Buddha's teachings include both sutras and tantras. The sutras present the basic themes of practice for gaining liberation from uncontrollably recurring problems (Skt. samsara) and, beyond that, to reach the enlightened state of a Buddha, with the ability to help others as much as is possible. The themes include methods for developing ethical self-discipline, concentration, love, compassion, and a correct understanding of how things actually exist. The tantras present advanced practices based on the sutras.
The Sanskrit word tantra means the warp of a loom or the strands of a braid. Like the strings of a warp, the tantra practices serve as a structure for intertwining the sutra themes to weave a tapestry of enlightenment. Moreover, tantra combines physical, verbal, and mental expressions of each practice, which braid together creating a holistic path of development. Because one cannot integrate and practice simultaneously all the sutra themes without previously training in each individually, tantra practice is extremely advanced.
The root of the word tantra means to stretch or to continue without a break. Emphasizing this connotation, the Tibetan scholars translated the term as gyu (rgyud), which means an unbroken continuity. Here, the reference is to continuity over time, as in a succession of moments of a movie, rather than to continuity through space, as in a succession of segments of pavement. Moreover, the successions discussed in tantra resemble eternal movies: they have neither beginnings nor ends.
Two movies are never the same, and even two copies of the identical movie can never be the same roll of film. Similarly, everlasting successions always maintain their individualities. Furthermore, the frames of movies play one at a time, with everything changing from frame to frame. In the same manner, moments in everlasting successions are ephemeral, with only one moment occurring at a time and without anything solid enduring throughout the successions.
The most outstanding example of an everlasting succession is the mental continuum (mind-stream), the everlasting succession of moments of an individual mind. Mind, in Buddhism, refers to an individual, subjective, mere experiencing of something and not to a physical or immaterial object that either does the experiencing or is the tool someone uses to experience things. Further, a mental continuum is not a flow of experiences that accumulate such that one person has more experience than does another. A mental continuum comprises simply an unbroken succession of moments of mental functioning – the mere experiencing of things. The things experienced include sights, sounds, feelings, thoughts, sleep, and even death. Mere implies that the experiencing of them need not be deliberate, emotionally moving, or even conscious.
Further, the experiencing of something is always individual and subjective. Two people may experience seeing the same movie, but their experiencing of it would not be the same – one may like it; the other may not. How they experience the movie depends on many interrelated factors, such as their moods, their health, their companions, and even their seats.
Individual beings are those with mental continuums. Each moment of their existence, they experience something. They act with intention – even if not conceptually planned – and subjectively experience the immediate and long-term effects of what they do. Thus, the mental continuums of individual beings – their experiencing of things – changes from moment to moment, as do they, and their mental continuums go on from one lifetime to the next, with neither a beginning nor an end. Buddhism accepts as fact not only that mental continuums last eternally, but also that they lack absolute starts, whether from the work of a creator, from matter/energy, or from nothing.
Individual beings, and thus mental continuums, interact with one another, but remain distinct, even in Buddhahood. Although Shakyamuni Buddha and Maitreya Buddha are equivalent in their attainments of enlightenment, they are not the same person. Each has unique connections with different beings, which accounts for the fact that some individuals can meet and benefit from a particular Buddha and not from another.
Movies maintain their individualities without requiring or containing innate fixed markers, such as their titles, ever-present as part of each moment, giving the films individual identities solely by their own powers. Movies sustain individual identities by depending merely on interwoven changing factors, such as a sensible sequencing of frames. Likewise, everlasting mental continuums go on without innate fixed markers, such as souls, selves, or personalities, that remain unaffected and unchanging during one lifetime and from one lifetime to the next and which, by their own powers, give them individual identities. To sustain their individual identities, mental continuums depend merely on interwoven changing factors, such as sensible sequences of experiencing things according to principles of behavioral cause and effect (Skt. karma). Even on a more general level, mental continuums lack inherently fixed identities such as human, mosquito, male, or female. Depending on their actions, individual beings appear in different forms in each lifetime – sometimes with more suffering and problems, sometimes with less.
Although mental continuums, and thus individual beings, lack innate souls that by their own powers give them their identities, nevertheless they have other features accompanying them as integral facets of their natures. These innate facets also constitute tantras – successions of moments with no beginning or end. The everlasting innate facets that transform into a Buddha's enlightening facets, or which allow each mental continuum to become the continuum of a Buddha, comprise that continuum's Buddha-nature factors.
