In the dialogue of Chan Buddhism, when a student asks, "What is the equal practice of concentration and insight?" the teacher rarely answers "fifty-fifty," nor does he answer "concentration first, insight later." Instead, he says something quite strange: Concentration is the substance, insight is the function; like water and waves—one body, with no before or after.
This statement is strange because it violates the mode of thinking we are most familiar with today—the division of labor. From childhood we are trained to "first build the foundation, then develop abilities"; "first learn to be calm, then learn to think." The Chan school's statement is meant to pull us entirely out of this "staged, categorized" way of thinking, telling us: what you think are two things are actually two aspects of the same thing; what you think has a sequence actually has no such thing as "water comes first, waves come later"—like water and waves.
Making this clear is precisely the work of the four characters "定慧等學" (samādhi-prajñā samatā, "the equal practice of concentration and insight"). It is not a particular meditation technique, nor the name of a particular state, but rather a coordinate system for calibrating the entire direction of your practice—are you cultivating "the stacking of two separate things," or "two appearances of one single thing"? If this calibration is not accomplished, all subsequent efforts may go astray.
Below we unfold this coordinate system in four layers.
I. What This Concept Is Saying
1. Substance and Function as One: "Equal" Does Not Mean "Half and Half"
The classical sources state it clearly: "equal" is not a numerical division, but the perfect fusion of substance and function as one. This is the first gate to understanding the entire concept.
- Concentration is the substance (體): Substance here is not "the body" but "the ontological ground"—the unmoving foundation that allows everything to stand. For the mind to observe, to think, to act, there must first be "a place that can abide." This "abiding place," the Chan school calls concentration. It is not merely the experience of "entering samādhi," but the stable ground upon which awareness itself can arise.
- Insight is the function (用): Function means "operation," "activity." Insight is not "knowledge," not "cleverness," not "having figured something out"; insight is the luminous discernment that naturally arises from that stable ground—it can see through things, is not entangled by surfaces, and in the midst of turmoil still clearly knows "what is happening right now."
Why are these two "equal"? Because function cannot arise without substance (without a stable ground, discernment is mere wandering thought), and substance cannot manifest apart from function (having only stability without arising illumination, that stability is just dead water). Concentration without insight is called "withered concentration" (枯定); insight without concentration is called "wild insight" (狂慧). The *Jingde Chuandeng Lu* (《景德传灯錄》, *The Jingde Record of the Transmission of the Lamp*, T2076) specifically points this out: 「專之以定，定猶有繫；濟之以慧，慧則無滯」— "If one relies solely on concentration to suppress the mind, the concentration itself becomes a fetter; only by letting insight penetrate it does one reach unobstructed passage."
So the character "等" (equal) is saying: structurally they stand on the same level, temporally they occur simultaneously, and essentially they are the same event.
2. The Water-Wave Metaphor: Different in Form, One in Substance
Next, a metaphor is used to reinforce this understanding: water and waves.
- Water is the "substance"—it has volume, weight, temperature; it is a real thing. - Waves are the "function"—they are the forms water takes when stirred by wind.
But we do not say "first there is water, then there are waves," nor do we say "waves are something other than water." Waves are water in motion; water is the same thing that, in stillness, is capable of giving rise to waves.
This tells us: do not think of concentration as some sacred, rare experience (like entering some deep samādhi) that you strive to obtain, and then from it produce "insight" as a byproduct. In the Chan view, the very fact that you can right now be aware that "my mind is disturbed" is already concentration and insight occurring simultaneously—there is an awareness that can abide (concentration), and a clarity that sees "the disturbance" (insight); the two are really two faces of one body.
3. The Pearl-and-Tray Metaphor: Mutual Need, Not Separate Roles
The entry also contains a more subtle metaphor, meant to supplement what the water-wave metaphor left unclear: "Like a pearl on a tray—the tray is concentration, the pearl is insight" (「如珠在盤，盤定珠慧」).
- The tray is like concentration—stable, still, holding things; it is the support. - The pearl is like insight—round, luminous, reflecting everything; it is the active function.
This metaphor adds one more layer beyond the water-wave metaphor: the pearl cannot exist apart from the tray, and the tray has no meaning apart from the pearl.
If the pearl has no tray, it will roll off and be lost—if you have discernment without a stable mind, that discernment will be swept away by the next thought, becoming "a principle you once heard," "words you read in a book"—unable to abide.
