《天原發微》Vol. 14

This passage explores the distinction between the concepts of "innate nature" (xiantian) and "acquired conditioning" (houtian) in Daoist philosophy and their manifestations in the natural world.

The earliest articulation of these concepts is attributed to four sages: Fuxi revealed the principles of innate nature through the Bagua diagrams; King Wen of Zhou developed the Zhouyi (Book of Changes); the Duke of Zhou created the line statements to demonstrate acquired conditioning; and Confucius synthesized both through the Ten Wings. Later, four scholars (Zhou Dunyi, Cheng Yi, Shao Yong, and Zhu Xi) further elaborated this theory. Shao Yong particularly emphasized the study of innate nature, while Zhu Xi unified both aspects, making the principles of the Yijing fully apparent.

Zhu Xi quoted Shao Yong's poetic lines: "The principles of innate nature are perfectly spontaneous, requiring no human effort, while acquired matters demand deliberate cultivation." This means the will of heaven is simply nature itself—there exists no other celestial intention beyond this. The author illustrates this with the example of a hen hatching eggs: the mother hen need not perform any special action, as the chicks naturally emerge when the time comes. Artificial intervention would only disrupt their normal development, proving that human effort cannot interfere at the level of innate nature.

Numerologically, numbers one through five represent the innate numbers of heaven and earth's generation, while six through ten signify the acquired numbers of their fulfillment. Other corresponding relationships include: the progression from Wuji to Taiji (Supreme Ultimate) belongs to innate nature, while Taiji generating yin-yang represents acquired conditioning; the state before manifestation is innate, while balanced expression after manifestation is acquired; initiating things pertains to innate nature, whereas accomplishing them belongs to acquired conditioning; the resurgence of purity (zhen) at the cycle's end is innate, while prosperous development (heng) constitutes acquired conditioning. Even the zhen hexagram itself divides into phases—the earlier yin half representing innate nature, the later yang half acquired conditioning.

This distinction between innate and acquired manifests universally: seasonal transitions and diurnal cycles reflect the biological level of yin-yang transformations, all expressions of innate nature; whereas concrete qi transformations, physical changes, and the operations of hun (ethereal soul) and po (corporeal soul) belong to the phenomenal level of yin-yang, falling within acquired conditioning—where yang actively transforms while yin remains relatively stable. Cai Yuanding further observed that this differentiation permeates not only hexagram imagery but the very operating principles of cosmic phenomena.

What makes Yin truly Yin is its quiescent and substantial nature. Fu Xi's Eight Trigrams (Bagua) belong to the innate realm (the primordial state of the cosmos), manifesting the celestial Qi movement, while King Wen's Eight Trigrams pertain to the acquired realm (the manifested world), expressing the material forms of earth.

The Spring and Autumn Annals Commentary states: In the innate state, Heaven does not oppose human will—this is unified will directing Qi movement. In the acquired state, humans must accord with celestial timing—this is unified Qi movement influencing will. Zhang Zai (Hengqu) proposed that Qi and will, Heaven and humanity, mutually influence each other. When sages govern the world, the people's aspirations shape the ruler's will (Qi moving will). Auspicious signs like the phoenix's arrival demonstrate the sage's will resonating with Heaven and earth (will moving Qi). Zhu Xi explained that "Heaven does not oppose the innate" resembles ritual-music systems: though no precedent existed, sages established new institutions according to Dao principles—such creations naturally align with heavenly patterns, thus Heaven cannot oppose them. "Accord with celestial timing in the acquired" means conforming to Heaven's established order—though these rules are divinely set, humans must still follow them. The innate and acquired work like coordinated hands—their core principles perfectly harmonize, just as a mother bird's pecking synchronizes precisely with her chick's shell-breaking.

Shao Yong (Shaozi) observed: The era before Emperor Yao belonged to the innate age; after Yao began the acquired age, later generations could only emulate predecessors. Cosmologically, Yang Qi grows from the Zi hour (winter solstice), forming pure Yang's Qian hexagram by the Si hour—this establishes Heaven's image. After the Wu hour (summer solstice), Yin Qi gradually emerges, culminating in pure Kun hexagram by the Hai hour. Yin's nature follows Yang's operational patterns—thus Qian governs "image formation" while Kun governs "pattern emulation." Calculated via Shao Yong's cosmic cycles (Yuanhui Yunshi), Emperor Yao's reign precisely straddled the Si-Wei transition. Pre-Yao sages could establish institutions, whereas post-Three Dynasties rulers could only imitate. The innate emphasizes the numinous essence of the Four Symbols (lesser/greater Yin/Yang), awaiting human application; the acquired focuses on the Five Phases' (Wood, Fire, Earth, Metal, Water) concrete operations—though involving human effort, they remain Heaven-ordained. Thus only great sages can accomplish innate endeavors. Yang Xiong (Ziyun) noted: Laws originated with Fu Xi—the dawn of civilization; they culminated with Emperor Yao—the pinnacle of innate Dao. Therefore the Zhouyi's thirteen hexagrams begin with Li and conclude with Guai.

Shao Yong further stated: Innate learning concerns the heart-mind's essence; acquired learning manifests as concrete phenomena. Only those who freely traverse being/nonbeing and life/death embody true Dao.

Before the formation of the cosmos, the principle of all things manifesting was a study of how original nature (the noumenon) reveals its traces. After the generation of all things, it became a study of tracing these traces back to original nature. Both original nature and the great Dao are empty and void, yet they contain a divine power that freely traverses between existence and non-existence, life and death, unobstructed by materiality.

Prior to the state of the pre-heaven realm, one cannot call it "non-being"; after the phenomena of the post-heaven realm, one cannot call it "being." Traces can never depart from this fundamental principle. Zhu Xi (Master Zhu) once remarked on Shao Yong's (Kangjie) scholarship, saying its essence lay in illuminating principle. What Cheng Hao (Mingdao) described as observing the transformations of heaven and earth to reach a state of transcendent detachment was precisely the height Shao Yong attained. His learning originated from the study of the pre-heaven realm, comprehending the patterns of all things, and thus naturally foreseeing the future. When observing phenomena, he could divide them into four developmental stages, much like viewing a flower: the budding stage marks the beginning of flourishing, half-bloom signifies gradual vigor, full bloom represents the peak, and afterward, decline is inevitable. When human power reaches its zenith, it must wane; a strong body will ultimately perish—this is the natural order. Shao Yong grasped this truth at a glance.

Moreover, those laws that are spontaneous and immutable belong to "inner images and inner numbers" (intrinsic principles), while all else falls under "outer images and outer numbers" (external manifestations). In the Book of Changes, "inner images" refer to the inherent principles of things, whereas "outer images" denote concrete, unchanging forms.

