《天原發微》Vol. 4

This passage explores the fundamental nature of Yin and Yang energies and their role in cosmic generation. Tang dynasty scholar Kong Yingda posited that Yin represents inward-nourishing qualities while Yang embodies outward-expansive properties. Yang Qi is symbolized by odd numbers, originating as undifferentiated primordial energy—eternally radiant like the sun. Yin Qi, represented by even numbers, manifests through concrete forms with cyclical changes like the moon's phases. The legendary Fu Xi observed these principles, using an unbroken line for Yang and a broken line for Yin—both being expressions of the same vital energy (Qi), appearing as Yang when active and reverting to Yin when dormant. All life and death depend on the coming and going of Yang Qi, ultimately returning to the singular Qi of the Supreme Ultimate (Taiji).

At the dawn of creation, Yin and Yang energies coalesced into form—the greater concentrations forming heaven and earth as embryonic foundations, which then generated parents, humanity, and all beings. Every cosmic phenomenon arises from the dynamic interplay of these two energies. During creation, Qi first shaped physical forms (Yin-Yang generating heaven-earth), then these forms became vessels sustaining Qi's circulation (heaven-earth operating Yin-Yang). Dong Zhongshu of the Han dynasty systematically articulated this theory, establishing Confucian scholarship on Yin-Yang cosmology.

Zhou Dunyi proposed the dialectical principle: "Water's Yin nature roots in Yang, fire's Yang nature roots in Yin"—water belongs to Yin yet originates from the Yang number one, while fire belongs to Yang yet stems from the Yin number two. Zhang Zai further explained how Yin and Yang essences mutually contain each other. Zhu Xi synthesized Zhou's teachings as revolving entirely around these two energies—from their dynamic, generative phase to stable, formed states. Before the Supreme Ultimate (Taiji) divides, Yin harbors Yang; after division, Yang differentiates Yin: Yang energy sinking into Yin creates water, while Yin energy penetrating Yang generates fire.

Zhang Zai described primordial Qi permeating the void in ceaseless rising and descending movements. Subtle shifts between substantial and insubstantial, movement and stillness initiate the differentiation of Yin-Yang's soft and hard aspects: ascending clear Qi belongs to Yang, descending turbid Qi to Yin. When these converging energies condense, they manifest as wind, rain, frost, snow, mountains, and rivers—even the ashes of burnt matter testify to Yin-Yang's transformative operations.

This scripture primarily explores the principle of how "wandering Qi" and the two energies of Yin-Yang give rise to all things. Zhu Xi (Master Zhu) employs vivid analogies to explain: wandering Qi resembles the wind produced by a fan, while Yin-Yang constitutes the fan itself; it is also like flour ground by a millstone, where Yin-Yang represents the millstone; or like a tree bearing flowers and fruit, with Yin-Yang being its roots. The void is filled with Qi that ascends, descends, and swirls—though invisible to human eyes, it truly transforms and generates all things (as observed by the ancients in phenomena like five-colored auspicious clouds).

The scripture points out that the two energies of Yin-Yang ceaselessly revolve between heaven and earth, imperceptibly giving birth to myriad phenomena. Every living being possesses a unique form and innate nature, all formed through the coalescence of Qi. Though the manifestations of things differ vastly, the two fundamental forces of Yin and Yang are ever-present. No two things are entirely identical, for each contains its own distinct combination of Yin and Yang.

Cai Yuan (of the Cai school) further elaborates that in the formation of living beings, Yin Qi governs stillness while Yang Qi governs movement. Still Qi remains relatively stable, whereas moving Qi circulates back and forth—when Yang Qi arrives, it brings growth (expansion), and when it recedes, it transforms into Yin Qi (contraction). The transformations of all things depend on this ebb and flow between the two energies. Just as there cannot be day without night, male without female, or front without back, all phenomena in the world exist in complementary pairs—nothing exists in absolute isolation. Opposites such as movement and stillness, bending and stretching, Dao and concrete forms (universal principles and particular things) mutually depend on each other, together constituting the complete mechanism of cosmic operation.

