A Deep Study of Xunzi's 'Jie Pi' Chapter: On the Cognitive Foundations of the Mind—Emptiness, Unity, and Tranquility
This paper provides an in-depth analysis of the core proposition in Xunzi's 'Jie Pi' concerning the nature of cognition: 'How does man know$41 By the mind. How does the mind know$42 By being empty, unified, and tranquil.' It systematically interprets the dialectical relationship and philosophical implications of 'emptiness' (xu), 'unity' (yi), and 'tranquility' (jing) in cognition, tracing their ancient intellectual origins to reveal the systematicity and sophistication of Pre-Qin cognitive theory.

Chapter Four: Stillness (Jing) – Not Allowing Dream-Fantasies to Disturb Knowledge
Section 1: The Dialectic of "Motion" (Dong) and "Stillness" (Jing)
Master Xunzi discusses "Stillness" following the same structure: "Acknowledging reality—proposing a requirement":
"The Mind has never been without motion (dong 動), yet there is what is called Stillness (jing 静)."
The Mind is never static. It is always active—thinking when awake, dreaming when asleep, and operating automatically even when relaxed. This is the Mind's natural state. Yet, Master Xunzi, while admitting "the Mind has never been without motion," posits the requirement of "Stillness."
"When the Mind lies down, it dreams; when idle, it acts on its own; when commanded, it plots; therefore the Mind has never been without motion; yet there is what is called Stillness; not allowing dream-fantasies and intense clamor (meng ju 夢劇) to disturb knowledge is called Stillness."
Step-by-step analysis:
First Level: "When the Mind lies down, it dreams"—When one sleeps, the Mind dreams. This shows that even in sleep, the Mind has not completely ceased activity.
Second Level: "When idle, it acts on its own"—When one relaxes, the Mind operates automatically. Tou (偷) means to be careless or relaxed. Even if you are not deliberately using the Mind to think, it operates on its own, generating various thoughts and associations.
Third Level: "When commanded, it plots"—When you mobilize the Mind to think, it engages in planning (mou 謀). This is the active application of the Mind.
Fourth Level: "Therefore the Mind has never been without motion"—So, the Mind is never static. Whether in dreams, relaxation, or active thought, the Mind is always moving.
Fifth Level: "Yet there is what is called Stillness"—But the Mind still requires "Stillness."
Sixth Level: "Not allowing dream-fantasies and intense clamor (meng ju) to disturb knowledge is called Stillness"—Preventing illusory and turbulent thoughts from disturbing true cognition is called "Stillness."
Here, "Stillness" does not mean "immobility," but rather "motion without disorder." The Mind is constantly active, but this activity must be orderly, clear, and not disturbed by chaotic thoughts—this is "Stillness."
Section 2: The Harm of "Dream-Fantasies and Clamor" (Meng Ju) – Why Do Distractions Disturb Cognition$27
Meng Ju—"Dream" refers to illusory, vain thoughts; "Clamor" (ju 剧) refers to turbulent, intense thoughts. Together, they denote those illusory and chaotic mental activities.
Why do these illusory and chaotic mental activities "disturb knowledge" (luan zhi 乱知)$28
This involves a fundamental issue: the Mind’s capacity for activity is limited. Although the Mind can perform multiple activities simultaneously ("never without motion"), when some of these activities become too intense or chaotic, they consume the Mind’s energy, preventing it from engaging in clear cognitive judgment.
A person who has suffered a nightmare often remains shaken and dazed after waking, unable to immediately enter a clear state of thought—this is the direct experience of "dreams disturbing knowledge."
A person filled with various distracting thoughts tries to focus on a problem but is constantly interrupted—this is the daily experience of "clamor disturbing knowledge."
