A Chan/Zen concept for the deep, broad root‑nature that is *able* to bear sudden awakening, paired with 大用 (dàyòng, "great function"), the responsive operation that flows from it.
What this concept is actually saying
In Chan (禪) discourse 大機 is not a word for "smart," "experienced," or "well‑read." It is a precise technical term for an *inner* dimension of awakening: the root‑faculty capable of receiving and bearing the sudden, direct teaching of one's own nature. It is the fixed left half of a pair — 大機大用 (dàjī dàyòng, "great capacity and great function") — that Chan teachers use to describe the full flowering of a realized life. The pair is so consistent across the records that we can almost hear it as a single compound: a coin with two faces.
But the two faces are *not* the same face, and the distinction matters. Getting it wrong in either direction is what the classical teachers keep warning against.
The two faces, distinguished
大機 (dàjī) names the *inner* threshold: the depth and breadth of root‑nature that can be trusted to bear sudden awakening without breaking, without flinching, without re‑packaging it as something more familiar. It is a capacity that *erupts* — the Yuanwu record (《圓悟佛果禪師語錄》) is unambiguous: 大機要頓發, "the great capacity must erupt suddenly" (T1997). It is not built up; it breaks open.
大用 (dàyòng) names the *outer*, responsive operation: the way awakened nature acts in the world without forcing, the unforced skillful responsiveness that teaches, engages, and liberates. Yuanwu says it bluntly: 大用要直截 — "the great function must cut straight through."
The two interpenetrate. Yuanwu puts it as a mutual containment: 大機中有大用，大用中有大機 — "Within great capacity there is great function; within great function there is great capacity". They are not separable in principle. But in a given human life they can be unequally developed — and the classical records are explicit about what that imbalance looks like.
The classical verdict: 百丈得大機，黃檗得大用
The most concrete classical illustration is preserved in the *Records of Ancient Worthies* (《古尊宿語錄》) and the *Record of Yangshan Huiji* (《袁州仰山慧寂禪師語錄》). It is a working judgment by Yangshan Huiji (仰山慧寂) about how the awakening of their common teacher Mazu Daoyi (馬祖道一) showed up in his two foremost heirs.
溈山問：「馬祖出八84人善知識，幾人得大機？幾人得大用？」 仰山答：「百丈得大機，黃檗得大用，餘者盡是唱道之師。」
*Weishan asked: "Of the eighty‑four knowers of the way that Mazu produced, how many got the great capacity? How many got the great function?" Yangshan answered: "Baizhang got the great capacity, Huangbo got the great function; the rest were all 唱道之師 — singers of the way."*
Two points to hold clearly:
- Baizhang Huaihai (百丈懷海) is judged to have gotten 大機 — the deep, broad root‑faculty that can fully bear sudden awakening. This is an *inner* accomplishment: his root‑nature could hold the shock of ground‑less ground without recoiling. - Huangbo Xiyun (黃檗希運) is judged to have gotten 大用 — the responsive, sharp, public operation. Huangbo is famous for the thunder of his " shout," for the way he cut through Linji Yixuan (臨濟義玄) three times. He is a man whose awakening *acts*. - The remaining eighty‑odd disciples are called 唱道之師 / 唱導之師 — "singers/chanters of the way": teachers who can faithfully transmit teachings but lack either the inner eruption or the outer operation at the realized level.
This is not a ranking of who is "better." Baizhang and Huangbo are two expressions of one realization. The point of the verdict is structural: *the awakening that lies in the root and the awakening that acts in the world are not automatically the same thing, and Chan takes their difference seriously enough to give them separate names.*
A separate passage in the same record has Huangbo, hearing Baizhang retell a Mazu story, say: "Today, because of the elder's telling, I have *seen* Mazu's 大機大用, and yet I do not *know* Mazu" (《古尊宿語錄》, chunk 47887). Seeing the form of the thing is not yet the thing itself. This is also a comment on the gap between 機 and 用 — a gap that the rest of the tradition keeps probing.
