Before he was Eliphas Lévi, the renowned occultist, he was Alphonse-Louis Constant, a radical socialist and Catholic thinker in 1840s France. His political and religious background is essential to understanding his later magical work; he saw occultism as the continuation of a "true" tradition of universal religion and a perfect social order, a secret doctrine passed down through heretical groups like the Gnostics and the Knights Templar. This mission to synthesize science, religion, and politics into one grand system would define his life's work and influence generations of occultists, including figures like Aleister Crowley.

Lévi's most famous contribution is his drawing of the Baphomet, often mistaken as a satanic idol. In reality, Lévi designed it as a complex symbol of the absolute: an embodiment of the equilibrium of opposites and the "Astral Light," a universal magical agent he adapted from magnetistic theories of his time. The androgynous, goat-headed figure was an eclectic assembly of older symbols—from the Tarot's Devil card to alchemical illustrations—re-imagined to represent the totality of existence and the ultimate goal of the great work. His major work on the subject is Transcendental Magic: Its Doctrine and Ritual.