A metaphor Master Xunzi uses later in the text exquisitely reveals the mechanism of Meng Ju Luan Zhi:
"Thus the Human Mind is like water in a shallow tray. If placed correctly and not stirred, the muddy sediment settles below, and the clear brightness remains above; it is then sufficient to see the eyebrows and hair and discern principles. If a slight breeze passes over it, the sediment below stirs, and the clear brightness above becomes chaotic, so that one cannot capture the true form. The Mind is just like this."
The Mind is like water in a tray. When placed correctly and left undisturbed, the sediment sinks to the bottom, and the clear water remains on top, enabling one to see the eyebrows and discern the features. But if a slight breeze blows, stirring the sediment below and clouding the water above, one cannot even see the general outline of the face. The Mind is just the same.
In the state of "Stillness," the Mind is like still, clear water, capable of accurately reflecting external things; but under the agitation of "dream-clamor," the Mind is like muddied water, losing its capacity for clear reflection.
Section 3: The Cultural Origins of the "Water Tray" Metaphor
Master Xunzi's metaphor of the "water tray" is not isolated; it has rich resonance in pre-Qin classics.
Master Laozi said:
"Who can make turbid water gradually clear by stillness$29" (Dao De Jing, Chapter 15)
Who can cause turbid water to slowly clear through stillness$30 This rhetorical question directly corresponds to the core meaning of Master Xunzi's water tray analogy—"Stillness" can make turbid water clear, just as "Stillness" can restore the Mind from chaos to clarity.
And further:
"Purity and stillness make the world right." (Dao De Jing, Chapter 45)
Purity and stillness are the standard for the world. When the Mind reaches a state of purity and stillness, it becomes a reliable criterion for judging right and wrong and perceiving things.
Master Zhuangzi also discusses a similar notion in Tian Dao (The Way of Heaven):
"When water is still, it clearly reflects mustaches and eyebrows; when level, it serves as a standard. Great craftsmen take this as their model. If still water is clear, how much more the spirit! How still the Sage’s Mind! It is the mirror of Heaven and Earth, the glass of the myriad things."
Water, when still, reflects mustaches and eyebrows clearly; when level, it becomes a standard. If still water is so bright, how much more the spirit! The Sage's Mind is still, hence it is the bright mirror of Heaven and Earth, the glass of the myriad things.
"The bright mirror of Heaven and Earth, the glass of the myriad things"—this shares a profound parallel with Master Xunzi’s description of the "Great Clarity and Brightness" state: "Sitting in a room, one sees the Four Seas; dwelling in the present, one discusses antiquity." When the Mind achieves this state of stillness, its cognitive capacity reaches its zenith, capable of reflecting Heaven, Earth, and all things.
Master Zhuangzi continues:
"Emptiness leads to stillness; stillness leads to motion; motion leads to attainment." (Zhuangzi, Tian Dao)
Emptiness leads to stillness; stillness produces appropriate motion; appropriate motion leads to attainment. This sequence of "Emptiness—Stillness—Motion—Attainment" structurally echoes Master Xunzi's "Emptiness, Singularity, and Stillness."
Section 4: The Dialectical Relationship Between "Stillness" and "Motion"
One of the most profound aspects of Master Xunzi’s concept of "Stillness" is that it does not reject "Motion," but rather, "Stillness" is for the sake of better "Motion."
"When commanded, it plots"—When the Mind is mobilized to think, it engages in planning. This purposeful, directed "plotting" is the positive form of "Motion."
The issue is not whether the Mind moves, but whether its motion is orderly. Disorderly motion (meng ju) must be eliminated; orderly motion (mou) must be maintained and utilized. The function of "Stillness" is to eliminate disorderly motion and create the conditions for orderly motion.
Master Zhou Yi (I Ching) stated:
"As Heaven’s movement is vigorous, the Gentleman ceaselessly strives for self-perfection." (Zhou Yi, Qian Hexagram, Image)
"As Earth’s potential is receptive, the Gentleman carries the world with broad virtue." (Zhou Yi, Kun Hexagram, Image)
The movement of Heaven is vigorous and ceaseless—this is the most fundamental "Motion." The nature of Earth is heavy and still—this is the most fundamental "Stillness." Heaven moves and Earth is still; motion and stillness complement each other, giving rise to the transformation of all things. Similarly, the Mind's "Stillness" is not meant to annihilate its "Motion," but to make its "Motion" more vigorous, clear, and orderly.
