Perfect Interpenetration

Huayan

The Huayan (Avatamsaka) school is particularly known for its development of the theory of interpenetration, which is also known as "perfect interfusion" (圓融; yuanrong), the non-obstruction of phenomena (事事無礙; shishi wu’ai), and "the dependent arising of the whole realm of phenomena" (法界緣起, fajie yuanqi; Sanskrit: dharmadhatu pratityasamutpada). This doctrine is central to Huayan thought and is described in various ways throughout the writings of Chinese Huayan scholars, dating back to the founder of the school, Dushun.^[14][15][16] Muller explains that the Chinese binome 通達 tōngdá "indicates both passing through that which is already open, and piercing through that which has been heretofore closed."^[13]

Huayan masters like Fazang and Chengguan developed this theory out of their interpretation of the doctrine of emptiness and their reading of the Avatamsaka Sutra. For them, all phenomena (dharmas) are mutually dependent on and interfused with each other as well as with the entire set of dharmas in the universe (the Dharmadhatu, "dharma realm"). As such, any individual dharma only exists as part of the cosmos as an interconnected nexus of dharmas, a system in which each dharma contains all other dharmas.^[17] This is described by Fazang with the phrases "one is many, many is one" (yi ji duo, duo ji yi) and "one in many, many in one" (yi zhong duo, duo zhong yi), which refers to how any dharma penetrates and is penetrated by the totality of all things.^[18] As Bryan Van Norden describes this theory, "because the identity of any one thing is dependent on the identities of other things, 'one is all,' and because the whole is dependent for its identity on its parts, 'all is one.'"^[19]

While the Avatamsaka Sutra does not itself expound the theory of interfusion as taught in Huayan, there are numerous passages which describe how each individual particle contains countless worlds within them, such as the following:

If untold Buddha-lands are reduced to atoms,
In one atom are untold lands, and as in one, so in each.
The atoms to which these Buddha-lands are reduced in an instant are unspeakable,
And so are the atoms of continuous reduction moment to moment, going on for untold eons;
These atoms contain lands unspeakably many, and the atoms in these lands are even harder to tell of.^[20]

The idea may also have been influenced by the Gaṇḍavyūha Sūtra's climax scene in Vairocana's Tower.^[12] In this passage, the sutra's protagonist Sudhana enters a towered temple hall (kūṭāgāra) and sees that the inside of it is vast as the sky, containing hundreds of thousands of other kūṭāgāras that coexist without obstructing each other. Inside, he witnesses bodhisattvas (including Maitreya) entering samādhi, emitting countless transformation bodies from their skin pores, and hearing melodious Buddhist teachings emanating from every pore. In one especially magnificent tower, he perceives the entire Buddhist cosmos in one single glance, and within each world, he observes Maitreya's birth, descent to earth, and the key events of his final existence.^[12] As the Gaṇḍavyūha Sūtra's fifty fourth chapter states:

He saw within the kūṭāgāra another hundred thousand with this kind of an array of adornments: adorned by countless precious parasols, banners, and flags, and so on, adorned by countless perfect excellent qualities. He saw that all those kūṭāgāras were in that way vast, immense, and immeasurable; were treasuries of space; and had been completely, beautifully adorned. He saw that these kūṭāgāras were perfectly arranged so that in a single perception they appeared in the manner of reflections that were separate from one another, not mingled with one another, and distinct from one another, and so that they appeared with all of them without exception being perceived in a single perception.^[21]

Furthermore, a common theme of the Avatamsaka Sutra is how the Buddha's Dharma is "one" or singular, while the perceptions and understands of all sentient beings are manifold. This is likened to how a luminous pearl can contain many reflections, and is used to explain how the Buddha's realm of nirvana manifests and suffuses all of samsara (highlighting the Mahayana doctrine of the non-duality of samsara and nirvana).^[16] These ideas led to Chinese exegetical discussions on the unity between the one (yi 一) and the many (duo 多) (as seen in Zhiyan's phrase “One is all” 一即一切), as well as further developments of the closely related Chinese philosophical theories like essence-function and the relationship between the ultimate principle (li) and the myriad phenomena (shi) — all of which were seen as interdependent and interconnected.^[16]

