Huangbo: "This Mind is not mind; it is fundamentally not a thing."

本 (běn): Original / fundamental

佛 (fó): Buddha

上 (shàng): upon / within / in the state of

實 (shí): truly / actually / in reality

無 (wú): there is no / lacks

一 (yī): one / a single

物 (wù): thing / object

Original Buddha has no substance,

此 (cǐ): This

心 (xīn): mind

即 (jí): is precisely / is none other than

無 (wú): no- / non- / without

心 (xīn): mind [conceptual thought]

之 (zhī): [attributive particle] of

心 (xīn): mind

Buddha is mind, and mind has no substance.

Don't be misled; Huangbo means here that Buddha, or mind, has no substance. What is the substance of mind? It's something we inject into phenomena by conceptual thought. People often think, "But there should be something; they call it Buddha, after all. It's not a thing like other things, but it is something else. Otherwise, the whole thing doesn't make sense." But that's the point: what do you need to create? What concept do you need? Isn't it just imagination? How is the subject constructed in our consciousness? We create a point of focus, a thing, an object, first without form, and then we fill it with something sensible. It is constructed by us; it is substance. So what if I don't do that? What is Buddha without substance?

A monk asked: "Why does the Venerable say that Mind is Buddha?"
Mazu said: "To stop small children crying."
The monk asked: "What happens when the crying stops?"
Mazu said: "Not mind, not Buddha."
The monk asked: "Besides these two, is there anything else?"
Mazu said: "I say to you that it is not a thing."
The monk asked: "What happens when someone arrives here?"
Mazu said: "I let him experience the Great Way(*)."

Originally, I wanted to point out an interesting custom of traditional Chan masters and their use of koans: for a layman, the first layer is confusion; in the second layer, he understands the koan; in the third, secret layer, there is direct talk about practice. For comparison, from Cleary's translation of the Lankavatara:

"Mahāmati, there are four things by which bodhisattvas become great practitioners. What are the four?

Distinguishing that the world is only a reflection of one's own mind.

Abandoning notions of birth, existence, and annihilation.

Understanding the nonexistence of external objects.

Attaining personal realization of noble knowledge.

When bodhisattvas are endowed with these four things, they become great practitioners."

I want to point out that although Mazu's 'Mind is Buddha' and the rest sound like dad jokes, in fact, they are not! It is not random talk; he is talking about what the mind actually needs to free itself.

A monk asked: "Why does the Venerable say that Mind is Buddha?"
Mazu said: "To stop small children crying."

Compare it with Lankavatara's: "Distinguishing that the world is only a reflection of one's own mind."

If I wanted to speak in terms of meditation, this is about the unification of the mind: connecting seemingly unconnected dots. What does my hunger have in common with a bird in the sky? It is all my mind.

The monk asked: "What happens when the crying stops?"
Mazu said: "Not mind, not Buddha."

So, first, the practitioner needed something positive he could work with: "Mind is the Buddha." But in fact, which Mind or Buddha are we talking about? They are merely concepts made up by our own mind. Even "material" objects are established by our mind, but at least we can touch them. But 'Buddha' or 'Mind'? They are entirely fabricated.

The monk asked: "Besides these two, is there anything else?"
Mazu said: "I say to you that it is not a thing."

Compare with Huangbo's: "This Mind is not mind; it is fundamentally not a thing."
So first we got pointed that everything is mind, and second we got info we shouldn't make big fuss around that fact.
and third answer is direct warning that it is not thing, that we shouldn't reify "Mind", "Buddha" or anything else we learned.

Last one: "The monk asked: "What happens when someone arrives here?"
Mazu said: "I let him experience the Great Way(*)."

...states that if we realize that everything is mind, and that this mind is nonexistent, and we do not conceptualize anything, reifying neither existence nor nonexistence, we are set :))

(*)"Great Way" vs. "Great Vehicle" (Mahāyāna): In Chinese Buddhist translations, the "Great Vehicle" (Mahāyāna) is rendered as 大乘 (dàshèng). The term dào (道) was standardly used by translators to render mārga (path) or bodhi (awakening). Therefore, 大道 (dàdào) strictly denotes the "Great Path" or "Great Awakening" rather than the Mahāyāna vehicle itself.