The warning: 祇得大機，不得大用
This phrase is the signature teaching voice of Weishan Lingyou (溈山靈祐), the Tang Chan master who co‑founded the Guiyang school (溈仰宗) with Yangshan. He repeats it in his recorded discourses (《潭州溈山靈祐禪師語錄》) almost as a refrain. "Only having the great capacity, without the great function."
The structure of the warning is precise, and it does work on each term:
- 機 (jī, "capacity/faculty") — the root‑nature that is *able* to bear sudden awakening - 用 (yòng, "function") — that capacity *actually operating* in present verification and responsive action
The danger being named is subtle and common. You can have the wide root‑nature. You can feel in your bones that awakening is possible. You can carry a deep trust that things could break open at any moment. You can be the kind of person to whom the masters would nod and say "you could bear this." And still — not yet. The capacity is there, the function is not. 大機 alone is a *suspended* possibility, and it can be indefinitely suspended.
Weishan illustrates this with two contrasting vignettes, and they are worth reading slowly.
Vignette one — Yangshan. Yangshan hears his teacher's warning, then walks down the mountain to consult a hermit about it. He is trying to use language to sort out the difference between 大機 and 大用. The hermit simply says "Say it again," and the moment Yangshan opens his mouth to repeat the teacher's phrase, the hermit pushes him over. (《潭州溈山靈祐禪師語錄》, chunk 44487.)
The classical reading is precise: the attempt to *grasp* the distinction conceptually *is* the symptom of "only having 大機." The push is 大用 — it cuts off the conceptual chase at the level of the body. Yangshan, who later becomes one of the great Chan masters of the Tang, learns here that the gap between 機 and 用 cannot be closed by thinking about it. It can only be closed by being done.
Vignette two — Jiufeng. When Weishan delivers the same warning in the assembly hall, Jiufeng (九峯) gets up, walks out, and does not look back even when his teacher calls after him. Weishan immediately approves: 「此子堪為法器」 — "This one is fit to be a vessel of the dharma" (chunk 44494).
Jiufeng's unburdened exit *is* 大用 showing itself. There was no chase, no conceptual sorting, no attempt to understand. The moment called, and the moment answered. 大機 and 大用 were not two stages here; they were one event. The vignette of Yangshan being pushed over and the vignette of Jiufeng walking out are held together for a reason: they show the same realization from two angles — one that the body had to learn, and one that arose already trained.
This is why the entry pairs naturally with the famous verse of Xiangyan Zhixian (香嚴智閑): 「我有一機，瞬目視伊，若人不會，別喚沙彌」 — "I have one capacity: a flick of the eye to meet you. If you don't get it, I'll call the novice instead." (《潭州溈山靈祐禪師語錄》, chunk 44494.) In that flick, 機 and 用 are not separable. The capacity *is* the function; the function *is* the capacity. Weishan's warning is not against capacity as such, but against capacity that has not yet, or will not, become event.
Sudden eruption, not gradual accumulation
Yuanwu's record on 大機 is the densest in the Chan library, and it is emphatic on one point: 大機 is not earned.
大機要頓發 當機直下沒纖毫 直下懸崖撒手便可承當 第一機上實無如是事
"The great capacity must erupt suddenly." "Right at the moment, straight down, not a single fiber (of residue)." "Let go off the cliff's edge straight down, and you can bear it." "On the first 機 there is actually no such thing" — no upstairs, no downstairs, no buddha, no ancestor.
The "first 機" (第一機) language here sits in the same Chan family as the well‑known rhetoric of "before the brush has touched the paper" (筆未點時) and the Yunmen "first phrase" tradition — that place where conceptual elaboration has not yet begun. Yuanwu is saying: at the moment of 大機, there is no object to stand on, no ladder of stages, no comparison to be made. Either it erupts now or it does not. Trying to climb toward it is already a different thing.