This passage explores the interdependent relationship of Yin and Yang, where one waxes as the other wanes. There are two types of Yin-Yang: dynamic Yin-Yang (constantly transforming) and correlative Yin-Yang (mutually corresponding). In dynamic Yin-Yang, Yang dominates, while correlative Yin-Yang maintains equilibrium between both forces. However, the Yin discussed here differs from dynamic Yin. All living organisms capable of growth and reproduction—even those with Yin nature—require Yang's vitalizing power. Only withered wood and cold ashes represent pure Yin.

Zhang Zai (Hengqu) observed: "Without opposing aspects, unity cannot manifest; without manifested unity, the interplay of opposites ceases." He further noted: "Unity reveals the divine mystery, while opposition drives transformation—both expressed through the waxing and waning of Yin and Yang." Zhu Xi praised this insight as profoundly precise—without unity, Yin-Yang fluctuations would have no framework; without these fluctuations, unity would remain unknowable. Yang cannot exist independently—it requires Yin as its foundation, making Yin the basis of Yang. Conversely, Yin cannot manifest itself—it depends on Yang for recognition, making Yang its counterpart. Phenomena like movement-stillness, coming-going, and summer-winter all emerge from Yin-Yang interaction, not deliberate design. Their perpetual seesaw dynamic—where either Yin overcomes Yang or vice versa—pervades all things at all times.

Yin and Yang are ultimately two states of the same reality: expansion is called Yang, contraction becomes Yin. Yang's retreat is simultaneously Yin's advance—not a replacement by some separate Yin entity. They form a single reality with dual aspects: all generative forces belong to Yang, yet with each increment of Yang's growth, a corresponding Yin emerges beneath. Yin isn't externally imposed—where Yang withdraws, Yin naturally appears. Yang's return represents the fundamental state (as in the Fu hexagram), while Yin's emergence signifies contingent encounters (as in the Gou hexagram). Yin-Yang operates at the Qi level, whereas hardness-softness manifests in material properties—only with concrete form can such qualities be distinguished.

Cheng Yi added: During Yin-Yang transformations, no absolute boundaries exist, yet their overarching patterns of ascent-descent and flourishing-decline remain clear. Their perpetual motion never ceases—Yang generally abounds while Yin often falls short, precisely this imbalance that generates all transformations. Like a turning millstone: while appearing uniformly in motion, every local point undergoes constant change.

This passage explores the fundamental Daoist concept of Yin-Yang—the two opposing yet complementary forces that form the foundational dynamics of the universe—and their manifestations in both nature and human affairs.

Zhu Xi, the Southern Song Dynasty Neo-Confucian scholar, regarded Yin-Yang as the root of cosmic creation, inseparable in their interdependence and governed by natural laws beyond human control. Yang represents generative forces—growth, virtue, and noble individuals—while Yin embodies constrictive energies—decay, vice, and petty people. When sages composed the Yijing (Book of Changes), they elucidated the principle of Yin-Yang interdependence while deliberately emphasizing the need to nurture Yang and restrain Yin. From nature's perspective, both forces are indispensable; yet in human affairs, we naturally aspire for a world governed by noble virtues rather than base tendencies.

The initial emergence of Yin resembles stepping on frost that foretells coming ice—a single Yin manifestation infiltrates like a thief. The transformation from Yang to Yin occurs through silent diminishment, termed "dissolution" (hua), whereas the shift from Yin to Yang manifests as visible growth, called "transmutation" (bian). The two forces maintain an inherent imbalance: Yang perpetually dominates in both quantity and potency.

Shao Yong, the Northern Song philosopher, proposed that Yang expresses the function of the Dao while Yin constitutes its foundational substance. Though mutually dependent, they emphasize different aspects. Zhang Zai, another Northern Song thinker, stressed Yang's dynamic nature and Yin's quiescence, with Yang embodying nobility and Yin representing humility—ultimately asserting Yin can never equal Yang. Yet in actual transformations, each contains the other's seed and alternates in dominance. When Yang exhausts itself, the Kun hexagram (pure Yin) prevails; when Yin dissipates, the Qian hexagram (pure Yang) ascends.

The text concludes by noting the annual cycle: from the eleventh lunar month (Zi) through the fourth month (Si), Yang should be revered, while after the fifth month (Wu), a new Yin-Yang cycle commences. These concepts epitomize Daoist understanding of cosmic patterns and the wisdom of aligning human affairs with the waxing and waning of these primordial forces.

