An exploration of the sexual practices and doctrinal secrets of Gnosticism * Reconstructs the lost world of Gnostic spiritual-erotic experience through examination of every surviving text written by heresiologists * Investigates the sexual gnosis practices of the Barbelo Gnostics of the 2nd century and their connections to the Gnostic Aeon Sophia, the Wild Lady of Wisdom * Explains the vital significance of "the seed" as a sacrament in Gnostic practice Examining every surviving text written by heresiologists, accounts often ignored in favor of the famous Nag Hammadi Library, Tobias Churton reveals the most secret inner teaching passed down by initiated societies: the tradition of sexual gnosis--higher union with God through the sacrament of sex. Discovering actual sex practices hidden within the writings of the Church's authorities, he reconstructs the lost world of Gnostic spiritual-erotic experience as taught by initiated masters and mistresses and practiced by Christian couples seeking spiritual freedom from the world. Churton explores the practices of the "first Gnostic," the historical Simon Magus, and explains the vital significance of "the seed" in Gnostic practice, showing it to be the sacramental substance par excellence. He illuminates the suppressed truth of why the name "Valentine" came to be associated with ennobling erotic love and reveals profound parallels between sexual gnosis and Tantra, suggesting that gnosis lies at the root of the tantric path. Solving a millennia-old riddle regarding the identity and secret symbol of Sophia, the mysterious Gnostic "Aeon," Churton investigates Sophia's connections to Barbelo, also known as Pruneikos, the Wild Lady of Wisdom, and the central focus of the Barbelo Gnostics of the 2nd century, whose religious sex practices so shocked orthodox Christian contemporaries that they were condemned, their cults of spiritual gnosis and "redemption by sin" driven underground. Churton exposes the mystery of Sophia in the philosophy of the medieval Troubadours and explores William Blake's inheritance of secret Renaissance sexual mysticism through the revolutionary English poet Andrew Marvell. Showing how Blake's sexual and spiritual revolution connects to modern sexual magic, Churton also examines the esoteric meaning of the free-love explosion of the 1960s, revealing how sex can be raised from the realm of guilt into the highest magical sacrament of spiritual transformation.