The phrase 直下懸崖撒手 ("let go straight off the cliff") is the same insight that the Diamond Sutra (《金剛經》) articulates, in a different register and a different text, as 應無所住而生其心 — "Give rise to a mind that does not abide anywhere." That famous line is not about 大機 by name, but it describes the same gesture: the moment the mind is not anchored in any particular position, awakening can occur there. The canonical vocabulary differs; the threshold is the same.
What this means practically is that 大機 cannot be produced by any program of self‑improvement. Meditation, study, koan work, retreat, ethical discipline — these can prepare the ground, can thin out the obstacles, can ripen the conditions — but 大機 as such *erupts*. Yuanwu uses the verb 奮 ("to rouse with effort") in 奮大機 (chunk 38983) but it is a rousing that runs counter to effort as ordinarily understood: a sudden, decisive willingness that is closer to falling than to climbing.
Sharpness and dullness — both can become obstacles
One of the most quietly radical moves on this concept comes from Dahui Zonggao (大慧普覺禪師) in his record (《大慧普覺禪師語錄》, T1998A, chunk 40655). Dahui is the great Song‑dynasty advocate of *kanhua Chan* (看話禪) — investigation of the critical phrase — and he pushes against the assumption that 大機 belongs to the intellectually brilliant.
利根者知見太多，宗師纔開口便從聰明知解上領會，因而於本分事上不得力；鈍根者少有惡知惡覺，反可能在「一機一境上一言一句下撞發」，達到無道理可障的地步。
"Those with sharp faculties have too many views. The moment a master opens his mouth, they grasp it through clever knowing, and so they have no power in the real matter. Those with dull faculties have fewer bad views and bad understandings. They may, at one capacity, one circumstance, one phrase, one word, collide with it and burst through, reaching a place no reasoning can block."
Dahui's conclusion is stark and quietly democratizing: 取捨利鈍在人不在心 — "Choosing or rejecting sharp and dull is in the person, not in the mind." The one mind is neither sharp nor dull; the demand that you become "sharp" enough to awaken is itself, frequently, the obstacle.
He makes a related distinction that is worth holding onto, using the Buddhist epistemological pair 現量 / 比量:
- 現量 (xiànliàng, "direct present perception") — realization that has come from the direct. Its 氣力 is 麁 ("coarse" in the sense of *strong*, able to bear weight). It can enter the buddha‑realm *and* the demon‑realm — neither side breaks it. - 比量 (bǐliàng, "inferential / comparative perception") — realization that has come through inference, comparison, conceptual reconstruction. Its 氣力 is 弱 ("weak"). It can sustain the buddha‑realm but collapses in the demon‑realm (chunk 40445).
This is a Chan working definition of what 大機 actually *is*, beneath the name: not cleverness, not eloquence, not even conceptual fidelity, but a kind of inner weight that holds under pressure. Whether that weight erupts in someone conventionally brilliant or someone conventionally ordinary, the name does not care. It only cares about the bearing.
Where 大機 sits in the larger path of liberation
In the rough architecture of the Chan path, 大機 names a specific node. It is not the first beginning, not the final stabilization. It is the threshold of genuine encounter with one's own nature, the moment the root‑nature has been prepared and ripened enough that awakening *could* happen — and is then the *event* of awakening if it does.
A very rough map:
1. 發心 (fāxīn) — arousing the mind of awakening. The first resolve. 2. 修學 (xiūxué) — study, training, doubt, ripening. The long middle. 3. 大機 — the capacity erupts; the threshold is crossed. 4. 大用 — the function responds; awakening acts in the world. 5. 圓證 (yuánzhèng) — full verification; the integration of capacity and function in everyday life.
The classical Chan verdict is not "either/or" but "neither without the other." 大機 without 大用 is the suspended possibility Weishan warned against. 大用 without 大機 is the operation without the root, which can run for a long time and then shatter under the first real pressure.