This scripture elucidates the dialectical relationship between Yin and Yang and their manifestations throughout heaven, earth, and all beings. Beginning with the waxing and waning of Yin-Yang in the twelfth lunar month (Hai month), it clarifies that while Qian (Yang) is honored and Kun (Yin) is humble, they cannot be equated—just as both parents are revered in a family, yet the mother ultimately cannot attain complete parity with the father. Cai Yuanding (Master Cai) posits their interdependence: Yang requires Yin to achieve completion, while Yin needs Yang to generate vitality; the two must cooperate harmoniously. At the level of Qi, Yang governs movement and Yin governs stillness; regarding form, Yin dominates rapid transformation while Yang oversees gradual development.

Zhu Xi (Master Zhu) further explains: The differentiation of Taiji (Supreme Ultimate) produces the two Qi of Yin and Yang, encompassing all phenomena under heaven. The Book of Changes (Yijing) speaks entirely of Yin-Yang transformations—though appearing infinitely varied, all celestial and terrestrial phenomena arise from the cyclical advance and retreat of these two Qi. Consider day and night, cold and heat: horizontally, they manifest as Yin and Yang's left-right, front-back, movement-stillness distributions; vertically, as their ascending-descending, pure-turbid alternations. Whether in the four directions, four seasons, or qualities like size and beauty, all things constantly embody Yin-Yang principles. Their subtle essences intercontain one another, their breaths alternate cyclically, and their forms interweave longitudinally and latitudinally—these transformations follow natural patterns, neither compelled nor obstructed by any force. In heaven they form celestial bodies like sun and stars; on earth they create substances of varying firmness; in humans they manifest as benevolence, righteousness, and virtue (De).

The text ultimately emphasizes their mutual rootedness: Yang relies on Yin to condense into form (the empty depends on the solid to stand), while Yin requires Yang to function (the solid arises from the empty). For instance, Kun hexagram (pure Yin) provides the foundation for the twelve Yang lines of Qian's transformations, while Qian hexagram (pure Yang) furnishes the support for Kun's twelve Yin lines. The thirty-one transformations beginning with Kun generate spring and summer (Yang-dominant phases), while those originating from Qian produce autumn and winter (Yin-dominant phases)—demonstrating how Yin and Yang perpetually serve as each other's instruments and accomplishments.

This scripture elucidates the patterns of waxing and waning between Yin and Yang, along with their correspondence between the Eight Trigrams (Bagua) and spacetime.

In celestial movements, the activity of Yang Qi diminishes Yin Qi, while in terrestrial transformations, the movement of Yin Qi reduces Yang Qi. When Yin reaches its extreme, the Kun trigram (representing pure Yin) retains twelve portions of Yang Qi, which ultimately transform into thirty-six portions of Yang Qi in the Qian trigram (representing pure Yang). Conversely, when Yang peaks, the Qian trigram preserves twelve portions of Yin Qi that eventually convert into thirty-six portions within the Kun trigram.

Through Kun's Yang energy emerge the Zhen, Kan, and Gen trigrams containing twenty Yang portions collectively, while Qian's Yin energy gives rise to Xun, Li, and Dui trigrams comprising twenty Yin portions. This "dispersing one into three" distribution marks the initial stage of all things' generation. At the ultimate "converging three into one" phase, Xun-Li-Dui's twenty-eight Yang portions coalesce into Qian's thirty-six Yang, while Zhen-Kan-Gen's twenty-eight Yin portions aggregate into Kun's thirty-six Yin.

Within the annual cycle, the sum of Yang numbers from Spring Equinox to Autumn Equinox totals sixty-four, with Yin numbers amounting to thirty-two—the reverse holds true from Autumn Equinox to Spring Equinox. This corresponds to the Bagua structure: four combined trigrams yield thirty-two (4×8), while all eight produce sixty-four (8×8). The diagram's symmetrical arrangement of thirty-two Yin and Yang portions each, combining into sixty-four hexagrams, manifests the principle of polarity reversal at their extremes.

