《天原發微》Vol. 2

This chapter of Tianyuan Fawei discusses how the movement and stillness of Taiji (the Supreme Ultimate, cosmic origin) generate the two energies of Yin and Yang. Taiji itself has no concrete form, yet through movement and stillness it manifests the Qi of Yin and Yang. Movement and stillness are modes of Qi's motion, while Li (cosmic principle) becomes evident through Qi's operation.

Odd and even numbers transform into each other, just as feminine and masculine principles complement one another. The acquisition of Yang Qi forms the Way of Qian (the Yang principle), giving rise to the masculine, while the acquisition of Yin Qi forms the Way of Kun (the Yin principle), giving rise to the feminine. When Qi accumulates, it takes shape; when forms interact, they generate new resonances of Qi. The intricate interweaving of Yin and Yang constitutes what the Yijing (Book of Changes) calls transformation. Between Heaven and Earth, there is only this fundamental cycle of movement and stillness—nothing else exists beyond it.

Someone asked: According to Zhou Dunyi, Yang’s movement represents function, while Yin’s stillness represents substance. Yet Zhouzi begins his discussion with movement, stating that Taiji moves and generates Yang. Doesn’t this imply that function precedes substance? If so, what was the state of Taiji before movement?

The response: Before movement, there was Li—the state of "Wuji (Non-Ultimate) and yet Taiji." Li itself cannot be described in terms of movement or stillness, for before movement there appears to be stillness, and before stillness there is the implication of movement. Ultimately, however, Li transcends the duality of movement and stillness. Although Li cannot be expressed through movement or stillness, it must manifest through them.

Shao Yong said, "Function arises before Heaven and Earth," and Zhu Xi stated, "The function of Taiji is what propels its operation." Both refer to the functional manifestation of Taiji. The state before "movement generates Yang" is a profound realm beyond words.

Zhou Dunyi explained: When Taiji moves, it generates Yang Qi; when movement reaches its limit, it returns to stillness. When it is still, it generates Yin Qi; when stillness reaches its limit, it resumes movement. Movement and stillness are each other’s root, thus giving rise to the two modes (Heaven and Earth).

Zhu Xi’s interpretation is particularly profound: The movement and stillness of Taiji are the way of Tianming (Heaven’s Mandate, cosmic law). Hence, the Yijing states, "One Yin and one Yang constitute the Dao." Ultimate sincerity (zhicheng) is the foundation of the sage, and the beginning and end of all things follow this principle. When Taiji moves, it is the flow of ultimate sincerity—inherited as goodness, from which all things arise. When it is still, it is the return of ultimate sincerity—fulfilled as nature, in which all things find their place. Movement and stillness alternate, ensuring the ceaseless circulation of Tianming. Movement generates Yang; stillness generates Yin. Yin and Yang divide, and thus the two modes are established.

This passage elucidates the relationship between Taiji (the Supreme Ultimate, cosmic origin) and movement/stillness, as well as Yin-Yang. Taiji is the fundamental principle transcending physical form, while Yin-Yang manifests as the expressive modes of concrete phenomena. Taiji resembles an eternal, unchanging principle, with movement and stillness serving as the Qi (vital energy) that carries this principle. Just as a rider mounts a horse, Taiji rides the dynamic interplay of Qi's movement and stillness to generate Yin-Yang—when moving, it manifests as Yang within Taiji; when still, it appears as Yin within Taiji.

From the perspective of Yin-Yang, these dual forces are always contained within Taiji; conversely, it's equally valid to say Taiji exists within Yin-Yang. Concrete phenomena tend to become confined to fixed forms, either excessively active and losing stillness, or overly still and losing movement. Yet the wondrous spiritual nature (Shen) can transcend physical limitations, achieving a harmonious state where movement contains stillness and stillness contains movement.

Tracing upward, the Five Phases (Wood, Fire, Earth, Metal, Water) and Yin-Yang all originate from Taiji's transformation between movement (Yang) and stillness (Yin)—this is the unified source of all things. Manifesting downward, Yin-Yang and the Five Phases disperse into myriad phenomena (Yin-stillness and Yang-movement), representing the process where a single essence differentiates into countless forms. Like moonlight reflecting on rivers and lakes—where every ripple carries a complete lunar image—each phenomenon inherently receives Taiji in its entirety, never fragmented.