Vocabulary across the records
Because the entry covers five different Chan records, the terms vary — and the variation is itself informative about the phenomenon being named:
- 《古尊宿語錄》: 大機大用 as a fixed pair; 發大機 as a verb ("to issue forth the great capacity"); 唱道之師. - 《潭州溈山靈祐禪師語錄》: 祇得大機，不得大用 as the only signature formulation; no synonyms. - 《袁州仰山慧寂禪師語錄: shares 大機大用 with the 古尊宿語錄; uses 唱導之師 (a slight variant). - 《圓悟佛果禪師語錄: the richest vocabulary — 顯大機, 明大機, 發大機, 奮大機, 大機要頓發, 第一機, 大機中有大用; for the people who bear it, terms like 利根上智之人, 上根大器, 有夙根, 倜儻漢. - 《大慧普覺禪師語錄**: does *not* use 大機 as a standalone defined term; uses 大根大器大力量, 大機大用大解脫, and the explicit 利根/鈍根 discussion.
What you can hear across these is that 大機 is one term for a phenomenon Chan teachers describe from many angles, all circling the same knot. The knot is the difference between being the kind of person who *could* awaken — and being the kind of person who *has*.
Walking it through in contemporary life
To keep the concept honest, we have to be strict in the mapping. 大機 is not "I had a spiritual insight." It is not "I read a book that explained everything." It is not "I've been meditating for fifteen years." It is the *root‑capacity that can bear sudden awakening, erupting now.* So the walkthrough has to use scenes where these distinctions actually matter, and where people commonly map them wrong.
Scene one: the meditator‑reader
Imagine a serious practitioner who has read widely — Pali suttas, Zen, Dzogchen, contemporary phenomenology of meditation — and who has sat, on and off, for a decade. They can articulate, with great precision, what non‑self is supposed to mean, what emptiness does and does not entail, what is meant by "no‑self" vs. "small self," and they can hold their own in sophisticated conversation about experience. In the Chan vocabulary, this is a person with a refined *intellectual map* of awakening.
If you ask this practitioner whether they are "awake," they will say something honest and accurate: they don't know. There have been moments, sometimes, on retreat — the moment after a long sit when the body was just the body and the mind was just the mind — where everything for a second fell away. They can describe those moments clearly, and the descriptions are not inflated.
Now apply the Chan lens. The capacity (機) is there, possibly in real form. The root‑nature may be ready. But the operation (用) — the moment the realization *acts*, cuts, liberates without a trace — has not yet become consistent. Worse, the very sophistication of the conceptual map can become a kind of *false 大機*: the person experiences "I understand this" as identical with "I am this," and stops. Dahui's diagnosis of the sharp‑facultied person is exact here.
Where people commonly map wrong: they assume the long list of books and the clarity of explanation *is* the capacity. The Chan records are unanimous: it isn't. 大機 is *eruptive*, not cumulative. You cannot add up enough right understanding to cross the threshold; the threshold is crossed, or it isn't.
Scene two: the startup founder
Different register, same structure. A founder has a vision — a felt sense of how a domain could be reorganized — that is unusually clear and unusually early. Investors, employees, and competitors who meet them often report the same feeling: this person *sees something I don't see*. This is, in the colloquial sense, a person with 大機: their root‑nature has access to a pattern that the environment has not yet formalized.
But 大機 without 大用 is a vision that never makes it out of the founder's head. The most common failure mode in early‑stage companies is not "no good idea" but "good idea that cannot be communicated, cannot be hired for, cannot be turned into an organization." That is precisely Weishan's warning: 祇得大機，不得大用. The hermit on the mountain would push this founder over too, the moment they started explaining.
The Dahui point is also live here: the founders most prone to "祇得大機" are often the smartest in the room. Their sharpness lets them substitute *talking about* the vision for *operating* the vision. A dumber, more stubborn founder who simply *does* — talks less, builds more, hires the obvious next hire — may carry less conceptual 大機 but more embodied 大用.