Shao Yong (Northern Song Neo-Confucian scholar) observed that the Li trigram (Fire) in the east and Kan trigram (Water) in the west occupy pivotal positions where Yin and Yang achieve equilibrium, corresponding to the vernal/autumnal equinoxes and diurnal transitions. In the innate sixty-four hexagram system, Qian corresponds to high noon (wushi), Kun to midnight (zishi), Li to sunrise (maoshi), and Kan to sunset (youshi). The remaining four trigrams distribute across chen-si (Dui), chou-yin (Zhen), wei-shen (Xun), and xu-hai (Gen) directions. Shao further noted that Kan and Li's actual correspondence to yin-shen positions frequently exhibits excessive Yin or Yang, reflecting how these forces inevitably surpass intermediate balance during their cyclical operations.

This passage elucidates the cyclical patterns of Yin-Yang waxing and waning, celestial movements, and the life-death rhythms of all beings, using the Tiangan-Dizhi (Heavenly Stems and Earthly Branches) system and Bagua (Eight Trigrams) – ancient symbols representing directions and natural phenomena – to calculate temporal transformations.

When Yang energy reaches the "Shen" period (3-5 PM), it has already passed the midpoint of the three Yin phases, like water overflowing at fullness. As the Yijing (Classic of Changes) states: "The sun begins declining at its zenith, the moon starts waning after becoming full." Shao Yong (Northern Song Neo-Confucian philosopher) similarly observed that phenomena must retreat after reaching their zenith, hence associating Mao-Chen hours (5-9 AM) with the Dui (Lake) trigram, Zi-Chou (11 PM-3 AM) with Zhen (Thunder), Wu-Wei (11 AM-3 PM) with Xun (Wind), and You-Xu (5-9 PM) with Gen (Mountain) – all representing states before reaching culmination.

The Kan (Water) and Li (Fire) trigrams each govern half of the Yin-Yang cycle. If Kun (Earth) corresponds to midnight's midpoint (11 PM-1 AM), then Mao (5-7 AM) and You (5-7 PM) become the equinox points of day and night. Mao marks the "gate of sunrise" in the east, while You signifies the "gate of moonrise" in the west. During spring equinox, Yang energy centralizes; during autumn equinox, Yin energy dominates – creating balanced day-night durations unlike the summer solstice's long days or winter's extended nights. This principle governs not just celestial motions but all life-death cycles.

Heaven-Earth awakens at Yin hour (3-5 AM), with all beings flourishing by Mao; contraction begins at Xu (7-9 PM), completing by You. Annual seasons, monthly lunar phases, and daily light-dark alternations all manifest through Kan-Li's interplay and solar-lunar movements, invariably pivoting around these crucial Mao-You junctures.

Li (Fire) governs daylight from Mao to Shen (morning to afternoon), while Kan (Water) rules darkness from You to Yin (evening to dawn). Li's radiance begins emerging before Mao at Yin hour, just as Kan's shadows start gathering before You at Shen hour – Yang consistently encroaches upon Yin, making days slightly longer than nights.

Zooming out: all beings grow after Jingzhe (Awakening of Insects solar term) and withdraw before Lidong (Beginning of Winter). When Qian (Heaven) fully manifests, Kun (Earth) completely recedes, with Kan-Li each exercising half-measures. These two trigrams represent the interlocking central lines of Qian-Kun: in pre-heaven arrangements, Kan-Li correspond to Mao-You (moon-sun); in post-heaven sequences, they align with Zi-Wu (water-fire). These four pivotal hours embody Yang-containing-Yin and Yin-containing-Yang principles – profound insights left by Fuxi and King Wen, unlike other lopsided or muddled trigrams.

As Zhu Xi summarized: "The Five Phases (Wood, Fire, Earth, Metal, Water) both constitute and contain Yin-Yang. Take spring for example..."

The text elucidates the operational principles of Yin and Yang energies in nature and their manifestations.