If the tray has no pearl, it is just an empty tray—if you have stability without illumination, that stability will slowly turn into dullness, numbness, stagnation—you won't even know what it is you are stable within.
So this metaphor is saying: concentration and insight are not two team members taking shifts; they are two parts of one organ—the tray is the skeleton, the pearl is the gaze; if the skeleton holds, the gaze has power; if the gaze is present, the skeleton knows where to look.
4. Not Relying on a Single Thing in All Twelve Hours: Bringing This into Daily Life
Speaking only of substance and function, water and waves, tray and pearl—that is doctrine; the Chan school must bring it down to the present moment of walking, standing, sitting, and lying. Thus the *Jingde Chuandeng Lu* records that Baizhang Huaihai (百丈懷海) specifically asked Huangbo (黃檗) "What about the equal practice of concentration and insight?" And Huangbo's reply was startlingly brief—"In all twelve hours, do not rely on a single thing" (「十二時中不依倚一物」).
This single sentence gathers all the previous metaphors and drops them directly into your life at this moment.
- The twelve hours (十二時): Ancient India divided day and night into twelve periods—that is, "from morning to night, from night to morning," all of time. - Not relying on a single thing (不依倚一物): The mind does not cling to, entrust itself to, or grasp any single thing.
Note: this is not the platitude "don't be attached." Huangbo is describing a state that is immediately operable right now: does your mind at this moment have a host? Is there something you subconsciously feel "as long as it's there, I'm stable"—perhaps a relationship, an identity, an emotion, a viewpoint, a plan, or even the very "concentration" you are practicing?
If the mind "relies on a single thing," it is tethered by that thing—the tray becomes the shape of that thing, the pearl becomes the shadow of that thing. This is no longer the equal practice of concentration and insight—this is handing both over to some one thing, and making yourself the appendage.
5. Do Not Chase Words and Phrases: Don't Turn This into a Philosophical Problem
The final warning is for those who "want to think it through with their minds." The text says: 「夫出家兒莫尋言逐語，行住坐臥並是汝性用，什麼處與道不相應。且自一時休歇去。」— "One who has left home should not chase words and phrases; walking, standing, sitting, lying—all are the functioning of your own nature. Where is there anything not corresponding to the Way? Just for a moment, rest and stop."
This is saying: the equal practice of concentration and insight is not a subject you study and clarify at a desk; it is itself the unfolding of your nature's functioning in walking, standing, sitting, lying. The real way to understand it is not to think it through, but to stop—"for a moment, rest and stop."
The following line—「若不隨外境風，心性水常自湛湛」—"If you do not follow the wind of external conditions, the water of your mind-nature is constantly clear and calm"—is the summary: if the mind is not blown by the external wind, that "water of mind-nature" which serves as the substance is already lucid and pure by itself. What is the wind? It is the force that gets pulled along by external conditions—the wind of news, the wind of evaluations, the wind of the next task, the wind of the next thought.
This "湛湛" (clear and calm) is not coldness, not deathly stillness—it is simply the state of water when it is not being blown by wind: transparent, able to reflect all things, settled, unturbid. This is the "original face" of the equal practice of concentration and insight—it does not require you to "cultivate" it separately; it only requires that you not be blown by the wind.
II. A Walkthrough in Daily Life
The concept is done. Let us bring it into today's life, walking through it scene by scene. Strictly mapping according to the definitions above, and flagging the places where mis-mapping most easily occurs.
Scene One: Commuting on the Subway, Scrolling Your Phone
Nine in the morning on the subway, you are standing (or sitting) staring at your phone screen, scrolling. Your body is not moving; it looks like "concentration." Your eyes are fixed on the screen; it seems like focus.
Walkthrough: - Your body indeed is not moving, but is there a "tray" within you? Is there an unmoving awareness there holding you up? - Or are you actually being blown by the algorithm's "wind"—it gives you the next item, you take the next item; it gives you an outrageous headline, and your tray gets shaped into the shape of outrage by that one thing? - In the process, is there a "pearl"? Is there a clear discernment saying: "I am not resting right now; I am being fed."
Mapping: - The most common mis-mapping here is mistaking "the body not moving" for "concentration." The Chan school's "concentration" is the stability of awareness, not the stillness of the flesh. So the "concentration" of phone-scrolling is actually an empty tray—the frame is there, but what it holds is whatever the algorithm has stuffed into it. - You might also think you are "absorbing information" (as if there were insight), but without a stable tray underneath, that "absorbing" is just drifting with the current, not discernment.
