What This Concept Is About
In the six-cause system (六因, ṣaḍ-hetavaḥ) unfolded in the *Abhidharmakośa-bhāṣya* (阿毘達磨俱舍論), 能作因 (kāraṇa-hetu, the "capable cause") is listed first. It is also the largest and most wide-ranging compartment in the entire system—the one most likely to surprise. One sentence defines it:
能作因者，除自体外，于他法生位不障碍之一切法。 *"The kāraṇa-hetu is: all dharmas which, apart from their own substance, at the moment of another dharma's arising, do not obstruct it."*
That is, when some thing A is arising (note: "in that very instant of arising"), everything except A itself—all the myriad things that have not blocked A's appearance—are simultaneously A's kāraṇa-hetu. The marvel of this definition is that it does not ask "what brought A into being" but "what did not block A." The latter is far more permissive than the former, which is why this slot of causation is so full.
The treatise summarizes this slot in a verse (頌文): 「除自余能作」—"Apart from self, the rest are capable causes." All conditioned dharmas (有為法, saṃskṛta-dharma), apart from their own substance, can be kāraṇa-hetu for the rest. If you are unfamiliar with conditioned phenomena: simply put, anything that arises through causes and conditions and perishes moment to moment is conditioned; the opposite, 無為法 (asaṃskṛta-dharma, unconditioned phenomena), refers to what neither arises nor ceases and undergoes no fabrication or change. The deciding criterion is the three characters 「無障住」—"non-obstruction abiding": when other things do not block A's arising, A establishes its cause through this "non-obstruction."
Reading the definition alone, one might feel it is a bit slippery: "Not blocking counts as a cause? Then anything I do has the whole universe as its cause?" To dispel this doubt, the treatise first gives two similes, then answers directly.
First simile: a ruler who does not harm his people. A sovereign holds the power of punishment and can inflict calamity; but as long as he does not exercise that power and does not harm his subjects, all their "comfortable" life—eating, marriage, daily rhythm, livelihood—can, in causal analysis, be attributed to his "non-harming," and calling him the "cause of their comfort" is not inappropriate.
Second simile: a powerless ruler. Extend the thought: even if this ruler has no wish to harm anyone, because he has no real governing power, he truly does nothing. Yet as long as he logically does not become an obstruction to his subjects' happiness, this causal chain still holds.
Together these two similes make three points:
1. The bar for establishing a cause is very low—merely not obstructing is enough; one need not actively promote. 2. A dharma that by nature could create obstruction, even if it never actually obstructs, is still established as a cause in causal analysis. 3. Establishing a cause and "personally producing" are not the same thing and must be kept separate.
But the treatise does not thereby reduce kāraṇa-hetu to a purely empty, effortless spectator. It immediately adds: those with conspicuous function—kāraṇa-hetu is not entirely without generative power. For example, the eye faculty (眼根, cakṣur-indriya) and visible form (色塵, rūpa) for the arising of eye consciousness (眼識, cakṣur-vijñāna), food and drink for the maintenance of the body, seeds for the sprouting of shoots—these are the "more substantial" roles within kāraṇa-hetu: not merely non-obstructing but having a relatively strong direct promoting function. Another view is more thoroughgoing, holding that all kāraṇa-hetu can, through successive relations, possess promoting power.
Time scope: pervading the three times and the non-temporal. The verse does not explicitly state which time-period kāraṇa-hetu belongs to; the treatise determines by meaning that it 「通三世非世」—"pervades the three times and the non-temporal": it extends across past, present, and future, and also includes what does not belong to the three times (i.e., unconditioned dharmas). That kāraṇa-hetu is established across the three times and admits the unconditioned lays the groundwork for the later discussion of the unconditioned's causal position.
The position of unconditioned dharmas (a point of dispute). This is the most interesting part. On one hand the treatise says: unconditioned dharmas have no six causes, no five fruits (五果, pañca-phalāni); 擇滅 (pratisaṃkhyā-nirodha, the quiescence realized by liberation) is not "produced" by the power of the path but merely realized by it. Seen this way, the unconditioned seems outside the causal system. But the same passage also says: by the standard of "not obstructing at another's arising," the unconditioned dharmas such as 虛空 (ākāśa, space) and 非擇滅 (apratisaṃkhyā-nirodha, cessation not through discernment) can also become kāraṇa-hetu. The unconditioned's "non-obstruction" can also establish a cause. Yet the unconditioned neither takes fruit nor gives fruit, so although it can serve as kāraṇa-hetu, it has no 增上果 (adhipati-phala, dominant fruit). At the same time, the text records a dissenting view from the 經部 (Sautrāntika, the "Scripture" school), unlike the 說一切有部 (Sarvāstivāda, the "All-Existence" school): the unconditioned is fundamentally not a cause at all, because the unconditioned is neither arising nor ceasing and has no "moment of arising" to speak of. The treatise makes no sectarian ruling; it leaves this dissent and the mutual objections on the table for scholars to adjudicate themselves.