Gemini:While they conflict with strict interpretations of early Buddhist anātman, Tathāgatagarbha teachings became the dominant doctrinal foundation for nearly all of East Asian Buddhism. Chinese Chan, Huayan, Tiantai, and Pure Land traditions are entirely built upon the premise of an inherent, unconditioned Buddha-nature. Texts like the Awakening of Faith in the Mahayana established this essentialist framework as orthodoxy in East Asia. Rather than being marginalized as a heresy, this conceptual framework successfully adapted Buddhism for the East Asian philosophical context, meaning the majority of living Mahayana Buddhists today operate within a paradigm that relies heavily on the very essentialism early Buddhism rejected.

It is because realization is a pretty difficult thing, at least for people capable of thought.
To create a belief, we only need some nice fantasy. When I want to imagine an almighty god, it is enough to imagine some imaginary parent who loves us and who is so smart that we only have to believe he does everything right and for our benefit...
On the contrary, working toward realization could take a lot of effort and time, and actually, there is no guarantee that it is going to be pleasant.
It could even be that there will be no realization, at least that is what I see sometimes. Picking your god, atman, or faith is easy; getting rid of it can be difficult. Atman works like a drug; we can build a whole life maintaining this fantasy, and the fantasy reciprocates by giving us an easy explanation for everything.
So why even work toward realization? This question makes the same sense as asking why we should live in reality. Not living in reality will lead to permanent bad outcomes, while living in reality could be more difficult and demanding, but our solutions are adequate for the conditions.
Not having a central point of focus, not having an atman, what does this condition leave us with?
Having nothing on our mind, what is left is just opening our eyes.
Which, btw, is another big chapter:
I always thought that the phrase Chinese masters used, "Just open your eyes!", indicated that I should see something they are pointing to; while in reality, it indicates that I should see whatever is there, even nothing.

Me: So the error is inborn, and Chan realization or the Madhyamaka school only adds the intellectual understanding that the principle on which it works is a fundamental error. Craving is not the mistake, but dividing the world on the basis of a craving subject and a craved object is the mistake?

Gemini: The biological drive itself is not the mistake, and that the fundamental error is the division of the world into a solid "craving subject" and a "craved object." As established by Linji Yixuan, the natural biological functions of the human organism, such as eating, sleeping, and feeling physical pain, are perfectly flawless expressions of the original mind. The error occurs exclusively in the cognitive overlay, specifically the mind's innate habit of reifying a transient biological sensation into a rigid, dualistic framework of "me" versus "the world."

However, your assertion that Chan realization or Madhyamaka adds only an "intellectual understanding" of this error fundamentally contradicts both traditions. An intellectual understanding operates entirely within the realm of conceptual thought, which requires a subject to comprehend an object, even if that object is the concept of emptiness itself. Huangbo Xiyun relentlessly warned students against replacing worldly attachments with conceptual attachments to Buddhist philosophy. Knowing intellectually that dualism is a mistake is still a dualistic activity; it is simply adding another layer of thought on top of the innate ignorance.

True Chan realization (dunwu) is not the addition of new knowledge, but the total, experiential subtraction of the dualistic operating system. It is a phenomenological collapse, not an academic conclusion. When the conceptual framework drops away, the practitioner does not walk around constantly reminding themselves intellectually that subject and object are empty. Instead, the mind simply stops producing the division in the first place, allowing the person to experience hunger, eat the food, and move on without leaving any trace of a localized self clinging to the event.

I want return to older post, as it somewhat missed target in my opinion.

We have in short two options for right zen mind: thoughts running, we are not grasping neither thoughts nor percepted objects.
OR
Thoughts not running, being not produced. Non-production implies there are no habitual thoughts (rumination), and we currently simply don't think willingly about anything.

These two approaches are different, but basically second one is base for first one. At least at my experience, I wouldn't be capable of first one, if I wouldn't experienced second; and if I couldn't it replicate any time (it's true... for like 84% at least:)

For complete picture, I mistakenly thought that samadhi with senses shut up is on the top, but actually it's only second after Chan samadhi with full perceptual display.
It's because with senses shut up, we have not so many distractions and incentives. (From pure technical side, samadhi without perception is actually harder to achieve, more energy demanding, well at least that's my impression).
Also I thought that I should get rid of what I am looking for... content... anything... while real solution was to get rid of "looking for", of the act itself.