Scene Two: "Deep Work" at Your Desk
Two in the afternoon, you have a difficult document in front of you. You force yourself to focus, staring at the screen, telling yourself "don't get distracted, don't open another tab."
Walkthrough: - Are you in "concentration"?—To some degree: you are forcing your attention to gather in one place. - Are you in "insight"?—Probably not yet, because you are using willpower to suppress stray thoughts; the pearl hasn't started turning. - Result: you usually freeze up, get irritable, and eventually can't help opening something else—this is the contemporary version of "relying solely on concentration, the concentration itself becomes a fetter."
Mapping: - Genuine deep work is often not something you "squeeze out" with willpower, but something that happens when, in an abiding state, you naturally see the structure clearly—that "seeing clearly" is the pearl turning, and you can see clearly because the tray is stable. - The mis-mapping point: taking "holding still by willpower" as concentration. Willpower is "exerting force"; the Chan school's concentration is "not exerting force." One is grasping; the other is letting go.
Scene Three: Late-Night Intimate Relationships
It's the night after a fight with your partner (or family member, or close friend). Your heart is still blocked. You want the other person to say something, to take a stance, to "stabilize you."
Walkthrough: - Where is your tray? Right now you are entrusting yourself to the other person's words, to their expression. - Do you have a pearl?—You actually cannot see clearly what you are angry about, cannot see clearly what you need; you can only see "the other person hasn't responded to me yet." - The line "in all twelve hours, do not rely on a single thing" surfaces right now—you are relying on the single thing called "the other person's reaction."
Mapping: - This is not saying you shouldn't need your partner. The Chan school is not calling you to isolation. - It means: when you outsource your "stability" to any one thing (partner, evaluation, future plans, religious identity, a streak of N days of abstinence), the moment that thing wavers, your tray collapses, and the pearl naturally cannot illuminate anything. - The wisdom of "equal" is: there can be dependence between you and your partner (that is normal human life), but the "clear and calm tray" within you must not be outsourced.
Scene Four: End of the Day, Scrolling Back Through Your Memory
Lying in bed at night, you look back on the day and realize that all you remember is what other people said, messages in the group chat, headlines in the news. You ask yourself: what did I actually do today, and where was my own judgment?
Walkthrough: - You absorbed a great deal of "information" today, but that is not insight—insight is the illumination that arises from your own abiding awareness; information is things others have already chewed. - You may also have "focused" several times today, but often it was "focusing on goals set by others"—the boss's goals, the algorithm's goals, society's expected goals—that is not your concentration; it is a borrowed tray. - What you lack is "for a moment, rest and stop"—to stop, to return to that clear and calm place of your own mind-nature, even for just one minute.
Mapping: - The greatest mis-mapping of our age: using "consuming information" to counterfeit "insight," and using "following instructions" to counterfeit "concentration." The consequence of this mis-mapping is not something you feel immediately; it is chronic—after a year or two you will find that you seem to know everything, but can see nothing clearly; you have done everything, but nothing is stable.
Scene Five: AI and Outsourced Thinking
This is a scene unique to our time. You have AI write your emails, make your decisions, analyze your pros and cons, summarize a book for you. AI has become your "thinking outsourcing contractor."
Walkthrough: - What is AI? In this metaphor, AI is like a super-tray—it is stable, it holds everything, it gives you answers. - But the pearl?—Where is your pearl? - The pearl depends on the tray, but the premise is "your own tray." When the tray is completely replaced by AI, the pearl also loses its support—you no longer even have the illumination of "why this choice," because that illumination has already been outsourced.
Mapping: - AI is not the enemy, nor is it liberation. It is a tool—the strongest gust among the contemporary versions of "the wind of external conditions." - The concrete meaning of "not relying on a single thing" in the age of AI includes: do not outsource judgment to any single system—whether AI, religious authority, experts, or group consensus. They can be consulted, but your tray must not be occupied by them. - Here we should also state a limitation clearly: AI and neuroscience research, though in some places they echo the dialectic between "stable awareness" and "flexible cognition" (for instance, research on the "default mode network" indicates that when the brain is in a "wandering" state, it is actually more conducive to the emergence of insight), findings of this kind in neuroscience are not equivalent to the Buddhadharma—neuroscience describes mechanisms; Buddhism points to liberation; the two cannot simply be equated. We borrow these comparisons so that modern readers have a handle, not in order to "prove" anything.