Cheng Yi (Master Cheng) further observes: The cycle of movement/stillness and Yin-Yang has no beginning. Movement generates Yang, yet its foundation is stillness; from stillness inevitably emerges movement again. This endless progression reflects the Dao's natural pattern. Human principles emulate heavenly principles—beginning with Yin and culminating in Yang, rooted in stillness while manifesting as movement. Yet Yang ultimately returns to stillness, while stillness itself is grounded in movement, forming an endless cycle without origin or conclusion. The term "root" is particularly meaningful, revealing the profound interdependence where movement and stillness serve as each other's existential foundation.

(Note: "Taiji" refers to the ultimate cosmic principle; "Yin-Yang" represents the duality and unity of opposites in phenomena; "Five Phases" denote the five fundamental elements of Metal, Wood, Water, Fire and Earth; "Two Qi" refers to Yin and Yang energies.)

This passage explores the fundamental origins and interrelationship of movement and stillness (dong-jing), with the core view that both stem from a deeper ontological source—the Taiji (Supreme Ultimate).

It first distinguishes two types of movement-stillness: the determined, visible forms and the undetermined, invisible root. The invisible constitutes the true foundation. This "root" defies simple explanation—to claim movement roots in stillness or vice versa merely describes their surface-level transformation. Zhu Xi (Master Zhu) offers deeper insight: yuan-heng (origination and development) represents the outward movement of "cheng" (authentic nature), while li-zhen (benefit and steadfastness) embodies its inward return to stillness. Though yuan manifests as movement, its essence springs from stillness; though zhen appears as stillness, it reveals itself through movement. This zhen state marks the pivotal point where all things culminate and regenerate.

Humans cannot remain absolutely still, yet to establish the fundamental human standard (renji), one must grasp stillness' essence. Only then can action maintain proper measure without losing innate tranquility. Stillness grounds our nature's establishment, while movement expresses life's operation. In truth, both are life's manifestations, while what permeates them constitutes nature's authentic state (xing zhi zhen). Thus the wuji (Limitless)'s zhen encompasses both movement and stillness, whereas the "unmanifest equilibrium" (wei fa zhi zhong) specifically denotes stillness. Here zhen seemingly serves as movement-stillness's root.

The author contends: yang qi's generation through movement doesn't originate from movement itself, but manifests through Taiji; similarly, yin qi's formation through stillness stems from Taiji's inward contraction. Taiji functions as heaven-earth's foundation, governing yin-yang and movement-stillness qi to transform and generate all things. How easily can this root be explained?

A tree-growth analogy follows: A hundred-foot tree forms an unbroken unity from roots to leaves—movement-stillness cannot be split as separate matters. Taiji resembles a tree: its trunk branches out, flowers bloom, fruits form in endless regeneration. Ripened fruit appears still yet harbors new vitality. The Yijing's Gen hexagram (symbolizing cessation) contains life-renewing meaning—this movement-stillness alternation follows natural law without artificial arrangement, demonstrating the truth of fundamental-peripheral continuity.

Zhu Xi adds that movement-stillness also divides into yin-yang: flowing transformation belongs to yang, while quiescent convergence to yin. Yet both remain different manifestations of Taiji's singular substance.

This passage explores the dialectical relationship between yin-yang and movement-stillness, and its manifestation in human nature.

It first explains the operational principles of yin-yang movement: the fundamental law governing all phenomena contains two states—"flowing transformation" (dynamic change) and "relative opposition" (static balance). Like the alternation of yin and yang, extreme movement transitions into stillness (yin-yang opposition), and extreme stillness transforms back into movement. For instance, the seasonal shift between winter and summer represents vertical change, while the directional attributes of east-west and south-north (east as yang, west as yin; south as yang, north as yin) demonstrate horizontal opposition. "Relative opposition" constitutes the essential state, while "flowing transformation" manifests as functional expression—the essence remains still while its functions move, thus the mutual generation of movement and stillness creates infinite transformations.