Throughout the four seasons, spring corresponds to Lesser Yang (incipient Yang Qi), summer to Greater Yang (flourishing Yang Qi), autumn to Lesser Yin (incipient Yin Qi), and winter to Greater Yin (flourishing Yin Qi). These transformations of Yin and Yang are evident not only in the annual cycle (six months of Yang, six months of Yin) but also in daily rhythms (daytime as Yang, nighttime as Yin; morning as Yang, afternoon as Yin), monthly phases (waxing moon as Yang, waning moon as Yin), and even the 60-year Jiazi calendrical cycle (e.g., Jiazi days as Yang, Yichou days as Yin). Such alternating and cyclical patterns emerge naturally from the grand Yin-Yang system of heaven and earth.

Concretely: In spring, nascent Yang Qi brings warmth; in summer, peaking Yang Qi turns to scorching heat; in autumn, nascent Yin Qi brings coolness; in winter, flourishing Yin Qi brings bitter cold. Warmth fosters growth, heat accelerates flourishing, coolness initiates contraction, and cold induces dormancy. Yang Qi ascends from below to stimulate growth, while Yin Qi descends from above to complete harvests. Yang dominates the southeast direction and the spring-summer seasons, whereas Yin governs the northwest and autumn-winter periods.

Shao Yong (Master Shao) further explains: Greater Yang manifests as the sun, Greater Yin as the moon, Lesser Yang corresponds to stars, and Lesser Yin to temporal divisions. These celestial variations generate climatic phenomena—heat and cold, day and night, wind and rain, dew and thunder. When Yin Qi condenses and traps internal Yang Qi, it erupts as thunder; when Yang Qi circulates externally without penetration, it persists as wind. These meteorological events manifest as varying intensities of wind and thunder depending on their concentration. Harmonious Yin-Yang interaction produces gentle rain, snow, frost, or dew, while disharmony breeds calamitous weather.

Zhang Zai (Master Zhang) adds: When Yang Qi is constrained by Yin Qi, rainfall forms; when Yin Qi is carried upward by Yang Qi, it rises as clouds. The floating clouds in the sky are essentially Yin Qi gathered and driven by wind. Shao Yong summarizes: The interplay of Yin and Yang generates distinct phenomena—Yang encountering Yin transforms into rain, Yin meeting Yang becomes wind, firm Qi encountering soft Qi forms clouds, and soft Qi meeting firm Qi generates thunder. Without Yin, rain cannot take form; without Yang, thunder cannot arise. Rain, being Yin-soft, requires Yang's activation; thunder, being Yang-firm, needs Yin's cooperation.

This scripture elucidates the principle of how the interaction between Yin and Yang energies generates natural phenomena. Master Zhang (likely Zhang Zai) explains: When Yang Qi (active energy) dominates while Yin Qi (receptive energy) follows, their flowing movement creates rain. When Yin Qi obstructs Yang Qi, forcing its dispersion, wind arises. Vigorous Yang Qi drives gentle Yin Qi upward to form clouds, while accumulated Yin Qi violently collides with potent Yang Qi to produce thunder. These phenomena demonstrate varying relationships of host-guest, sequence, Yin-Yang, and opposition-conformity.

Since wind and rain descend from heaven, they are described through Yin-Yang dynamics; whereas clouds and thunder ascend from earth, they are analogized through rigidity-softness. Heavenly Yang Qi cannot form rain without Yin Qi's cooperation, just as earthly Yin Qi cannot generate thunder without Yang Qi's activation. Though rain belongs to Yin, its gentle form originates from heavenly Yang Qi; though thunder belongs to Yang, its fierce sound actually stems from earthly Yin substance. This reveals the mutual interdependence of Yin and Yang.

When someone consulted Cai Jiezhai using Bagua (Eight Trigrams) symbolism, he responded: In the Kan trigram (representing water), when Yin Qi is propelled upward by Yang Qi, clouds form; with insufficient Yang Qi, it becomes fog. When Kan's Yang Qi is weighed down by Yin Qi descending, it manifests as rain; with deficient Yin Qi, dew appears. When external Yin Qi blocks Yang Qi's path, thunder erupts; if Yin Qi remains congealed, earthquakes (Zhen trigram) occur. When internal Yin Qi obstructs Yang Qi's entry, wind arises; stubborn Yin Qi transforms into gales (Xun trigram). When Yang Qi envelops Yin Qi, the Li trigram (representing fire) produces hail; harmonized Yang-Yang interaction brings snow (intersection of Li and Kan). When Yin Qi encases Yang Qi, the Kan trigram generates thunder; Yin Qi invading Yang Qi creates frost (intersection of Kan and Li). When Yin-Yang essences mutually contain each other, Li transforms into the sun and Kan into the moon. Violent Yin-Yang friction produces lightning, while their misalignment creates rainbows.