Correspondence with the dominant condition and dominant fruit. In another set of terms in the *Kośa*—the four-condition system (四緣, catvāraḥ pratyayāḥ)—「增上緣」 (adhipati-pratyaya, dominant condition) corresponds exactly to the kāraṇa-hetu here. The treatise puts it bluntly: 「增上緣性即能作因」—"the nature of the dominant condition is precisely the kāraṇa-hetu." In other words, what is called "kāraṇa-hetu" in the six-cause system is called "dominant condition" in the four-condition system: different names, same substance. In the fruit system, what the kāraṇa-hetu obtains is the 「增上果」 (adhipati-phala, dominant fruit). What does "dominant" (增上) mean? The first layer of meaning is "non-obstruction"—being dominant need not be a thunderous, powerful augmentation; it can also be a clean and clear non-obstruction. At the same time, it may also have a more conspicuous or successive augmenting function.
The five causes of the great elements toward derived matter—a concrete form. In the treatise's concrete analysis, the most frequently cited example of kāraṇa-hetu is the relation of the four great elements (四大, mahābhūta: earth, water, fire, wind) toward 所造色 (bhautika-rūpa, derived matter, i.e., all material dharmas produced from the four great elements). This relation is subdivided into five functions: 「生、依、立、持、養」:
- 生 (birth): causing derived matter to arise; - 依 (dependence): following along with the great elements; - 立 (establishment): supporting so that it becomes established; - 持 (maintenance): keeping it from being interrupted; - 養 (nourishment): making it grow.
Taken together, these can be summarized by five characters: 「起、變、持、住、長」—"arising, transforming, sustaining, abiding, growing." The reason one cause is split into five is not to complicate matters but to let students see: even the kāraṇa-hetu that appears to be merely "non-obstruction," when its function is especially conspicuous, can be decomposed into multiple specific facets. As for the kāraṇa-hetu relation among derived matters themselves, the treatise says "無差別轉"—they operate without discernible difference, so the differences are too slight to count separately.
Its position in the path of liberation. The decomposition of causes, from the *Kośa* to Yogācāra, ultimately serves to make clear the basis to which "self" is attached—the so-called "self" is merely a nominal designation (假名, prajñapti) established in dependence upon a web of conditions. As the widest slot, kāraṇa-hetu is the final net that catches everything when the work of decomposing "cause" is done: when we have exhausted the fine-grained divisions of 俱有因 (sahabhū-hetu, coexistent cause), 同類因 (sabhāga-hetu, homogeneous cause), 相應因 (samprayukta-hetu, associated cause), 遍行因 (sarvatraga-hetu, pervasive cause), and 異熟因 (vipāka-hetu, retributive cause), and look back at the world, a vast stretch of "that which did not obstruct" is still present. What it decomposes is not any one specific thing but the layer of cognition that "everything depends on an entire background that set up no checkpoints"—this is precisely a foundational support for the stability of the view of no-self (無我, anātman).
A Walkthrough in Daily Life
To grasp kāraṇa-hetu, the fastest way is to return to a concrete scene and walk through the meaning of "non-obstruction" step by step.
Scene one: this morning you woke up normally and went to work on time.
This scene seems ordinary, but following the verse's meaning: this morning, as long as your body opened its eyes on time and stepped out the door—apart from your body itself—nearly all the presently operating things around you became kāraṇa-hetu for your going out: the neighbor did not pile renovation debris at your door (non-obstruction), the property management did not do construction in the elevator you were waiting for (non-obstruction), the weather did not suddenly bring a downpour (non-obstruction), the scheduled subway station did not suddenly close (non-obstruction), the company did not suddenly shut down collectively today (non-obstruction)… All these "things that did not happen," at the moment you smoothly left the house, participated in the event through "not constituting an obstruction."
Note: it is not that the neighbor, property management, weather, subway, or company "caused" you to go out; rather, none of them came to block you. This is a cause of "open possibility"—kāraṇa-hetu is especially suited to naming this kind of thing.
Scene two: you cooked a table of food for friends, and you all chatted late into the night.