Two transformation patterns are described: "mutual change" (bianyi) refers to yin and yang converting into each other (like old yang transforming into young yin), which forms the principle of divination; "interactive exchange" (jiaoyi) denotes yin and yang interacting (as seen in heaven-earth positioning), which governs the arrangement of trigrams.

The discussion then turns to human nature: Only after Mencius did people begin understanding human nature's essence through Zhou Dunyi's (Lianxi) theory of movement-stillness and yin-yang. Before birth, humans possess only heavenly principle (cosmic law), and it's through receiving this principle that "nature" (xing) forms. Pure heavenly nature embodies cosmic principle, but when combined with yin-yang and the Five Phases, it creates differentiated "temperamental nature"—the mixture of principle and qi produces variations from clarity to turbidity, while the Five Phases' influence distinguishes good and evil. Nature belongs to metaphysical heavenly principle, qi constitutes physical impurities, and the physical form represents the most turbid aspect of qi.

Finally, it contrasts ordinary people and sages: Though commoners possess the principles of movement-stillness, they often cling to extremes—either indulging desires (movement without stillness) or sinking into passive inertia (stillness without movement), making them no different from animals. Sages perfectly embody the De (virtue/power) of movement-stillness, using stillness as foundation while properly applying movement. Movement and stillness originally form the unity of opposites within natural cosmic principle—losing this balance means departing from the Dao.

This passage explores the philosophical concepts of dynamic-stillness, yin-yang, and firm-yielding as complementary opposites, and their manifestations in cosmic operation and human cultivation.

Between movement and stillness exists a relationship of mutual dependence. When things are in motion, the principle of stillness does not disappear; when things are at rest, the principle of movement never ceases. Therefore, one's actions should accord with the Middle Way, affairs should be handled with rectitude, intentions should arise from benevolence, and decisions should be made with appropriateness. Whether in motion or stillness, one can fully embody the Dao of Taiji (Supreme Ultimate). Achieving this state can pacify the disturbances caused by impulsive desires, emotional excesses, and conflicts of interest.

Shao Yong (a Northern Song Dynasty Neo-Confucian scholar) proposed: Heaven originates from movement, Earth originates from stillness. At the beginning of movement, yang qi emerges; at its extreme, yin qi is produced. At the beginning of stillness, yielding manifests; at its extreme, firmness appears. Within yin and yang there are further divisions—hence we have Great Yin, Great Yang, Lesser Yin, and Lesser Yang. Within firmness and yielding there are also gradations—thus we have Great Firmness, Great Yielding, Lesser Firmness, and Lesser Yielding.

From Taiji differentiate movement and stillness—this is "One generating Two." From movement-stillness emerge yin-yang and firm-yielding—this is "Two generating Four." Further distinguishing between "Great" and "Lesser" forms the Bagua (Eight Trigrams). Through this progression, the patterns of all phenomena between heaven and earth are encompassed.

Regarding the movement-stillness relationship, the author maintains that movement originates from stillness. Just as the celestial movements of the four seasons operate ceaselessly, they all take stillness as their foundation. Without night, day would lack definition; without winter, the growth of all things during spring, summer, and autumn could not be completed. Like humans needing rest after daily labor to restore their shen (spirit), if the four seasons lacked winter's dormancy and continued growing perpetually, primordial qi would eventually be exhausted.

The Yijing states: "Closing the gate is called Kun (Earth), opening the gate is called Qian (Heaven)"—this describes the process from stillness to movement. Kun begins at the summer solstice with yin qi moving rightward, causing all things to contract—hence "closing." Qian begins at the winter solstice with yang qi moving leftward, prompting all things to expand—hence "opening." Kun's closure transforms yang into yin; Qian's opening transforms yin into yang. This alternation of opening and closing constitutes change itself.

The transformations between heaven and earth never cease, manifesting in the alternation of cold and heat throughout the year and the cycle of day and night within a single day. For humans, these changes appear as the rhythm of breathing and the cycle of life and death. Without absolute stillness, there can be no true movement—it is precisely through these transformations that humanity comprehends the world.