Where people commonly map wrong: equating 大機 with "having a vision." Having a vision is necessary but not sufficient; 大機 specifically names the *capacity that can bear what the vision will require of you*, which is different from the capacity to articulate it.
Scene three: the therapist or teacher
A seasoned therapist can read a person in the first five minutes. They can name the defense, name the attachment pattern, name the developmental wound. They have a felt sense of where this person is stuck. In supervision conversations they describe this with extraordinary precision. In the Chan frame, this is a person with a high degree of *diagnostic 大機*: their root‑nature has access to patterns the client cannot see.
But therapeutic 大機 is only useful if it can become 大用: if the *seeing* can land in the client's body in a way that actually moves something. Some therapists can name everything and the client feels only mildly seen. Some therapists can hardly name anything and the client weeps on the couch in the second session. Weishan's two vignettes — Yangshan being pushed over, Jiufeng walking out — are both about the gap between the analytic grasp of the situation and the embodied gesture that actually moves it.
This is also where Dahui's 現量/比量 distinction is clinically useful. The therapist who works primarily from 比量 (comparative, inferential, drawing on training cases) can hold the buddha‑realm — they can sit with the long‑term client making slow, predictable progress. The moment the unexpected 50‑year‑old walks in with the trauma they've never spoken about, the inferential framework cracks. The therapist who has access to 現量 — a direct, pre‑conceptual reading of the person in front of them — has 氣力麁 and can enter either realm.
Where people commonly map wrong: assuming that having more *information* about human nature equals having 大機. The classical Chan vocabulary is precise — 知見 (conceptual views) can *prevent* the eruption, even when they are accurate views.
Scene four: the long‑term couple
Two people have been together for twenty years. One of them, often quietly, sees *much further ahead* in the relationship than the other — can feel where a fight is going before it gets there, can name the pattern underneath the pattern, can hold the whole shape of a long history in a single glance. This is the partner with 大機.
The other partner, possibly less articulate about the relationship as a system, is the one who *does* — who makes the phone call after the fight, who cooks the meal that lands, who moves the body in the right direction at the right moment. This is the partner with 大用.
Couples who last are almost always those in whom both capacities exist, even if unequally distributed. Couples who break are often those where one partner has 大機 without 大用 ("I see exactly what is happening and I cannot make a single thing change") or, more painfully, where one partner has 大用 that has run out of 大機 — operating on momentum, with the root now dry. Weishan's two vignettes here: one partner who has to learn the bodied lesson (Yangshan), one partner who already moves without residue (Jiufeng). Both are forms of 大用; the second cannot be willed by the first.
Where people commonly map wrong: thinking that "intimacy" means being the one with the deeper seeing. In the Chan frame, intimacy is 機用合一 — capacity and function as one event. That can show up as the deeper seeing, or as the gesture that lands, or, most often, as a long‑practiced alternation between them.
Scene five: the "ordinary" practitioner
A person starts meditating in their forties after a divorce. They have no prior exposure to Buddhism, no philosophical training, no particular talent for introspection. They sit. They do not understand the koan they are given. They keep sitting. Six months in, during a routine sit at the kitchen table before work, something breaks — there is no story, no insight, no description that survives. What remains afterward is quieter, more ordinary, and more useful to other people than anything they have been before.
This is the Dahui case. The dull‑facultied practitioner with fewer bad views and bad understandings, who collides with the thing at "one capacity, one circumstance, one phrase, one word" (一機一境, 一言一句) and bursts through to a place no reasoning can block. The classical Chan verdict is unambiguous: this person, in this moment, has 大機. The fact that they cannot tell you what just happened, cannot cite a scripture about it, cannot defend it in a debate, is irrelevant — in fact, it is the diagnostic. If they could tell you, the diagnostic would tilt toward 比量.