The text further notes: Qi movement ascends from Zi hour (midnight) to Wu hour (noon), then descends from Wu to Zi. Specifically: From Zi to Yin hour (3-5am), Yang Qi rises from earth's depths to surface; from Mao to Si hour (5-11am), it ascends from ground to celestial zenith. From Wu to Shen hour (11am-5pm), Yang Qi descends from heaven's center to earth; from You to Hai hour (5pm-midnight), it sinks from surface into subterranean depths.

The author adds: The division of Zi-Wu periods into six phases reflects earth's regulation of Qi movement. Yang Qi is born at Zi hour (corresponding to the eleventh month), reaching earth's surface by Yin hour (first month) - this young Yang (Shaoyang) manifests as the number seven, representing Yang within Yin. From Mao (second month) to Si (fourth month), Yang Qi rises from earth to heaven's center - this mature Yang (Laoyang) appears as nine, pure Yang within Yang. From Wu hour (fifth month) when initial Yin emerges to Shen (seventh month), Yin Qi descends from heaven to earth - this young Yin (Shaoyin) manifests as eight, Yin within Yang. From You (eighth month) to Hai (tenth month), Yin Qi sinks from earth's surface into its depths - this mature Yin (Laoyin) appears as six, pure Yin within Yin. This pattern equally applies to solar and lunar cycles, with Yin, Shen, Si and Hai hours fundamentally corresponding to the operational framework of Qian (heaven) and Kun (earth).

This scripture primarily explores the manifestation of Yin-Yang transformations throughout natural phenomena. Yin and Yang represent core Daoist concepts, denoting the two fundamental yet complementary forces that permeate the cosmos.

The text begins by correlating the Tai and Pi hexagrams with the three Yang and three Yin lines. The Zhen trigram (one of the Bagua, representing thunder) belongs to Lesser Yang (Shaoyang), which evolves into Pure Yang (Lao Yang) when fully developed as the Qian trigram. Similarly, the Xun trigram (representing wind) belongs to Lesser Yin (Shaoyin), progressing to Pure Yin (Lao Yin) as the Kun trigram. The Kan (water) and Li (fire) trigrams employ four Yin and four Yang lines respectively to generate all things. The six Yin and six Yang lines of Qian and Kun mirror each other like snowflakes formed by water's numerical correspondence to six, demonstrating nature's creative patterns.

The commentary then explains the Five Phases attributes: water corresponds to supreme softness, fire to supreme hardness, earth to lesser softness, and stone to lesser hardness. These elements transform into various life forms including animals and plants. Zhu Xi (Southern Song Neo-Confucian scholar) observed that all phenomena fundamentally embody Yin-Yang principles, with even the smallest plants and creatures adhering to this pattern. For instance, carp possess thirty-six scales (a Yin number), while dragons bear eighty-one dorsal scales (a Yang number). A turtle's shell features five central plates corresponding to the Five Phases, flanked by eight plates representing the Bagua, surrounded by twenty-four plates matching the solar terms. Plants like ginkgo, phoenix trees, and bamboo also exhibit gender differentiation.

Zhang Zai (Northern Song philosopher) proposed that even ashes contain cosmic principles. Using the framework from Huangji Jingshi (Charting the Cosmos), the author categorizes creatures into flying beings (Yang) and walking beings (Yin), further subdivided into birds, flying insects, and quadrupeds. Horses belong to Yang while oxen to Yin; horns represent Yang and tails Yin—demonstrating how nothing escapes Yin-Yang patterning. All organisms possess sensory capacities for color, sound, Qi, and taste, though less refined than humans'.

Cheng Yi (Northern Song scholar) asserted that the human body encapsulates cosmic principles, with each breath revealing Yin-Yang expansion and contraction. The nose serves as the Celestial Gate (Tianmen), the body's conduit to heavenly Qi: exhalation (Yang) governs dispersion while inhalation (Yin) governs contraction in an endless cycle. Scholar Hu Wending further noted how human respiration mirrors cosmic Yin-Yang fluctuations. Through concrete examples, this passage systematically illustrates how Yin-Yang theory interprets the natural world.

