《易象圖說外篇》

The Yijing (Classic of Changes) expounds the fundamental laws of the cosmos (encompassing the operating principles of Heaven, Earth, and humanity). Ancient sages observed nature and established human norms by inheriting the Dao of Heaven. Fearing later generations might fail to comprehend these truths, they revealed these patterns through symbolic notation. These laws have no traceable beginning (Yin-Yang inherently lacks origin) and no conceivable end (following celestial principles eternally). They penetrate the smallest particles of existence yet encompass the vastness of Heaven and Earth.

When Heaven embodies this law, the sun and moon move in perpetual cycles; when Earth masters this principle, mountains and rivers remain steadfast. Observing Heaven's mysterious celestial phenomena, sages used the unbroken line "—" (Yang Yao) to symbolize Heaven; examining Earth's receptive form, they employed the broken line "--" (Yin Yao) to represent Earth (the Yijing diagram's upper Yang and lower Yin symbols correspond to Zhou Dunyi's "Taiji generates the Two Modes" — where Taiji's movement produces Yang Qi and stillness generates Yin Qi).

Heaven possesses dual energies of Yin-Yang, Earth exhibits qualities of firmness and softness. Thus Yang and Yin lines combine to form the Four Images: Great Yang, Lesser Yin, Lesser Yang, and Great Yin (celestial phenomena descend while earthly Qi ascends; the Yijing diagram's interplay of Yin-Yang and firmness-softness reflects Zhou Dunyi's "Two Modes generate the Four Images" — where Yin-Yang transformations produce the Five Phases). Heaven cycles through four seasons (spring, summer, autumn, winter), Earth has four directions (east, south, west, north). Therefore, the Four Images further interact with Yin-Yang to form the Eight Trigrams (Bagua): Qian (Heaven), Dui (Lake), Li (Fire), and Zhen (Thunder) represent celestial phenomena (requiring upward observation); Kun (Earth), Gen (Mountain), Kan (Water), and Xun (Wind) symbolize terrestrial forms (requiring downward examination).

Among these: pure Yang and unyielding strength manifest in Qian; receptive softness and containment characterize Kun; outward radiance belongs to Li (Fire); hidden depth resides in Kan (Water); mountainous elevation appears in Gen; marsh-like depression forms Dui; thunderous vibration emerges in Zhen; gentle dispersion flows through Xun. The mutual interpenetration of these eight trigrams reveals the complete system of the Yijing. And humanity stands as the only being between Heaven and Earth capable of comprehending these profound mysteries.

Standing between heaven and earth, humans resonate with the cosmos (The Book of Rites states that humans are the essence of heaven and earth, the convergence of Yin-Yang, and the gathering of spirits and deities). We are the most refined manifestation among the Five Phases (Wood, Fire, Earth, Metal, Water). Our rounded heads symbolize the Qian trigram (one of the Bagua, representing heaven), while our full bellies embody the Kun trigram (representing earth). The Zhen trigram (thunder) governs our arms and hands, while the Xun trigram (wind) directs our legs and feet. The Gen trigram (mountain) corresponds to our nose, the Dui trigram (lake) to our mouth; the Kan trigram (water) to our ears, and the Li trigram (fire) to our eyes. When thirsty we drink, when hungry we eat, working at sunrise and resting at sunset—such routine existence seems no different from ordinary creatures.

Thus sages emerge (ordinary people unconsciously practice these principles daily, yet only sages transcend the mundane). Their virtue (De) aligns with heaven and earth, their wisdom shines like sun and moon. They comprehend cosmic patterns and harmonize Yin-Yang transformations. Their benevolent wisdom embraces all under heaven, their grace benefits future generations. Achieving perfect equilibrium, they stabilize heaven and earth while nurturing all beings; through utmost sincerity, they commune with spirits and tame wild creatures. The sage's path embodies cosmic principles. Mencius said: Though all are human, those pursuing great truths become noble, while those indulging petty desires remain petty. All universal principles exist within us—the key lies in self-reflection and earnest practice (humanity, wisdom, propriety, and righteousness are innate: humanity and wisdom emulate heaven's Yin-Yang; righteousness and propriety mirror earth's softness and firmness. Specifically: humanity belongs to Yin while wisdom to Yang; propriety governs gentleness while righteousness governs strength).