For example, unbroken successions of moments of physical appearance, communication, and mental functioning (body, speech, and mind), the operation of good qualities, and activity forever accompany the succession of moments of each mental continuum, although the particular forms of the five vary each moment. The physical appearance may be invisible to the human eye; the communication may be unintentional and merely through body language; and the mental functioning may be minimal, as with being asleep or unconscious. Good qualities, such as understanding, caring, and capability, may operate at miniscule levels or may only be dormant; and activity may be merely autonomic. Nevertheless, individually and subjectively experiencing something each moment entails continually having some physical appearance, some form of communication of some information, some mental functioning, some level of operation of good qualities, and some activity.
The fact that unbroken successions of moments of the five innate facets accompany the mental continuum of each being in every rebirth accounts for the fact that successions of the five continue to accompany each being's continuum also as a Buddha. From another point of view, moments of the five continue to occur in unbroken succession even after enlightenment, but now their forms manifest as a Buddha's five enlightening facets. They are enlightening in the sense that they are the most effective means for leading others to enlightenment.
As tantras, the everlasting continuities of an individual's Buddha-nature factors braid together to form integrated wholes in each moment, functioning together like a network. In another sense, the everlasting continuities constitute the strings of warps upon which successions of moments of further accompanying features of mental continuums interweave. Many intertwining features are also beginningless, but not all of them continue forever. Some can have an end and thus do not constitute integral facets of the continuum's nature. The most significant ones are beginningless continuities of confusion about how things exist, the habits of such confusion, and the uncontrollably recurring problems and limitations that they produce. Here, to simplify the discussion, we are using the term confusion in place of unawareness (ignorance), but without any connotation of disorganization, disorientation, or dementia.
Beginningless successions of moments of different levels of confusion and their habits can end, because their exact opposites, succession of moments of understanding and its habits, can replace and remove them forever. While successions of moments of confusion and its habits accompany mental continuums, their Buddha-nature factors cannot function at their full capacities. So long as mental continuums are in that condition, the individuals denoted by them are limited beings (sentient beings). The factors function at peak levels only with the total removal of all limiting features or "fleeting stains," namely with the total removal of all levels of confusion and their habits. When the continuities of all limiting features stop forever, the individuals are no longer limited beings. Their unending continuities as individuals go on, but the beings have now transformed into Buddhas.
All four traditions of Tibetan Buddhism – Nyingma, Kagyu, Sakya, and Gelug – accept as a meaning of tantra the everlasting successions of moments of interwoven Buddha-nature factors. The special explanations of each tradition shed further light on the topic and complement each other. Let us look first at the general presentation common to Nyingma and Kagyu, since it specializes in discussing tantra in terms of Buddha-nature in general. Their presentations derive from Maitreya's Furthest Everlasting Continuum.
Maitreya explained that although successions of moments of Buddha-nature factors continue forever, they may be unrefined, partially refined, or totally refined. The distinction derives from whether successions of moments of all levels of confusion and their habits accompany the mental continuum without a break, only some of them do for some of the time, or none of them accompany it ever again. These three conditions of the everlasting continuities of Buddha-nature factors are the basis, pathway, and resultant tantras.
As basis tantras, the always-available continuities of Buddha-nature factors are the working materials for achieving enlightenment. From this perspective, the factors are unrefined or "impure" in the sense that successions of moments of all levels of confusion and their habits interlace with the factors at all times, limiting their functioning to varying extents.
On the path to enlightenment, practitioners work to remove the limitations by stopping, in stages, the continuities of the various levels of confusion and their habits that interweave with their bodies, communication, minds, good qualities, and actions. Consequently, during the purification process, the continuities of Buddha-nature factors, as pathway tantras, are partially refined and partly unrefined. Sometimes, periods of full understanding accompany the factors; at other times, periods with merely the momentum of understanding ensue. Occasionally, successions of moments of confusion temporarily cease. Afterwards, continuities of some levels resume, but gradually none of them ever return. Similarly, the habits of confusion occasionally stop giving rise to moments of confusion; but eventually, the continuities of the habits cease forever.