The "inner images and inner numbers" displayed in the pre-heaven Yin-Yang diagrams follow a strict sequence—disrupting it leads to chaos, as they are naturally formed and unalterable. In contrast, other systems like the post-heaven hexagram-qi diagrams are intricate and without fixed rules; human emotions and material states are either false or illusory. Thus, when Confucius compiled the post-heaven Book of Changes, he arranged it solely according to principle. "Inner images and inner numbers" establish the foundational laws of the noumenon, while "outer images and outer numbers" are the changing forms of practical application. Hence, though the three versions of the Changes—Lianshan, Guicang, and Zhouyi—underwent multiple revisions, the pre-heaven principle remained eternal.

"Principle-realization" (intrinsic patterns) refers to essential attributes like the firmness of the Qian hexagram or the mutability of the Xun hexagram; "designating a concrete thing" refers to specific hexagram images like "wood growing from earth" or "fire in the heavens." "Inner images" have no concrete form, and "inner numbers" have no fixed numerals—they exist within the Great Void. Seemingly mutable yet ultimately immutable, these principles arise spontaneously as they must; even the highest wisdom cannot alter their intrinsic laws or evade their destined patterns. Meanwhile, though "outer images and outer numbers" appear fixed, the lines have hidden and visible states, and hexagrams wax and wane—the positions of the six lines and the images of the eight trigrams are not entirely determinate. Thus, what seems to change remains fundamentally unchanged, while what seems unchanging will ultimately transform. Cai Jiezhai (Cai Yuanding) remarked that the study of the pre-heaven realm precisely reveals this eternal, unchanging truth.

This passage primarily discusses the relationship between the Pre-Heaven Bagua (Eight Trigrams) diagram (created by Fuxi) and the Taiji (Supreme Ultimate) diagram, and how they embody the principles of heaven, earth, and all things.

Zhu Xi stated that the Pre-Heaven Bagua diagram represents Fuxi's original cosmological schema, not a later creation by Shao Yong (Kangjie). This diagram uses a simple symbolic system to encompass the laws governing all phenomena, including the complete cycle of Yin-Yang transformations. Every character and principle in the current Yijing (Book of Changes) originates from this diagram.

When asked which holds greater significance between the Taiji diagram and the Pre-Heaven Bagua diagram, Zhu Xi maintained that while the Pre-Heaven diagram demonstrates grander scope and detail in structure, the Taiji diagram excels in conceptual refinement and conciseness. However, the Taiji diagram fundamentally operates within the framework of the Pre-Heaven diagram. Shao Yong's concept of "Pre-Heaven learning" traces the cosmic process from the state before trigrams were drawn to the complete formation of six-line hexagrams. As Confucius described in the Ten Wings regarding trigram arrangements and the Taiji generating Two Forms (Yin-Yang), Four Symbols, and Eight Trigrams—all derive from Fuxi's original intent in creating the trigrams.

Before Fuxi drew the trigrams, no symbolic diagrams existed. When cosmic principles began differentiating, they first produced the single solid (Yang) and broken (Yin) lines—the primal stroke forming the Two Forms. Adding another solid or broken line to these created four possible two-line combinations (Four Symbols), and a third iteration yielded the eight three-line trigrams. These formations emerged naturally without human contrivance or explanation. Though representing the most fundamental Yijing principles, few throughout history truly comprehended them until Shao Yong revived this tradition.

Zhu Xi further noted that Fuxi's four diagrammatic schemas (horizontal trigram arrangement, horizontal hexagram arrangement, circular trigram directional chart, and circular hexagram directional chart) were transmitted through Shao Yong's teachings. The original horizontal trigram diagram, through superposition, generated the 64-hexagram horizontal chart, while the circular trigram directional diagram similarly produced its 64-hexagram counterpart.

The Pre-Heaven diagram's structure features an outer circle symbolizing heaven and an inner square representing earth. Cai Yuanding (Xishan) explained: In the circular 60-hexagram arrangement, the Qian (Heaven) trigram reaches its zenith at the noon position, while Kun (Earth) culminates at the midnight position; Li (Fire) occupies the dawn (east) position and Kan (Water) the dusk (west) position. Yang energy emerges at midnight, peaking at noon, whereas Yin energy arises at noon, climaxing at midnight. In circular configurations, Yang resides south and Yin north, whereas in square arrangements, Qian begins northwest and Kun terminates southeast—here Yang occupies north and Yin south. These two arrangements demonstrate the complementary opposition of Yin and Yang.

This passage discusses the theory of cosmic Yin-Yang and Bagua (Eight Trigrams) orientations in the Tianyuan Faming (The Subtle Origins of Heaven). The circle represents Yang (symbolizing Heaven), while the square represents Yin (symbolizing Earth). In the circular diagram, the Qian trigram (representing Heaven) is positioned in the south, and the Kun trigram (representing Earth) is placed in the north—whereas in the square diagram, their positions are reversed.

The arrangement of the Bagua follows the principle of Yin-Yang pairing: the Qian trigram predominantly consists of Yang lines, the Kun trigram primarily contains Yin lines, with each polarity returning to its respective category. The circle encompassing the square symbolizes Heaven enveloping Earth. Zhu Xi (Master Zhu) explains that this harmonious pairing of circle and square demonstrates exquisite refinement. Shao Yong (Master Shao) poetically describes it: "The positioning of Heaven and Earth forms the opposition of Pi and Tai (two hexagrams); the communication between mountain and marsh reveals the principles of Xian and Sun (two hexagrams); the mutual stimulation of thunder and wind generates the meanings of Heng and Yi (two hexagrams); the interaction of water and fire constitutes the relationship of Jiji and Weiji (two hexagrams)."

The intersection of the Four Symbols (Great Yang, Lesser Yang, Great Yin, Lesser Yin) produces sixteen transformations, while the mutual interaction of the Bagua evolves into sixty-four hexagrams. Zhu Xi further elaborates: "The northwest corner corresponds to Qian, the northeast to Kun—this is the 'positioning of Heaven and Earth.' Following Qian comes Dui, and after Kun comes Gen, forming the 'communication between mountain and marsh.' Then comes the 'interaction of water and fire' through Li and Kan, and finally the 'mutual resonance of thunder and wind' through Zhen and Xun."

The innate circular diagram contains sixteen hexagrams on the exterior, while the square diagram also holds sixteen hexagrams within. These sixteen hexagrams are generated by four paired trigrams—Qian-Kun, Gen-Dui, Kan-Li, and Zhen-Xun—collectively forming the complete circular-square schema. The circular diagram symbolizes the Yin-Yang transformations of the Heavenly Dao, manifesting in the movements of sun, moon, and stars, as well as the alternation of seasons and day-night cycles. This is called the "flowing changes of the Yi," representing its ceaseless circulation in harmony with the rhythms of Heaven, Earth, and the four seasons.

This scripture primarily elucidates the correspondence between the hexagrams of the Book of Changes (Yijing) and the patterns of natural cycles. It begins by describing the alignment of the four seasons with the sixty-four hexagrams: summer corresponds to the thirty-two yin hexagrams (referring to the Kun hexagram system), governing the growth of all things; autumn corresponds to contraction, and winter to storage. In this way, each season is paired with sixteen hexagrams, collectively forming the sixty-four hexagram system. Further subdivided, each season's sixty-four hexagrams are divided into four phases, ultimately forming a system of 1,536 lines (yao) that corresponds to the laws of celestial movement.