Heaven's Dao (the Way) is ceaselessly vigorous—we emulate its unyielding progress; earth's nature is profoundly receptive—we follow its virtue (De) of bearing all things. We inherit the Li trigram's illuminating radiance and learn the Kan trigram's steadfast constancy. We abide by the Gen trigram's principle of knowing one's place without overstepping, and when thunder-like shocks occur, we remain vigilant in self-cultivation. Valuing the Xun trigram's transformative power, we implement governance; embracing the Dui trigram's harmony, we exchange knowledge with companions (the first six trigrams from Qian to Zhen focus on self-cultivation, while Xun and Dui concern interpersonal relations). In times of Tai hexagram (heaven-earth communion), we assist cosmic principles and nurture all beings (the Tai hexagram's imagery shows heaven and earth uniting—rulers thus complete heaven-earth's Dao, supporting all growth to govern people); in times of Pi hexagram (heaven-earth separation), we practice frugal virtue and detachment (the Pi hexagram's imagery shows disconnection—noble ones thus cultivate modest virtue to avoid calamity, spurning wealth and status). When encountering the Yi hexagram (wind over thunder), we correct faults and embrace improvement.

The hexagram transformations in the Book of Changes (Yijing) contain profound principles. The Wind-Thunder Increase hexagram teaches us: when noble persons witness virtuous conduct, they should emulate it; when discovering faults, they should correct them. The Mountain-Lake Decrease hexagram reminds us to restrain anger and moderate desires. Whether in matters of state like abdication and military campaigns or in daily speech and conduct, these principles are clearly manifested in the Yijing.

Externally manifested, these principles form the systems of rites and music; internally concealed, they relate to the ways of spirits and deities. Ethical norms like the Three Bonds and Five Constants have been transmitted through generations, just as the Commentaries on the Changes state: "Heaven and Earth establish their order, and the principles of Change operate within them." Maintaining the purity of one's original nature is the gateway to the great Dao. The Yijing was created by sages to cultivate virtue (De) and expand achievements, and fearing that later generations might not comprehend these principles, they composed the Yijing to enlighten humanity.

Though my learning is shallow, I dare follow the ancient worthies in exploring the ultimate principles of Heaven and Earth. By observing the hexagram images and creating diagrams, I gradually reveal the origins of the Yijing's hexagram lines and the mysteries of its image-number system.

The Commentaries on the Changes state "In Change there is the Supreme Ultimate (Taiji)," which Zhu Xi explains: "Change speaks of Yin-Yang transformation, while the Supreme Ultimate is its fundamental principle." The term "Supreme Ultimate" (Taiji) contains the meaning of "ultimate extremity"—being both the highest standard and the pivot of all creation, the foundation of all existence. It has no concrete form itself; it was Master Zhou Dunyi of the Song dynasty who first represented it with a circle, a convention followed in later diagrams. The Shuowen Jiezi explains: "In the beginning was the Supreme Ultimate; the Dao begins with 'One,' which divides to form Heaven and Earth, transforming to produce all things. 'One' is the origin of numbers."

Regarding image-number theory: the above diagram shows how Heaven, Earth and Humanity each embody the principle of the Supreme Ultimate. Shao Yong said: "Heaven begins at the Zi hour (midnight), Earth manifests at the Chou hour (1-3 AM), and Humanity is born at the Yin hour (3-5 AM)." The Xia dynasty took the Yin month (when the Big Dipper's handle points to Yin) as its first month, calling it "Humanity's System"; the Lianshan Yi begins with the Gen hexagram, which symbolizes humanity. The Shang dynasty took the Chou month as its first month, calling it "Earth's System"; the Guicang Yi begins with the Kun hexagram, symbolizing Earth. The Zhou dynasty took the Zi month as first month, calling it "Heaven's System"; the Zhou Yi begins with the Qian hexagram, symbolizing Heaven. Various commentaries observe: "Mountains can inhale and exhale clouds, Earth can store all things, Heaven can encompass all phenomena"—these explanations clarify the meanings of Qian and Kun, but understanding of Gen remains incomplete. In truth, Gen represents the ultimate completion of all things while also...

This scripture primarily elucidates the relationship between humanity and the cosmos, along with the principles of mutual generation and restraint among the Five Phases (Wuxing).

It first establishes humans as the most spiritually endowed beings among all creatures. The Three Dynasties each emphasized distinct values: the Xia dynasty prioritized "loyalty" (human morality), the Shang dynasty emphasized "substance" (earthly principles), and the Zhou dynasty valued "culture" (heavenly symbolism). When Confucius answered Yan Hui's question on governance, he advocated synthesizing the strengths of all three dynasties: adopting the Xia calendar (harmonizing with celestial timing), riding Shang chariots (utilizing terrestrial advantages), and wearing Zhou ceremonial caps (emulating human ethics). This reflects the wisdom of unifying the Three Powers (San Cai)—heaven, earth, and humanity.