On the resultant level of Buddhahood, the continuities of Buddha-nature factors, as resultant tantras, are totally refined in the sense that they are completely free, forever, of accompanying periods of any levels of confusion or their habits. Thus, the Buddha-nature factors function everlastingly at their full capacities as the interwoven enlightening facets of a Buddha, for example as a Buddha's enlightening physical, communicative, and mental faculties, good qualities, and activities.
Buddha-figures represent the Buddha-nature factors during refined or "pure" phases when successions of moments of full understanding accompany their continuities. Because Buddha-figures have bodies, communication, minds, good qualities, and actions that work together like an integrated network, they are fit to represent these Buddha-nature factors. Moreover, the figures often have multiple faces, arms, and legs. The array of faces and limbs represent themes from sutra, many of which are also among the Buddha-nature factors. Tantra practitioners use the figures in meditation to further the purification process.
The Sanskrit term for Buddha-figures, ishtadevata, means chosen deities, namely deities chosen for practice to become a Buddha. They are "deities" in the sense that their abilities transcend those of ordinary beings, yet they neither control people's lives nor require worship. Thus, the Tibetan scholars translated the term as lhagpay lha (lhag-pa'i lha), special deities, to differentiate them from worldly gods or from God the Creator.
The more common Tibetan equivalent, yidam (yi-dam), denotes the intended meaning more clearly. Yi means mind and dam stands for damtsig (dam-tshig, Skt. samaya), a close bond. Tantra practitioners bond with male and female Buddha-figures, such as Avalokiteshvara and Tara, by imagining themselves as having the enlightening facets of physical appearance, communication, mental functioning, good qualities, and activities of these figures. More precisely, while the continuities of their Buddha-nature factors are still partly unrefined as pathway tantras, practitioners bond or mesh them with continuities of the factors imagined as the totally refined facets of Buddha-figures. Even when practitioners have gained only incomplete understandings of how things exist, imagining their partially unrefined Buddha-nature factors functioning as totally refined Buddha-figure facets is the general tantra method for removing the fleeting stains of periods of confusion and its habits from everlasting continuities of Buddha-nature factors.
In short, the Buddha-nature factors remain the same factors whether they function as basis, pathway, or resultant tantras. The mental continuum always manifests some form of physical appearance, communication of something, and mental functioning, as well as some level of operation of good qualities and some activity. The only difference is the extent to which successions of moments of different levels of confusion and their habits accompany the continuities of the factors and limit their functioning.
According to the Nyingma and Kagyu presentations, then, the subject matter of tantra is the intertwining of the basis, pathway, and resultant conditions of everlasting continuities of Buddha-nature factors to weave a method for achieving enlightenment. Specifically, tantra concerns methods for working with periods of the Buddha-nature factors as pathway tantras to purify successions of the factors as basis tantras so that they ultimately function as the everlasting continuities of resultant tantras. Tantra practice effects this transformation by bonding continuities of unrefined Buddha-nature factors with successions of moments of their refined situation as represented by the enlightening facets of Buddha-figures.
The Sakya presentation of the meaning of tantra derives from The Hevajra Tantra, a text from the highest class of tantra. This presentation elucidates the relation between Buddha-figures and everyday beings that allows for a bonding of corresponding facets of the two in tantra practice.
An exclusive topic of highest tantra is the clear light continuum (clear light mind), the subtlest level of everyone's mental continuum. All mental continuums have clear light levels of experiencing things, which, as the ultimate Buddha-nature, provide them with deepest everlasting continuity. Coarser levels of experiencing things, such as those at which sense perception and conceptual thought occur, do not actually continue without a break from one lifetime to the next. Moreover, they stop forever with the attainment of enlightenment. Only successions of clear light levels continue without interruption, even after becoming a Buddha. If individual beings are analogous to radios, then the coarser levels of their mental continuums are similar to the radios' playing on different stations, while their clear light levels resemble the radios' simply being on. The analogy, however, is not exact. Radios can stop playing, whereas mental continuums never cease their flow.
Regardless of the level at which it occurs, the mere, individual, subjective experiencing of things entails giving rise to appearances of things (clarity) and mentally engaging with them (awareness). In other words, one does not directly perceive external objects, but merely appearances or mental representations of them that arise as part of the act of perceiving. Appearances, here, include not only the sights of things, but also their sounds, smells, tastes, and physical sensations, as well as thoughts about them. Western science describes the same point from a physical perspective. In perceiving things, one does not actually cognize external objects, but only complexes of electrochemical impulses that represent the objects in the nervous system and brain. Although all levels of experiencing things entail the arising of appearances of them, the clear light continuum is the actual source that gives rise to all appearances.