The Book of Changes (Yijing) states that the highest state is one of no-thought and non-action (Wuwei), utterly tranquil and unmoving, yet capable of resonating with and penetrating all things under heaven. Cheng Yi explained that "centrality" (zhong) refers to this state of quiescent stillness, while "harmony" (he) denotes the capacity to resonate and comprehend. This stillness is perpetually responsive, and this responsiveness never departs from stillness—this is the complete manifestation of heavenly mandate and the purest state of the human heart-mind. When thoughts have not yet arisen, one can perceive the substance of resonance; when thoughts begin to stir, one can observe the function of stillness. The human heart-mind and heavenly principle are originally one.

Shao Yong held that the subtle transformations between movement and stillness constitute the most profound mystery of heaven, earth, and humanity. The expansion of yang qi manifests as movement, while the contraction of yin qi manifests as stillness. The true marvel lies neither in clinging to movement nor stagnating in stillness, but in transcending both to attain the state of sovereign mastery. As the Scripture of Great Mystery (Taixuan Jing) states, yang qi lies concealed within the foundational huangzhong pitch (the first of the twelve musical tones), and "sincerity" (cheng—authentic and free from delusion) is the essence that permeates it.

In his Penetrating the Book of Changes (Tongshu), Zhou Dunyi pointed out: "Yuan-heng (origination and flourishing) is the unfolding of sincerity, while li-zhen (benefit and steadfastness) is its return. Between this unfolding and returning lies genuine principle." The transition from li to zhen represents the mysterious storing of heaven-earth-humanity's essence, while the shift from zhen to yuan marks the inception of their mystery. This state of steadfast authenticity is the unchanging substance within the transformations of all things, as well as the profound mystery by which the Wuji (Ultimateless) and Taiji (Supreme Ultimate) penetrate heaven and humanity.

The sages established the standard for human conduct by taking stillness as fundamental (zhujing), precisely because they grasped this most subtle pivot. This marvel defies description—when movement reaches its extreme and returns to stillness, it is death; when stillness reaches its limit and renews movement, it is rebirth. The shift from yang at its zenith to yin is transformation (hua), while the reversal from yin at its peak to yang is metamorphosis (bian). Those who comprehend the true meaning between movement and stillness can penetrate the mysteries of life-death transformation.

This passage discusses the relationship between Yin-Yang transformation and Wuji (the Limitless) and Taiji (the Supreme Ultimate). Before Wuji (referring to the undifferentiated primordial state of the cosmos), Yang was contained within Yin; after forms and appearances emerged, Yin was differentiated from Yang. Zhu Xi explained that from the Gou hexagram to the Kun hexagram, Yang is contained within Yin, while from the Fu hexagram to the Qian hexagram, Yin is differentiated from Yang.

The state between the Fu and Gou hexagrams is Wuji. The process of returning from the Kun hexagram to the Gou hexagram represents the state before Wuji. This is primarily understood through the cyclical transformations depicted in the Taiji diagram. The Kun hexagram represents Yin-Qi (Yin energy) condensed to its extreme, while the Fu hexagram represents Yang-Qi that has not yet manifested—this is the most fundamental state of stillness, not opposed to movement but rather the root of both stillness and movement.

Early Confucian scholars regarded this kind of stillness, which is not opposed to movement, as the state of "Wuji er Taiji" (the Limitless giving rise to the Supreme Ultimate). In the most profound stillness, there is only the perceiving subject, with no perceived object. In the Book of Changes, this corresponds to the Kun hexagram, which is pure Yin without Yang, yet contains within it the unchanging principle. As for the Fu hexagram, it must be understood in conjunction with the state of emerging perception.

Shao Yong's statement, "At the moment of the first stirring of Yang, before the birth of all things," captures this idea. Using the human mind as an analogy, it resembles the moment when compassion is about to arise but has not yet fully manifested—like the instant one sees a child about to fall into a well. This state can only be grasped through quiet contemplation.