In pre-Qin thought, a crucial concept is that the highest form of "Motion" actually stems from the deepest form of "Stillness."
Master Laozi said:
"Heaviness is the root of lightness; stillness is the master of agitation." (Dao De Jing, Chapter 26)
Stillness is the master of agitation. Only those whose inner minds are still can make correct judgments and actions when facing the complex external world.
And further:
"Stillness overcomes agitation; cold overcomes heat. Purity and stillness make the world right." (Dao De Jing, Chapter 45)
Stillness can overcome agitation, not by suppressing agitation's power, but by providing a stable foundation so that all actions can proceed unhurriedly and accurately.
Section 5: Cultivation and Practice of "Stillness"
Master Xunzi states:
"Those who have not yet attained the Dao but seek the Dao are called Empty, Singular, and Still. Putting this into practice (zuo zhi): ... then the one who will contemplate the Dao, if still, will discern (cha 察)."
Those about to contemplate the Great Dao, if they can achieve "Stillness," will be able to discern (cha)—Cha (discernment) is the highest achievement of cognitive activity. "Stillness" is the necessary prerequisite for attaining "Discernment."
How is the cultivation of "Stillness" practiced$31 Master Xunzi provides a general guideline:
"Therefore, guiding it with principles (dao zhi yi li 导之以理), nurturing it with purity (yang zhi yi qing 养之以清), and letting nothing incline it (wu mo zhi qing 物莫之倾), then it is sufficient to determine right and wrong and resolve suspicion."
First, "guiding it with principles" (dao zhi yi li)—Using principles (li 理) to guide the Mind. When the Mind understands the principles of things, it is less easily confused by distracting thoughts.
Second, "nurturing it with purity" (yang zhi yi qing)—Nurturing the Mind with purity. This is not a one-time event but a long-term effort of cultivation. "Purity" (qing 清) is the prerequisite and foundation for "Stillness"—a clear Mind is a still Mind; a still Mind is a bright Mind.
Third, "letting nothing incline it" (wu mo zhi qing)—Not allowing external things to overthrow the Mind's stability. The character qing (倾, incline/topple) is crucial here—it implies that the Mind’s stability is like the balance of a vessel; once it is tipped by external force, it loses its equilibrium.
Once these three points are achieved, the Mind is "sufficient to determine right and wrong and resolve suspicion."
Conversely:
"If drawn away by small things, its rectitude is externally compromised; if its inner core leans, it is insufficient to resolve even crude principles."
If attracted by trivial external things, the Mind’s rectitude shifts outward, its inner core loses balance, and it cannot even judge crude principles.
The cultivation of "Stillness" involves two aspects: removing interfering factors and safeguarding the Mind's openness.
Section 6: "Stillness" and Ancient Sacrificial Traditions
The concept of "Stillness" has deep roots in ancient culture, particularly connected to sacrificial traditions.
Ancient peoples had requirements for "fasting and purification" (zhai jie 斋戒) when conducting sacrifices. The Rites of Zhou: Rites of Sacrifice states:
"The purification inside is brought to completion, the purification outside is dispersed. On the day of purification, one contemplates the place where the object dwells, the words it spoke, the intentions it held, what it enjoyed, and what it desired. After three days of purification, one can then see what one intends to purify."
The process of purification involves eliminating external interference and concentrating the spirit, eventually reaching a state where one can "see" the object of the sacrifice. This "seeing" (jian 见) is not with the physical eye but with spiritual communion.
The most important requirement during purification is "Stillness"—stillness of mind, body, and dwelling. In a quiet environment, by eliminating all distracting thoughts, one concentrates the spirit on the object of sacrifice. Only by achieving sufficient "Stillness" can one commune with the spirits.