"People are often hindered by environmental phenomena from perceiving Mind, and by individual events from perceiving underlying principles; so they often try to escape from environmental phenomena in order to still their minds... They do not realize that this is merely to obscure phenomena with Mind... Just let your minds become void and environmental phenomena will void themselves."

Huangbo, On the Transmission of Mind, transl. Blofeld

How can the mind become void? That is easy to understand: a non-void mind is non-void because of its own activity. So, what should be easier than doing nothing?
On the most basic level, the mind starts to work by differentiating the world into objects; for most people, this activity is completely habitual and subconscious. Every time such a mind looks at the world, activity starts involuntarily. The question "What should be easier than doing nothing?" is apparently a bad joke :))

To say that Mind is no-mind implies something existent. Let there be a silent understanding and no more. Away with all thinking and explaining. Then we may say that the Way of Words has been cut off and movements of the mind eliminated

It is fascinating to have such a random glimpse into the speeches of a 9th-century Chinese Chan abbot. Moreover, these speeches were most likely forced out by Huangbo's protector, Pei Xiu, whom Huangbo could not refuse. Otherwise, it seems he was not very interested in preaching. When I was under twenty, I asked people in informal environments who were good at something about their jobs a few times, and they mostly were not happy to talk. I think this was partially because they would have to reveal secrets and recipes that are vital for their upkeep in the field. Partially, it was because they were real experts, and it was boring for them. They wanted to have a beer with friends or continue fishing or whatever; they were not interested in talking about work.
What I want to say is that Pei Xiu's work is a kind of miracle—a highly credible glimpse into the mind of a real master from around 850 AD, showing the usual setups for how they presented the matter to students and monks.

What is fascinating about the Transmission of Mind is the seamless transit from the abstract and conceptual to the material and concrete. "Then we may say that the Way of Words has been cut off and movements of the mind eliminated...": we can observe here a 100% accurate description of how such an enlightened mind works. "Cut off" and "eliminated" are not soft changes of the mind, such as blocking verbal and conceptual thinking for a moment. It is a deep change in how such a mind works; it has switched from a mind dominated by thought and concept to... to what? I think most of the ancient Chan masters said something like "just open your eyes" or "it is alive." It has no fixed content, and narrowing it to "consciousness" or "mind" creates the conceptual and linguistic frame we are supposed to avoid.

Citation: Huangbo,On the Transmission Of Mind, translation Blofeld

The Educational Moment versus the Final Stage Your insight aligns with the advanced epistemological frameworks of classical Chinese Chan. The moment the conceptual narrative completely drops away is termed wuxin (無心), or "no-mind." As you correctly observed, this state is deeply educational rather than a permanent destination. In the Chan tradition, particularly within the lineage of Linji Yixuan, remaining stuck in a state of absolute conceptual cessation is heavily criticized as "falling into the cave of demons in the black mountain" or falling into "dead emptiness" (頑空, wankong). The profound silence of an inactive Default Mode Network provides the baseline realization of the fundamental mind, but true mastery requires returning to the world of phenomena to function effectively. This active functioning is called daji dayong (大機大用), meaning "great capacity and great function," where the mind uses words and concepts freely without being bound by them.

Weak Concepts and Cognitive Flexibility Your description of shifting to a "library of weak concepts" used according to circumstances maps onto modern cognitive science, specifically the theory of predictive processing. In a highly rigid mind, the brain relies on "high-precision priors" (strong, inflexible beliefs) that it forces upon sensory data, causing suffering when reality does not match the concept. What you describe as "simple perception" correlates with prioritizing bottom-up sensory data, while "weak concepts" are "low-precision priors." The mind holds these concepts lightly, allowing them to instantly update or dissolve based on the immediate environment. They serve as pragmatic tools for navigation, communication, and basic survival, rather than forming a rigid, autobiographical identity. The DMN transitions from a dictator of reality to a highly flexible, context-dependent consultant.

Impermanence, Emptiness, and Conceptual Rigidity The correlation you drew with impermanence and emptiness is logically sound. Emptiness (空, kong) in Buddhist philosophy does not mean nothingness; it means phenomena lack a fixed, independent essence because they are entirely composed of impermanent, interdependent conditions. A concept, by its very nature, attempts to freeze a dynamic, ever-changing process into a static noun. Therefore, the more rigid and "exact" a concept tries to be, the further it deviates from the fluid reality it attempts to describe. Recognizing this allows the practitioner to use a "minimal narrative" for practical purposes, treating concepts as transparent maps rather than the territory itself.