The Huayan theory of interpenetration was first presented in Dushun’s Threefold Discernment of the Dharmadhatu which provides a progressive meditative framework for understanding reality which moves from the classic Mahayana view of emptiness to a radical vision of cosmic interpenetration. Dushun begins with the first discernment, which establishes the classic identity between form and emptiness. The second discernment introduces the distinctive Huayan categories of li (universal principle) and shi (particular phenomena), arguing that these two dimensions of reality are mutually non-obstructive and pervade one another like water and waves. The third and highest discernment completely transcends the dualism of the ultimate principle and myriad phenomena, focusing on the "total pervasion" of shi with shi." In this final stage, reality is viewed as a groundless, center-less, fractal web where every individual dharma fully contains and is contained by every other thing in the universe.^[22][23]

The Huayan teaching of interpenetration is depicted through various metaphors, such as Indra's net, an infinite cosmic net that contains a multifaceted jewel at each vertex, with each jewel being reflected in all of the other jewels, ad infinitum. Thus, each jewel contains the entire net of jewels reflected within.^[12] This idea was also first described by the first patriarch Dushun who writes in his Calming and Contemplation in the Five Teachings of Huayan (Huayan wujiao zhiguan 華嚴五教止觀, T1867):

The manner in which all dharmas interpenetrate is like an imperial net of celestial jewels extending in all directions infinitely, without limit. … As for the imperial net of heavenly jewels, it is known as Indra’s Net, a net which is made entirely of jewels. Because of the clarity of the jewels, they are all reflected in and enter into each other, ad infinitum. Within each jewel, simultaneously, is reflected the whole net. Ultimately, nothing comes or goes. If we now turn to the southwest, we can pick one particular jewel and examine it closely. This individual jewel can immediately reflect the image of every other jewel.^[24]

Another popular metaphor is the rafter-building metaphor which can be found in Fazang's famous "Rafter Dialogue."^[14] This is found in the Huayan Wujiao Zhang 華嚴五教章 (Treatise on the Five Teachings, T.45.1866), where Fazang states:

The rafter is the building. Why? Because the rafter by itself establishes the building. Without the rafter, the building is not established. When there is the rafter, there is the building...Question: Why would there be no building if a single rafter is absent? Answer: That would be a spoiled building, not a perfect building. Therefore, you should know that the perfect building is inherent in the one rafter. Since it is inherent in this one rafter, you should know that the rafter is the building....Question: Since the building is the rafter, then the planks, roof tiles, etc. should also be the rafter? Answer: They all are the rafter. Why? Without the rafter, there would be no building. If there is no rafter, the building is spoiled. If the building is spoiled, then you cannot speak of the planks, roof tiles, etc. Hence, the planks, roof tiles, etc. are the rafter. If they were not the rafter, the building could not be established. The rafter, tiles, etc. could not be established. Now they are all established, we know they are identical with each other.^[1]

According to Fazang, any rafter (any part) is essential to the existence of its building (standing in for the universe, the dharmadhatu). Likewise, the identity and existence of any rafter is also dependent on it being part of a building.^[25][26] Therefore, any phenomenon is necessarily dependent upon all phenomena in the universe.^[27] Philosophers like Graham Priest and Li Kang interpret this argument as being based on the notion of definitional identity. Each part of a whole contributes to defining what the whole is. The absence of any part of a thing means that the whole thing is no longer the same thing without that individual part.^[1] Yet another example used to illustrate interpenetration is that of a hall of mirrors arranged in an octagon so they each reflect each other. Fazang was said to have constructed such a hall of mirrors as a way to teach interpenetration.^[28] Huayan patriarch Qingliang Chengguan explained the example as follows:

If we use the example of the ten mirrors (arrayed in a circle or sphere so that all face all the others) as a simile [for phenomenal interpenetration], one mirror is the one, nine mirrors are the many [...] one mirror includes in it reflections of nine mirrors, meaning that one mirror is that which includes and nine mirrors are that which is included—yet because the nine mirrors also are that which includes (because they contain the reflection of the one mirror), the aforementioned one mirror which includes also enters the nine mirrors, so one mirror enters the nine mirrors.^[29]