Han Yu (Master Han) divided the cosmos into three tiers: the upper realm is heaven (sun, moon, and stars), the lower realm is earth (plants, mountains, and rivers), and the middle realm is humanity (including foreigners, beasts, and birds). Cheng Yi (Master Cheng) further clarified that the interaction of heaven and earth generates all things, among which humans, as the most spiritually refined, hold the highest position.

Regarding the symbolic numerology of the Five Phases (Wood, Fire, Earth, Metal, Water): Wood corresponds to the east, Metal to the west, Fire to the south, Water to the north, and Earth to the center. Wood and Fire belong to Yang, Metal and Water to Yin, while Earth encompasses both Yin and Yang. The sequence of the Five Phases' generation is: "Heaven generates Water first" (represented by the numbers 1 and 6 in the north on the Hetu diagram), "Earth generates Fire second" (2 and 7 in the south), "Heaven generates Wood third" (3 and 8 in the east), "Earth generates Metal fourth" (4 and 9 in the west), and "Heaven generates Earth fifth" (5 and 10 in the center). Earth acts as the pivot connecting the four seasons—the manifestations of the Five Phases appear in heaven, their substance resides in earth, and humans embody the qualities of both.

Through the doctrines of the Three Powers and the Five Phases, this scripture constructs a cosmology of "harmony between heaven and humanity," emphasizing humanity's unique position in the cosmos and its correspondence with nature.

All life forms are composed of five fundamental energies (Wu Qi) that shape their physical bodies, and endowed with five intrinsic natures (Wu Xing) that determine their moral character. Those who discourse on innate nature and heavenly principles invariably base their arguments on this foundation. Those who receive balanced and unobstructed manifestations of these energies become sages, while those who receive partial or obstructed manifestations become foolish and unworthy. Yet the customs of the five regions are each constrained by their particular limitations, and human desires and preferences differ accordingly.

The East is where life germinates and the sun rises, hence its landscapes commonly display vibrant vitality. This is why Laozi (Lao Shi) developed his doctrine of longevity. The West is where things withdraw and the sun sets, commonly exhibiting phenomena of decay, hence giving rise to Buddhism's philosophy of extinction. The South is bright and flourishing, where Yang energy expands and divine spirits manifest; the North is dark and concealed, where Yin energy contracts and ghostly phenomena emerge. Only the sage dwells at the center of the world, pacifying the people of all directions, governing the realm by facing the light, practicing Wuwei (non-action), maintaining emptiness and stillness yet resonating with all affairs under heaven - this constitutes the supreme divine state. Zhou Dunyi (Zhou Zi) said: The sage takes centrality, correctness, benevolence and righteousness as standards, with quiet cultivation as the foundation, thereby establishing the highest human ideal.

On Image-Numerology (4): Zhou Dunyi stated that when Yang energy moves and interacts with Yin, it generates the five energies of Water, Fire, Wood, Metal and Earth. The orderly movement of these five energies creates the four seasons. The Five Phases are fundamentally Yin-Yang; Yin-Yang originates from Taiji (Supreme Ultimate); and Taiji emerges from Wuji (Ultimate Non-being). The true essence of Wuji mysteriously combines with the quintessence of Yin-Yang and the Five Phases: the Qian (Heavenly) principle forms males, the Kun (Earthly) principle forms females. The interaction of these two energies transforms and generates all things. The myriad things produce and reproduce endlessly with infinite variations. Only humans receive the most refined essence and become the most spiritual - when physical form is established, spirit manifests; when the five natures interact, good and evil are distinguished, and all affairs thereby arise. The sage regulates with centrality, correctness, benevolence and righteousness, establishing the human way with quiet cultivation as fundamental. When noble persons follow this, there is good fortune; when petty persons violate it, misfortune follows. This is the supreme expression of the great principles in the Book of Changes.

On Image-Numerology (5): The arrangement of numbers intersecting the nine palaces mentioned above follows the numerical patterns of the Luo River Writing. The heavenly numbers (Yang numbers) one, three, nine and seven are all odd, their movement trajectories circular. The number three symbolizes the rotation of Qi - the numerical sequence rotates leftward: beginning with one at due north; one multiplied by three yields three, hence two is positioned at due east; three multiplied by three yields nine, hence nine is at due south; three multiplied by nine is twenty-seven (taking the unit digit seven), hence seven is at due west; three multiplied by seven is twenty-one (taking the unit digit one)...