The text mentions the "Four Images" (Shaoyang, Taiyang, Shaoyin, Taiyin) as the fundamental structure of the cosmos, while the "Six Jias" (the sixty-year cycle of the sexagenary calendar) circulates endlessly, revealing the historical trajectory of order and chaos from the Yellow Emperor to the Five Hegemons of the Spring and Autumn period. The annual cycle of 366 days is governed by the Qian and Kun hexagrams, representing the creative transformations of the Dao of Heaven. Meanwhile, the square diagram (referring to Shao Yong's "Innate Square Diagram") represents the Dao of Earth, composed of elements such as water, fire, earth, and stone, manifesting the principle of unity in opposition through natural phenomena like wind, rain, dew, and thunder, thereby nurturing all things in harmony with the seasons.

In terms of hexagram arrangement: the northwest corner is the Qian hexagram, and the northeast corner is the Tai hexagram, totaling thirty-two yang hexagrams; the southwest corner is the Pi hexagram, and the southeast corner is the Kun hexagram, totaling thirty-two yin hexagrams. These combine to form the sixty-four hexagrams, which are further divided into four levels according to the "yuan-hui-yun-shi" (Shao Yong's cosmic cycle units), resulting in 256 variations of hexagram structures that correspond to the growth patterns of all things on Earth.

Shao Yong believed that the number "sixteen" encapsulates the fundamental law of the mutual generation of the Four Images. All transformations in heaven and earth, as well as the rise and fall of history, follow this numerical principle. All opposing phenomena—opening and closing, expansion and contraction, fortune and misfortune, good and evil—are precisely aligned. The text later adds: among the sixty-four hexagrams of the Zhouyi, the "Upper Canon" contains eighteen pairs of inverted hexagrams (where reversing the hexagram forms a new hexagram), twelve of which are completely opposite and six unchanged (Qian, Kun, Kan, Li, Yi, and Daguo). The "Lower Canon" also has eighteen pairs of inverted hexagrams, sixteen of which are opposite and two unchanged (Zhongfu and Xiaoguo). Finally, it notes that when King Wen divided the sixty-four hexagrams into the Upper and Lower Canons, he arranged them according to the sequence of the later heaven hexagrams as inverted pairs. Among the eight trigrams, the four unchanging ones are Qian, Kun, Kan, and Li, while the two that can be reversed are Zhen and Dui (Zhen reversed becomes Gen, and Dui reversed becomes Xun). In this way, the six primary trigrams form the eight trigrams through transformations. In the hexagrams (six-line figures), four more unchanging hexagrams—Yi, Zhongfu, Xiaoguo, and Daguo—are added, completing the entire system.

The Tianyuan Fawei discusses the transformational principles of the Eight Trigrams (Bagua) and the structural mysteries underlying the upper and lower sections of the Zhouyi (Book of Changes). Among the Eight Trigrams, Qian (Heaven), Kun (Earth), Kan (Water), and Li (Fire) remain fundamentally unchanging. Yet through their combinations and transformations with the other four trigrams—Gen, Zhen, Xun, and Dui—they ultimately form the complete system of the sixty-four hexagrams.

It is particularly noted that while certain combinations—such as Gen and Zhen forming the Yi hexagram, Zhen and Gen forming Xiaoguo, Xun and Dui forming Zhongfu, and Dui and Xun forming Daguo—may appear unchanged on the surface, they are still part of the dynamic system of transformation. For example, when the Qian hexagram transforms to its extreme, it becomes Kun, and when Kun reaches its limit, it reverts to Qian. The same principle applies to the mutual transformation of Kan and Li, as well as the transitions between Yi and Daguo, and Zhongfu and Xiaoguo.

The arrangement of the upper and lower sections of the Zhouyi follows a corresponding logic: the upper section begins with Qian and Kun, symbolizing Heaven and Earth, while the lower section starts with the Xian hexagram (representing the resonance between young man and maiden). The hexagrams of the two sections mirror each other—for instance, Xu and Song in the upper section correspond to Jin and Mingyi in the lower section, as they can transform into one another through complete inversion of their Yin and Yang lines. The pairing of Tai and Pi, as well as Sun and Yi, reflects the differing states of Yin and Yang interaction—whether they intersect or remain separate.

From Tun and Meng in the upper section to Lin and Guan, and from Dun and Zhuang in the lower section to Ge and Ding, there exists a relationship of polar transformation. Notably, Yi and Daguo appear before Kan and Li in the upper section, while Zhongfu and Xiaoguo precede Jiji and Weiji in the lower section—an arrangement that hints at deeper patterns of Yin-Yang interplay.

Shao Yong (a Northern Song Confucian scholar) proposed that Qian and Kun represent the vertical axis of Heaven and Earth as the fundamental basis, while the other six trigrams (Zhen, Xun, Kan, Li, Gen, Dui) represent horizontal transformations in application. Like the warp and weft in weaving, Qian and Kun form the vertical foundation, while the six trigrams interweave horizontally, creating the complete hexagram system through the interplay of Yin and Yang. Unfortunately, the intricate principles behind this arrangement were not fully transmitted, and thus King Wen’s profound intent in dividing the Zhouyi into upper and lower sections remains obscured.

This passage elucidates the arrangement principles and symbolic meanings of the Eight Trigrams (Bagua) - Qian (Heaven), Kun (Earth), Li (Fire), Kan (Water), Gen (Mountain), Dui (Lake), Zhen (Thunder), and Xun (Wind) - in the Later Heaven (Houtian) Bagua diagram. The Qian and Kun trigrams occupy the north and south positions respectively, establishing the fundamental orientation of heaven above and earth below. The Qian trigram contains twenty-six Yang lines and twelve Yin lines, while the Kun trigram comprises thirty-six Yin lines and twelve Yang lines - this distribution of Yin-Yang forms the basic framework of heaven and earth.

The Li trigram in the east and Kan trigram in the west symbolize the movement of sun and moon; the Gen trigram in the northwest corresponds to Dui in the southeast, and Zhen in the northeast pairs with Xun in the southwest, representing transformations of natural phenomena like mountains-lakes and thunder-wind. Notably, Xun, Li, and Dui are originally Yin trigrams but contain more Yang lines, thus classified as assistants to Qian; while Zhen, Gen, and Kan are Yang trigrams with more Yin lines, serving as Kun's auxiliaries. This crisscross arrangement creates Yin-Yang correspondences that form the fundamental system of the Yijing (Book of Changes).

The Later Heaven Bagua centers on Zhen and Dui trigrams, symbolizing the seasonal cycle of spring growth and autumn harvest. Zhen's Yang energy activates the six Yang lines accumulated from Xun, Li, and Dui to form Qian (located in the northwest, representing paternal authority), while Zhen's Yin energy incorporates the three Yin lines from these same trigrams, ultimately resonating with Kun's six Yin lines (situated in the southeast, embodying maternal virtue). The east governs generation while the west governs maturation, creating a "one-horizontal-six-vertical" structure where the horizontal relationship holds greater significance.

