No being of any kind is without the Buddha-dhatu (Buddha-nature). It is indicated in the Angulimaliya Sutra that if the Buddhas themselves were to try to seek for any sentient being who lacked the Buddha-nature, not one such person would be found. In fact, it is stated in that sutra that it is impossible for Buddhas not to discern the presence of the everlasting Buddha-nature in each and every being:
"Even though all Buddhas themselves were to search assiduously, they would not find a tathāgata-garbha (Buddha-nature) that is not eternal, for the eternal dhātu, the buddha-dhātu (Buddha Principle, Buddha Nature), the dhātu adorned with infinite major and minor attributes, is present in all beings" ("Tathagatagarbha Buddhism" http://www.webspawner.com/users/tathagatagarbha21/index.html)
The eternality, unshakeability and changelessness of the Buddha-nature (often referred to as "Tathagatagarbha") is also frequently stressed in the sutras which expound this Buddha Element. The Srimala Sutra, for example, says:
"The Tathagatagarbha is not born, does not die, does not transfer [Tib: ’pho ba], does not arise. It is beyond the sphere of the characteristics of the compounded; it is permanent, stable and changeless.
The development of the Buddha-nature doctrine is closely related to that of tathagatagarbha (Sanskrit: "Buddha-matrix"). In the Anunatva-Apurnatva-Nirdesa, the Buddha links the tathagatagarbha to the Dharmadhatu (ultimate, all-equal, uncreated essence of all phenomena) and to essential being, stating:
"What I call 'be-ing' (sattva) is just a different name for this permanent, stable, pure and unchanging refuge that is free from arising and cessation, the inconceivable pure Dharmadhatu.
This eternal refuge of the Dharmadhatu / Buddha-dhatu (transcendentally empty of all that is conditioned, afflicted, defective, and productive of suffering) is equated in the Nirvana Sutra with Buddhic Knowledge (jnana). Such Knowledge perceives both non-Self and the Self, Emptiness (sunyata) and non-Emptiness, wherein "the Empty is the totality of samsara [birth-and-death] and the non-Empty is Great Nirvana."
A central aspect of the Buddha-dhatu (sometimes called the Tathagata-dhatu) is that it is utterly indestructible, invulnerable to all harm and contamination, and truly everlasting. It is the innermost, irreducible pure core within the being that cannot be eradicated or killed. The Buddha says so in terms in the Mahaparinirvana Sutra (Tibetan version):
"The Tathagata-dhatu is the intrinsic nature of beings. Therefore, it cannot be killed by having its life severed. If it could be killed, then the life-force (jivaka) could be annihilated; but it is not possible for the life-force to be annihilated. In this instance, the life-force refers to the Tathagatagarbha. That Dhatu [immanent Buddha Element, Buddha Principle] cannot be destroyed, killed or annihilated.
The Mahaparinirvana Sutra (Dharmakshema version) further makes clear that the act of seeing this Buddha-dhatu bestows upon the seer a body-and-mind (kaya) which is "without temporal limits, eternal." The Buddha (in the Dharmakshema version of the sutra) tells of how beings who fail to see the Buddha-dhatu are still afflicted by mental defilements ("kleshas"), but that once the Buddha-dhatu is seen, Awakening is the consequence. The Buddha says that this was his own experience:
"One who has not yet seen the Buddha-dhātu is said to have a body associated with the afflictions (kleshas), a carnal body, a body circumscribed by a future limit ... I beheld the Buddha-dhātu and attained supreme, fully perfect Awakening." (Mahaparinirvana Sutra, Chapter Two, "Cunda"). In this Awakened mode, life everlasting (nitya) and boundless is secured.
In the Tibetan Book of the Dead, it is taught that at death there is an encounter with our true nature, sugatagarbha or Dharmata, when the veils of egocentricity tend briefly to drop away, and shining, unobstructed Awareness is disclosed to us. In line with Tibetan Nyingma doctrine, Tibetan lama, Chokyi Nyima Rinpoche, equates this radiant essence with the Buddha Nature. He writes:
"... all sentient beings already possess an enlightened essence, the sugatagarbha [i.e. the Buddha Nature]. This essence is present and permeates anyone who has mind, just as oil completely permeates any sesame seed ... The moment our ego-clinging falls apart, then our innate wisdom, the luminosity of dharmata, will vividly, nakedly appear. This ground luminosity is not just empty; it is also luminous - aware." (The Bardo Guidebook by Chokyi Nyima Rinpoche, Rangjung Yeshe Publications, Hong Kong, 1991, pp. 116, 121).
An important Sanskrit treatise, entitled the Ratnagotravibhaga, on the Buddha Nature sees the Tathagatagarbha (Buddha Nature) as "Suchness" or "Thusness" - the abiding Reality of all things - in a state of tarnished concealment within the being. The idea is that the ultimate consciousness of each being is spotless and pure, but surrounded by negative tendencies which are impure. Professor Paul Williams comments on how the impurity is actually not truly part of the Buddha Nature, but merely conceals the immanent true qualities of Buddha Mind (i.e. the Buddha Nature) from manifesting openly:
"The impurities that taint the mind and entail the state of unenlightenment (samsara) are completely adventitious ... On the other hand from the point of view of the mind's pure radiant intrinsic nature, because it is like this [i.e. pure and Buddhic], it is possessed of all the many qualities of a Buddha's mind. These do not need actually to be brought about but merely need to be allowed to shine forth. Because they are intrinsic to the very nature of consciousness itself they, and the very state of Buddhahood, will never cease." (Professor Paul Williams, Buddhist Thought, Routledge, London 2000, p. 166).