This passage elucidates the ancient principles of Yin-Yang numerology and geographical division. The earthly numbers (representing Yin even numbers) follow a cyclical sequence of 2, 4, 8, 6: beginning with 2 in the southwest, doubling to 4 in the southeast, then to 8 in the northeast, doubling to 16 (retaining the single digit 6) in the northwest, and finally doubling to 12 (returning to 2). This clockwise rotation of Yin-Yang dynamics differs from the Hetu (River Chart), an ancient mystical diagram.

The Inner Canon states that heavenly numbers (representing Yang odd numbers) progress from 1 to 9: 1 symbolizes heaven, 2 earth, and 3 humanity. Multiplying these three (heaven × earth × human) yields 9, corresponding to nine major geographical regions: due north Jizhou (modern Beijing/Hebei), due east Qingzhou (eastern Shandong), due south Yangzhou (Jiangsu-Zhejiang-Fujian-Jiangxi), due west Liangzhou (Sichuan-Yunnan), central Yuzhou (Henan), northeast Yanzhou (central-western Shandong), southeast Xuzhou (northern Jiangsu/northern Anhui), southwest Jingzhou (Hunan-Hubei), and northwest Yongzhou (Shaanxi-Gansu). When Yu the Great demarcated these nine provinces and established their tributes, and when Jizi derived the Nine Categories from the Hongfan, they laid the foundation for subsequent Yin-Yang numerology and medical theories based on this nine-palace numerical system.

Within the diagram, the five Yang numbers (1, 3, 5, 7, 9) encompass the Two Modes (Yin-Yang), Four Symbols (Lesser Yang, Greater Yang, Lesser Yin, Greater Yin), and Eight Trigrams (Bagua). While Yang governs movement and substance, Yin governs stillness and emptiness, what appears as binary actually implies the Three Powers (heaven-earth-human), the Four Symbols imply the Five Phases (Wood, Fire, Earth, Metal, Water), and the Eight Trigrams imply the Nine Palaces. This demonstrates that all things in heaven and earth must harmonize Yin and Yang to manifest—the fundamental law of natural creation.

The concluding reference to the "generative patterns of ten × in the Hetu-Luoshu" points to these legendary mystical diagrams (River Chart and Luo Writing), which sages emulated to establish cosmic principles. The "ten ×" likely denotes the crisscrossing numerical arrangements characteristic of these diagrams.

The relationship between images (xiang) and numbers (shu) unfolds as follows: Numbers begin with one, which through minor derivation (xiao yan) forms five, then through major derivation (da yan) forms ten. The number ten represents the ultimate summation of numerical principles, upon which the Hetu (River Chart) and Luoshu (Luo Writing)—ancient mystical diagrams—are fundamentally constructed, serving as the standard for delineating trigrams.

At the center of the Hetu, the pattern reveals the interaction between the heavenly number five and the earthly number ten. The circular symbol represents the essence of "Yi" (Change), the core dynamic principle underlying both diagrams. When active, it manifests as Yang, ascending to correspond with Heaven, denoted by ○; when still, it manifests as Yin, descending to correspond with Earth, denoted by ●. Heaven's ○ descends to generate Yin-Yang, while Earth's ● ascends to produce hardness and softness—this is the Yin-Yang relationship revealed by the numerical arrangements in the four directions of the diagrams.

Specifically: The Yang number is one, the Yin number four; the hard number three, the soft number two. Through derivation, these yield the paired numbers one-six, two-seven, three-eight, and four-nine, corresponding to the four cardinal directions (east, south, west, north) in the Hetu. These further differentiate into the Eight Trigrams (Bagua) and synthesize into the Five Phases (Wood, Fire, Earth, Metal, Water). Each Phase has its distinct generative property: the Hetu displays their production sequence, while the Luoshu manifests their transformative states.

Following the sequence of cosmic generation: The Kan (Water) and Xun (Wind) trigrams originate from Earth's firm attribute. What Zhu Xi termed "Lesser Yang" (shaoyang) resides in the Yin position (northeast), corresponding to spring and the number three. Through minor derivation yielding two and major derivation yielding seven (both associated with Fire), Fire Qi arises in the Yin position and flourishes at the Wu position (due south). In the Hetu, two-seven occupies the southern sector, where the Qian (Heaven) and Dui (Lake) trigrams find their respective places.