The Kan-Li pair represents water-fire interaction, and the Zhen-Dui pair shows wood-metal each maintaining their proper positions - these combinations collectively form the practical system of Later Heaven Bagua, corresponding to various human phenomena. Some question why the corner trigrams (Gen, Xun etc.) that seem indirectly related still function effectively. The response clarifies: when the four primary directional trigrams activate, the four corner trigrams naturally become incorporated into the holistic operation. As Master Zhang explained: the Earlier Heaven (Xiantian) Bagua corresponds to seasonal celestial timing, while the Later Heaven Bagua aligns with eight-directional earthly patterns - nothing in creation lies beyond their sphere of influence.

Shao Yong (a Northern Song Dynasty Neo-Confucian scholar) stated: The Prenatal Yi (Fu Xi's Bagua) represents the fundamental laws of the cosmos, while the Postnatal Yi (King Wen's Bagua) governs practical applications. In the Prenatal system, the Kan (Water) and Li (Fire) trigrams symbolize the movement of sun and moon, manifesting the alternation of strength and softness, day and night. The Postnatal system employs the Qian (Heaven) and Kun (Earth) trigrams combined with the numbers nine and six (Yin-Yang line transformations in the Yijing), demonstrating the waxing and waning of Yin-Yang and seasonal transitions.

The Prenatal Yi corresponds to celestial Dao's operational principles, whereas the Postnatal Yi aligns with terrestrial spatial arrangements. In Prenatal Bagua's directional scheme: Qian (Heaven) resides south, Kun (Earth) north, Li (Fire) east, and Kan (Water) west—also incorporating the Yi, Fu, Daguo, and Xiaoguo trigrams. The Postnatal Bagua divides into four cardinal positions (Kan, Li, Zhen, Dui) and four corner positions (Qian, Kun, Gen, Xun). Within Prenatal Bagua, Qian and Kun establish the cosmic framework as heaven and earth; in Postnatal Bagua, they recede to northwest and southwest as parents of all things.

In Prenatal Yi, Kan and Li represent sun and moon positioned at Mao-You (east-west) like celestial gates; in Postnatal Yi they transform into water and fire occupying north-south in generative sequence. Prenatal Bagua reveals primordial creation laws governing celestial mechanics—heaven-earth oscillations, solar-lunar cycles, seasonal transitions, lunar phases, and daylight variations. Postnatal Bagua emphasizes earthly growth patterns where Kan-Li correspond to winter/summer solstices, Zhen-Dui to spring/autumn equinoxes—fixed seasonal nodes unlike fluctuating day-night durations.

The Zhouyi·Xici discusses seasonal orientations mentioning Kun trigram solely as earth and Kan trigram merely as water, neither addressing subterranean principles. Prenatal Yi manifests Yang emerging from Yin (like moonlight growing), while Postnatal Yi shows Yin arising within Yang (like shifting shadows). Prenatal Four Symbols (Great Yang, Lesser Yang, Great Yin, Lesser Yin) generate sun and moon—Yang qi enveloping Yin substance forms the sun, Yin substance containing Yang qi creates the moon. Postnatal systems sustain life through solar-lunar motion—flourishing during Yang abundance and withering during Yang decline.

Regarding celestial motion: Prenatal Yi holds that sun, moon and five planets rotate leftward (clockwise) with heaven, while Postnatal Yi describes their counter-heaven rightward (counterclockwise) movement. Prenatal classification uses Four Substances (water, fire, earth, stone), whereas Postnatal explanation employs Five Phases (Wood, Fire, Earth, Metal, Water). In trigram arrangements: Prenatal Yi's left-side thirty-two Yang trigrams position Guimei with Dui above Zhen below; Postnatal Yi places Zhen east and Dui west. Among Prenatal right-side thirty-two Yin trigrams, Jian shows Xun above Gen below; Postnatal reverses this to Gen above Xun below. These transformations embody the shift from cosmic principles to concrete applications.

The Tianyuan Fawei explains the evolutionary principles of the Pre-Heaven (先天) and Post-Heaven (后天) Bagua (Eight Trigrams). In the Pre-Heaven Bagua (the original trigrams created by Fuxi), each trigram can transform into seven others—one being its original form (本体) and seven representing its functional applications (功用). In contrast, the Post-Heaven Bagua (developed by King Wen of Zhou) allows each trigram to transform into six others, with the trigram itself as the essence and its lines (爻) as the function.

The Pre-Heaven system has a transformation number of 42, while the Post-Heaven system derives 50 variations. In the Pre-Heaven arrangement, the trigrams Qian (乾), Dui (兑), Li (离), and Zhen (震) are the four Yang trigrams, representing Heaven, with eight Yang and four Yin aspects. The trigrams Xun (巽), Kan (坎), Gen (艮), and Kun (坤) are the four Yin trigrams, representing Earth, with eight Yin and four Yang aspects—thus creating an imbalance in Yin-Yang quantities. In the Post-Heaven system, Qian, Kan, Gen, and Zhen are the four Yang trigrams (symbolizing one father and three sons), while Xun, Li, Kun, and Dui are the four Yin trigrams (symbolizing one mother and three daughters), achieving a balanced Yin-Yang distribution.

From a directional perspective, the trigrams Kun, Dui, Qian, and Kan are distributed across the southwest and north, while Gen, Zhen, Xun, and Li are positioned in the northeast and southeast. The Pre-Heaven Bagua takes the winter solstice as the starting point for the birth of all things, whereas the Post-Heaven Bagua begins with the spring equinox as the origin of growth.

Zhu Xi commented that the Post-Heaven Bagua is the system currently used in the Zhouyi (周易, Book of Changes), having been elaborated by King Wen of Zhou. Confucius later composed the Ten Wings (Shiyi, 十翼, the Commentaries on the Yi) based on King Wen's interpretations. However, without tracing back to Fuxi's original trigrams, scholars might mistakenly attribute King Wen's developments to Fuxi, focusing only on the later evolution while neglecting the foundational source. It was only after King Wen expanded Fuxi's Pre-Heaven Yi that the Zhouyi system, as we know it today, took shape.

This passage primarily discusses the relationship between the Primordial (先天) and Manifested (后天) Eight Trigrams (Bagua) in the Zhouyi (Book of Changes), along with theories of hexagram transformation. When Confucius composed the commentaries on the Zhouyi, he divided them into ten sections (known as the "Ten Wings"), including the Tuanzhuan (Commentary on the Judgments), Xiangzhuan (Commentary on the Images), and Xici (Great Commentary). The author points out that merely understanding King Wen's Manifested Yi learning is insufficient—one must trace back to Fuxi's Primordial Yi learning to grasp its fundamental origins.

Zhu Xi held that both Primordial and Manifested Yi learning have their own logic. The theory of hexagram transformation (referring to the reasoning behind changes in hexagram images) in Manifested Yi learning is evident in nineteen hexagrams. However, Cheng Yi (Master Cheng) attempted to explain all hexagram transformations using only the Qian (Heaven) and Kun (Earth) hexagrams, which has limitations. For instance, the transformation process of the Bi (Adornment) hexagram is difficult to interpret solely through changes in Qian and Kun. In reality, once the sixty-four hexagrams were established, the sages derived their meanings based on the hexagram images—all of which belong to the domain of Manifested Yi learning.

