Chapter Two: Xu -- Do Not Let What Has Been Stored Impede What Is Yet to Be Received

Section 1: The Dialectic of "Storing" and "Openness"

Master Xun's discussion of xu begins with a profoundly perceptive observation:

"The mind has never ceased to store; yet there is what is called xu (openness)." (xin wei chang bu cang ye, ran er you suo wei xu)

Cang means to store, to preserve. The mind is never devoid of content; it is perpetually storing accumulated knowledge, experience, and memory. This is the mind's fundamental condition. And yet, precisely upon the premise that "the mind never ceases to store," Master Xun put forward the requirement of xu.

Here lies an exquisitely subtle dialectical relationship: xu is not the absence of accumulation, but the state of having accumulated without being constrained by one's accumulations.

"A person is born with the capacity to know; knowing, one has memory; memory is storing. Yet there is what is called xu: not letting what has already been stored impede what is yet to be received -- this is called xu."

Let us parse the logic of this passage layer by layer:

First layer: "A person is born with the capacity to know" -- human beings possess an innate capacity for cognition. This is Master Xun's affirmation of the cognitive faculty inherent in human nature.

Second layer: "Knowing, one has memory" -- cognitive activity gives rise to memory and accumulation. Zhi (memory) here means to record and retain.

Third layer: "Memory is storing" -- memory is the process of preservation. The mind continuously stores the fruits of cognition; this is its natural function.

Fourth layer: "Yet there is what is called xu" -- yet the mind still requires xu.

Fifth layer: "Not letting what has already been stored impede what is yet to be received -- this is called xu" -- refusing to let existing stores obstruct the reception of new content: this is xu.

Why would existing knowledge "impede" future reception$12 This is a question well worth pursuing.

Section 2: Why Does "What Has Been Stored" Impede "What Is Yet to Be Received"$13

Why did Master Xun believe that accumulated knowledge could obstruct the reception of new knowledge$14 Behind this insight lies a profound understanding of the limitations of human cognition.

Human cognition has a natural tendency: to frame the unknown through the lens of the known. Once we have formed a conception of something, we tend to interpret every new instance of a related phenomenon through that existing conception. This tendency is useful in most cases -- it helps us make quick judgments and responses; yet at certain critical junctures it becomes a serious obstacle -- it prevents us from seeing things as they truly are.

At the opening of the "Jiebi" chapter, Master Xun enumerated many examples of those "obscured by one partial view and thereby blinded to the greater principle" (bi yu yi qu er an yu da li):

"Mozi was obscured by utility and blind to cultural refinement; Songzi was obscured by desire and blind to attainment; Shenzi was obscured by law and blind to the worthy; Shen Buhai was obscured by positional power and blind to wisdom; Huizi was obscured by words and blind to reality; Zhuangzi was obscured by Heaven and blind to the human."

Master Mo's mastery of "utility" caused him to be obscured by it, preventing him from seeing the value of "cultural refinement." Master Zhuang's deep comprehension of "Heaven" caused him to be obscured by it, preventing him from seeing the needs of "the human." Each thinker's obscuration arose precisely from his own cang -- his stored knowledge. It was precisely because each had profound accumulation and refined understanding in a particular area that he was constrained by that very accumulation and understanding.

This is the concrete manifestation of "letting what has been stored impede what is yet to be received." Existing knowledge constitutes a framework; while this framework helps us understand the world, it simultaneously limits the manner in which we understand the world.

The Most High (Laozi) said:

"In the pursuit of learning, one gains daily; in the pursuit of the Way, one diminishes daily. Diminish and diminish again, until one arrives at non-action (wu wei)." (Daodejing, Chapter 48)

"In the pursuit of learning, one gains daily" -- the process of study is one of ceaseless accumulation, the process of cang. Yet "in the pursuit of the Way, one diminishes daily" -- the pursuit of the great Way demands continual diminution, the shedding of those existing conceptions that might obscure the Way. This resonates deeply with Master Xun's xu -- both perceive the obscuring effect that the accumulation of knowledge may produce.