At the table there was edible food, drinkable water, chairs to sit on, topics to open, and space to hold your gathering—all of these accomplished this gathering through "not obstructing." If one link—say, a sudden power outage—had actually occurred, the gathering would have stalled; but it did not occur, and this "non-occurrence" participated in the pleasantness of your evening through "non-obstruction." This is not mysterious—the treatise's simile of "the ruler who does not harm his people" means exactly this: the ruler need not cook for every citizen every day; he only needs to issue no prohibitions and not damage infrastructure. His "not doing" is already a cause of the people's comfortable life.
Scene three: a long-term intimate relationship between you and your partner.
In an intimate relationship, the fact that both parties are willing to stay together rests on countless "things that did not become obstacles": you did not say the cruel words at the critical moment that would have broken the relationship, you did not pull the other person into a pattern that kept harming them, you did not suddenly disappear at an important occasion… These "non-occurrences" are just as much causes of the relationship's continuation as the sweet words you can say, the resources you can provide, and your support for the other's career. In this wisdom, the weight of "not harming" in an intimate relationship is often no less than "active giving." It is often underestimated because it is silent and looks like "doing nothing"; but without it, no amount of sweet words can make up the difference.
Scene four: you scrolled your phone all night and woke up the next day in a daze.
If someone asks "what made me dazed," we usually think only of "scrolling the phone"—the active side. But through the lens of kāraṇa-hetu, one would also ask: what things did not come to block? No friend suddenly called to get you out? No colleague sent an urgent email in the small hours? No power outage that woke a crying child? None of these interruptions happened—so "I scrolled continuously into the night" flowed downstream without any obstruction. This lesson is somewhat counterintuitive: often we fall into affliction because a vast stretch of "clean background" that could have interrupted but did not is silently wasted. At its conclusion, kāraṇa-hetu gently reminds us—the so-called "default non-action" sometimes bears far more causal weight than "active destruction."
Where the general public most easily errs mainly includes these points:
1. Narrowing "non-obstruction" to "irrelevance." We are used to thinking "I didn't cause trouble, that's enough." Kāraṇa-hetu reminds you: precisely because I did not cause trouble, your matter succeeded—there is a share of "not obstructing" here. 2. Equating kāraṇa-hetu entirely with "active production." The treatise specifically distinguishes: non-obstruction is not equal to personal production, but the personal producer is still a more conspicuous type within kāraṇa-hetu. In other words, kāraṇa-hetu includes both the strong personal producers and the silent presences that merely did not block. When we hear "cause," we think of the former and miss the latter. 3. Thinking "apart from self" is unimportant. This is the core of the verse. If "apart from self" were omitted, A would become its own cause, meaning "an already-existing dharma gets produced by itself again"—this violates the basic setting that the same dharma is not re-established in the same moment. So "apart from self" is a boundary that must be attended to, not glossed over.
Why Contemporary People Need It
The default thinking of contemporary people is to understand causality as "who pushed what"—more plainly, as what was done that led to what result. This kind of thinking resonates especially in individualism and competitive ethics: my achievements are my ability, my failures are my fault, and the overall functioning of society is the sum of a chain of individual efforts.
This kind of thinking has two blind spots it cannot see.
First, it makes us blind to the things that "did not happen." How many times does a project advance because no key person, at the most critical moment, gave up? This phenomenon is called in engineering culture a kind of "silent majority of no-faults"—no one stalls, so the thing succeeds. The "non-obstruction" criterion of kāraṇa-hetu essentially makes this implicit rule explicit: the reason a project succeeds includes that batch of people who did not block and their timing and fortune.
Second, it makes us place the entire weight of ethics on "what one actively does," ignoring the importance of "ceasing to do harm." If a culture defaults to the idea that all causality must be initiated by someone's active behavior, then behaviors like "staying quiet," "not getting involved," and "actively withdrawing from exploitative structures" have difficulty being empowered ethically. Buddhism from the very beginning established the fundamental precept 「不害」 (ahiṃsā, non-harming), precisely seeing the danger of active fabrication; and the *Kośa* makes this ethical foundation explicit through the slot of kāraṇa-hetu—"non-harming" is established as a cause at the root of the theory of causation. In other words: as long as one does not harm, one already occupies a slot in the enterprise of bringing ease to sentient beings.