The contemporary consequence: the meditator‑reader in Scene one, and the "ordinary" practitioner in Scene five, may have arrived at structurally similar moments of 大機, but the route was completely different. The classical frame holds both without ranking.
Where people commonly map wrong: assuming that the *narrative* of spiritual attainment (years of practice, training lineage, articulate insight) is the same as 大機. It can correlate. It can also obstruct. The Chan records keep both possibilities live.
Scene six: when sharpness is the obstacle
A senior engineer at a major tech company. Diagnostically sharp — sees systems, sees failure modes, sees organizational pathologies. Their sharpness is what got them promoted. They sit down to meditate and the sharpness turns immediately into *analytical commentary on their own experience*: noting, framing, evaluating, comparing to prior states, generating a model of what awakening *would* look like. The noting itself prevents what it is trying to note.
This is the case Dahui names directly. 利根者知見太多 — the sharp‑facultied person whose very sharpness has built the obstacle. 鈍根者少有惡知惡覺 — the dull‑facultied person who may have less to *unlearn* and can therefore, in some cases, collide with the thing faster.
The contemporary fix is not "become dumber." It is the strange discipline of putting the sharpness down — not forever, not by denigrating it, but in the specific domain of practice. The Dahui line 取捨利鈍在人不在心 ("choosing or rejecting sharp and dull is in the person, not in the mind") is a warning against making your spiritual practice into another meritocracy.
Why contemporaries need this concept
Three reasons, briefly.
First, modern life is a 比量‑saturated environment. We are constantly in the mode of comparison, inference, conceptual reconstruction. Algorithms are trained on the same. The workplace increasingly rewards the *capacity to articulate* a position over the *capacity to bear* a situation. The Chan concept of 大機 names exactly the thing that this environment tends to atrophy: a root‑capacity that can bear pressure without needing to be redescribed in the moment of pressure. 大機 is, in a precise sense, an antidote to the virtualization of life.
Second, the democratizing move of Dahui — that sharp can obstruct and dull can break through — is genuinely needed in a culture that has turned spiritual attainment into a meritocracy. The meditator‑reader, the articulate dharma teacher, the eloquent retreat guide: these are the people our culture *recognizes* as spiritually advanced. The Chan concept of 大機 says: not necessarily, and the recognition itself may be part of what is in the way. The "ordinary" practitioner in Scene five has a structural legitimacy that our cultural narratives tend to deny.
Third, and most concretely, 大機 paired with 大用 names something modern people privately long for and rarely find: the *integrity* of inner root and outer response. We meet people whose root is dry but who operate brilliantly (大用 without 大機), and people whose seeing is deep but who can do nothing (大機 without 大用), and very few people in whom the two are one event. The concept names a kind of person we want to be around, and a kind of person we want to become — without telling us how to acquire it, which is precisely its function.
A note on AI, briefly, because it will come up. Contemporary language sometimes reaches for "capacity" and "function" in describing neural networks: a model's *capacity* (its architecture, parameter count, training) and its *function* (what it does on a given prompt). The Chan concept of 大機 is not that, and the analogy should not be pressed. A model's "capacity" is built by training, scaled by data, and is observable in its outputs. 大機 is built by ripening, scaled by no metric, and is observable precisely when it *stops being observable as an output*. Treating 大機 as a property that can be trained into a system, or scaled by data, misses the entire point. If the analogy is useful at all, it is in the failure mode: a system that has great capacity but no function is *running but not yet doing anything*; a system that has great function but no capacity will eventually collapse under distribution shift. Chan would say the same about people, with the additional note that neither side is fixable by adding more parameters.
The same caveat applies to neuroscience. The brain does have latent capacities and active operations, and contemporary neuroscience has a great deal to say about plasticity, latent neural pathways, and the difference between implicit and explicit processing. None of this *is* 大機; all of it is a useful partial analogy for the *shape* of the distinction Chan is drawing. The classical Chan claim is that the threshold itself is not a neural state but a *mode of recognizing*, and that mode is not in any current neuroscience textbook under that name.
