What This Concept Is About
In the everyday intuition of most people, "space" is a container. We place tables and chairs into a room, pack our bodies into a subway car, store files on a hard drive. Deep in our awareness, there is always first a solid spatial "frame," and then solid objects are placed inside it.
Yet when Buddhism dissects life and all things, it puts forward an extremely subversive concept——虚空界 (ākāśa-dhātu, "realm of space"), which in the classics is also often abbreviated simply as 空界 (ākāśa-dhātu, "space element").
In the Buddha-dharma, the space element is neither an independently existing substantial container, nor a vague, drifting fantasy. It is precisely defined as: the measureless spatial extent that is unobstructed (无碍, anāvaraṇa) and devoid of self-nature (无自性, niḥsvabhāva). It is both one of the six fundamental elements (地 pṛthivī, earth; 水 ap, water; 火 tejas, fire; 风 vāyu, wind; 空 ākāśa, space; 识 vijñāna, consciousness) that constitute our body-mind and the material world, and the supreme simile for the intrinsic nature of all dharmas, the Tathāgata's dharma-body (法身, dharmakāya), and non-discriminating wisdom (无分别智, nirvikalpa-jñāna).
To thoroughly understand the space element, one must grasp it precisely at the two levels defined by the classical scriptures:
1. Constituents of Body and Mind: The Inner Space Element and the Outer Space Element
The classics divide the space element into the inner space element (内虚空界, adhyātma-ākāśa-dhātu) and the outer space element (外虚空界, bahirdhā-ākāśa-dhātu):
* Inner space element (内虚空界): refers to the space and cavities received and taken hold of within one's own body or another's body. Specifically, it means all the hollows and passages inside the body (such as the cavities of the nostrils, the oral cavity, the esophagus, the lumina of the stomach and intestines, the channels of the blood vessels, and even the minute interstices of the bone marrow, etc.)——that is, the empty apertures which the classics designate as falling within the "number of the aggregates" (阴数, i.e., the five aggregates 五蕴, pañcaskandha), the "number of the sense-fields" (入数, i.e., the twelve sense-fields 十二处, dvādaśāyatana), and the "number of the elements" (界数, i.e., the eighteen elements 十八界, aṣṭādaśa-dhātu). It is not a purely physical vacuum, but the unobstructed space that a living body must occupy and depend upon in order to maintain metabolism, respiration, and circulation. * Outer space element (外虚空界): refers to all places outside body and mind that are non-material (without material obstruction), up to the point where there is not even a hair's breadth of non-empty space.
In the *Madhyama-āgama* (《中阿含经》), when the Buddha directed the monks in cultivating "mindfulness of the body" and "contemplating the body as the body," he gave the famous "butcher dividing the cow" (屠儿分牛) simile:
就像一个熟练的屠夫杀牛之后，剥下牛皮铺在地上，将牛肉骨骼精准地剖分为各个部分；修行者观照自身时，也必须将这个被视为「我」的身体，解构剖析为地界（坚固性）、水界（湿润聚性能）、火界（温热代谢）、风界（推动气机）、空界（无碍孔隙）与识界（觉知心识）。 *"Just as a skilled butcher, after slaughtering a cow, flays it, spreads the hide on the ground, and precisely dissects the flesh and bones into their several parts; so too the practitioner, when contemplating his own body, must deconstruct and dissect this body taken as 'I' into the earth element (solidity), the water element (moisture and cohesion), the fire element (warmth and metabolism), the wind element (the driving of vital energy), the space element (unobstructed cavities), and the consciousness element (awareness and mind)."*
This dissection thoroughly shatters people's attachment to the idea that "this physical body is a single, undivided, substantially real self." Without the unobstructed passage of the inner space element, the stomach and intestines cannot churn, breath cannot enter and leave, blood cannot flow; without the accommodation of the outer space element, the body could not exist or move at all.
2. Supra-Physical Attributes and the Ultimate Simile
When elevated from the physical level to the ultimate (胜义, paramārtha) level——the level of dharma-nature (法性, dharmatā)——the space element reveals extremely profound attributes of non-arising and unobstructedness:
* Absence of self-nature and absence of substance: The space element "is not an existent dharma" (非是有法), and it is "neither male nor female"; because it is "without substance," it is spoken of as empty. It is not a fabricated thing, but a state that manifests because there is no material obstruction. * No arising or ceasing, no increase or decrease: Even if the world goes through formation, abiding, destruction, and emptiness (成住坏空), space itself has no arising, no burning, cannot be destroyed, and has neither weariness nor heat and distress; it has no thoughts of day and night, seasons, or kalpas. * Supremacy and identity with the dharma-body: In the *Avataṃsaka Sūtra* (《大方广佛华严经》) and the *Mahāratnakūṭa Sūtra* (《大宝积经》), the self-naturelessness and unobstructedness of the space element are used as the supreme simile for the Tathāgata's realm. The sūtra says: "如来即是虚空，虚空如来无二无别" (*The Tathāgata is space itself; space and the Tathāgata are non-dual and non-differentiated*). When the Tathāgata attains perfect awakening, he is able to obtain the "body equal to the space element" (虚空界等身), indicating that the awakened dharma-body is pervasively unobstructed and transcends language and characteristics.