Buddha-nature is completely rejected by Theravada Buddhism due to the fact that the concept comes from later Mahayana sutras which it sees as inauthentic.
Though not explicitly denied in any form of Indian Mahayana, some scholars, especially those associated with Madhyamaka, did not have an active interest in this doctrine. Nevertheless, the Buddha-nature doctrine did become a cornerstone of East Asian Buddhist and Tibetan Buddhist soteriological thought and practice. Buddha-nature remains a widespread and important doctrine in much of Far Eastern Buddhism today. (Buddhist Thought by Professor Paul Williams, Routledge, London 2000, p. 161).
"the inherent nature that exists in all beings. In Mahayana Buddhism, enlightenment is a process of uncovering this inherent nature … The Buddha nature [is] identical with transcendental reality. The unity of the Buddha with everything that exists."''
In the Tibetan Kagyu tradition, Thrangu Rinpoche sees the Buddha Nature as the indivisible oneness of Wisdom and Emptiness:
"The union of wisdom and emptiness is the essence of Buddha-hood or what is called Buddha-nature (Skt. Tathagata-garbha) because it contains the very seed, the potential of Buddhahood. It resides in each and every being and because of this essential nature, this heart nature, there is the possibility of reaching Buddhahood." (Buddha Nature and Buddhahood: the Mahayana and Tantra Yana, Khenchen Thrangu Rinpoche, http://www.simhas.org/teaching14.html
In contrast to this, the 14th Dalai Lama, representing the Gelukpa School of Tibetan Buddhism, sees the Buddha Nature as the "original clear light of mind" but is at pains to point out that it ultimately does not really exist, as it is Emptiness:
"Once one pronounces the words emptiness and absolute, one has the impression of speaking of the same thing, in fact of the absolute. If emptiness must be explained through the use of just one of these two terms, there will be confusion. I must say this; otherwise you might think that the innate original clear light as absolute truth really exists.
In a similar vein, the Buddhist scholar, Sallie B. King, sees the Buddha Nature (tathagatagarbha) as merely a metaphor for the potential in all beings to attain Buddhahood, rather than as an ontological reality. She writes of the Tathagatagarbha Sutra in particular: "The tathagatagarbha [Buddha Nature] is here a metaphor for the ability of all sentient beings to attain Buddhahood, no more and no less."
Professor Paul Williams puts forward the Madhyamaka interpretation of the Buddha Nature as Emptiness in the following terms:
"… if one is a Madhyamika then that which enables sentient beings to become buddhas must be the very factor that enables the minds of sentient beings to change into the minds of Buddhas. That which enables things to change is their simple absence of inherent existence, their emptiness. Thus the tathagatagarbha becomes emptiness itself, but specifically emptiness when applied to the mental continuum.
Contradicting this, the Jonangpa School of Tibetan Buddhism, headed historically by the Buddhist lama, Dolpopa, sees the Buddha Nature as the very ground of the Buddha himself, as the "permanent indwelling of the Buddha in the basal state"; Dolpopa comments that certain key Tathagatagarbha sutras indicate this truth, remarking:
"These statements that the basis of purification itself, the matrix-of-one-gone-to-bliss [i.e. Buddha Nature], is Buddha, the ground of Buddha, and the pristine wisdom of a one-gone-thus [Tathagata] also clear away the assertion by certain [scholars] that the matrix-of-one-gone-to-bliss [Buddha Nature] is not Buddha.
Speaking for the Tibetan Nyingma tradition, Tulku Urgyen Rinpoche sees an identity between the Buddha Nature, Dharmadhatu (essence of all phenomena and the noumenon) and the Three Vajras, saying:
"Dharmadhatu is adorned with dharmakaya, which is endowed with dharmadhatu wisdom. This is a brief but very profound statement, because 'dharmadhatu' also refers to sugata-garbha or buddha nature. Buddha nature is all-encompassing ... This buddha nature is present just as the shining sun is present in the sky. It is indivisible from the three vajras [i.e. the Buddha's Body, Speech and Mind] of the awakened state, which do not perish or change.
Independent lay yogi lineage of Dzogpachenpo by Chögyal Namkhai Norbu Rinpoche identifies and asserts the primordial non-dual awareness itself as the Buddha Nature, the only non-fabricated and pristine element of our existence.
Discussion of the precise nature, meaning and implications of the Buddha Nature doctrine continues to the present day.
"Many venerable saints and scholars have argued for the Self in the past and do so in the present. Great teachers of the Tibetan Nyingma, Kagyu and Sakya schools have and do argue that such a view [i.e. the reality of an essential Self] is fundamental to the practice of the Buddhist path and the attainment of Enlightenment".