The Qian and Dui trigrams originate from Heaven's Yang energy, termed "Greater Yang" (taiyang) by Zhu Xi, positioned at Si (southeast), corresponding to summer and the number one. Minor derivation yields four, major derivation yields nine (both Metal numbers), hence Metal Qi arises at Si and flourishes at You (due west). In the Hetu, four-nine occupies the western sector where Xun and Kan reside. Transformative exchanges occur between Qian and Kan, Xun and Dui.

The Li (Fire) and Zhen (Thunder) trigrams emerge from Heaven's Yin energy, called "Lesser Yin" (shaoyin) by Zhu Xi, positioned at Shen (southwest), corresponding to autumn and the number four. Minor derivation yields one, major derivation yields six...

This passage explains the correspondence between numbers in the Hetu (River Chart) and the Five Phases (Wuxing) with their directional associations, as well as the arrangement principles of the Earlier Heaven (Xiantian) and Later Heaven (Houtian) Bagua (Eight Trigrams).

In the Hetu, the numbers one and six represent Water, whose growth direction is Shen (southwest) and peak position is Zi (due north). The Kun trigram (representing Earth) and Gen trigram (representing Mountain) occupy the one and six positions respectively. Zhu Xi (Master Zhu) states this is the position of Great Yin (Taiyin), corresponding to the Hai hour (9-11 PM) and symbolizing winter. The number two undergoes minor derivation (xiao yan) to become three, and major derivation (da yan) to become eight. Three and eight represent Wood, whose growth direction is Hai and peak position is Mao (due east). The Zhen trigram (representing Thunder) and Li trigram (representing Fire) occupy the three and eight positions.

The Earlier Heaven Bagua arrangement follows the Hetu: the Qian trigram (representing Heaven) and Dui trigram (representing Lake) embody firm attributes, while Li and Zhen embody yielding attributes - these represent the four heavenly phenomena interacting with Earth. Kun and Gen embody yin attributes, while Kan (representing Water) and Xun (representing Wind) embody yang attributes - these represent the four earthly phenomena interacting with Heaven.

The Later Heaven Bagua arrangement also derives from the Hetu: Qian and Dui are born from Heaven's yang qi, where numbers one and nine sum to ten; Li and Gen are born from Heaven's yin qi, where seven and three sum to ten; Kun and Zhen are born from Earth's yielding qi, where two and eight sum to ten; Kan and Xun are born from Earth's firm qi, where six and four sum to ten. Shao Yong (Master Shao) describes this as the "eldest daughter replacing the mother" arrangement. The perfect correspondence between numbers and trigrams in both Earlier and Later Heaven arrangements demonstrates the profound logic underlying both the Hetu and Bagua configurations.

This passage comes from the "Supplementary Chapters on Diagrams of Yi Symbolism" by the Yuan Dynasty scholar Zhang Li (courtesy name Zhongchun), which primarily explains the relationship between the hexagrams and the Three Powers (Heaven, Earth, and Humanity) in the Book of Changes (Yijing).

The ancient sages created the Yijing to align with the inherent patterns of all things in Heaven and Earth. They established the Way of Heaven as the alternation of Yin and Yang, the Way of Earth as the interplay of softness and firmness, and the Way of Humanity as benevolence and righteousness. Combining these three principles in pairs formed the six-line hexagrams, where the alternation of Yin-Yang and the balance of softness-firmness ultimately create the complete six-line system.

The diagram shows: Heaven's Yin-Yang divides into the four images of Qian (Heaven), Dui (Marsh), Li (Fire), and Zhen (Thunder); Earth's softness-firmness divides into Kun (Earth), Gen (Mountain), Xun (Wind), and Kan (Water). These elements intermingle—Qian descends to intersect with Kun, Xun ascends to meet Zhen, Li descends to connect with Kan, and Gen rises to join Dui. Humanity stands at the center where these Qi currents converge, receiving the energies of Heaven and Earth's four images and eight trigrams to form physical bodies while simultaneously embodying their corresponding principles.

Specifically: The human head's round shape positioned above corresponds to Qian; the hollow abdomen capable of containment corresponds to Kun; movable limbs correspond to Zhen and Xun; seeing eyes correspond to Li; hearing ears correspond to Kan; speaking mouth corresponds to Dui; and smelling nose corresponds to Gen (with Yang eyes and mouth governing movement, while Yin ears and nose govern stillness).