Cai Yuanding (Jiezhai) proposed that hexagram transformation is fundamentally the result of the interaction between Yin and Yang: the dynamic Qi of Qian (Heaven) interacts with Kun (Earth) to produce the Zhen (Thunder), Kan (Water), and Gen (Mountain) trigrams, while the yielding Qi of Kun interacts with Qian to produce the Xun (Wind), Li (Fire), and Dui (Lake) trigrams. Terms like "the firm comes" or "the firm descends" refer to Qian being above and descending to interact with Kun, while "the yielding comes" or "the yielding descends" describe Kun being above and descending to interact with Qian. This dynamic interplay of Yin and Yang constitutes the true principle of hexagram transformation.

This passage explains the operational principles of the Pre-Heaven (先天) and Post-Heaven (后天) Bagua (Eight Trigrams) from the Yijing (易经), along with the interrelationships between hexagrams like Qian (Heaven) and Kun (Earth), Kan (Water) and Li (Fire).

First, let's examine the characteristics of the Qian and Kun hexagrams: The vigorous Qi of Qian (symbolizing Heaven), though naturally positioned above, descends to interact with Kun; while the yielding Qi of Kun (symbolizing Earth), though naturally positioned below, ascends to unite with Qian. This dynamic constitutes the fundamental interaction between these two primary hexagrams. Both the Conflict (讼) and Innocence (无妄) hexagrams mention the concept of "vigor coming from outside," referring to the influx of Yang energy from external sources. These hexagrams each contain four Yang lines and two Yin lines, not resulting from direct vertical interaction between Qian and Kun—the Qian hexagram remains unmoved in its upper position, while the vigorous Qi in Kan and Zhen hexagrams originates externally. These principles emerge from the Post-Heaven Bagua system.

Zhu Xi explains: Fu Xi's circular Bagua arrangement (Pre-Heaven Bagua) manifests the static relationship of Yin-Yang opposition, while the linear 64-hexagram diagram displays the dynamic process of Yin-Yang transformation. A system based on opposition necessarily functions through circulation—this opposition is fundamentally static, precisely as seen in Fu Xi's Bagua. The auspicious or inauspicious outcomes arising from this stillness depend entirely on human agency, hence its designation as "Pre-Heaven." Its arrangement follows the waxing and waning patterns of Yin and Yang Qi, embodying the fundamental principle of creation.

King Wen's circular Bagua arrangement, conversely, emphasizes transformative circulation, while his linear 64-hexagram diagram reveals oppositional relationships. A system based on circulation necessarily operates through opposition—King Wen's Bagua is dynamically generated. The fortune or misfortune emerging from this movement depends on heavenly mandate, thus termed "Post-Heaven." Its arrangement follows the cycles of growth and decline in all things, manifesting the laws of cosmic operation.

The principles governing heaven and earth manifest in just two modes: opposition and circulation. Qian and Kun represent pure opposition; Kan and Li (symbolizing water and fire) represent fusion within opposition; Xian and Heng represent movement within opposition; while Jiji and Weiji represent complex opposition. In oppositional relationships, Yin and Yang interact in balance, whereas circulatory relationships emphasize the operation of Yang energy. In stillness, Yin and Yang coexist; in motion, they unite as one. Opposition can transform into circulation, and circulation can return to opposition.

Zhu Xi further elucidates the mysteries of the Pre-Heaven diagram: The 192 lines on the left fundamentally belong to Yang, while the 192 lines on the right fundamentally belong to Yin—yet Yin contains Yang and Yang contains Yin, creating a dynamic of mutual exchange. Though appearing as alternating Yin-Yang movement, this isn't physical displacement but rather a presentation of symbolic imagery. The diagram's left side belongs to Yang, progressing from Zhen (one Yang line) through Li and Dui (two Yang lines) to Qian (three Yang lines), demonstrating the gradual increase of Yang energy.

This passage explains the patterns of Yin-Yang transformation in the Primordial (Fuxi) Bagua diagram. When Fuxi first observed the Taiji (Supreme Ultimate), he perceived the two energies of Yin and Yang below it, and thus drew one Yin and one Yang symbol. From this single Yang line, another Yang and a Yin were generated; from this single Yin line, another Yin and a Yang emerged. This process continued to multiply—two becoming four, four becoming eight—until finally forming the sixty-four hexagrams. The entire progression occurs spontaneously, revealing the profound mysteries of heaven and earth.

The Primordial Diagram (Fuxi Bagua) encapsulates the operating principles of the cosmos. Whether observing daily or monthly changes, or the grand cycle of 129,600 years known as the "Epochal Cycles of Time," all follow the same waxing and waning rhythm of Yin and Yang. Things grow from small to large, and upon reaching their peak, return again to smallness in an endless cycle. Shao Yong (Master Shao) described the Primordial Diagram as the "Center of the Circle" (the cosmic axis of cyclical movement), while Zhang's commentary explains that the circle represents heaven, the square represents earth, and humans dwell in the pivotal position between them.

From the vertical perspective, the Qian (Heaven) trigram resides in the south as the sky, while Kun (Earth) occupies the north as the land. Horizontally, the left side from Zhen to Qian represents heaven, containing the four celestial phenomena: Greater Yang, Greater Yin, Lesser Yang, and Lesser Yin. The right side from Xun to Kun represents earth, containing the four terrestrial manifestations: Greater Firmness, Greater Softness, Lesser Firmness, and Lesser Softness. Heaven envelops earth, and though the Yin-Yang energies transform endlessly, they follow the same fundamental patterns in perpetual circulation. Humans positioned at this pivotal center must comprehend the operating principles of heaven and earth while properly managing ethical relationships in the human realm.

This scripture elucidates the Daoist understanding of cosmic operation, centered on the concept of the "Ring's Center" (huánzhōng) — the fundamental law governing universal movement. All phenomena follow this primordial principle: the Qian trigram represents heaven and sovereign authority, Kun symbolizes earth and subjects, the Family hexagram embodies father-son relationships, while Xian and Heng hexagrams exemplify marital harmony, from which all sixty-four hexagrams derive their transformations.

The celestial mechanism operates like an endless circle: the Celestial Gate (tiānmén) has no upper limit, the Earthly Portal (dìhù) knows no lower boundary. Rivers flow ceaselessly eastward into the sea yet never exhaust their waters; Mount Kunlun towers immeasurably in the northwest. The sun rises in the east bringing luminous Yang, while the moon gestates soft Yin in the west. Thunderclaps revive all creatures, yet winds entering the Xun position usher decay. These phenomena all manifest the "Ring's Center" principle.