Walking Through It in Daily Life
To avoid reducing the space element to an abstract philosophical term, we can walk it through, strictly according to the classical definition, using the most familiar daily scenes of contemporary people:
Scenario One: The Morning Rush-Hour Subway Crush and the Body's Gasp for Air
Mapping of the contemporary experience: You are squeezed into a full subway car during the morning rush hour, body against body, person packed against person. You feel intensely oppressed and blurt out: "This space is way too cramped——it's crushing me!"
* Where people most commonly map it wrong: They take "space" to be the iron box of the subway car, and their own body to be a dense, solid lump of flesh. * The correct walk-through according to the classical definition: * Inner space element (内虚空界): When you feel tight-chested and take a deep breath, the air passes through the nasal cavity, the throat, the trachea, and into the alveoli——the cavities of these passages and air sacs are your body's "inner space element." If your intestines were obstructed or your blood vessels blocked, that would be a disorder of the inner space element. It is precisely because these unobstructed apertures exist within the body that the vital energy and blood of life, and the taking in and letting out of breath, become possible. * Outer space element (外虚空界): The gaps between two people's bodies in the car——even the space beyond the cell gaps that the naked eye cannot see——are the "outer space element." * Contemplative observation and breaking attachment: Through the contemplation of the "butcher dividing the cow," you discover that the so-called "my body" is nothing but a brief interweaving of the earth element (flesh and bone), the water element (bodily fluids), the fire element (body heat), and the wind element (breath), taking place in the cavities of the "inner space element" by way of the space of the "outer space element." Your fear of oppression comes from a rigid grasping at the "substantial reality of the physical body."
Scenario Two: Scrolling Your Phone, a Full Cloud Drive, and Algorithmic Life
Mapping of the contemporary experience: Your phone pops up a notification: "Storage space full. Please clear WeChat cache or upgrade your cloud storage." You look at the screen full of photos, videos, and documents, and feel agitated.
* Contemporary experiential counterpart (AI/information age): The "storage space" of the digital age offers us an excellent physical analogy. Whether your hard drive is 128 GB or 1 TB, the physical chip itself (the silicon wafer) cannot store any data unless there is an "unobstructed writable region" of charge states. * The correct walk-through according to the classical definition: The fact that information can be written in essentially depends on "unobstructedness." If the chip's circuits are physically destroyed (full, short-circuited), it loses its capacity to contain. However, it must be pointed out where the scientific analogy is limited and unresolved: the storage space of a contemporary computer is a finite set of physical states (the magnetic-medium/capacitor states of 0s and 1s); it arises and ceases, it has a capacity limit; whereas the "space element" in the Buddha-dharma is boundless, beyond arising and ceasing, and devoid of self-nature. When a phone's memory is full it must be deleted (there is increase and decrease), but the space element itself neither decreases when filled with objects nor increases when objects disappear.
Scenario Three: The Suffocation of Intimacy and "Giving Each Other Some Space"
Mapping of the contemporary experience: In a romantic relationship or marriage, one party tries to control the other's every itinerary, WeChat record, and social circle. The controlled party feels "suffocated" and yells: "Can you give me some space?!"
* Where people most commonly map it wrong: They mistake "psychological space" for some kind of physical distance (such as sleeping in separate rooms, or taking independent trips). * The correct walk-through according to the classical definition: The suffering in a relationship arises because both parties take the other and themselves to be stubborn "entities" (material dharmas with self-nature, 有自性的色法), trying to collide with and squeeze the other through their own desire for control. At the ultimate level, the bodhisattva seals all dharmas with the space seal (虚空印, ākāśa-mudrā)——space has no mark, no mark of conditioned things, no mark of language. If one understands the "absence of self-nature" and "unobstructedness" of the space element, one will understand: true unobstructedness is not physical separation, but the mind's non-attachment to phenomena. The bodhisattva contemplates all dharmas as like space, yet with regard to the "space element" itself he also "dwells nowhere" (无所住). In a relationship, not fixing the other person as "my person," not fixing the relationship as "my possession," not clinging to some fixed mark——this is the "space element" that is unobstructedly penetrated at the level of wisdom.
