The Kagyü tradition is one of the major schools of Tibetan Buddhism, among whose contemporary masters are His Holiness the Karmapa, Khenchen Thrangu Rinpoche, and Kalu Rinpoche. Finding inspiration in Milarepa (1052-1135) and many other classical saints of the lineage, the Kagyü tradition is now known for its teachings on mahamudra and the six yogas of Naropa.
By spiritual exercises and the application of Tantric techniques-such as the Six Yogas - one can soon realize that his body, mind, and the "objective world" are all manifestations of the divine Buddhahood.
The basic doctrine of Tibetan Tantrism can thus be called a doctrine of viewing man's body-mind complex as corresponding to, if not identical with, that of Buddha. The spirit and practice of all Tantric Yogas are also directed toward the unfoldment of this basic principle.
In the Arising Yoga practice, the yogi is taught to visualize and thus identify the outer world as Mandalas, his body as the Body of the Patron Buddha, his nervous system as the Three Channels and the nadis of the four Cakras his secretions as the bindus of the positive and negative elements, his aspiration and energy as the Wisdom-Prana and "Light".
Tibetan Tantrism offers two Paths, or types of Yoga, both leading to the same goal. One is called the Path of Liberation, or "Mind Yoga", and the other - the Path of Skillfulness or "Energy Yoga". The former is in many ways like Ch'an (Zen) Buddhism because it stresses the observation and cultivation of the Innate Mind, and requires only a minimum of ritual and yogic preparations.
The latter is a series of rigorous and complex Yoga practices known as the Arising and Perfecting Yogas. The three excerpts dealing with Mahamudra in the first part of this book are of the former group, which the reader may soon discover to be strikingly similar to early Zen Buddhism.
The Six Yogas of Naropa are of the latter group - a synthesis of the Arising and Perfecting Yogas, with special emphasis on the latter.
From the yogic viewpoint, among the group of the Six Yogas those of the Heat and Illusory Body are the primary ones, and the other four: Dream, Light, Bardo, and Transformation, are ramifications of them.