Section 3: The Archaic Origins of "Xu": The Usefulness of a Vessel Lies in Its Emptiness

The concept of xu possesses an exceedingly rich history in pre-Qin thought, traceable to observations that the ancient ancestors made about vessels and implements.

The Most High (Laozi) used the metaphor of vessels to reveal the fundamental significance of xu:

"Thirty spokes converge at one hub; it is the emptiness at the center that makes the wheel useful. Clay is shaped into a vessel; it is the emptiness within that makes the vessel useful. Doors and windows are cut for a room; it is the emptiness within that makes the room useful. Therefore, 'having' provides advantage, while 'not-having' provides function." (Daodejing, Chapter 11)

The empty center of a wheel allows it to turn; the empty interior of a clay vessel allows it to hold things; the empty space within a room allows it to shelter people. "Having" provides the conditions; "not-having" (xu) provides the function.

This metaphor reveals a profound truth: it is precisely xu that makes "receiving" possible. A cup already full of water cannot accept more; a mind already filled to the brim with existing knowledge cannot admit new understanding.

We may further ask: why did the ancient ancestors come to conceive of xu$15

Examining the developmental history of ancient implements, we discover an interesting clue: from the Stone Age to the age of pottery, one of the core techniques humans developed for making implements was "creating emptiness" -- producing interior space within objects. The earliest stone tools were solid, useful only for striking and cutting. The invention of pottery marked the moment when humans learned to make hollow containers. This "emptiness" was the very key to the implement's function.

Through the daily making and use of pottery, the ancient ancestors must have gradually come to appreciate the importance of xu: a good vessel is defined not by the thickness of its walls but by the spaciousness of its interior. This humble experiential insight, through long cultural sedimentation and intellectual sublimation, eventually became one of the wellsprings of the concept of xu in pre-Qin philosophy.

The Guanzi, in the "Xinshu Shang" (Art of the Mind, Part I) chapter, also used the metaphor of a dwelling for the mind, emphasizing the importance of xu:

"The mind's position in the body is that of a sovereign. The nine apertures each have their duties, like officials with their allotted roles. When the mind abides in its proper Way, the nine apertures follow principle. When cravings and desires overflow, the eyes cannot see color and the ears cannot hear sound. Therefore it is said: when the ruler above departs from the Way, the subordinates below lose their functions."

The mind is like the sovereign within a dwelling; the nine apertures are like officials each attending to their duties. If the mind is filled to overflowing with cravings and desires, the sensory organs -- eyes, ears, and the rest -- can no longer function properly. This "overflowing of cravings and desires" is precisely another expression of "letting what has been stored impede what is yet to be received."

Section 4: "Xu" Is Not "Emptiness": Active Openness versus Passive Vacancy

It must be particularly emphasized that xu as Master Xun intended it is absolutely not the "emptiness" of possessing nothing at all.

Master Xun stated explicitly that "the mind has never ceased to store" -- the mind is never empty; it always possesses accumulated content. Xu does not demand the erasure of all existing knowledge and experience; rather, it demands that while maintaining one's existing accumulations, one not let these accumulations obstruct the recognition of new things.

This is an active, dynamic xu, not a passive, static emptiness.

To use an analogy: a fine scholar has read a thousand volumes and accumulated rich learning; yet when confronted with an entirely new problem, he can temporarily set aside his existing preconceptions and approach it with an open mind -- observing, reflecting, and judging afresh. His xu does not mean he has forgotten his learning; it means he is not bound by it.

The Lunyu (Analects) records a passage about the Master that may serve as mutual corroboration:

"The Master was free from four things: he did not speculate (wu yi), he did not insist on certainty (wu bi), he was not inflexible (wu gu), and he was not self-centered (wu wo)." (Lunyu, "Zihan")

"Wu yi" -- no idle speculation. "Wu bi" -- no absolutism. "Wu gu" -- no rigidity. "Wu wo" -- no egocentrism. These four "wu" are precisely the xu that the Master practiced. The Master's learning was the most extensive in all the world of his time, yet he was able to refrain from speculation, absolutism, rigidity, and egocentrism -- this is the finest gloss on "the mind has never ceased to store, yet there is what is called xu."