Tiantai

The Chinese Tiantai school also developed a theory of interpenetration in parallel with the developments in the Huayan school. The Tiantai school develops its interpenetration theory from the philosophy of its central founding figure, Zhiyi, as well as from its readings of the Mahayana Sutras, especially the Lotus Sutra. Tiantai authors use terms such as "mutual containment" (相攝, Skt. anyonya-samavasaraṇa), "mutual inclusion" (互具; hu ju), "nature inclusion" (性具; xing ju) or "inherent inclusion" (本具; ben ju) to describe their view of the interpenetration of all phenomena.^[30][31] For Tiantai scholars, this meant that any individual phenomenon (dharma) includes or entails every other phenomenon. This holism also entails that each phenomenon includes the entirety of the ultimate truth (and vice versa, that the ultimate truth includes all other particular phenomena).^[32] This view that "everything contains everything else, and the whole contains all things" was also termed "the interinclusiveness of the ten realms" and "the interpenetrating unity of all aspects of reality".^[33]

According to Brook Ziporyn, the Tiantai school's view of interfusion is derived from a passage in the Chinese translation of the Lotus Sutra which states (key section bolded for emphasis):

Only a Buddha together with a Buddha knows the ultimate reality of all things: how they appear, what their natures are, what they're made of, what they are capable of, what they are doing, what their causes are, what their conditions are, what their effects are, what their consequences are, and the way in which all these factors from beginning to end are equally ultimate and are ultimately one and the same.^[34]

According to modern Buddhist studies scholar Brook Ziporyn, Tiantai authors interpret this passage as pointing to how "each particular aspect of the world as we see it and feel it is ultimately real, that each one is in fact the Absolute itself, the Buddha-nature, the final fact about the universe," and also how "each thing, each appearance, each action" is "the ultimate reality "of " all other things".^[34]

The foundational thinker of the Tiantai school, Zhiyi, saw the teaching of mutual inclusion as being entailed by the doctrine of emptiness, dependent arising and the threefold truth (his own reworking of Nagarjuna's two truths). Zhiyi writes in his Móhē Zhǐguān: "If one relies on the circumstances of deluded attachment and discrimination, then phenomena are not mutually contained. But if one relies on the function of the dependent arising of the mind-nature, then there can be mutual containment (相攝)."^[35] According to Zhiyi, the third truth of the Middle (which is the non-duality of the conventional and the ultimate truths) transcends and includes all extremes, such as self and other, "inside" or "outside", whole or part, the one and the many. As such, any specific phenomenon cannot be ultimately separate from all others and thus "entails" or includes all other phenomena.^[36]

According to Li Kang, Zhiyi derives his view of interpenetration from Nagarjuna's doctrine of emptiness, which says that all phenomena exist only as conventional conceptual constructs (prajñaptis). If this is the case, then the boundaries between all individual things are not inherent, substantial or fixed. Since there is no inherent boundary between phenomena, then there is no ultimate separation between things, and so, all things are interpenetrating. Zhiyi thus relies on the view of emptiness to establish conventionality of boundaries to establish the nonseparateness of all things. It is like how the boundaries between the five oceans are merely conventional.^[1]

Zhiyi further explains interpenetration with the phrase: "a single thought [or “one mind”] comprises the ten dharma-realms" (一念三千 yīniàn sānqiān). According to this teaching, each of the ten realms of Buddhist cosmology contains / possesses (具; ju) all other realms.^[37][1] Furthermore each realm (or phenomenon) contains all others or "inherently entails" all others, hence they are "mutually inclusive".^[38][39] In explaining this view, Zhiyi's Móhē Zhǐguān explicitly rejects two specific interpretations:

But it cannot be said that one single thought is before, and that all dharmas are after. Nor can it be said that all dharmas are before, and that one single thought is after… If one single thought gives rise to all dharmas, it is vertical. If one single thought contains all dharmas at a time, it is horizontal. It cannot be vertical. Nor can it be horizontal.^[1]

