From about the eighth century onward, we start to see numerous examples of Indian mahasiddhas repudiating traditional tantric methods and advancing instead a direct perception of the nature of the mind as the quintessential method for realizing enlightenment. According to the well-known Tibetan author and translator Go Lotsawa (ca. 1392--1481), "the great brahmana Saraha was the first to introduce the Mahamudra as the chief of all paths."
The situation arose where some mahasiddhas continued to promote Mahamudra as the apex of tantric practices and conventions, while others, such as Saraha and Maitripa, began to disassociate themselves and their Mahamudra teachings from Tantrism.
[Shifting to a discussion of the Kagyu school] It was not until the eleventh and twelfth centuries that Mahamudra doctrine attained a distinct position within the Kagyu school, after Gampopa formally introduced the approach into the mainstream Buddhist practices of his lineage. ... It was only Gampopoa, toward the end of his life, who began to emphasize a practice of Mahamudra independent of tantric practices and empowerments that became a separate practice unto itself. As Takpo Tashi Namgyal explains in his famous Mahamudra manual:
The teachers of this meditational lineage up to Milarepa meditated mainly on the key instructions of the Mantrayana mysticism [Tantra] while at various times incorporating vital instructions on mahamudra from the discourses on the yogas of inner heat and lucid awareness [tantric practices]. Yet, the great master Gampopa, having been moved by immeasurable compassion, expounded mainly on the quintessential instructions on mahamudra. As a result it became widely known as the single path for all predestined seekers.
Go Lotsawa also mentions that, prior to Gampopa, the Mahamudra teachings were exclusively given as a highly secret instruction to practitioners who had received tantric initiation. Gampopa was revolutionary in this matter as well. Not only did he extract the Mahamudra practice as a self-sufficient doctrine; he also significantly liberalized its dispersion by giving instructions outside of the tantric environment. While Milarepa did not teach Mahahmudra separate from the tantric teachings, Gampopa began to give tantric initiations to select students and Mahamudra teachings to all the rest without giving them tantric initiations. He thus initiated a widespread practice of separating the Mahamudra cycle of teachings from their tantric origins.
The Tibetan tradition usually divides the different historical and philosophical approaches to Buddhist practice into three vehicles (yanas). These are the Hinayana (small vehicle), the Mahayana (great vehicle), and the Vajrayana (indestructible vehicle). Sometimes a fourth vehicle is also included in Tibetan literature, as noted by some twentieth-century Indian historians. This is the Sahajayana (the vehicle of coemergence). In Tibetan this is called lhen chig kye pa (lhen chig
equivalent to saha
is the same as ja
). Sahaja literally denotes "being born (ja) together with (saha)" and was applied to the teachings and dohas of many of the Indian mahasiddhas who were associated with the Indian Mahamudra lineage. Therefore the Mahamudra approach can also be described as the Sahajayana (the vehicle of sahaja) as opposed to the Tantrayana (the vehicle of Tantra). It might be useful to use the notion of the Sahajayana here to emphasize that the Mahamudra teachings are a unique and separate vehicle in their own right.
The Kagyu tradition extends this classification further by identifying four fundamental approaches to enlightenment: renunciation, purification, transformation, and self-liberation. Each approach corresponds to one of the four vehicles. The Hinayana corresponds to the approach of renunciation, the Mahayana to the apporach of purification, the Vajrayana to the approach of transformation, and the Sahajayana (or Mahamudra) to the approach of self-liberation.
We shall add one further overarching typology to those above. All the Buddhas teachings can be divided into exoteric, esoteric, and mystical categories. IN general terms, these three could be said to correspond respectively to codified orthodoxies, secret teachings given only to initiates, and mystical teachings that transcend the reference points of most worldy activities. The Hinayana and Mahayana fall into the general category of the exoteric approach, the Vajrayana (tantric) is the esoteric approach, and the Mahamudra tradition is the mystical approach.