Mentally engaging with appearances means to see, hear, smell, taste, physically sense, or think them, or to emotionally feel something about them. The mental engagement may be subliminal or even unconscious. Further, giving rise to appearances of things and mentally engaging with them are two ways of describing the same phenomenon. The arising of a thought and the thinking of a thought are actually the same mental event. A thought does not arise and then one thinks it: the two mental actions occur simultaneously because they describe the same event.
The Sakya discussion of tantra focuses on a specific Buddha-nature factor, namely the everlasting succession of moments of the clear light continuum's innate activity of giving rise to appearances from itself. The appearance-making is automatic, nondeliberate, and unconscious. One may deliberately look at something; but when one sees it, one's clear light continuum does not deliberately construct an appearance of it. Moreover, the appearances that arise from the clear light continuum may be of the continuum's physical basis – one's body – or of any other objects that it perceives.
Here, the main point is that appearance-making occurs inseparably on two levels: coarse and subtle. Inseparably (yermey, dbyer-med) means that if one level validly occurs, the other level validly occurs as well. In this context, coarse appearances are of everyday beings and their environments; subtle appearances are of Buddha-figures and their surroundings.
Everyday beings and Buddha-figures are like quantum levels of clear light continuums. Subatomic particles have several quantum levels of energy at which they resonate equally validly. At any moment, the level at which a particle is resonating is a function of probability: one cannot say for sure that the particle is resonating at only one level and not the other. In fact, according to quantum mechanics, a particle may resonate at several levels simultaneously. Similarly, because the level at which a clear light continuum is appearing at any moment is a function of probability, one cannot say that at a particular moment an individual being has only one appearance and not another.
The everlasting continuity of mental activity producing this innately bonded pair of appearances may be unrefined, partially refined, or totally refined, depending on the successions of moments of confusion and its habits that accompany it. The process whereby a continuity of practice with Buddha-figures purifies this factor of Buddha-nature so that it produces an everlasting succession of appearances completely free of accompanying periods of confusion and its habits is the primary subject matter of tantra as discussed in the Sakya school.
The Gelug tradition follows The Guhyasamaja Appendix Tantra in explaining the meaning of tantra as an everlasting continuity. The main aspect of Buddha-nature emphasized here is the voidness (emptiness) of the mental continuum – its absence of existing in impossible ways. Mental continuums do not exist as inherently flawed and impure by nature. They never have and never will. No everlasting continuities of innate features accompany them that, by their own powers, make them exist in that impossible manner. Because this total absence is always the case, when practitioners fully understand this fact, they can stop continuities of confusion and its habits from accompanying their mental continuums so that their Buddha-nature factors may function fully as the enlightening facets of a Buddha. Since mental continuums go on forever as everlasting continuities, their voidness remains always a fact enabling purification and transformation.
The purification method refers to the stages of practice with Buddha-figures. Unlike ordinary people, Buddha-figures do not grow from fetuses, age, or die. Because they are always available in the same form, meditation with them may form an everlasting continuity. The result of the purification process is the everlasting continuity of Buddhahood.
In short, through an everlasting continuity of meditation practice of bonding with Buddha-figures, tantra practitioners attain the everlasting continuity of Buddhahood, based on the everlasting fact of the voidness of their mental continuums. Because tantra practice entails producing appearances of oneself as Buddha-figures that resemble the resultant state of enlightenment, tantra is called the resultant vehicle.
The subject matter of tantra concerns everlasting continuities connected with the mental continuum. The continuities include such Buddha-nature factors as basic good qualities, a clear light level of experiencing things, its activity of producing self-appearances, and its voidness. The continuities also include Buddha-figures and the enlightened state. The four traditions of Tibetan Buddhism explain varied ways in which successions of moments of these everlasting continuities intertwine as bases, pathways, and results. They share the feature that tantra involves a pathway of practice with Buddha-figures to purify a basis in order to achieve enlightenment as the result. They also agree that the physical features of the Buddha-figures serve as multivalent representations and provide the warps for interweaving the various themes of sutra practice. The term tantra refers to this intricately interwoven subject matter and the texts that discuss it.