Thus, the Tiantai position is not that there is any single phenomenon that generates all dharmas, nor is there a single phenomenon that contains all dharmas within it as its parts. Instead, Zhiyi claims "It is just that one single thought shi 是 (is) all dharmas. All dharmas shi (are) one single thought."^[1] This is true even though "each of the ten dharma (realms) has its own causes and own results. They are not mixed or confused with the others; therefore, they are called “ten dharma realms." Furthermore, Zhiyi also writes that one single thought and all dharmas are "neither identical nor distinct".^[1]

As Brook Ziporyn explains, for Zhiyi, each thing or thought has a kind of potential which can be "opened up" to reveal all other things; every thing leads to everything else, and so "the whole is present in each part; every particular is itself the whole".^[40] Thus we can say that "one short thought contains all of reality" and that "the Buddha and ordinary worldlings, body and mind, cause and effect, subject and object, sentient and non-sentient are mutually encompassed in every moment of thought."^[39][41]

Further maxims which are influential in Tiantai Buddhism as ways of discussing the implications of interpenetration include: "afflictions (kleśa) are precisely enlightenment (bodhi)," "saṃsāra is precisely nirvāṇa," "sentient beings are precisely original enlightenment," and "this sahā world is precisely the [pure] land of silent illumination".^[35] However, Ziporyn notes that the Tiantai view does not mean that each phenomenon literally contains every thing else, but that "as a sound is contained in a musical instrument", each phenomenon has the same nature (Chn. xing), which can lead to, connect to or become all other things.^[40] As such, while we can say that all phenomena entail all other phenomena, they don't contain all phenomena pre-existent within it. This would be a non-Buddhist view called satkaryavada which existed in India and is explicitly rejected in Mahayana Buddhist philosophy.^[40] Ziporyn describes the Tiantai view of reality which holds to the mutual inclusion of the whole in each individual thing as an "omnicentric holism". In this view, no phenomenon has a clear singular identity of its own. Instead, each thing is a nexus of all other things and exists in an infinitely multi-sided way. Furthermore, no single phenomenon is an exclusive core or foundation of reality, all phenomena are ontological equal.^[42][43] Nevertheless, in spite of this mutual interfusion, individual phenomena do not lose their particular individuality and functioning as conventional truths.^[44]

Sanlun (Chinese Madhyamaka)

The Chinese Madhyamaka school (known as Sanlun) also saw the development of a theory of interpenetration or mutual dependence (相待; xiang dai), based on Nagarjuna's theory of emptiness, which sees all conventional phenomena as conceptual imputation. The idea is developed in the works of the Sanlun philosopher Jizang (549–623).^[1] In the Erdi Yi 二諦義 (Meaning of the Two Truths, T.45.1854), Jizang explains mutual dependence as follows:

The original meaning of mutual dependence requires mutual revelation and mutual establishment. For example, long and short are mutually dependent. Without short, there is no long; without long, there is no short. Long reveals what is short, and short reveals what is long. This is called mutual dependence.^[1]

This is a mutual dependence of particular characteristics. But Jizang's Erdi Yi also discusses a more general type of mutual dependence between seemingly unrelated things:

Shi (is) and fei (is not) are mutually dependent. Vase depends on non-vase. (Non-vase depends on vase.) If so, a piece of clothing is a non-vase; since non-vase depends on vase, a piece of clothing depends on a vase. Once a piece of clothing depends on a vase, then a vase and a piece of clothing are (each other’s) causes and conditions. A piece of clothing embodies the meaning of a vase, and a vase embodies the meaning of a piece of clothing. Once a piece of clothing embodies the meaning of a vase, all things embody the meaning of a vase.^[1]

According to Kang, the basic argument here is that opposing concepts mutually depend on each other, and that for any two things, there will always be opposing concepts that apply to each thing which mutually depend on each other. The argument posits that if the concepts defining two objects are mutually dependent, then the objects themselves must share a reciprocal dependence relationship, effectively "embodying" each other's meaning. Since any two arbitrary objects (which in Madhyamaka are prajñaptimatra, "mere conceptual constructs") can be mapped onto such opposing conceptual pairs, Jizang concludes that every individual phenomenon in the universe is inextricably linked to every other, suggesting that the any single thing contains the essence of the totality.^[1]