Consider another passage from the Master:

"Do I possess knowledge$16 I do not. When a rustic fellow comes to me with a question, I am empty as can be (kongkong ru ye). I tap both ends of the matter and exhaust it." (Lunyu, "Zihan")

The Master said he "did not possess knowledge," that when facing a question he was "empty as can be" -- this is not genuine ignorance but the maintenance of an open and luminously empty state of mind. Then "I tap both ends and exhaust it" -- exploring from both sides and pursuing the matter to its utmost. First xu, then knowing: this is a vivid demonstration of the practice of xu.

Section 5: The Relationship Between "Xu" and "Receiving": The Openness of Cognition

Master Xun constructed a pair of concepts -- "what has been stored" (suo yi cang) and "what is yet to be received" (suo jiang shou) -- to reveal the core function of xu: preserving the openness of cognition.

The character shou (to receive) carried rich meaning in pre-Qin texts. The Shuowen glosses shou as "mutual transfer," signifying acceptance and reception. In cognitive activity, shou refers to the mind's reception and absorption of external information.

Why must the mind continually "receive"$17 Because the world is ever-changing and inexhaustibly rich; no existing system of knowledge can exhaust it entirely.

The Yijing (Book of Changes) says:

"Daily renewal -- this is called the fullness of virtue." (Xici Shang)

And further:

"When a path is exhausted, it changes; when it changes, it opens; when it opens, it endures." (Xici Xia)

The world is forever in transformation, and cognition must be renewed accordingly. If the mind is so filled with existing knowledge that it has lost its capacity to "receive," it becomes a stagnant pool, unable to admit the inflow of living water.

The Most High (Laozi) also offered profound reflections on this:

"Attain the utmost of xu; hold fast to the depth of stillness. The myriad things arise together; I thereby observe their return. Things flourish in profusion, yet each returns to its root. Returning to the root is called stillness; stillness is called returning to one's destiny. Returning to one's destiny is called the constant. To know the constant is called clarity. Not to know the constant is to act blindly and court disaster." (Daodejing, Chapter 16)

"Attain the utmost of xu" -- push xu to its extreme. Only by reaching the utmost of xu can one accommodate the simultaneous arising of all things and observe the cyclic patterns of their return. This resonates deeply with Master Xun's "do not let what has been stored impede what is yet to be received."

Section 6: The Unfolding of "Xu" in Cognitive Practice

Master Xun's xu is not merely a theoretical concept but a requirement for cognitive practice.

In actual cognitive activity, xu encompasses at least the following dimensions:

First, openness to new information. Not refusing to receive new information that differs from one's existing judgments. This is the most fundamental meaning of xu.

Second, reflection upon existing judgments. Regularly examining one's existing understandings to see whether they remain correct and whether they need correction. This is the deeper meaning of xu.

Third, tolerance of different viewpoints. Being able to accommodate viewpoints that differ from one's own, and judging only after thorough understanding. This is the social dimension of xu.

In the Lunyu, the Master said:

"When three people walk together, there must be one among them who can serve as my teacher. I select what is good in them and follow it; what is not good, I correct in myself." (Lunyu, "Shu Er")

Among any three companions, there must be one who can serve as one's teacher. This attitude of humble receptivity is the concrete embodiment of xu in human interaction and the pursuit of learning.

Again, the Lunyu records:

"When the Master entered the Grand Temple, he asked about everything." (Lunyu, "Ba Yi")

The Master entered the Grand Temple and inquired about every matter. Some questioned his learning on this account. But the Master's "asking about everything" was precisely a demonstration of never being complacent with what he already knew, of always maintaining a humbly inquiring spirit. This is the paradigm of "not letting what has been stored impede what is yet to be received."