This experience of "Stillness" in ancient ritual can be seen as a cultural predecessor to the philosophical concept of "Stillness" in pre-Qin thinkers. The transition from the ritualistic cultivation of the ancient shamans to the rational cultivation of the pre-Qin philosophers shares a common core: through "Stillness," one can enhance spiritual perceptive power.
The Zhou Yi, Appendix A, states:
"When utterly motionless (ji ran bu dong 寂然不动), one responds and immediately penetrates the causes of all things under Heaven."
Utter motionlessness is the extreme of "Stillness." In this utmost stillness, once a response occurs, one can penetrate the principles of all things under Heaven. This reveals the deep relationship between "Stillness" and "Knowledge": knowledge does not arise from "Motion," but "Stillness" makes knowledge possible. In the state of utmost stillness, the Mind’s perceptive capacity reaches its maximum, and all responses can be accurately received and understood.
Section 7: "Stillness" and "Clarity and Brightness"
Master Xunzi calls the comprehensive effect of "Emptiness, Singularity, and Stillness" the "Great Clarity and Brightness" (Da Qing Ming):
"Emptiness, Singularity, and Stillness—this is called Great Clarity and Brightness."
"Clarity" (qing 清) means purity without impurities or interference. "Brightness" (ming 明) means illumination, penetration, and insight. "Great Clarity and Brightness" is the ultimate pure and insightful state.
In this state, the Mind becomes a perfect mirror, accurately reflecting all things.
Master Xunzi then describes the cognitive capacity in the state of "Great Clarity and Brightness":
"Nothing having form is unseen, nothing seen is unanalyzed, nothing analyzed loses its proper place. Sitting in a room, one sees the Four Seas; dwelling in the present, one discusses antiquity. Broadly observing the myriad things, one knows their true feelings; comparing and correlating governance and disorder, one comprehends their standards; weaving heaven and earth and assigning offices to the myriad things, dividing and cutting the Great Principles, the universe is brought within."
This passage paints a stunning picture: In the state of "Great Clarity and Brightness," all things with form can be seen, what is seen can be analyzed, and what is analyzed can each be put in its proper place. This is comprehensive, accurate, and orderly cognition—no omissions, no errors, no chaos.
"Sitting in a room, one sees the Four Seas; dwelling in the present, one discusses antiquity."
One can understand affairs in the Four Seas without personally traveling there, and discuss past events without having lived through them. Why is the Mind capable of transcending spatial and temporal limitations in this state$32 Because although things are distributed across different times and spaces, the "principles" (li) contained within them are interconnected. If the Mind grasps the "principles," it can extend from the self to others, from near to far, and from present to past—this is not supernatural power, but the power of rational deduction.
"...weaving heaven and earth and assigning offices to the myriad things, dividing and cutting the Great Principles, the universe is brought within."
From the true feelings of all things to the standards of governance, from the warp and weft of Heaven and Earth to the entirety of the cosmos, all are clearly presented within the "Great Clarity and Brightness" of the Mind.
This is almost a description of omniscience—yet Master Xunzi emphasizes that this is not supernatural ability, but the natural manifestation of the Mind’s potential when the condition of "Emptiness, Singularity, and Stillness" is met, and the "obscurations" are removed.
Section 8: "Great Clarity and Brightness" and the "Great Man" (Da Ren)
Master Xunzi refers to the person who attains the state of "Great Clarity and Brightness" as the "Great Man" (Da Ren):
"Vast and broad, who knows its limits$33 High and far-reaching, who knows its virtue$34 Effervescent and abundant, who knows its form$35 Its brightness matches the sun and moon, its vastness fills the Eight Extremities—this is what is called the Great Man. Ah, where would obscuration be found!"
