The Eight Yoga of Naropa: Sexual Yoga with a Consort

There is a saying in the mahamudra system of meditation, based on the Six Yogas of Naropa, which goes, "There can be no mahamudra or nirvana without karmamudra or sexual yoga.” According to Himalayan meditation theory, sexual yoga is the central completion stage practice that results in nirvana, or the union of the Three Bodies. Both the Chinese and Tibetan civilizations have been heavily influenced by individuals who achieved whole-brain activation through the use of sexual yoga practices. These individuals include the Yellow Emperor, Lao Tzu, and Padmasambhava. Padmasambhava studied with Sri Simha on Wu Tai Shan in China, as well as with Indian masters.

According to the great historian of religion, Mircea Eliade, tantric theory was originally described in India as the “Chinese method.” Thomas Cleary felt that the descriptions of Padmasambhava practicing sexual yoga for longevity in caves throughout scholars have ignored the emphasis on sexual yoga as the completion stage of meditation in Himalayan yoga lineages. Jung pointed out that the majority of Asian and hermetic art points to the union of opposites, resulting in non-duality. He called this "the actualization of the self after the conscious and unconscious minds have united." However, he had no idea that the goal of sexual yoga is to activate the kundalini through the union of gross, subtle, and void levels of consciousness. This is the basis of both Western alchemy and Eastern medical science. Chinese Internal Alchemy is based on the idea that the lifespan of an individual can be greatly extended through the successful practice of sexual yoga.

As Joseph Campbell tells us:
In the Buddhists lamaseries of Tibet...the holy images and banners show the various Buddhas and Bodhisattvas joined with their Shaktis in embrace, in the yogic posture known as Yab-Yum, "Father-Mother." And the great prayer of the old prayer wheels of Tibet, OM mani padme HUM, "the jewel (mani) in the lotus (padme)," signifies, on one level: the immanence of nirvana (the jewel) in (samsara the lotus); another: the arrival of the mind (the jewel) in nirvana (the lotus); but also, as in the icon of the male and female joined: the lingam in the yoni. “Buddhatvam yosidyonisamsritam,” states a late Buddhist aphorism: "Buddhahood abides in the female organ."
Joseph Campbell, Oriental Mythology: The Masks of God