Eulis! is Randolph's statement of his central doctrine, and the reason it is difficult to read is that he could not say plainly what it is about. His position was that the moment of sexual union is a condition in which the will, correctly directed, can act on the world and on the participants, and that this is the key to the whole of practical occultism. Writing that in 1874, in America, in a book he expected to be seized, required circumlocution, and the book is accordingly full of it.
The material is arranged as a set of teachings on the will, on the conditions required, and on the ethics of the thing, with the operative content distributed among passages that read as moral exhortation until the reader has understood what is being described. Randolph insisted throughout on the mutual consent and the mutual benefit of both participants, which distinguishes his position sharply from some of what followed.
His influence is larger than his readership. Randolph was a free Black man writing in the American nineteenth century, and the sexual magic that reached twentieth century European occultism, including the Ordo Templi Orientis, runs back to him whether or not those who used it acknowledged the source.