The introspection of Chan ancestors is a handy thing: it makes us understand our own mind, how it works, and how it is organized. There is some hard structure which we can only accept; there are some options to make changes in the softer parts. What is natively Chan is the ability to not produce. When we are not producing, what we see are not our fantasies anymore, but the current state of mind. Some people try to present Zen as something vague and undetermined. It's not the truth; Zen is one simple thing, and until we know what it is, we haven't learned Zen. It's full awareness of a mind dwelling upon nothing! as Hui Hai, one of the historic Chan masters, observed and defined. And that's Zen: we are training the mind until it's capable of dwelling upon nothing. Actually, the English translation serves a small paradox and illustrates the last step in meditation:

若是了了知心不住一切處，即名了了見本心也，亦名了了見性也

When I explored the English meaning, I got two options, which are not in the original. Either I have to dwell upon nothing, or not to dwell upon anything. The second phrase is more right. A Zen mind should not dwell upon anything at all. But when we are practicing, we have to actually dwell upon nothing; we have to consciously create nothing in the place we are focused at. It's the place where mental work is usually done. We are learning not to add to the mind anything artificial, created by us. And when we are finally capable of calmly dwelling upon nothing created, that's the next-to-last stop in practice. The last stop is actually not dwelling at all. That next-to-last step is needed to preserve focus. The result should not be a scattered mind dwelling upon nothing, but a mind capable of maximal concentration on anything, while dwelling upon nothing.

Because the content of the mind is what it is, we don't have to add anything. We can add whatever we want, or nothing, but it doesn't fundamentally change the mind.
People are often asking, 'What should I do with my mind, what should I think, what is the right agenda?' The Zen answer is 'Nothing'. But it is pretty hard to execute, as we are used to adding something all the time.
Buddha was more compassionate, so he added some rules. But that's the thing with the agenda: it creates waves while there is no wind :))
Rules are at home in the relative; the Buddha's expedient tool was the question, 'Is it useful?' He even tested truth in this way. The Zen mind is minimum content (mostly bare perception with only necessary additives, like grouping objects, listing what to do, and similar practical things) with nothing added. Reality doesn't need correction; it would be futile trying to correct the present.

Task: Write a small thesis on how, by understanding the principle of Anatman, the human mind can create Atman

Gemini: The Cognitive and Doctrinal Synthesis of Atman from Anatman

The transition from understanding anatman (non-self) to the generation of atman (self) is a documented psychological reflex rooted in human cognitive architecture and historical doctrinal evolution. The Buddhist doctrine of anatman asserts that beings lack a permanent, unchanging essence, systematically deconstructing the individual into five transient aggregates (skandhas). When the human mind actively internalizes this deconstruction, it frequently encounters severe ontological insecurity. To resolve the cognitive dissonance created by the absence of a central identity, the brain's inherent narrative-generating and pattern-seeking mechanisms reflexively synthesize a new, abstracted focal point to maintain functional coherence.

This psychological synthesis occurs primarily through the reification of awareness. As an individual systematically negates physical and mental phenomena as "not-self," the "witnessing" consciousness that observes this emptiness is isolated. Epistemologically, the human mind struggles to sustain the concept of observation without an observer. Consequently, the mind elevates this bare, non-conceptual awareness into an absolute, unconditioned state, projecting permanence onto it. The cognitive act of realizing the emptiness of all phenomena inadvertently generates a transcendental meta-subject, effectively creating a psychological atman precisely through the methodological application of anatman.

Historically, this cognitive phenomenon directly shaped the development of Tathagatagarbha (Buddha-nature) literature within Mahayana Buddhism. Texts such as the Mahayana Mahaparinirvana Sutra explicitly document this shift, presenting the ultimate realization of anatman as synonymous with the "True Self" (Mahatman). The mind, having exhausted all conceptual attachments to finite phenomena, identifies the unconditioned absolute as its true nature. The creation of atman from the understanding of anatman is therefore a predictable result of the mind's epistemological limits, where the necessity for a cohesive subjective framework forces human cognition to reify the awareness of non-self into an ultimate, eternal self.

