A truly dark undercurrent penetrating Western religious imagination, from the era before Christ up until this very day and age, has been the nightmarish fantasy of sexual license and the perversion of sacred ritual. The effects of the anguish by the presence of such a nightmare can be seen in merciless attacks on the Gnostics, the massacre of the Cathars, and the persecution of the Templars, yet never fully manifesting until the conjuration of the unholy principles and aesthetics of the Black Mass inverting the Holy Eucharistic through sin, violence, and ungodly sexuality.
By the nineteenth century, images and tales of Black Masses had possessed European literary and popular imagination, with the most choreographed and perpetuating literary rendition of the Black Mass being that of Joris-Karl Huysmans presented in his classic decadent novel Là Bas. According to Urban,
Increasingly interested in the occult arts, witchcraft, and Satanism, Huysmans allegedly sought out a series of guides to lead him to the Black Mass. There is a great deal of controversy as to whether Huysmans ever did in fact witness a Black Mass or whether he simply fabricated the event and embellished the already long history of Western fantasies of satanic ritual.
According, Huysmans’ personal account is that he did witness the Black Mass, where he had encountered Abbé Van Haecke, whom he believed was the “greatest Satanist of all times, the Gilles de Rais of the nineteenth century.” Huysmans also made the acquaintance another controversial character who openly confessed to blasphemy and illicit sex through his Society of the Reparation of Souls, the defrocked priest Abbé Boullan. In his book, the Temple of Satan, Stanislas de Guaita described him as a “pontiff of infamy, a base idol of the mystical Sodom, a magician of the worst type, a wretched criminal, an evil sorcerer, and the founder of an infamous sect.” In 1889, Huysmans heard about Boullan and sought him out in order to learn more in regards to the occult. Boullan denied that he was a Satanist, but did confess that he was a master of incubi and succubi. Both Boullan and van Haecke appear fictionalised in his book, with the former being the learned priest, Dr Johannes, whilst the latter appearing as the sinister and defrocked priest, Canon Docre, who is the one who officiates over the Black Mass. The main character, who is Huysmans alter ego, Durtal, seeks out a performance of the Black Mass during his research about the life of Gilles de Rais. Despite his account of the Black Mass being an imaginary weaving of blasphemy, ungodly sexuality, and infernal cravings, it remains one of the most widely read accounts of the Black Mass.
The Black Mass takes place in the remains of an Ursuline convent, where a grotesque and naked image of Christ laughing sinisterly has replaced the crucifix, and the choir boy is a demonic faery. Canon Docre decries Jesus as a hoax and a liar, whilst praising Satan as, “King of the Disinherited, Son who art to overthrow the inexorable father… Master of slanders, Dispenser of the benefits of crime, Administrator of sumptuous sins and great vices, Satan, thee we adore, reasonable God, just God!” The Black Mass escalates into a spiritually violent and bizarre chaos of blasphemy and disgust, as the prostitutes and degenerate old women, who act as the congregation, writhe in infernal ecstasy on the floor as Canon Docre chews up and spits out the host to desecrate it. In Huysmans’ words,
In a solemn but jerky voice he said “Hoc est enim corpus meum,” then instead of kneeling… before the precious Body, he faced the congregation and appeared tumified, dripping with sweat… raising the chausible, displayed his naked belly. Docre made a few passes and the host sailed, tainted and soiled, over the steps… A whirlwind of hysteria shook the room… Women rushed upon the Eucharist and, grovelling in front of the altar, clawed from the bread humid particles and divine ordure… Docre… frothing with rage, was chewing up sacramental wafers, taking them out of his mouth… and distributing them to the women, who ground them underfoot, howling, or fell over each other struggling to get hold of them and violate them. The place was simply a madhouse, a monstrous pandemonium of prostitutes and maniacs.
So distraught and disturbed by his experience, or personal vision into this dark world sinful delusions and infernal howlings, Huysmans became convinced of the ontological existence of evil and eventually returned seeking salvation within the Church. As he put it, “the devil drew me toward God.”
 Hugh B. Urban, Magia Sexualis: Sex, Magic, and Liberation in Modern Western Esotericism, 2006, page 197.
 Robert Baldick, The Life of J.-K. Huysmans, 1955, pages 149-150.
 Robert Baldick, Down There (Là Bas): A Study in Satanism, 1958, page vii.
 Joris-Karl Huysmans, Down There (Là Bas): A Study in Satanism, 1958, pages 268-269.
 Joris-Karl Huysmans, Down There (Là Bas): A Study in Satanism, 1958, page 272.
 Robert Baldick, Down There (Là Bas): A Study in Satanism, 1958, page 27.