Seasonal transitions obey this same law: at winter solstice's Zi hour, Yang qi first stirs; summer solstice's Wu hour sees Yin qi recede. Equinoxes balance both forces equally, while lunar phases and diurnal cycles reveal the rhythms of Yin-Yang's opening-closing, advance-retreat, existence-dissolution. Heaven and earth perform a cosmic symphony: heaven conducts celestial bodies through their courses, while earth resonates with water, fire, soil and stone — this dynamic interplay constitutes the most authentic Dao.

Fuxi formulated the Round-Square Diagram from this principle, Emperor Shun composed the Xiaoshao music accordingly, and Shao Yong (styled Kangjie) derived his Huangji Jingshi treatise from it. Humans dwell within this "Ring's Center" pattern unknowingly. Shao Yong claimed that upon realizing this truth, his mind became undisturbed, having internalized this fundamental law.

Zhu Xi explains: the blank center in the Primal Diagram represents Taiji (Supreme Ultimate), with thirty-two Yin and Yang strokes forming the Two Modes, sixteen strokes the Four Symbols, and eight the Bagua (Eight Trigrams). All things emerge from Taiji — this non-dual origin — before manifesting as Yin-Yang polarities. In the Diagram, what arises from Kun begins with the Fu hexagram, while Qian's lineage starts with Gou, both converging at heaven-earth's core. This "Center" is the heart-mind, is Taiji itself — transcending all phenomena yet permeating them, absolute and beyond opposition.

(Note: Fu and Gou refer to specific hexagrams in the Yijing system; Shao Yong was a Northern Song Neo-Confucian philosopher whose Primal Diagram mapped cosmic evolution.)

This passage discusses the theory of the "Innate Diagram" (先天图) by the great Song Dynasty Confucian scholar Shao Yong (style name Kangjie). Though the Innate Diagram—a symbolic representation of cosmic principles—contains no written explanations, Shao Yong claimed that all principles he discussed daily were encompassed within it, for it contained the fundamental patterns of heaven, earth, and the myriad beings.

The diagram expresses all phenomena through trigram positions and numerical relationships without relying on language. Its scope is all-encompassing: above, it includes the sun, moon, and stars; below, it accounts for water, fire, earth, and stone. Temporally, it manifests as the alternation of cold and heat, day and night; naturally, it transforms into wind, rain, dew, and thunder. Through resonance, it generates emotions and physical forms; through correspondence, it produces plants and animals. Humans possess ears, eyes, noses, and mouths; all things exhibit colors, sounds, scents, and tastes. Time expands into grand cosmic cycles (元会运世, the temporal units Shao created) and contracts into years, months, days, and hours. Imperial achievements divide into four ranks (皇, 帝, 王, 伯), while classical texts categorize into the Four Books (易, 书, 诗, 春秋). Though principles appear scattered, they unite in this diagram.

Zhu Xi praised Shao Yong as a peerless genius, describing how he "could touch the lunar palace with his hand and tread upon heaven's root with his foot"—where "lunar palace" (月窟) refers to the Gou hexagram (姤卦) representing yin's zenith, and "heaven's root" (天根) denotes the Fu hexagram (复卦) symbolizing yang's inception. Through quiet sitting, Shao could deduce the patterns of all creation. His poetic line "All thirty-six palaces are spring" (三十六宫都是春)—referring to the thirty-six harmoniously balanced hexagrams among the sixty-four—expresses the natural operation of heavenly principle.

Within the diagram, the progression from Fu to Qian hexagrams represents yang qi's growth, while Gou to Kun shows yin qi's waxing and waning. As yin and yang differ in nature, so humans and creatures receive varying degrees of purity in their endowments—yang primarily governs humans, yin dominates creatures. Gou's upper position explains the "hand touching" metaphor, while Fu's lower position justifies the "foot treading" imagery. Cai Yuanding (style name Xishan) explained: "Heaven's root" signifies the noble character of gentlemen, while "lunar palace" symbolizes the base dispositions of petty men.

The Tianyuan Fawei scripture primarily explores the relationship between Yin-Yang energies and the generation of all things, along with the scholarly thought of Shao Yong (courtesy name Kangjie).

Regarding the relationship between Yin-Yang and creation: The Thirty-Six Palaces (referring to hexagram arrangements in Yi studies) manifest the transformations of Yin and Yang lines within the Bagua (Eight Trigrams). One cannot simplistically divide good and evil using the categories of "human" and "thing," just as spring contains the generative impulse of all beings. Zhu Xi maintained that fundamentally, Yang represents goodness and Yin represents evil, yet they mutually depend on each other. Shao Yong likely approached this from the perspective of life's origin: upright Qi (vital energy) generates humans, while partial Qi generates things - this being the distinction between Yin and Yang. Cai Yuanding (courtesy name Jitong) provided further elaboration on this. When questioned whether "all is spring" refers exclusively to Yang energy, the response clarifies that venomous creatures and poisonous plants also arise from Yin-Yang energies - Yin Qi forms humble creatures, while Yang Qi forms the noble heavens.

The text then employs Yi principles to illustrate: From the Fu hexagram to Qian hexagram there are 112 Yang lines and 80 Yin lines, with the reverse pattern appearing from Gou hexagram to Kun hexagram - this crisscrossing movement of Yin and Yang contains the seed of life. This same cyclical interplay exists within the human body: During summer solstice (when the sun reaches the Well constellation), though all things flourish, humans should practice inward cultivation; during winter solstice (when the sun reaches the Ox constellation), though all things lie dormant, humans should expand outward. Thus the alternation of day and night also manifests this vital circulation - daytime creativity expresses life's expansion, while nighttime rest embodies life's contraction, with "spring's vitality" permeating all phenomena.

Concerning Shao Yong's scholarship: Cheng Hao (called Bozi) considered his teachings to encompass the "inner sagehood and outer kingship" ideal. In his youth, Shao Yong studied the philosophy of cosmic principles and human nature under Li Zhicai (sobriquet Lord of Qingshe), later comprehending its essence through observing movement and stillness. His poetic lines like "My body follows heaven-earth's creation, yet my mind precedes their formation" reveal his unique realization. Zhu Xi remarked that Shao Yong's learning could encompass cosmic space-time, with Huangji Jingshi (Supreme Principles Governing the World) as its core and poetry as its outward expression. The author suggests "inner sagehood" corresponds to pre-celestial studies (such as the Prenatal Diagram) encompassing cosmic and temporal dimensions, while "outer kingship" corresponds to post-celestial studies manifested in his contemplative analysis of historical cycles (the ways of emperors, kings, and hegemons).

The Tianyuan Fawei passage discusses two main topics: the transmission requirements of the "Learning of the Prior Heaven" (referring to Shao Yong's system of Prenatal Image-Numerology), and four interpretations of the "Thirty-Six Palaces."