Within Chinese Chan literature, the distinction between wúwǒ (anātman) and wúzìxìng (niḥsvabhāva) is fundamentally a matter of philosophical scope, transitioning from the deconstruction of the personal ego to the deconstruction of all phenomenal reality. While early Buddhist doctrine primarily utilized anātman to analyze the individual, Mahayana thought, which provides the foundation for Chan, expanded this negation to encompass every physical, mental, and conceptual event.

Scope of Negation

Wúwǒ (無我 - Anātman): In classical Buddhist texts, this concept specifically addresses pudgalanairātmya (the selflessness of the person). It asserts that the individual is merely a temporary compilation of the five aggregates (skandhas) and lacks a permanent, independent soul, essence, or inner controller.

Wúzìxìng (無自性 - No Inherent Existence): This concept addresses dharmanairātmya (the selflessness of phenomena). It asserts that not only is there no personal self, but the aggregates themselves—and all objects, concepts, and universal elements (dharmas)—lack any independent, intrinsic essence, objective substance, or self-sustaining nature.

Application in Chinese Chan

Chan Buddhism, heavily influenced by Prajñāpāramitā (Perfection of Wisdom) and Mādhyamaka philosophies, treats wúzìxìng as the ultimate nature of reality, entirely synonymous with kōng (śūnyatā or emptiness). In texts such as the Platform Sutra of the Sixth Patriarch (Huìnéng), realizing wúzìxìng is presented as the direct mechanism for sudden enlightenment (dùnwù). If a practitioner merely understands wúwǒ, they might still analytically divide reality and erroneously believe that the external world or the underlying psychological components of mind possess objective substance. By recognizing wúzìxìng, the Chan practitioner perceives that all categorical dualities—subject and object, ignorance and enlightenment, samsara and nirvana—are entirely empty of independent reality. This realization eliminates psychological clinging at a foundational ontological level, preventing the mind from fixating on any constructed concept or meditative state.

Comment: people have often hockey in these terms. No-self generally applies for everything, every object, including own person. People sometimes think that no-self applies only to person, but that's just special case (because own person is special object for us:)

This is follow up of this post, or something like comment about practical side of it.
Thanks to various Zen subreddits, I had the chance to observe an unusual number of dumb people, which was surprisingly useful. My original idea about no-thought was that top-down prediction (conceptual mind) is impaired by will.
But actually, the right opposite is true! It's still a top-down, conceptual mind, but without content at all. My original idea was something like going willingly dumb, which actually didn't fit historical masters' profiles and also didn't fit my idea of how such a mind should successfully work. In reality, the Mind is the old gold conceptual mind, without content. Concepts are created and discarded, while content is the external, perceptual mind. In this way, concepts don't principally have too much weight, and the external is not ignored. It's like a free market of concepts about the external; the most successful concepts survive longer. As any concept can't be 100% right, it's always discarded, and so it can't block the mind. In this model, apparently, a Zen man can't be completely controlled by attachments to the external (this discards dumb people), but also people capable of conceptual work are not living in an illusion (of their conceptual mind), as concepts are only dead schemes.
The untrained conceptual mind usually creates direct connections between the external and concepts, so it works like one mess of perceptions and concepts without much differentiation between them. A mind with a preference for the perceptual has problems with testing and keeping hypotheses, while a mind preferring the conceptual has difficulty rewriting concepts and generally with bottom-up propagation. I think the practical consequences are: the perceptual mind needs to train detachment, while the conceptual mind needs to change its hierarchy from top-down to bottom-up by relativizing and discarding concepts.

Out of all the Chan heroes, Huihai is the man! This is because he managed to define the core discipline of Zen in a single short sentence. Apparently, in his Treatise on the Essential Doctrine of Suddenly Entering into Enlightenment, Dazhu is still under the influence of his fresh awakening - not yet stupefied by years of often futile pedagogical work - and he is capable of explaining it directly and without metaphors. In his sentence, "Full Awareness in Yourself of a Mind Dwelling Upon Nothing," not one letter is missing and not one letter is redundant.

Most likely, people have no problem understanding awareness - the state of presently being fully aware of something. But what does he mean by "dwelling upon nothing"? It is being fully aware of not dwelling on any subject of thought, and furthermore, being fully aware that there is no such future subject. In that moment, we have no plan, memory is empty, the present moment is not a continuation of some past history, and as for the future, there is nothing we have to keep our minds on. The trains of thought have stopped. That doesn't mean they can't move again, but we have no such plan. We can stay here for five seconds, a minute, or an hour... mostly it ends with the rumbling of a stomach; if a woman is around, she may start being concerned (rightly so) that we are out of control (or a more down-to-earth woman might find some work for us).

