Eulis! is a late work of Paschal Beverly Randolph (1825-1875), the African American physician, Spiritualist and occultist, published in 1874, in which he set out, in deliberately guarded and often oblique language, the sexual and magical doctrine of the circle he called the Brotherhood of Eulis. Its central teaching is that the affections and the sexual force are the great creative power in the human being, and that the moment of union, rightly used with focused will and prayer, is the supreme opportunity for magical and spiritual realisation.
Randolph is a pivotal and long-underrated figure: he is arguably the first to introduce systematic sex magic into modern Western occultism, decades before it became central to the O.T.O. and to Crowley, and his ideas passed, sometimes without acknowledgement, and sometimes distorted, into the later tradition. As a free man of color writing frankly about sexuality in nineteenth-century America, he worked under real social danger, which partly accounts for the veiled manner of the book. The historian Hugh Urban and the biographer John Patrick Deveney have recovered his importance.