled Fortune from the Golden Dawn for revealing the order's secrets. Psychic Self-Defence grew out of Fortune's belief that Moina Mathers was attacking her magically, and it provides information about warding off such assaults.

One of Fortune's major contributions was her departure from the male-dominated archetypes of the Golden Dawn and her exploration of feminine archetypes. Her novels are perhaps the only literary works of her time that present a feminine view of sex magic. She went on to establish her own occult society, which became known as the Society of the Inner Light, in London. She died in 1946.