From the perspective of the Taiji diagram: the right side belongs to Yin, which governs contraction. Within Yin, there is Yang. The process of diminution from the Xun hexagram to the Kun hexagram represents the state before Wuji, where Yin contains Yang. The left side belongs to Yang, which governs expansion. Within Yang, Yin is differentiated. The process of growth from the Zhen hexagram to the Qian hexagram represents the state after forms emerge, where Yang divides into Yin.

When the Qian hexagram produces one Yin line, it becomes the Gou hexagram, akin to a father giving birth to his eldest daughter. When the Kun hexagram produces one Yang line, it becomes the Fu hexagram, akin to a mother conceiving her eldest son. This is discussed from the holistic perspective of Qian-Kun and Yin-Yang. If we speak solely of Wuji, it exists only between the Fu and Gou hexagrams and cannot be broadly applied to states after forms emerge.

Thus, the return from the Kun hexagram to the Gou hexagram represents the state before Wuji, while the space between the Fu and Gou hexagrams is Wuji itself. What does this "between" signify? It means a state without movement or stillness yet containing both, without Yin or Yang yet encompassing both, with principle yet without form, utterly silent and profoundly subtle. Zhou Dunyi's phrase "Wuji er Taiji" expresses this—indescribable in words. It is like the sudden clap of thunder in the dead of night, startling countless households with its abrupt and unpredictable nature.

This passage explains the Daoist understanding of cosmic operations. It begins by distinguishing two types of primordial origins: the "Taiji" (Supreme Ultimate) that generates heaven and earth, and the "life origin" that gives birth to all things.

Using temporal metaphors: the Hai hour (9-11 PM), the tenth lunar month, and the state before Taiji's movement all represent "Kun" (pure Yin state). The Zi hour (11 PM-1 AM), winter solstice, and the initial movement of Taiji correspond to the "Fu" hexagram (first stirrings of Yang qi). The winter solstice marks the beginning of heaven-earth's primordial qi, while the spring equinox initiates the growth of all things. "One" represents the substance of primordial qi, while "two" signifies its functional manifestations.

The seasonal cycle operates thus: spring begins with closure before opening, summer reaches full openness, autumn transitions from opening to closing, and winter achieves complete closure. Though winter appears as nature's dormant phase, it actually initiates new life. Primordial qi circulates through "unhindered flow - beneficial fulfillment - harvest - steadfast preservation" - the more rigorous winter's storage, the more vigorous spring's vitality. An unseasonably warm winter leads to poor harvests because Yang qi disperses prematurely.

Zhu Xi (Master Zhu) illustrated this with a metaphor: in utter stillness we perceive heaven-earth's essential heart, like glimpsing light within darkness. When three Yang lines flourish in abundance, nature's essence becomes obscured; only in the silent purity before creation, when Yang qi stirs beneath Yin, do we witness heaven-earth's true heart. Shao Yong (Master Shao) declared "heaven's heart never alters," referring to this eternal principle.

Hexagram analysis clarifies: Fu hexagram's single Yang line reveals heaven-earth's essential heart; Dazhuang hexagram's four Yang lines manifest their disposition; Kun hexagram's six Yin lines embody their fundamental nature. The passage concludes by emphasizing stillness mastering movement: maintaining mental clarity and emptiness allows natural responsiveness to all phenomena, while selfish desires inevitably lead one astray from the Dao.

The human mind should be as pure and focused as a calm, clear water surface, free from any selfish thoughts or distractions. In this state, one can accurately perceive external phenomena, with all actions and stillness naturally aligning with heavenly principles. I once heard Master Yanping (Li Tong) instruct his disciples: the key is to recognize one's original mind in stillness and observe the inner state before emotions arise, so that handling affairs will naturally be appropriate. This is the essential teaching passed down through generations in the Guishan school (followers of Yang Shi).

The human mind should resemble a bright mirror and still water, not lifeless wood or cold ashes. Though a bright mirror and still water are fundamentally motionless, they can reflect all things—this illustrates the principle of movement within stillness and function within substance. The profundity of the human mind lies precisely here. If it becomes like lifeless wood that cannot grow or ashes that cannot reignite, it turns into something useless. The human mind inherently contains all principles and responds to all affairs—how can we let it become useless?