Chan / Zen

East Asian views on mutual interfusion were also influential on the development of the Chan (Zen) tradition, which drew on them to explain the Mahayana concept of nonduality (bu-er 不二).^[1] Huayan and Sanlun influences can be found classic Chan texts such as the Platform Sutra and the Harmony of Difference and Sameness.^[1]

Chan masters applied the idea that the universal principle (li, equated with the Buddha mind and Buddha-nature) was entirely immanent within every particular event (shi) to the Chan idea of kensho (Chn. 見性; jianxing), a direct perception of ultimate reality in each mundane thought or moment. For Chan masters like Mazu Daoyi, the interfusion of buddha-nature with all things meant that enlightenment was fully present in daily thoughts or acts like carrying water or chopping wood.^[45] The doctrine also served to defend the view Chan Buddhist view of the path, which shifted from gradual progression toward "sudden awakening", a sudden realization that Buddhahood was already here and now, interfused with our very mundane existence.

The idea continued to influence later Zen figures throughout East Asia. For example, the concept appears in the works of Korean Seon masters like Jinul (1158–1210) and Kihwa (1376–1431), both of whom were influenced by Huayan thought.^[46] These authors do not just rely on the concept to explain Seon (Zen) practice and philosophy, but also to defend the classic East Asian Buddhist ethics. As such, Kihwa (who was also a scholar of Confucianism), writes:

Humaneness implies the interpenetration of heaven and earth and the myriad things into a single body, wherein there is no gap whatsoever. If you deeply embody this principle, then there cannot be a justification for inflicting harm on even the most insignificant of creatures.^[10]

Pure Land

Chinese masters often drew on Tiantai and Huayan teachings of interpenetration to explain the nature of the Pure Land Buddhist path and the functioning of Pure Land practices, such as nianfo. Pure Land masters like Yunqi Zhuhong, Ouyi Zhixu and Yinguang argued that because all phenomena are mutually inclusive and interfused, the mind of the nianfo reciter and Amitabha Buddha's mind were fundamentally inseparable and interlinked. Because of this, a single faithful invocation of the nianfo actually activates the Buddha's virtuous qualities in one's mind here and now, and plants seeds for future rebirth in the Pure Land of Sukhavati. Furthermore, due to the interpenetration of all phenomena, reciting the name of Amitabha Buddha fully encompasses all buddhas. As Master Yinguang writes:

You should not think that the merits and virtues of reciting the name of, or visualizing one Buddha are less encompassing than those received from reciting the name of, or visualizing many Buddhas. You should realize that Amitabha Buddha is the Dharma Realm Treasure Body. All the virtues of the Buddhas in the ten directions of the Dharma Realm are fully encompassed in Amitabha Buddha. This is like the jewelled net of Indra, whose thousands and thousands of jewels are fully reflected in one jewel, the image of one jewel is reflected in thousands and thousands of jewels, and each and every jewel encompasses every other, in perfect, unimpeded fashion.^[47]

This doctrine also provides metaphysical foundation for the Pure Land doctrine of ganying, "stimulus-response," in which the practitioner’s "stimulus" (the focused chanting of nianfo) and the Buddha’s "response" (the compassionate vow to save all beings) are not separate distinct things. Because the practitioner’s mind and Amitabha’s Pure Land interpenetrate without obstruction, the act of calling upon the Buddha is able to collapses the distinctions between the mundane world of samsara and the pure land. Likewise, according to masters like Yuan Hongdao, the single easy practice (nianfo) encompasses and accomplishes all other Buddhist practices due to perfect interfusion.^[48] Furthermore, all worlds and realms are interfused with the Pure Land itself. As such, through the doctrine of interpenetration, the pure land was understood as an ever-present dimension which could be accessed by means of faith and nianfo practice, which allows us to become aligned with the interfusion of the Buddha and sentient beings.^[49]