Vast and broad—who knows its boundary$36 High and far-reaching—who knows its virtue$37 Effervescent and abundant—who knows its form$38 His brightness rivals the sun and the moon, his vastness fills the Eight Extremities—this is the "Great Man." Where could obscuration possibly exist!
The "Great Man" is the pinnacle of cognitive realization and cultivation in Master Xunzi’s view—characterized by being without obscuration, clear and bright, and vast.
This concept of the "Great Man" has extensive background in pre-Qin thought.
The Zhou Yi, Appendix on the Qian Hexagram, states:
"The Great Man harmonizes his virtue with Heaven and Earth, his brightness with the sun and moon, his order with the four seasons, and his fortunes with spiritual beings. He precedes Heaven and Heaven does not oppose him; he follows Heaven’s time and Heaven does not cross him. If even Heaven does not oppose him, how much less so man$39 How much less so spiritual beings$40"
The Great Man’s virtue aligns with Heaven and Earth, his brightness with the sun and moon, his order with the seasons, and his fortune with spirits. The phrase "his brightness with the sun and moon" directly corresponds to Master Xunzi’s "brightness matches the sun and moon"—the "Brightness" of the Great Man reaches the zenith, equal to that of the sun and moon—this is the extreme of "Great Clarity and Brightness."
Master Mengzi also speaks of the "Great Man":
"To be filled full is called beauty; to be filled full and shining forth is called Great; Great and transforming others is called Sage; Sage and unknowable is called Spirit." (Mencius, Book 7, Part 2)
From beauty to Great, from Great to Sage, from Sage to Spirit—this is a layered progression of personal attainment. The characteristic of "Great" is "filled full and shining forth"—internally substantial, externally bright. This aligns with the meaning of "Great" in Master Xunzi’s "Great Clarity and Brightness."
Section 4: "Seeing" (Jian) in the State of "Great Clarity and Brightness"
Master Xunzi repeatedly uses the character jian (见, to see) when describing the state of "Great Clarity and Brightness":
"Nothing having form is unseen (bu jian 不见).""Sitting in a room, one sees (jian 见) the Four Seas."
This character jian deserves careful examination. In pre-Qin thought, jian refers not only to physical sight but also to spiritual insight. Physical sight is limited—it can only see things in the present and nearby; spiritual sight is infinite—it can "see" things far away, in the past and future, and the subtly hidden.
Master Zhuangzi has a famous passage in Yang Sheng Zhu (Nourishing Life):
"When I first began to butcher oxen, I saw the whole ox before me. After three years, I no longer saw the whole ox. Now, I meet the ox with my spirit and do not see it with my eyes; my senses stop, and my spirit moves."
Cook Ding’s butchering—initially he saw the entire ox; after three years, he no longer saw the whole ox—he saw the spaces between the bones and sinews. Eventually, he no longer looked with his eyes, but "met the ox with his spirit" (yi shen yu 以神遇)—his spirit connected directly with the inner structure of the thing.
Cook Ding’s "meeting with spirit" is a state of "Great Clarity and Brightness"—no longer relying on superficial sensory observation, but directly grasping the inner essence of things.
Section 5: The Final Affirmation: The Great Man and the Absence of Obscuration
"Ah, where would obscuration be found! (Fu e you bi yi zai! 夫恶有蔽矣哉!)"
Master Xunzi concludes the description of the "Great Clarity and Brightness" state with a forceful rhetorical question: How could such a "Great Man" still suffer from "obscuration"$1
This rhetorical question implies that before reaching the state of "Great Clarity and Brightness," "obscuration" is universally present—almost everyone is obscured, to a greater or lesser degree. Only the rare few who attain "Great Clarity and Brightness" can be completely free from the troubles of bi.
This is a view both awe-inspiring and encouraging. It is awe-inspiring because it reveals the universal limitation of human cognition—we are all obscured. It is encouraging because it points to the possibility of transcending this limitation—through the cultivation of "Emptiness, Singularity, and Stillness," man can reach the state of "Great Clarity and Brightness."