This passage explores the correspondence between the human body and the natural cosmos, employing Yin-Yang and Five Phases (Wuxing) theory to interpret life phenomena. It cites perspectives from several Neo-Confucian scholars:

Zhang Zai (Master Hengqu) posits that during sleep, when the spirit (Shen) and soul interact, dreams emerge with a tumult of sensations. This state contrasts with wakefulness, forming the body's own cycle of day and night. The movement of Qi creates spring, where all things grow and intertwine, standing in opposition to autumn—together constituting heaven and earth's alternation of day and night.

Zhu Xi (Master Zhu) proposes: The Supreme Ultimate (Taiji) represents innate nature, while movement and stillness embody the heart-mind's nature. The Five Phases—Metal, Wood, Water, Fire, and Earth—correspond to the five virtues of benevolence, righteousness, propriety, wisdom, and faithfulness, with the human fleshly body manifesting these phases. What the eyes perceive is invariably either Yin or Yang, either benevolence or righteousness. Advancing belongs to Yang, retreating to Yin; solitude corresponds to a Yin line in the hexagrams, while social interaction aligns with a Yang line. Unsettled matters pertain to Yang, while resolved matters belong to Yin.

Shao Yong (Master Shao) observes: Heaven has four seasons, earth has four directions, and humans have four limbs. Finger joints reveal celestial patterns, palm lines disclose terrestrial configurations—the principles of heaven and earth are fully mapped in the palm. An upturned palm symbolizes closeness to heaven, while downward-facing soles signify connection with earth. That palms can turn but feet cannot reflects Yang's capacity to encompass Yin, whereas Yin cannot encompass Yang.

In palmistry, the southeastern region shows more water lines, the northwestern more mountain patterns, with convergence points resembling river courses. From wrist to shoulder, three segments correspond to the twelve double-hours; the four limbs match the four seasons and directions; each finger's three sections represent the twenty-four solar terms. The thumb's three sections—with two visible (Yin-Yang) and one hidden—symbolize the Supreme Ultimate (Taiji). The entire palm contains thirty-two correspondence points, representing the celestial trigrams; combined with the feet's thirty-two points totaling sixty-four, they mirror the earthly hexagrams.

The Yellow Emperor's Inner Canon records twelve primary meridians corresponding to twenty-four solar terms, each meridian divided into three regions with three diagnostic indicators, matching the three ten-day periods of a month. Pulse conditions manifest as deep, floating, or balanced—reflecting either Yin-Yang harmony or disharmony.

The conclusion synthesizes: Heaven and earth originate from unified Qi, dividing into Yin-Yang as two manifestations. Yang embodies benevolence, Yin represents righteousness, yet each can further bifurcate—illustrating the Daoist cosmogonic principle: "From the One comes Two, from Two comes Three, from Three the myriad things are born."

This passage discusses the relationship between Yin-Yang transformation and natural laws. Yin-Yang initially manifest as Wood (spring season) and benevolence (ren De), reaching their peak expression as Fire (summer) and ritual propriety. Yin first appears as Metal (autumn) and righteousness, culminating in its ultimate form as Water (winter) and wisdom. These four attributes (Wood, Fire, Metal, Water) combined with Earth (representing central harmony) constitute the fundamental elements of all phenomena between heaven and earth.

Yin-Yang can be perceived as an integrated whole (single Qi) or separately as two distinct forces (dual Qi), with both interpretations being valid depending on context. From the macroscopic perspective, the universe undergoes grand cycles of expansion and contraction (such as the 129,600-year great cycle); microscopically, smaller rhythms of opening and closing occur within a year, a month, a day, or even an hour. Though manifestations vary endlessly, the underlying principle remains constant.

The text concludes by quoting the Yijing: "The alternation of Yin and Yang is called the Dao," meaning this cyclical transformation constitutes the fundamental pattern of the cosmos. Understanding and harmonizing with this principle constitutes wisdom, while embodying it fulfills human nature. To study these truths, one must contemplate their essence with sincere attention.