True stillness practice is not about shutting oneself away in solitary sitting, completely detached from worldly matters. As the Gen hexagram in the Book of Changes (Zhouyi) speaks of "stopping," this stillness is meant for better action—it is the wisdom of movement within stillness. Laozi's (Laozi) teachings emphasize movement within stillness, while the theories of Su Qin and Zhang Yi (Su Zhang) excessively pursue movement at the expense of stillness.

Some people single-mindedly pursue a state of absolute stillness, yet when faced with affairs, they become flustered and disrupt their original tranquility. Others focus solely on handling specific matters while completely neglecting fundamental cultivation. One must integrate the higher and lower, the external and internal, just as "abiding in benevolence" naturally leads to "acting with righteousness," and "acting with righteousness" naturally sustains "abiding in benevolence." An upright heart naturally enables square dealings, and square dealings in turn nourish an upright heart—this is complete cultivation.

The practice of "reverence" (jing) spans both movement and stillness, encompassing both seeking the lost original mind (qiu fang) and preserving it (cao cun). It is not rigidly clinging to silence. The learning of a noble person (junzi) is a unified whole of internal and external, not to be fragmented. If one only cultivates during the state before emotions arise but fails to control faults after they emerge, this is having only the stillness practice without the movement practice. If one only knows to control arisen emotions but neglects cultivation before they arise, this is having only the movement practice without the stillness practice.

Preserving the mind and nurturing nature are practices for times of stillness, where the mind remains centered and unbiased. Reflection and observation are practices for times of movement, where words and actions maintain harmony without transgression. Maintaining awareness without dullness in stillness allows one to perceive the heart of heaven and earth when returning to the original mind—this is the true meaning of movement within stillness.

This passage elucidates the natural patterns of celestial and terrestrial Yin-Yang movement. In the Five Phases system, the northern direction corresponds to Water, represented by the Kan trigram (☵) in the Bagua (Eight Trigrams). The Kan trigram symbolizes water, featuring a single Yang line submerged between two Yin lines, signifying peril, hardship, and concealment. The north is traditionally called the "Dark Capital" (Youdu) or "Resurgent Quarter" (Shuofang), where "shuo" implies rebirth—just as all things perish here only to be renewed, and the moon wanes before its crescent reappears.

In the Early Heaven Bagua arrangement, Qian (Heaven ☰) occupies the southern position while Kun (Earth ☷) resides in the north. The interaction between Qian and Kun generates the Kan and Li (Fire ☲) trigrams. Yang energy emerges at midnight (the Zi hour), while Yin energy peaks at noon (the Wu hour). The Kan and Li trigrams mutually resonate, with Zi and Wu positions opposing yet complementing each other—Yang as the dominant force, Yin as its counterpart. Both heaven and humanity face south with backs to the north, making the southern direction manifest while the northern remains concealed. The North Star anchors the celestial sphere, with all stars revolving around it, establishing the north's preeminence among the cardinal directions.

Cheng Yi (Master Cheng Shuzi) observed that "shuo" represents the birthplace of nascent Yang energy—the north being where Yin concludes and Yang commences. Shao Yong (Master Shao) proposed that Yang originates in the north and ultimately returns there, demonstrating the cyclical nature of Yin-Yang transformation. Notably, ancient texts like the Canon of Yao describe eastern, western, and southern directions simply as orientations, yet uniquely characterize the north with the term "shuoyi" (resurgent change).

The Monthly Ordinances records how the year's end simultaneously marks conclusion and renewal. Cheng Yi (Master Yichuan) explained this dual process—completing the current cycle while preparing for the next—as embodying the dynamic interplay of Yin-Yang's two modes. When the Kun trigram transforms into Kan, one trigram divides into two, symbolizing how last year's Yang concludes as this year's Yang begins anew. Just as dragons and snakes must hibernate before soaring, or inchworms must contract before extending, these natural processes reveal inevitable cosmic principles. The noble person emulates this wisdom—cultivating hidden potential while awaiting the proper moment for action.

