The philosophical view of Indo-Tibetan Vajrayāna is based on the
Madhyamaka and
Yogacara schools of
Buddhist philosophy. The major difference seen by Vajrayāna thinkers between tantra and common Mahayana is that tantric Buddhism contains numerous useful methods (
upaya) not found in Mahayana, which provide a faster vehicle to liberation. For example, the
Nyingma scholar
Ju Mipham writes that secret mantra has a "distinctive abundance of skillful methods" which allows one to awaken in a swift manner and without hardships. In Tibetan Buddhist tantra, the Madhyamaka theory of
emptiness is central, and it is generally held that one must have some understanding of emptiness before practicing tantra. The doctrine of
Buddha-nature or "Buddha embryo" (
tathāgatagarbha) and the doctrine of the
luminous nature of the mind (
Skt: ,
T. ’od gsal gyi sems) or purity of the mind (
prakrti-parisuddha) are also important theories for Tantric practice. According to Tibetan Buddhism, all beings are seen as containing the "buddha embryo". Even though this Buddha potential is innately present, it is covered over by
defilements. In Tibetan Buddhism, there is said to be no strict separation between
samsara and
nirvana, rather they exist in a continuum. Indeed, "continuum" is the main meaning of the term "tantra" (Tib.
rgyud). It is this continuum that connects samsara and nirvana that forms the theoretical foundation for Vajrayana practice. This "tantra" is referred to by numerous terms, such as the causal continuum, Buddha nature,
ultimate bodhicitta, mind's emptiness of true existence,
the ground, the ground maṇḍala, the "ground of all", the
original Buddha, the authentic condition, primordial reality, "affinity for enlightenment", "essence of enlightenment", "pristine awareness", and "ineffable emptiness and clarity." The Nyingma master
Longchenpa meanwhile refers to this ground as "basic space, the utterly lucid nature of phenomena, completely pure by its very nature" and as "timeless awareness as the basic space of phenomena." In Tibetan Buddhism, there are actually said to be three "continuums" ("tantras"): • The continuum of cause (Tib.
rgyu, Skt.
hetu), the Buddha embryo, the fundamental cause for awakening. • The continuum of method (
thabs, upaya), the practices and skillful means which are the contributory condition for awakening. • The continuum of result (
’bras bu, phala), full Buddhahood, complete awakening. As Jamgön Kongtrül states, the tantra of cause "denotes the mind of awakening [bodhicitta],
Ever-Perfect (Samantabhadra), which has neither beginning nor end, in nature luminous clarity. It is 'continuous' since, from time without beginning up to the attainment of enlightenment, it has always been present without any interruption." Furthermore, from the perspective of Unsurpassed Yoga Tantra, the causal continuum is said to abide in the center of the body as "the pristine awareness dimension of the nature of great bliss." Thus, the
Hevajra Tantra states: Great pristine awareness is present in the body. Totally devoid of all conceptuality; It is that which pervades all things. Although abiding in the body, it did not arise from it. There is disagreement among the different Tibetan scholars on the nature of the ground continuum. Some explain it as a mere emptiness of inherent existence (i.e. as a non-implicative negation sometimes termed
rangtong). Others explain it as a negation that implies the presence of positive qualities, a view called
shentong. There is further disagreement among Tibetan Buddhist thinkers on whether Buddhist tantra has a different view than non-tantric ("Sūtra") Mahayana Buddhist thought. In the
Gelug school for example, it is said there is no difference in the view of tantra and the Madhyamaka view of emptiness of inherent existence (which is considered the highest). The only difference is in method. However, some thinkers of the
Nyingma school (such as
Rongzom and
Ju Mipham) do argue that there is a higher view in tantra. According to Mipham, this difference lies in "the way that the subject sees the basic space of phenomena." Mipham explains this view as follows: "all phenomena that comprise appearance and existence are primordially pure as the maṇḍala of enlightened body, speech, and mind." This "maṇḍala of the ground", is "the ultimate natural state of all phenomena, which is primordially of an enlightened nature within great purity and equality."
Tantric yoga theory A key fundamental theory of Tantric practice is the theory of transformation, which states that negative mental factors such as desire, hatred, greed, pride may be used and transformed as part of the path to liberation. This view can be seen in the
Hevajra tantra which states "By passion the world is bound, by passion too it is released" and "one knowing the nature of poison may dispel poison with poison." Tibetan Buddhist tantric practice generally focuses on
Unsurpassed Yoga Tantra, which is said to be superior to other "lower" tantric practices. According to the 14th Dalai Lama, this is because only Unsurpassed Yoga Tantra teaches "the extremely subtle fundamental innate mind of clear light
." In the Nyingma school, this is also called "essential purity", while in the New Translation Schools it is also called "the completion stage of ultimate clear light." Tantric yoga is usually divided into two stages, the generation stage (
utpattikrama) and the completion stage (
nispannakrama). In the generation stage practice of deity yoga (
devata-yoga), one dissolves oneself and the world in emptiness and visualizes oneself as a "cherished divinity" (Skt.
Iṣṭa-devatā, Tib.
yidam). This involves the recitation of mantras, prayers and visualization of the deity along with the associated
mandala of the deity. In the completion stage yogas, the visualization of and identification with the deity is dissolved in the realization of luminous emptiness. Various
subtle body yogas such as
tummo (inner heat) and other techniques such as
dream yoga also belong to this stage. == Classification ==