Other sutras which mention the Self in a very affirmative manner include the Lankavatara Sutra (in the "Sagathakam" chapter - e.g. "The Self characterised with purity is the state of Self-realisation; this is the Tathagata-garbha, which does not belong to the realm of the theorisers"), the Shurangama Sutra, the Mahavairocana Sutra: "Those who have been initiated into the Mahayana Mandala Arising from Great Compassion, who are honest and pliant, and who always have great compassion ... They know their hearts to be the Great Self" and the Sutra of Perfect Wisdom called The Questions of Suvikrantavikramin:
"...one who wisely knows himself (atmanam) as nondual, he wisely knows both Buddha and Dharma. And why? He develops a personality which consists of all dharmas ... His nondual comprehension comprehends all dharmas, for all dharmas are fixed on the Self in their own-being. One who wisely knows the nondual dharma wisely knows also the Buddhadharmas. From the comprehension of the nondual dharma follows the comprehension of the Buddhadharmas and from the comprehension of the Self the comprehension of everything that belongs to the triple world. 'The comprehension of Self', that is the beyond of all dharmas.
The teaching on the Self which is attributed to the Buddha in the Mahayana Mahaparinirvana Sutra insists upon the True Self's ultimacy, sovereignty and immortality. The Buddha states (in the Tibetan version of the Sutra): "all phenomena (dharmas) are not non-Self: the Self is Reality (tattva), the Self is eternal (nitya), the Self is virtue (guna), the Self is everlasting (shasvata), the Self is unshakeable (dhruva), and the Self is peace (siva)." In the Chinese versions of the Sutra, the Self is also characterised as autonomous or sovereign (aishvarya).
The Mahaparinirvana Sutra specifically contrasts its doctrine of the Self with that of the Astikas in order to remove the reifying notion that the Self was a little person or homunculus, the size of a grain of rice or of one's thumb, sitting in the heart of the being, thus: "mundane [philosophers] mistakenly imagine it to be a person (puruṣa) the size of a thumb, the size of a pea or a grain of rice that dwells shining in the heart." This, the Buddha says, is a misconception of the nature of Self, for "that opinion of theirs is a mistaken opinion, one that is transmitted onwards from person to person, but it is neither beneficial nor conducive to happiness." The Self of which the Buddha speaks is said by him to be the "essential intrinsic being" (svabhava) or even "life-essence" (jivaka) of each person, and this essential being is none other than the Buddha himself - "radiantly luminous" and "as indestructible as a diamond".
Moreover, the Buddhist tantric scripture entitled Chanting the Names of Mañjusri (), as quoted by the great Tibetan Buddhist master, Dolpopa, repeatedly exalts not the non-Self but the Self and applies the following terms to this ultimate reality:
In the Ghanavyuha Sutra (as quoted by Longchenpa) this immutable, universal and salvific Buddha Essence (the True Self of the Buddha) is said to be the ground of all things, but it is viewed by fools as something changeful and impermanent, whereas in fact it is stated by the Buddha to be the very opposite of such impermanence:
"... the ultimate universal ground also has always been with the Buddha-Essence (Tathagatagarbha), and this essence in terms of the universal ground has been taught by the Tathagata. The fools who do not know it, because of their habits, see even the universal ground as (having) various happiness and suffering and actions and emotional defilements. Its nature is pure and immaculate, its qualities are as wishing-jewels; there are neither changes nor cessations. Whoever realizes it attains Liberation ...
The Buddha in the Mahayana Mahaparinirvana Sutra insists that the Self of the Buddha (the Buddha Nature which is present in all beings) is everlasting, pure and blissful and is most definitely not transitory and impermanent:
"The Buddha-Nature is the Eternal, Bliss, the Self, and the Pure ... The Buddha-Nature is not non-Eternal, not non-Bliss, not non-Self, and not non-Purity.
The Buddha-Nature is in fact taught in such Tathagatagarbha sutras to be ultimate, conceptually inconceivable, immortal Reality. The Buddha-Nature concept remains an important doctrine in Mahayana Buddhism, especially in its Far Eastern manifestations (Buddhist Thought, Professor Paul Williams, Routledge, London 2000, p.161).
Jamgon Kongtrul says about the two systems:
Madhyamika philosophies have no differences in realising as 'Shunyata', all phenomena that we experience on a relative level. They have no differences also, in reaching the meditative state where all extremes (ideas) completely dissolve. Their difference lies in the words they use to describe the Dharmata . Shentong describes the Dharmata, the mind of Buddha, as 'ultimately real'; while Rangtong philosophers fear that if it is described that way, people might understand it as the concept of 'soul' or 'Atma'. The Shentong philosopher believes that there is a more serious possibility of misunderstanding in describing the Enlightened State as 'unreal' and 'void'. Kongtrul finds the Rangtong way of presentation the best to dissolve concepts and the Shentong way the best to describe the experience."
In 2006 Khentrul Rinpoche Jamphal Lodro founded "The Tibetan Buddhist Rime Institute" in Melbourne, Australia. It aims to propagate the Rime view of harmony within all Buddhist traditions and to introduce the rare Jonang Kalachakra Tantra lineage teachings in the western world .