Regarding the transmission of Prenatal Learning, Shao Yong (referred to as "the Master" in the text) was extremely cautious. When Zhang Dun (styled Zihou), then magistrate of Shangluo County, repeatedly sought his teachings, Shao Yong responded that while the system itself wasn't difficult, one must first live with him in mountain seclusion for ten years until worldly distractions faded before transmission could occur. When Xing Shu (styled Heshu) came to study while constantly quoting classics, Shao Yong instructed him to first empty his mind of miscellaneous thoughts. Shao Yong's poetic line "If you ask about the Prior Heaven—not a single word exists" emphasizes this learning requires complete self-emptying. Though Xing Shu once prepared medicine for the ailing Shao Yong, the master clarified this wasn't like Huang Shigong testing Zhang Liang (where passing a shoe-kneeling test sufficed)—without sincere devotion, one remains far from the Dao. The text notes how figures like Qin Jie and Zheng Kui attempted to steal the teachings through cunning methods, all meeting unfortunate ends, illustrating that Prenatal Learning demands pure heart-mind cultivation for mastery.

Concerning the "Thirty-Six Palaces," four interpretations exist: First, sequential addition following the Bagua order (Qian-1, Dui-2, Li-3, Zhen-4, Xun-5, Kan-6, Gen-7, Kun-8); Second, calculation based on each hexagram's yin-yang line count; Third, pairwise combinations of the eight trigrams; Fourth, the sum of primary hexagrams and their inverted forms totaling thirty-six. The author considers the fourth interpretation most accurate, while Master Xugu Fang criticized the first three as either inappropriate, fabricated, or unclear.

(Note: The Prenatal Diagram is an Yijing schematic created by Song dynasty's Shao Yong, arranging sixty-four hexagrams to reveal cosmic patterns. "Thirty-Six Palaces" denotes thirty-six fundamental configurations of hexagram transformations in Yijing studies.)

This scripture explores the correspondence between Yin-Yang transformations and temporal cycles. In the circular diagram of the Pre-Heaven Bagua (Eight Trigrams), the left semicircle beginning with Fu hexagram (symbolizing the birth of Yang Qi) spans 180 days corresponding to 18 palaces; similarly, the right semicircle starting from Gou hexagram (symbolizing the birth of Yin Qi) also covers 180 days across 18 palaces. With each palace representing 10 days, the 360-day annual cycle completes more coherently than the four previous theories.

The author further explains: The six time periods from Zi hour to Si hour correspond to the six Yang hexagrams from Fu to Qian; while the six periods from Wu hour to Hai hour align with the six Yin hexagrams from Gou to Kun. When the initial Yang line (9th line) of Qian hexagram does not intersect with the initial Yin line (6th line) of Kun hexagram, Fu hexagram emerges—the symbolic hexagram of the eleventh month, which Shao Yong called the "Heavenly Root," signifying the sprouting of Yang Qi at Zi hour. Conversely, when Kun's initial Yin line intersects with Qian's initial Yang line, Gou hexagram forms—the symbolic hexagram of the fifth month, termed the "Lunar Cavern," marking the emergence of Yin Qi at Wu hour.

Qian and Kun act as the great parents giving birth to Fu and Gou, which in turn serve as lesser parents generating the alternation of single Yin and Yang. The waxing and waning of Yin-Yang begins here: From Fu and Gou to Lin and Dun hexagrams manifests the transformation of two Yin and two Yang lines, corresponding to the twelfth and sixth months; from Lin and Dun to Pi and Tai hexagrams shows three Yin and three Yang lines, matching the first and seventh months; progressing further to four Yin/Yang lines in Guan and Dazhuang hexagrams, five Yin/Yang lines in Guai and Bo hexagrams, until completing the mutual transformation of six Yin and six Yang lines. Fu and Gou then return to Qian and Kun, which again transform into Fu and Gou, cycling endlessly through the twelve palaces.

Yin and Yang always coexist and mutually generate—when separated, they manifest as 36 Yin and 36 Yang distributed across 360 days; when unified, they become the Five Phases (Wood, Fire, Earth, Metal, Water) transformation of "one Yin and one Yang," which constitutes the meaning of "Thirty-Six Palaces." All things flourish through this Yin-Yang alternation, and humanity thrives in harmony accordingly. This principle permits infinite expansion: from 36 to 72, the numbers extend limitlessly; it also allows endless subdivision: a day contains 3,600 moments, a month holds 360 time periods—down to every insect, fish, plant, and tree, all embodying the principles of Yin-Yang transformation.

This passage explains the patterns of celestial movement and the principles of Yin-Yang's left-right rotation. Though these phenomena surround us, ordinary people often fail to perceive them. The wise who truly understand these principles can follow the Mandate of Heaven (Tianming) without worry.

The movement of the Heavenly Dao (Tiandao) operates in two directions: the heavens themselves rotate leftward, while the sun and moon move rightward. This theory has three foundations: first, the celestial movements themselves; second, the Hetu and Luoshu (ancient astrological diagrams); and third, the Pre-Heaven Bagua (Xiantian Bagua) arrangement. Directions are determined by facing south with the back to north—east is left, west is right. The left-right division in the Pre-Heaven Bagua follows the patterns of the Hetu and Luoshu, which were themselves drawn based on the phenomena of heaven's leftward rotation and the sun-moon's rightward movement. Thus, the most evident celestial phenomena are the movements of the sun and moon, through which the Heavenly Dao reveals itself clearly to humanity.

Ancient texts record: the celestial sphere rotates leftward from west to east, while the sun and moon move rightward from east to west. The Twenty-Eight Lunar Mansions (Ershiba Xiu) all follow the heavens' leftward turn, while the sun, moon, and five planets move rightward along the Earth's path. The sun travels through the six Jia (Heavenly Stems and Earthly Branches) cycles, corresponding with the Big Dipper (Beidou). The Dipper's handle points leftward according to the lunar months, while the sun meets the moon in rightward motion. For example, in the first lunar month, the Dipper points to the Yin position (east) while sun and moon meet at the Hai position (north); in the fourth month, the Dipper points to Si (south) while sun and moon meet at Shen (west).

Each day, the heavens rotate leftward by one degree, distributing vital Qi (Shengqi) to nourish all things; each day, the sun and moon shift rightward by one degree, adjusting temporal sequences to accord with the Heavenly Dao. When celestial and solar-lunar movements resonate harmoniously, climatic patterns become balanced. The Year Star (Jupiter, Suixing) and the Grand Year (Tai Sui, the Earthly Branch deity) also move in left-right opposition: Tai Sui moves leftward from Zi to Hai (following the Earthly Branch sequence), while Jupiter as the essence of Wood moves rightward through the heavens, corresponding to the Twelve Celestial Stations; Tai Sui belongs to Yin and moves leftward through earthly positions corresponding to the Twelve Earthly Branches. This twelve-year cycle is called one epoch (Ji).

Shao Yong (Northern Song Neo-Confucian scholar) further explained: heaven rotates left while the sun moves right, with the Kan trigram (north) and Li trigram (south) serving as left-right gates for the sun and moon's passage. The Hetu Kua Di Xiang records: heaven begins its rotation from the left at the Ox Star (Niuxing), while earth initiates movement from the right at the Net constellation (Bi Su), separated by 182.5 degrees (corresponding to 182.5 earthly days). At winter solstice, the sun's leftward movement covers 182.5 degrees—this celestial measurement manifests as the "number of heaven" in human affairs.