Third, a repair for the contemporary spiritual condition. When kāraṇa-hetu is decomposed to the end, it stably points to an anti-self conclusion: the so-called "I" appears complete only when countless conditions that never became obstacles are gathered in one place. When we puff up over our achievements, kāraṇa-hetu quietly spreads out a list beside us—for an achievement to be established, it needs so many people who did not obstruct, an environment that did not obstruct, and fortune that did not obstruct. This quiet practice of deflating one's focus is a calm preparation before any fierce practice of "letting go."
As a comparison, one might mention something similar: modern network science, when describing "why a distributed system can complete a certain task," often distinguishes key "facilitators" from "neutral nodes"—if the former is missing the task collapses; if the latter is missing the task merely slows down slightly. Kāraṇa-hetu roughly corresponds to the causal version of these "neutral nodes"—it participates in the process by not obstructing, allowing the whole to proceed smoothly. But this is only an analogy, not an equivalence: Buddhist causality is a more thoroughgoing interdependence, whereas the nodes in systems science can still operate independently of one another; the two are only comparable in form, and one cannot say science has already "proved" kāraṇa-hetu.
Common Misreadings and Clarifications
Misreading one: kāraṇa-hetu = active production cause, mistaking "non-obstruction" for "doing nothing." This is the most common narrowing. The treatise specifically distinguishes: non-obstruction is not equal to personal production, but the personal producer is still a particularly conspicuous type within kāraṇa-hetu. In other words, kāraṇa-hetu includes both the strong personal producers and the silent presences that merely did not block. We generally hear "cause" and think of the former, thus missing the latter.
Misreading two: "All dharmas are kāraṇa-hetu" would imply "one person kills and everyone shares in the killing karma." The treatise addresses this directly: the establishment of kāraṇa-hetu uses "non-obstruction" as its criterion, not "all have generative power." So that stretch of dharmas merely did not block; they did not personally kill, let alone generate a murderous mind—how could they bear the killing karma? Responsibility is not contagious. This is a very important logical patch in this teaching, often overlooked.
Misreading three: The unconditioned is not a cause / the unconditioned is a cause—which school is right? To this day there is no sectarian consensus on this question. The Sarvāstivāda, based on the "non-obstruction" criterion, includes the unconditioned in kāraṇa-hetu while simultaneously admitting that the unconditioned has no function of taking or giving fruit; the Sautrāntika directly cuts the unconditioned out of the causes, holding that the unconditioned has no "moment of arising" to consider. When reading this passage in the *Kośa*, one should be clear that this is the Sarvāstivāda position coexisting with the Sautrāntika dissent, not a settled conclusion.
Misreading four: the dominant condition = kāraṇa-hetu, so "dominant" means "forceful promotion." The first layer of meaning of "dominant" (增上) is in fact "non-obstruction"—this is a special kind of "strength": not strength in function, but strength in not obstructing. The reason the ear and so forth appear to "promote" eye consciousness is still that they do not block the arising of eye consciousness; this "not blocking" in special contexts looks very much like "promotion," but its criterion remains "non-obstruction," unchanged.
Misreading five: kāraṇa-hetu = all of causation. Kāraṇa-hetu is only the first of the six causes; it is still one member of the cause family and cannot in turn reduce the other five causes (coexistent, homogeneous, associated, pervasive, retributive) to kāraṇa-hetu. Each of these five causes has its own criterion and special conditions of establishment; kāraṇa-hetu is only the "catch-all" broadest slot and cannot replace the fine-grained analysis of the other five.
Misreading six: the five causes of the great elements toward derived matter are the entire content of kāraṇa-hetu. This is an error of dragging an abstract concept back to a concrete physical form. The five causes "birth, dependence, establishment, maintenance, nourishment" are only the specific unfolding of kāraṇa-hetu in the relation of "the four great elements to derived matter." Kāraṇa-hetu itself is far larger than these five causes—it covers nearly all conditioned dharmas that did not become obstacles; the five causes are only one corner of it.
After reading all this, one should be able to feel: although the concept of kāraṇa-hetu is briefly defined, its content is by no means light. It is neither a vague "where there is a cause there must be an effect," nor the everyday imagination of "do something active and get something." With "non-obstruction" as its entry point, it quietly divides the world into two layers—"what was done" and "what did not block"—allowing us to see, in the broadest view, that an ordinary morning, a dinner that went off without a hitch, a sustained intimate relationship—behind each of them stands an entire stretch of conditions that did not block.
This is the most plain, and most easily missed, slot in the Buddhist view of causation. Plain, because its criterion is as simple as "did not block"; easily missed, because our default imagination of "cause" is too active, too focused, and is thus shut out by this very plainness.