III. Why Contemporary People Need It
Having walked through these scenes, we can already see the concrete value of the old concept "定慧等學" in our time. It does not solve an ancient meditation problem; it addresses several imbalances that are particularly pronounced in our era.
1. Our "Concentration" Has Almost Entirely Been Taken Over by External Forces
Contemporary society trains people extensively to enter states of "focused attention"—work requires deep work, learning requires flow state, fitness requires zone out. But most of these "concentrations" are concentrations directed at external goals, conscripted by some system: the company's concentration, the fitness app's concentration, the learning platform's concentration.
The Chan school's "concentration" is not this thing. The Chan school's concentration is your own awareness itself being able to abide—it points to no external goal, is conscripted by no system.
When all our "concentration" is conscripted by external systems, the "tray" is in effect being sold at a high price—what we get in return is efficiency, performance, output; but that inner abiding place of your own is left idle. That is why we have so much of "I didn't really do anything but I'm exhausted" and "I rested but didn't recover"—the tray is empty.
2. Our "Insight" Is Almost All Growing on Other People's Ground
The symmetrical opposite extreme: the information age lets us encounter a vast amount of "insight"—books, podcasts, short videos, other people's experiences. But most of this insight grows on top of other people's experience. You read a hundred people talk about "how to face anxiety"; you may become more familiar with descriptions of anxiety, but your own anxiety is still exactly where it was.
This is the typical manifestation of "insight" separated from "concentration": without your own stable tray underneath, other people's pearls roll in, roll out, and leave nothing behind.
3. Our Most Common Mis-mapping: Thinking "Just a Little More Effort" Will Solve It
This is the underlying logic of contemporary workplace culture, academic culture, and self-improvement culture—when there's a problem, it's "not enough concentration" or "not enough awareness"; the solution is "meditate more," "read more," "be more mindful."
The line from the *Jingde Chuandeng Lu*—「專之以定，定猶有繫」—"relying solely on concentration, the concentration itself becomes a fetter"—is aimed directly at this misconception: pure "try harder" is itself a kind of fetter. You think you are cultivating concentration, but actually you are grasping with force; you think you are increasing insight, but actually you are piling up knowledge. The problem is not insufficient effort; the problem is the tray and the pearl have already been separated—everything you give out is only one of the two sides.
The contemporary meaning of "定慧等學" is precisely to pull us back at that moment: stop, and look at this very moment—is there that clear and calm tray? Is there an awareness that does not move with the wind of external conditions? If there is, the pearl is right there. This is not a question of working one more shift; it is a question of changing the structure.
4. The Full-Scale Siege of the Attention Economy Is the Contemporary Background of This Practice
We live in an era where every business model is "borrowing your tray and buying your pearl." Every algorithm, every push notification, every pop-up window is essentially doing one thing: making you lose that clear and calm place, making you rely on the one thing it gives you.
"定慧等學," this ancient concept, becomes under this backdrop a kind of restoration of sovereignty—not demanding that you stay off the internet, not use your phone, not interact with people; but rather not outsourcing the tray and the pearl to any single thing. Your awareness is yours, your insight is yours, your abiding is yours. This sovereign awareness is the most scarce, and the most easily overlooked, thing for contemporary people.
IV. Common Misreadings and Clarifications
Because this concept is short, pleasant-sounding, and has a Chan flavor, it is particularly prone to being misread. Let us point out the most common readings.
Misreading One: "Equal" Means "Half and Half"
The most intuitive misreading: equal practice of concentration and insight = concentration 50%, insight 50%.
Wrong. "Equal" is the "sameness" of substance and function as one, not a numerical "division into equal parts." The *Jingde Chuandeng Lu* says explicitly 「非二法、非異法、非先後法」—"it is not two dharmas, not a different dharma, not a dharma of before and after"—it is neither two things, nor one thing, nor sequential. How can this "neither two, neither different, neither sequential" be fitted into a 50/50 split?
Reading "equal" as "half each" sends people in a wrong direction: spend half the day meditating, half the day reading sutras—turning practice into an arithmetic problem of time allocation.
Misreading Two: Concentration Is "Sitting Meditation," Insight Is "Reading Sutras"
Narrowing the concept into actions: concentration = sitting on a cushion; insight = reading books and thinking.
This is the pitfall modern people fall into most easily, because we have been trained to understand everything through "behavior."
But the Chan school says 「行住坐臥並是汝性用」—"walking, standing, sitting, lying—all are the functioning of your own nature"—all four forms of deportment are the field of the equal practice of concentration and insight. You can sit on a cushion and have a galloping mind (no concentration, let alone insight); you can be standing on the subway with one thought clear (concentration and insight both complete). Form is not the point; the substance-function structure of awareness is the point.