This passage explains the ancient astronomical laws governing the sun's movement and the transformations of Yin-Yang, primarily using the Diagram of Prior Heaven (Xiantian Tu) to illustrate the relationship between celestial motion and seasonal changes.

The sun's annual cycle divides into two phases: From Summer Solstice moving rightward for over 180 days to Winter Solstice (totaling 360 days), called the "expansion phase" when daylight gradually lengthens; from Winter Solstice moving leftward begins the "contraction phase" as daylight shortens. The Kan trigram (representing north) and Li trigram (representing south) serve as portals for the sun and moon's passage.

Master Heshan's interpretation states: Calendrical science holds that heaven rotates leftward while the sun and moon move rightward. Yet both heaven and the sun possess distinct left-right directional movements when viewed temporally. In the Diagram of Prior Heaven, Yang energy emerges at Winter Solstice when heaven turns left, while Yin energy arises at Summer Solstice when heaven turns right.

Specifically: When heaven rotates left (from the Yi trigram to Qian trigram), the sun moves right; when heaven rotates right (from the Daguo trigram to Kun trigram), the sun moves left. Though Yang energy's nature is ascendant, it germinates from below (the Fu trigram); though Yin energy's nature is descendant, it initiates from above (the Gou trigram). Thus Yin and Yang cycle endlessly without cessation.

In the Diagram of Prior Heaven, Yang energy begins rightward movement from the Bo trigram to Gou trigram, then reverses at Fu trigram to generate 32 Yang units; Yin energy starts leftward from the Guai trigram to Fu trigram, reversing at Gou trigram to produce 32 Yin units. This constitutes the grand cycle of Taiji (Supreme Ultimate) generating heaven and earth, with Qian and Kun as cosmic parents through six transformative phases.

Regarding celestial and solar motion: At Kun trigram occurs the intersection of Bo and Fu; at Qian trigram unfolds the meeting of Guai and Gou. This forms the minor cycle of heaven-earth generating myriad beings, with Fu and Gou as microcosmic parents through five transformations (one phase being quiescent). Leftward rotation disseminates vital breath (Qi) to create all things, while rightward rotation produces seasonal nodes.

During solstices, heaven and sun align north-south while following Yin-Yang's left-right movements. Simply put: heaven turns left, the sun moves right. Master Shao Yong's Diagram of Prior Heaven maintains that conformity with celestial motion constitutes leftward rotation.

This passage explains the operational principles and Yin-Yang transformations within the Pre-Heaven (Xiantian) Bagua diagram. In the diagram, the already-generated trigrams (Qian, Dui, Li, Zhen) are arranged in sequence from one to four, extending from south to north. This is called "leftward rotation" (zuoxuan), mirroring the movement of Yang Qi (vital energy) in the Dao of Heaven. Yang Qi begins its growth in the eleventh month (Zi month) with the Fu hexagram, progresses through Zhen's single Yang line, reaches the two Yang lines of Li and Dui at the spring equinox, and culminates in Qian's six Yang lines at the beginning of summer. The trigrams are counted from bottom to top, reflecting the natural growth patterns of all things during spring and summer.

The trigrams yet to be generated (Xun, Kan, Gen, Kun) are arranged in sequence from five to eight, extending from west to north. This is called "rightward movement" (youxing), mirroring the movement of Yin Qi in the Dao of Earth. Yin Qi begins in the fifth month (Wu month) with the Gou hexagram, develops through Xun's single Yin line at the summer solstice, reaches the two Yin lines of Kan and Gen at the autumn equinox, and culminates in Kun's six Yin lines at the beginning of winter. These trigrams are counted from top to bottom, reflecting the natural maturation patterns of all things during autumn and winter.

In the circular-square diagram, the Yin-Yang left-right operational principle follows this pattern: the first four trigrams in the circular diagram generate the latter four. When counting Yang, the sequence moves rightward from Kun to Gou and leftward from Fu to Qian. When counting Yin, it moves leftward from Qian to Fu and rightward from Gou to Kun. Yin Qi originates in the south while Yang Qi begins in the north, both starting from the number twelve. The movement of Yin from south and Yang from north ultimately reaches the extreme number thirty-six. In the square diagram, Kun's movement progresses left-to-right and top-to-bottom, while Qian moves right-to-left and bottom-to-top—both adhering to this numerical logic.

Zhu Xi explains: The Hetu (River Chart, representing the Pre-Heaven Bagua) operates sequentially from east to south, center, west, and north. After completing a leftward rotation, it returns to the east—symbolizing Heaven's leftward rotation that transforms and generates all things. The Luoshu (Luo Writing) operates sequentially from west to south, east, center, and north. After completing a rightward rotation, it returns to the west—symbolizing Earth's rightward rotation that brings all things to completion.

Cai Jiufeng (a Song Dynasty scholar) explains in his Tianyuan Fawei: The River Chart (Hetu, an ancient cosmological diagram) has a fixed structure of ten as its foundational number and ninety as its functional number—this arrangement is immutable. In contrast, the nine numbers of the Luo Writing (Luoshu, another cosmological diagram) are subject to transformation. The River Chart establishes its essence through symmetrical arrangement, while the Luo Writing achieves universality through interlaced patterns. Once the essence is established, if the numbers remain unchanged, they cannot fulfill their function.

Calculating with the variable numbers of the Luo Writing: In one diagram, both leftward and rightward rotating numbers are complete. The Yang number "three" moves leftward, symbolizing the circular motion of heaven (as the ancients believed heaven was round and earth square). If the diameter is one, the circumference is three—this is heaven's principle. The number "one" resides in the north; multiplying "one" by "three" yields "three" in the east; "three" multiplied by "three" gives "nine" in the south; "nine" multiplied by "three" produces twenty-seven in the west; and "three" multiplied by twenty-seven returns eighty-one to the north. Thus, the cycle flows from north to east, then south, west, and back to north, endlessly circulating in accordance with heaven's leftward rotation.

For the square earth (as earth was considered square), if the diameter is one, the circumference is four—a multiple of "two." Earth's numbers begin with "two," and the Yin numbers start from the southwest, rotating rightward: "two" multiplied by "two" gives "four" in the southeast; "two" multiplied by "four" yields "eight" in the northeast; "two" multiplied by "eight" produces sixteen in the northwest; and "two" multiplied by sixteen returns thirty-two to the southwest. This cycle moves from southwest to southeast, then northeast, northwest, and back to southwest, endlessly repeating in accordance with earth's rightward motion.

The Yang numbers—one, three, seven, and nine—occupy the four cardinal directions, while the Yin numbers—two, four, six, and eight—reside in the four corners. Left and right rotations intertwine, forming the exquisite mechanism of creation. All things between heaven and earth have left-right distinctions, from human hands, feet, ears, and eyes, to the rituals of men on the left and women on the right, or hosts on the left and guests on the right—all originate from the preordained patterns of creation (natural laws). The same principle applies when calculating with the River Chart, though the distribution of Yin-Yang and the interlacing of inner and outer differ in method.