Zhu Xi observed that some aspects of the cosmos remain constant, such as the four cardinal directions (east, south, west, north), while others follow cyclical patterns, like the seasonal progression of spring, summer, autumn, and winter. The northern direction embodies dual significance: the winter solstice marks its midpoint, with the preceding forty-five days belonging to the current year and the following forty-five days to the next. Similarly, the zi hour (11 PM–1 AM) divides into four ke—the first two belonging to today, the latter two to tomorrow. The Gen hexagram symbolizes the cyclical completion and renewal of all things. Among the celestial creatures—the Azure Dragon, White Tiger, and Vermilion Bird—all represent singular beings, except the Dark Warrior (Xuanwu), which combines the forms of a turtle and snake.

The cosmos operates according to inherent principles: the heavens manifest through seasonal climatic shifts, while the earth remains anchored in fixed directions. The northwest encompasses both the general northern region (shuofang) and true north. Celestially, the southeast hosts the sovereign fire (heart fire) and ministerial fire (gate of life fire). The sun and moon embody the quintessence of yin and yang, giving rise to the dual manifestations of water and fire. Thus, among the seven luminaries (sun, moon, and five planets), both the sun and Mars represent fire, while the moon and Mercury embody water. In the human body, the heart is protected by the pericardium, and the kidneys pair with the gate of life—each element of water and fire thus possesses dual attributes. The sovereign fire is the refined, substantial true fire, while the gate of life fire is the formless Qi. The heart corresponds to odd numbers (one), the kidneys to even numbers (two), mirroring how the Vermilion Bird is singular while the Dark Warrior unites two creatures.

In the Yijing, the Li hexagram evokes the imagery of a turtle (via its shell patterns) and also symbolizes armor. The Sun, Yi, and Yi hexagrams all reference turtles, with Li subtly embedded in their structures. A turtle’s breath draws inward, akin to yang energy concealed within the earth. The five central ridges of its shell extend outward, forming the eight trigrams (Bagua), which further expand into the twenty-four solar terms. Though this symbolism is apt, it remains unclear why the turtle corresponds to the earthly branch "si" (snake) rather than the northern direction. Classical texts offer no definitive explanation—perhaps the sinuous strokes of the character "xuan" (玄, "dark") resemble a snake’s movement, capable of transforming into a dragon. The Zhen hexagram represents the dragon, latent beneath the Kun hexagram to form the Fu hexagram—this interpretation may approach the truth.

An alternate view holds that within the Dark Warrior, the snake embodies yang and the turtle yin. Wang Bi’s commentary notes that the kidneys correspond to two creatures (turtle and snake), reflecting the dual nature of northern change—both upright and steadfast. The concept of "wisdom" (zhi) also carries duality: its first half pertains to yin’s contracting energy, the latter to yang’s expansive force. The Rites of Zhou describes the turtle and snake as fourfold wanderers, symbolizing the constellation Ying Shi. The turtle’s shell, defensive in nature, justifies the "warrior" (wu) epithet, while water’s black hue explains "dark" (xuan). Wei Boyang’s analogy of inseparable male and female pairs mirrors the entwined turtle and snake—an implicit revelation of yin and yang’s interdependent roots.

This passage explores the profound mysteries of natural Yin-Yang transformations. Phenomena like intertwined tortoises and snakes or a hen incubating eggs all embody the inseparable interplay of strength and softness when Yin and Yang unite. Such patterns operate beyond human control—just as the union of man and woman creates life, or the dead return to nature—these are all natural laws of cosmic creation.

Cai of West Mountain (a Song Dynasty scholar) observed: Odd numbers represent Yang while even numbers signify Yin—this constitutes the fundamental nature of Yin-Yang. The waxing of Yang with waning Yin, or vice versa, manifests their dynamic functions. Consider how spring, summer and autumn nurture growth while winter brings dormancy; how the eastern, southern and western directions are perceptible while the north remains concealed; how human eyes see forward and sideways but not behind—all these reveal the wondrous workings of natural creation. Yang Xiong (styled Ziyun) of the Han Dynasty regarded the north as "Xuan" (the profound and unfathomable), believing it governed the other three directions precisely based on this understanding.