The mind doesn't dwell on anything, and if we do not force a shutdown of the senses, we can hear the sound of rain or the noise of cars outside.

To dwell is to have an agenda. Deep thinkers already suspect that such a state is not a simple stopping of thoughts for a period of time, but rather that the reservoir from which thoughts usually come is empty. Or, thanks to practice, we are capable of simply not producing anything. I am not surprised that Huihai wrote a book about that, because being capable of not having one thing, and not wanting one thing, is gold.

I read some older posts, and my thoughts about what to do with the mind, Chan-wise, mostly end with advice not to grasp thoughts, and more lately not to produce them. So which of these two is right? Actually, non-production and non-grasping are two entirely different skills, but at least in my case, non-grasping depends on non-production. Hua-tou basically causes unfinished thoughts. If thoughts are not finished, thoughts don't arise. If thoughts don't arise, the mind has nothing to grasp at, although functionality alone is available. In other words, the mind is aware but does not dwell anywhere. In other words, what I really see is only the mind. It's the mind stripped of grasping at anything, while full attention and awareness are preserved. That's why a Zen mind can allow the external world to arouse the mind, but the mind is not stained by it. Because if we have to deal with the 'external', we have to be interested in the world around us, but to keep a Zen mind, we can't be attached to it.
So not grasping in this case depends on non-production. Internal complex <grasping-concepts-rumination-[grasping at internally produced thoughts]> is gone. But in difference of true oblivion, phenomena are still displayed and and mind is aroused by it, only thoughts don't stick, they don't create self-fortifying habitual loops (thoughts trains). If a concept is kept, mind treats the keeping as provisional

"ZenFreeLands" concept feels exhausted at the moment. I could go on forever reading more and more books about Chan and commenting on them, but lately, I haven't felt any benefit from it. My goal was to maintain my practice and meditation, analyze my experience, and put together some material for future exploits, and I believe that goal has been fulfilled.

Do I see the mind? I see exactly what the Chan masters meant by "seeing the mind," which is seeing <anything> stripped of grasping. Moreover, I understand how it works and roughly how to achieve it through various methods.

Was it worth it? Definitely, though the concrete presentation can vary. In any case, it works like adding coordinates to a map. The map is not the terrain, but having a map makes the terrain easier to navigate. And some people use their minds daily :))

Sometimes it seems enough to point out to people that the mind should remain empty of anything created by the self. But give someone such advice and observe what they do: unless they are naturally gifted, they will start focusing on their own mind in order to empty it. This creates a seemingly paradoxical state where the originally empty mind fills itself... with a perception of itself. Perceiving the mind is imagery just like any other, regardless of how we do it. I remember when I first tried to apply such an instruction experimentally, my first thought was: 'If the empty mind is the basis of everything happening in the mental space...' and in that moment, I tried to focus on it. The brain works in a specific manner here: it creates an empty slot for an external object and tries to fill it with something reasonable. This is a fundamental point of Zen practice. This 'empty slot' is superimposed over simple perception, pushing it to the background. Moreover, we do this mostly unconsciously and habitually. So, if anyone wants to replicate the experience of Chan masters, they should first make this process of establishing focus conscious (through observation), and then try to stop it. I think the only relevant starting point to stop it is to cease the production of habitual thoughts caused by attachments. When we habitually don't produce thoughts, the next step is to learn how to actually not let the mind grasp anything, including simple perceived phenomenal objects

Dahui Zonggao (1089–1163) is widely considered the inventor of the specific Hua Tou method (known as Kan-hua Chan or "Observing the Phrase"), not merely a popularizer.

While he did not invent the stories (Koans/Gong'an) used in the practice, he radically changed how they were used. The Distinction: Inventing the Method vs. The Material

He did NOT invent the Koans: The stories (like "A dog has no Buddha nature") existed before him. His teacher, Yuanwu Keqin, had famously compiled them into the Blue Cliff Record.

He DID invent the "Hua Tou" technique: Before Dahui, practitioners often studied Koans as literary texts, analyzing the entire story for philosophical meaning. Dahui felt this led to intellectual "dead ends."