Misreading Three: First Cultivate Concentration; Once Concentration Is Sufficient, Insight Will Naturally Arise
This is the "ladder-style practice" misreading—first train the fundamentals, and when the skill matures, enlightenment naturally comes.
The *Jingde Chuandeng Lu* answers: 「從定起慧，從慧歸定，如水與波一體更無前後。」—"From concentration arises insight; from insight returns to concentration; like water and waves, one body, with no before or after." There is no such thing as "before and after."
In actual practice, when concentration is insufficient, insight indeed cannot be clear; but this is not because "concentration hasn't been finished yet," but because the substance-function structure of the present moment has not yet been calibrated to the state of "not two." The moment you recognize "ah, right now I can both be aware that the mind is disturbed and see the source of this disturbance"—in that moment, concentration and insight are already present together; there is no need to wait.
Misreading Four: Pure Sitting Meditation Is Enough; No Need for Insight
This misreading is especially common in meditation circles—the feeling that "as long as I sit long enough, I will naturally awaken."
The *Jingde Chuandeng Lu* specifically exposes it: 「專之以定，定猶有繫」—"relying solely on concentration, the concentration itself becomes a fetter"—you think you are cultivating concentration, but your "concentration" itself is a form of clinging: you are tightly gripping a particular state, a particular experience, a particular feeling of "emptiness"—that is the fetter.
True concentration is always the tray that allows insight to turn; a "concentration" that cannot let insight turn is not concentration at all—it is dead water.
Misreading Five: Treating It as a Philosophical Problem to Study
「行住坐臥並是汝性用」, 「莫尋言逐語」—these two lines are aimed directly at those who "want to think it through with their minds."
After reading this article, you may feel you "understand"—but "understanding" itself is not insight; it is knowledge. If it has not enabled you, the next time you become agitated, to stop for an instant, to see the agitation without being swept away by it, then it is still just something on paper.
The test of the equal practice of concentration and insight is not "can I write an article explaining it," but "at this moment, is my mind relying on a single thing, or is it clear and calm, not relying on a single thing?"
Misreading Six: Reading "湛湛" (Clear and Calm) as "Cold" or "Numb"
「若不隨外境風，心性水常自湛湛」—this "湛湛" is easily read as "no longer feeling anything," "no longer being moved."
Wrong. "湛湛" is the clear state of water, not water turning into ice. Water turning into ice is death; water remaining clear is alive, still flowing, but not muddied. You can have deep feeling for a friend, enthusiasm for things, sensitivity to beauty—none of these are "wind"; these are the luminosity inherent in the water itself.
True "湛湛" is having feeling without being governed by feeling. This is entirely different from numbness.
Misreading Seven: Thinking This Is Only for "Practitioners" and Has Nothing to Do with Ordinary People
This one, strictly speaking, is the most common mistake among contemporary readers—classifying a Chan concept as "professional terminology of religious practice."
But after reading the "walkthrough in daily life" above, you can see that this concept was never designed exclusively for monastics—its designed object is every person living in the dust of the world. "In all twelve hours, do not rely on a single thing"—the "twelve hours" means exactly the same thing for a monastic and for an office worker.
Placing this concept back into daily life, it is a "program for repairing one's inner structure" for contemporary people: do not keep running on the pure-concentration mode of "holding yourself up by willpower," and do not take the pure-insight mode of "stuffing yourself with information and thinking"; let the two return to the position of substance and function as one.
In Closing
The four characters "定慧等學" are a brief reminder left by the Chan school for all who live amid busyness, turmoil, and information overload: you do not need to choose between "becoming still" and "seeing clearly"; you only need to recognize afresh that they have always been the same thing.
The moment of fresh recognition is the moment of "for a moment, rest and stop." In that rest, the clear and calm water of mind-nature, which serves as the substance, will naturally be there—neither shaken by the wind of external conditions, nor requiring you to grasp it with force.
This is an ancient concept, but in our time its value is even more concrete than in antiquity. Because the "wind of external conditions" of our era is stronger, denser, and more sustained than that of any other age—without recognizing this concept, one can barely take a step.
May you, after reading this article, in some morning commute, or some late night of overtime, or some moment after speaking with someone close to you, recall that reminder of "not relying on a single thing." And then stop for an instant—and see that clear and calm original state, there all along.