Why Contemporary People Need It
Contemporary life is saturated with "overcrowding" and "anxiety about substantiality."
1. Dissolving the mental attrition produced by "substantialization": Contemporary people habitually substantialize every concept——turning "career" into a solid mountain that must be climbed, "age" into a solid burden pressing down on the body, "self" into a solid fortress that must never be harmed. This inertia of "substantializing" body-mind and external circumstances produces endless anxiety and collision. The wisdom of the space element reminds us: the nature of all things is, like space, devoid of self-nature. The arising, unfolding, development, and destruction of the world (成住坏空, formation, abiding, destruction, emptiness) are like clouds gathering and scattering in the sky. Space has never been wounded by a sky full of dark clouds, nor has it increased by a clear sky of ten thousand miles. Penetrating the space element enables people, when faced with life's upheavals, to gain a confidence that is not destroyed by circumstances.
2. Establishing a "butcher dividing the cow" deconstructive perspective: When we face the body's illness, aging, and loss of control, we often sink into deep fear. If, as the classics teach, we can deconstruct the body into earth, water, fire, wind, space, and consciousness, realizing that the body is but a temporary combination of these elements, and that most of its space is nothing but the "inner space element," we will not fall into a rigid, single-minded attachment to the flesh, and can thereby establish a transcendent capacity for awareness.
3. Reaching the universally unobstructed "space wisdom" (虚空智, ākāśa-jñāna): In the age of algorithmic recommendation and information cocoons, contemporary minds are being sliced ever narrower, and it is all too easy to fall into binary, oppositional abuse and bigotry. The *Avataṃsaka Sūtra* uses "equal to the space element" (虚空界等) to measure the Buddha's samādhi (三昧) and wisdom. If the mind's capacity is like space, it can contain all difference and impermanence, and thereby attain the "subtle wisdom" (微细智, sūkṣma-jñāna)——the space wisdom——that transcends binary opposition.
Common Misreadings and Clarifications
Misreading One: Equating the Space Element with Physics' "Physical Vacuum" or "Outer Space"
* Clarification: The "vacuum" of physics still has quantum fluctuations and zero-point energy in quantum field theory; it is part of physical spacetime. Outer space, likewise, is a locus where material dharmas (matter and radiation) are distributed. The space element in the Buddha-dharma includes the unobstructedness of physical space (inner/outer space element), but its more central connotation is the ultimate characteristic of absence of self-nature, absence of substance, and being a non-existent dharma (非有法). It cannot be reduced to any physical medium or particle field.
Misreading Two: Believing That the Space Element Is Annihilationist Emptiness, a "Nothingness" in Which Nothing Exists
* Clarification: The classics clearly state that although the space element is "spoken of as empty because it has no substance," it is not the annihilationism of nihilism. It is the manifestation of unobstructedness——precisely because space is unobstructed and devoid of self-nature, all things (earth, water, fire, wind) can arise and operate within it; precisely because the space element is beyond arising and ceasing, the Tathāgata's bodhi (菩提) and dharma-body can be universally pervasive and constantly without increase or decrease. It is the unobstructedness that "can contain all existents," not the nothingness that "cancels all existents."
Misreading Three: Confusing the Inner Space Element with "Psychological Space/Thoughts"
* Clarification: In the precise definitions of the Abhidharma (阿毗达磨) and the Āgama (阿含) scriptures, the "inner space element" belongs to the unobstructed apertures of the material/space category (色法, rūpa-dharma)——such as the cavities of the body's organs and the interstices of the bone marrow——and is the physical/physiological condition for the maintenance and functioning of the living body; whereas psychological activities, thoughts, and emotions belong to the "mind dharmas" (心法, citta-dharma) and "mental factors" (心所法, caitta-dharma) (such as the perception aggregate 想蕴, saṃjñā-skandha, the formation aggregate 行蕴, saṃskāra-skandha, and the consciousness element 识界). One must never blur, narrow, or inflate the "inner space element," which has a clear physiological mapping in the classical lists, into "inner feelings" in the modern psychological sense.
Misreading Four: Thinking That Contemplating Space Means "Dwelling in Space"
* Clarification: The *Mahāratnakūṭa Sūtra* (《大宝积经》) specifically warns: when the bodhisattva is practicing, although he observes all dharmas as like space, with regard to the "space element" itself he must also "dwell nowhere" (无所住). If one clings to a realm called "space," or even indulges in experiencing the pure clarity of space, one falls into a secondary attachment to emptiness (空执, clinging to emptiness). Only by not dwelling on the space element either can one truly give rise to the equal, unobstructed wisdom and the vast compassionate mind that delivers sentient beings.