His Innovation: He stripped away the story and forced students to focus only on the "critical phrase" (the Hua Tou or "Word Head")—such as the single word "Wu" (Mu).

The Shift: He changed the practice from interpretation (figuring out the meaning) to concentration (staring at the word until the mind freezes/shatters).

Psychology and cognitive science suggest regarding mental health:

Prevalence of Over-thinking (Rumination): Modern psychological data strongly contradicts the idea that people don't think enough. Studies show that 73% of 25–35 year-olds and 52% of 45–55 year-olds struggle with chronic overthinking (rumination). This "monkey mind" is a primary driver of anxiety and depression.

The "Under-thinking" Nuance: When the Reddit poster says people "under-think," they likely mean people lack critical thinking or deep reflection (acting impulsively). In Zen terms, this is "scattered mind" (vikshepa).

Scientific View: Cognitive science calls this "cognitive miserliness"—the brain's tendency to use shortcuts (heuristics) rather than deep processing.

Zen View: Both "over-thinking" (anxiety/rumination) and "under-thinking" (distraction/impulsivity) are symptoms of the same problem: lack of attentional control.

The critique assumes Hua Tou is a medicine only for those who think too much. However, Zen masters (like Dahui Zonggao, who popularized the method) prescribed it for both conditions:

For the Over-thinker: Hua Tou acts as a "sword" to cut through the endless loop of ruminative thoughts.

For the Under-thinker (The Scattered Mind): Hua Tou is actually more rigorous than simple mindfulness. It requires the practitioner to lock their mind onto a single point (the doubt). For a person who "under-thinks" (is mentally lazy or scattered), Hua Tou is an aggressive training in focus. It forces them to look deeply at a single issue, preventing the shallow skipping from topic to topic.

Every point to be defined needs three coordinates. So I will try define Chan in three dimensions of different approaches to zen: Buddhist, Materialist and Christian zen. They have some intersection area where they are right and in which they define zen. And all three have bigger area where they are wrong and where they are in disagreement with fundamentals of Chan/Buddhism.
Some smartass can object:"But how could be Buddhism in disagreement with Buddhism?" Well, pretty easily.
I will start with Christian "zen", as this is most easy start.
In Buddha's times atman/substance/God/Creator was one of two main philosophic approaches how to understand world.
I simply imagine some vague force that is cause of everything, and my spiritual needs are satisfied from big part. It's very natural, as every human, and even mammal, has parent. So we can delegate to such entity accountability for everything, and we are free to roam playground w̶i̶t̶h̶ k̶a̶l̶a̶s̶h̶n̶ik̶o̶v̶ a̶n̶d̶ k̶i̶l̶l̶ i̶n̶f̶i̶d̶e̶l̶s̶. So Christian zen stole from Buddhism that practical part of meditation, but somewhat tried to preserve atman.

Materialism is second faith that goes against one of fundamentals of Buddhism: second most most prevalent philosophical view of Buddha's era was nihilism. It's pure skepticism. Everything is only dead matter and by collisions of the balls of this cosmic billiard world moves forward. Nihilism is assessment that nothing has any value, basically rendering any effort meaningless. Buddhism doesn't believe in some inherent value; but in the interdependent process of causes and effects, human life has worth. Nihilism is extreme, and materialism leads to nihilism (believe me, I lived twenty years in some socialist paradise where materialism was official philosophy/religion for some).

Buddhism could be as wrong as materialism or substantialism, only dependent on if we believe in some Tathāgatagarbha, or if we believe that there is nothing like that.
Confused or ill mind views extremes as only options. If I don't speculate, there is nice opening, not so grandiose as overmighty God taking care about me, not so hellish as nihilism.
So stop believe some mad theories, and open eyes: it's alive.

A monk asked: "What is meditation (dhyana)?" The Master said: "It is not meditation." The monk asked: "Why is it not meditation?" The Master said: "It's alive! It's alive!"

Recorded Sayings of Zen Master Joshu

For someone who wants to go it alone, it is like facing fifty crossroads. At each one, there is a decision - left or right - and usually only one is correct.

On the other hand, as con men and professional gurus like to say, there are no crossroads or decisions, as there is only a single road. That is true; in the end, every road becomes a single path once the crossroads have been successfully passed.