Common misreadings and clarifications
Misreading 1: 大機 means "intelligent" or "well‑read." It doesn't. Dahui is explicit that 知見 (conceptual views) can obstruct 大機 even when those views are accurate. The meditator‑reader in Scene one is the standing refutation of this misreading. 大機 names a kind of *bearing*, not a kind of *knowing*.
Misreading 2: 大機 means "senior years of practice." It doesn't, necessarily. Weishan's Jiufeng can erupt and walk out *now*; a thirty‑year practitioner can remain in the suspended state of 祇得大機，不得大用 for the entire thirty years. The classical frame is precise: 大機 *erupts*, it does not accumulate. Time spent in practice can ripen the conditions for the eruption; it cannot substitute for the eruption.
Misreading 3: 大機 is the same as 大用. This is the most subtle misreading, because the two really are mutually containing. 大機中有大用，大用中有大機 (Yuanwu). But they are not identical, and the distinction is what allows Weishan to diagnose 祇得大機，不得大用 as a real failure mode. 大機 is the *capacity*, 大用 is the *event*. The Jiufeng vignette shows the two as one event; the Yangshan vignette shows them as a capacity that has not yet become the event. Both are Chan; only the second is incomplete.
Misreading 4: 大機 is something you can acquire through effort. The verb in Chan is 奮 ("to rouse"), but Yuanwu's 奮大機 is closer to *letting go* than to *taking hold*. The 懸崖撒手 ("let go off the cliff") image is not "climb harder." Effort, in the Chan frame, has its place — study, training, ripening, doubt — but the eruption of 大機 is not the *outcome* of effort, it is the moment effort can stop. This is the same structural claim as the Diamond Sutra's 應無所住而生其心.
Misreading 5: 大機 is a "spiritual" thing disconnected from ordinary life. The opposite is closer to the Chan frame. 大機 is what allows ordinary life to bear the kind of pressure that would otherwise break a person. Yuanwu's warnings about 利根 who are "根浮腳淺" — floating root, shallow footing — and who "遇境界便不能透脫" — cannot break through at the moment of encounter — are explicit: 大機 is named precisely because *life keeps presenting the kind of moment that requires it*. The Chan teaching is not about producing a special experience; it is about whether there is root to bear the moment when there is no longer a special experience to lean on.
Misreading 6: Dahui's "dull is better" line means intelligence is bad. Read carefully. Dahui says 取捨利鈍在人不在心 — the choice between sharp and dull is in the person, not in the mind. He is not arguing against intelligence. He is arguing against the *identity* of intelligence with 大機. A person with sharp faculties has more to put down in the moment of practice, not less to bring to it. A person with dull faculties has less conceptual scaffolding and may, in some cases, be able to collide with the thing faster. Neither rule is absolute; both are diagnostic of specific failure modes. The classical Chan frame holds the two together, refuses to rank them, and uses them as mirrors for what a given practitioner is doing with their own root.
Misreading 7: 大機 is a goal. It is a *threshold*, not a goal. The full sequence — 機 then 用 then 圓證 (full verification) — names a movement. Stopping at 大機 because you can feel the threshold is, again, 祇得大機，不得大用. The Yangshan vignette exists to make this point vividly: even the great Weishan Yangshan, one of the founders of a Chan school, had to learn it bodily, by being pushed over.
A closing image, since 大機 is hard to talk about without a picture. The Jiufeng vignette is the cleanest. Weishan says "only having 大機, without 大用." Most people in the room shift in their seats, glance at the person next to them, mentally compose a question. One person stands up, walks toward the door, and at the moment his teacher calls after him, he does not turn around. Weishan says, "This one is fit to be a vessel of the dharma."
That is what the Chan tradition is pointing at, when it uses the term. It is not a description of a person. It is a description of a *moment in a person* — and the moment is not separable from the walking out.