The Tantras, which are the almost exclusive preserve of Tibetan Buddhism, form part of the teachings of the Mahāyāna. Like the Mahāyāna sūtras, they are animated by the attitude of Bodhichitta, the determination to attain supreme Buddhahood for the sake of all beings. A number of features distinguish the tāntric teachings, or Vajrayāna, from those of the sūtra. One of these is the great variety of skillful means whereby the process of attainment is vastly accelerated. According to the sūtra teachings, the two accumulations of wisdom and merit required to produce the state of enlightenment are expected to require continuous practice over a period of three countless eons. By contrast, through the implementation of the most advanced tāntric yogas, and given favorable kārmic circumstances, the fruit of Buddhahood may be actualized within the course of a single human life.
The reason for the esoteric character of the tāntric teachings is given by Guru Padmasambhava. He says that they are kept secret not because they are in some way shameful or defective, but because their power renders them proportionately precious and perilous. Being profound, they are easily misunderstood and are to be transmitted only to appropriate persons at the right time. They are likened to the milk of the snow lion, an elixir of such potency that it will shatter a vessel of anything but the purest gold.
In contrast with the ascetic approach of the Hīnayāna teachings, and unlike the meditative antidotes used on the Mahāyāna sūtra path to counteract emotional defilement, the Vajrayāna is characterized by its direct utilization of emotion, as well as the psychophysical energies of the mind and the body. The external supports of ritual, visualization, mantra recitation, and yoga are all of great importance. It is convenient to speak of the tāntric path in terms of four initiations or four levels of empowerment that introduce the disciple to the different aspects of the fully enlightened state. In the simplest terms, the first of the four initiations empowers the disciple to undertake the yogas of the Generation Stage. These aim at the realization of the true nature of all phenomena and mainly involve the practice of visualization and recitation. The second initiation introduces the disciple to the practices of the Perfection Stage, in which the subtle channels, energies, and essences of his or her own body are meditated upon and brought under control. When this has been perfectly accomplished, the disciple is ready to receive the third initiation, which empowers him or her to practice a similar type of yoga but this time taking support of another person, in other words, a consort. Finally, the fourth initiation is directly concerned with the introduction to the nature of the mind itself.
The most striking aspect of the yoga related with the third initiation and one that many will find intriguing and perhaps troubling is that it specifically involves the use of sexual energy. Given that Tantra works directly with emotions and utilizes various physical and psychic yogas, it would be surprising if it neglected what is after all a driving impulse in human existence. Even so, for many people, the idea of using the sexual act as a spiritual path may seem strange if not actually contradictory. perhaps this is due to the fact that in western religions, the morally correct environment for sexual activity is considered to be marriage, and the spiritual dimension of sex is intimately associated with the begetting of children. At the other end of the spectrum, it is evident in secular life that sex is often trivialized and debased in exploitative and degrading ways. These two contrasting attitudes are apt to complicate our approach to this aspect of the tantra, and in the task of interpretation, it is hard to find a vocabulary able to express the notions of both physical intercourse and spiritual purity in ways that are not either unduly diffident or else tainted by prurience and vulgarity. In Tibetan Buddhism, the instructions associated with the third initiation are regarded as extremely high teachings and are the object of profound respect. they are not widely disseminated and are well beyond the reach of the majority of practitioners.
The ability to feel but not to crave, to experience, and yet not hanker for more, or indeed for anything at all, is the mark of long training and a sign of great spiritual stature. The practice of the third initiation can only be implemented by people who are able to feel and yet remain without attachment, even in the situation of physical climax. It stands to reason that individuals who are genuinely able to practice in this way (as distinct from those who merely think they are) are few and far between. On the other hand, for those who can implement it, the yoga of the third initiation is said to be of immense power and swiftness. At the same time, it is a profoundly dangerous path, involving an area in which people are particularly fragile and prone to self-deceit. It is hazardous even for advanced and sincere practitioners because the arising of attachment can be extremely subtle, with the result that they may go astray and fall from the path. It is no doubt for this reason that few people are encouraged to attempt these practices. Active discouragement is much more likely to be encountered.
In his commentary on the Treasure of Precious Qualities, Khenpo Yonten Gyasto says: The teachings say that those who take and practice explicitly the third initiation must have previously trained their own bodies by the path of skillful means so that their subtle channels are perfectly straight, the wind energy is purified and the essence-drops brought under control. Trained in the view of the two previous empowerments, they must be able to tread the path with the help of the extraordinary view and meditation, without any craving for pleasure. If a beginner, who lacks this capacity, goes around claiming to be a practitioner of Mantra and becomes enmeshed in ordinary desire, he is destined for the lower realms. It is better to practice according to one’s true capacity and to the limit of one’s ability.
In this advanced yoga, sexual energy is used in a way entirely cleansed of the impurities of ordinary passion and lust.