The Taixuan Jing (Classic of Supreme Mystery) elaborates further: The north is called "Wang" (formless state), akin to all things hidden in the Yellow Springs; the east represents "Zhi" (nascent state), the south "Meng" (growing state), and the west "Qiu" (mature state). "Wang" serves as the repository where existence returns to non-being, while "Ming" (darkness) becomes the concealment of illumination (where light dwells in obscurity). Yang energy accumulates in "Wang" and returns to its source through "Ming". The cyclical transformations of life and death, the succession of old and new—all complete themselves within this hidden state. When form dissolves into formlessness and formlessness generates form, this constitutes the most mysterious "Wang" state.

The text further proposes: Heaven takes the invisible as its Xuan (mystery), Earth takes the formless as its Xuan, and humans take profound thought as their Xuan. Heaven's mystery lies in the northwest (during the tenth lunar month's pure Yin when Yang energy lies dormant); Earth's mystery resides in the Yellow Springs (nourishing all things without manifestation); humanity's mystery dwells in thought (containing ultimate essence). Through this analysis, we comprehend the true meaning of the northern "Wang-Ming"—when all things return northward transforming from being to non-being, this is "Ming"; when all things emerge northward transforming from non-being to being, this is "Wang".

This passage elucidates the fundamental principles governing cosmic operations. Master Zhang (referring to Zhang Boduan) explains that "ming" represents the phase of latent Yang qi before the winter solstice, marking the conclusion of the current year, while "wang" signifies the initial emergence of Yang qi after the winter solstice, heralding the beginning of the new year. The process first enters the hidden state of "ming" before manifesting as the generative phase of "wang." "Ming" corresponds to the northern direction, while "wang" aligns with the center. Thus, the true celestial center lies in the north—this is precisely the position of Polaris.

The cosmos operates through four major seasonal cycles, with winter representing the phase of rest and recuperation. The earth has four cardinal directions, with the north governing storage and conservation. Similarly, the human body has four limbs, with the back presiding over stillness and preservation. This pattern of "one stillness and three movements" reveals the most profound mysteries between heaven and earth. Some scholars suggest that "ming" resembles the mysterious De (Virtue) abiding motionless at the center, while "wang" parallels the four virtues of "yuan, heng, li, zhen" from the Qian (Heaven) hexagram in the Yijing (Book of Changes)—an apt comparison indeed.

Zhu Zhen (also known as Hanshang) posits that the Kan (Water) hexagram originally belonged to the Kun (Earth) hexagram system, positioned in the north and governing celestial and terrestrial spiritual affairs. The northern direction symbolizes the celestial phenomenon of entering the hidden darkness, with Kan serving as the dwelling place of spirits. The Big Dipper represents the celestial temple, while the Xu constellation (one of the twenty-eight lunar mansions) presides over sacrificial rites. In the Early Heaven Bagua arrangement, the Kun hexagram is placed in the north corresponding to the Qian (Heaven) hexagram in the south, encompassing all cosmic affairs. When King Wen of Zhou developed the Later Heaven Bagua, he introduced a single Yang line from the Qian hexagram into the Kun hexagram to form the Kan hexagram, creating a complementary opposition with the Li (Fire) hexagram that establishes the harmonious interaction of water and fire, thereby generating all things.

The Kan hexagram contains the hidden structure of the Gen (Mountain) hexagram, symbolizing the cessation of northwestern Yin qi, while the southeastern Yang qi harbors the generative power of the Zhen (Thunder) hexagram. Within the Kun hexagram lies the latent potential of Kan—the sixth line of Kun in the Zhouyi (Book of Changes) states "the heavens are mysteriously dark (xuan) and the earth is yellow (huang)." Here, "heaven's xuan" refers to the Yang line within Kan, while "earth's huang" denotes the surrounding four Yin lines. Thus, during the winter solstice, when the sun, moon, and five planets all begin their cycles from the first degree of the Ox constellation (one of the twenty-eight mansions), this constellation corresponds to the water position and Kan hexagram. This explains why the hexagram-qi system begins with the Zhongfu hexagram, and why the Taixuan Jing (Classic of Supreme Mystery) commences with the "Central Head" chapter.