Role in practice and ethics

The ethical import of interpenetration is based on the link between individuals and collectives. If the "self" is actually composed of "non-self" elements, then the well-being of any individual is inseparable from the well-being of the environment, society and ultimately the entire cosmos. Thus, a person is composed of many elements beyond their personal self boundary, such as their parents, ancestors, plants, and animals, as well as water, sunlight, food, education, and life experiences.^[57] It is only the belief in a separate self that confines us, falsely separating the "I" vs others.^[57] As such, if one can see the nature of interbeing between oneself and others, one can see that others' suffering is one's own suffering, and others' happiness is one's own happiness.^[55] Thus, Nhat Hanh teaches that harming other people, animals or the ecosystem is a form of self-harm, since there is no ontological boundary separating the two. This realization requires a life of mindfulness in the present moment, where every mundane action like washing a bowl or walking becomes a meditative act of "being peace" in relation to oneself and to the world.^[52]

In this way, the view of interbeing functions as a corrective to many deluded harmful concepts that trap human thought, mainly concepts of separation and independence. By dissolving these rigid constructs of the mind and our attachments to them, practitioners of interbeing are invited to return to the immediate experience of the present moment. Nhat Hanh’s teachings therefore emphasize that enlightenment is to be found in this insight into the interconnectedness of all things.^[52] Interbeing thus enriches the practice of Zen by framing the Mahayana practices of compassion, mindfulness, and ethical living. It encourages practitioners to extend their awareness beyond the self, to better engage with their environment.^[58] Interbeing also supports the idea that mindfulness should extend beyond ourselves to encompass our society and ultimately the whole interconnected web of existence, since well-being is intimately tied to the well-being of others and the environment.^[59] This understanding encourages practitioners to act compassionately, reducing suffering not only for themselves but also for all sentient beings.^[8] Practitioners are encouraged to be mindful not only of their own thoughts and actions but also of how they affect and are affected by the world around them.^[59][50]

While traditional Zen practice often involves meditation and solitary retreats, interbeing, as an integral part of Nhat Hanh's Engaged Buddhism, also encourages practitioners to be actively engaged in the world and to improve it for the better, bringing meditative insights into activism and environmentalism.^[60][61] Nhat Hanh's Interbeing teaching thus has a heightened environmental awareness, emphasizing that our actions have a direct impact on the natural world and that we are interconnected with all living beings. In response to this awareness, Zen practitioners who embrace interbeing often engage in environmental advocacy and sustainable living as a natural manifestation of their practice.^[58]

Order of Interbeing and Plum village

Thích Nhất Hạnh founded the Order of Interbeing and Plum Village Tradition as new Buddhist movements that work to embody a life of mindfulness of interbeing. The Order of Interbeing comprises monastic and lay practitioners, this community adheres to the philosophy and practice of interconnectedness, emphasizing mindfulness, compassion, and ethical living.^[62] Members follow the Fourteen Mindfulness Trainings as ethical guidelines, engage in communal practices, and apply interbeing principles in their daily lives.^[63]

Within the Plum Village Tradition, interbeing is based on Mahayana teaching and is an understanding that there is a deep interconnection between all people, all species, and all things based on non-duality, emptiness, and dependent co-arising (all phenomena arise in dependence upon other phenomena).^[64] Plum Village does not try to prove the truth of interbeing, but instead emphasizes the importance of recognizing its truth through meditation (generating mindfulness, insight, and concentration).^[52][65] Understanding interbeing is essential for overcoming suffering and reaching enlightenment, which is the ultimate goal in Buddhism.^[52] This insight into interbeing helps in particular by revealing that nothing is ever truly created or destroyed, which removes the fear of death or loss.^[52]

Plum Village, founded in 1982 in France by Thich Nhat Hanh, serves as a central location for the practice and learning of Interbeing. The community, comprising both monastics and laypeople, engages deeply with the principles of interconnectedness and mindfulness that are fundamental to the concept of Interbeing.^[66] Here, individuals immerse themselves in practices that underscore the interdependent nature of existence, fostering a life that reflects awareness, compassion, and ethical living. The tradition of Plum Village extends globally through various centers, each committed to promoting the understanding and practice of Interbeing.^[50]