Consider also:

"The Master said: 'To learn without reflecting leads to confusion; to reflect without learning leads to peril.'" (Lunyu, "Wei Zheng")

"Learning" is the outward reception of new knowledge; "reflecting" is the inward digestion and integration. If one only learns without reflecting, what one learns remains disorganized and cannot form systematic understanding; if one only reflects without learning, one is confined to existing knowledge and falls into difficulty. The union of learning and reflecting is the maintenance of balance between cang and xu -- possessing accumulations without being trapped by them.

Section 7: The Difficulty of "Xu": Why People Struggle to Achieve It

If xu is so important, why do people so often fail to achieve it$18

Master Xun provided a penetrating analysis in the latter half of the "Jiebi" chapter. He enumerated numerous phenomena of bi (obscuration), demonstrating how human cognition is obscured by various factors:

"Whenever one observes something with doubt, and the mind within is unsettled, then external things appear unclear. When my thinking is unclear, I cannot determine what is so and what is not."

When doubt dwells in the mind and it cannot settle, perception of external things becomes blurred. Judgments made at such times are unreliable.

Master Xun offered a series of vivid examples:

"One who walks in darkness sees a crouching stone and takes it for a crouching tiger, sees an upright tree and takes it for a standing person -- the darkness obscures his clarity."

"A drunkard leaps over a ditch a hundred paces wide, thinking it a tiny channel one step across; he stoops to exit a city gate, thinking it a small doorway -- the wine has disordered his spirit."

"One who presses his eyes sees one thing as two; one who covers his ears hears silence as clamor -- external force has disrupted his organs."

These examples vividly illustrate how human cognition is disrupted and distorted by various factors -- darkness, alcohol, physical force. At a deeper level, existing knowledge, emotional inclinations, and vested interests similarly disrupt and distort cognition -- which is precisely why xu is so important and so difficult.

The fundamental reason people struggle to achieve xu is this: existing knowledge and experience have become deeply integrated into our cognitive processes, forming the "default framework" through which we observe and understand the world. To break through this framework requires tremendous self-awareness and effort.

Section 8: The Significance of "Xu" as Spiritual Cultivation

Within Master Xun's intellectual system, xu is not merely an epistemological concept but a concept of cultivation (gongfu) -- it points to a state of mind that requires sustained practice and training.

Master Xun said:

"Those who have not yet attained the Way but seek it are told: xu, yi, and jing. Put this into practice: those about to pursue the Way who achieve xu will find it entering them."

"Put this into practice" (zuo zhi) -- carry it out. Those who are about to follow the great Way, if they can achieve xu, will find the Way entering their minds ("entering" -- ren, here a variant of ru, "to enter"). Here, xu is an active spiritual discipline, not merely a passive cognitive state.

The Guanzi, in its "Neiye" (Inner Cultivation) chapter, also contains a similar discussion:

"As for the form of the mind: it fills itself, replenishes itself, generates itself, completes itself. What causes it to be lost is invariably worry, joy, delight, anger, desire, and profit-seeking. If one can remove worry, joy, delight, anger, desire, and profit-seeking, the mind will return to its full capacity."

The mind inherently possesses the capacity for self-fulfillment and self-perfection, but emotions such as worry, joy, delight, anger, desire, and profit-seeking cause it to lose this capacity. The ability to remove these disturbances is the practice of xu.

And further:

"The true disposition of the mind is to seek peace and tranquility. Do not vex it, do not disorder it, and harmony will naturally arise."

The mind's nature is to seek tranquility; do not agitate it, do not disturb it, and harmony will form of its own accord. This "do not vex, do not disorder" is yet another expression of the cultivation of xu.

Therefore, the cultivation of xu may be summarized in two aspects: first, "removing" -- removing those factors that disrupt cognition; second, "guarding" -- guarding the mind's openness and luminous clarity. Removing and guarding in tandem is the only way to truly "not let what has been stored impede what is yet to be received."