Human wisdom emulates Heaven's Yang aspect, corresponding to Kan (Water governs wisdom); benevolence emulates Heaven's Yin aspect, corresponding to Gen (Mountain governs benevolence); ritual propriety emulates Earth's yielding quality, corresponding to Li (Fire governs ritual); and justice emulates Earth's firmness, corresponding to Dui (Metal governs justice). These all constitute humanity's inherent nature formed through receiving Heaven-Earth principles.

Endowed with such physical forms and inherent nature, humans naturally develop desires: eyes crave beauty, ears pursue melodious sounds, mouths relish flavors, noses enjoy fragrances, and limbs seek comfort. When desires stir and emotions dominate—with love and aversion clashing—auspicious or ominous fortunes arise. Thus, the sages created the Yijing in accordance with inherent patterns to teach moral cultivation and career development. By observing celestial movements of sun, moon and stars; seasonal shifts between cold and heat; day-night alternations; examining forms of mountains, rivers and vegetation; transformations of water, fire, earth and stone; and changes in rain, dew, wind and thunder—they comprehended the Dao of Heaven.

This passage explains the patterns of celestial and terrestrial Yin-Yang transformations in relation to seasonal cycles. The Four Symbols (Taiyang, Shaoyang, Taiyin, Shaoyin) and Eight Trigrams (Bagua) correspond to the changes across four seasons and six climatic periods. Seasonal transitions result from the opening and closing of Qian (Heaven) and Kun (Earth), manifesting as the dynamic interplay of Yin-Yang's rising and descending movements.

At the winter solstice, Yin energy (Qi) reaches its zenith and begins yielding to Yang, while at the summer solstice, Yang energy peaks and starts transitioning to Yin. The autumn equinox represents balanced Yin energy in a state of contraction aligned with Kun (Earth), whereas the spring equinox shows balanced Yang energy in a generative state corresponding to Qian (Heaven). The solstices mark moments of Yin-Yang communion, while the equinoxes signify their separation. This schematic reveals the underlying cosmic principles.

Seasonal divisions are precisely mapped: thirty days before and after the winter solstice form one period (from Minor Snow to Major Cold), sixty days preceding the spring equinox constitute another (Major Cold to Spring Equinox), followed by sixty subsequent days (Spring Equinox to Grain Buds). Similarly, thirty days flanking the summer solstice (Grain Buds to Major Heat) and two sixty-day spans around the autumn equinox (Major Heat to Autumn Equinox, then Autumn Equinox to Minor Snow) complete the six phases totaling 360 days—mirroring Heaven and Earth's harmonious climatic rhythm.

Among the Eight Trigrams, Xun governs warmth, Qian controls heat, Zhen regulates coolness, and Kun commands cold—these represent the four seasons' essential energies. The remaining four trigrams (Kan, Li, Gen, Dui) correspond to transitional energies manifesting as rain, sunshine, warmth, chill, and wind. Though these shifting energies appear unpredictable, when the Five Phases' (Wuxing) energies arrive timely, abundant harvests and lush vegetation follow; their excess or deficiency causes crop failures and ominous portents.

Only sage rulers can harmonize Yin-Yang into perfect equilibrium, ensuring all beings flourish naturally. The human body mirrors this cosmic pattern: its six meridians (three Yin, three Yang) above resonate with celestial energies (cold, heat, dryness, dampness, wind, fire), while the five viscera and six bowels below correspond to Earth's stable energies. Herein lies the profound principle of Heaven-human resonance.

This passage primarily discusses the correspondence between the human body and the cosmic patterns of Yin-Yang and the Five Phases (Wood, Fire, Earth, Metal, Water), as well as the principles of meridian circulation.

In the cyclical movement of the Five Phases (Wuxing), there occur variations of excess or deficiency, while the Six Qi (wind, cold, summer heat, dampness, dryness, and fire) manifest transformations through ascending/descending movements and waxing/waning phases. The so-called "quiescent positional guardians" refer to the annual fixed Host Qi, also called Earth Qi or Root Qi, with each phase governing a period of 60 days and 87.5 ke (ancient time units). For instance, from Major Cold to Spring Equinox, the Jueyin Wind-Wood Qi dominates as the First Qi, when winds prevail and all things begin to grow; from Spring Equinox to Grain Buds, the Shaoyin Sovereign Fire Qi prevails as the Second Qi.

The text then explains body-cosmos correspondences: Human anatomy mirrors heaven and earth, with the back belonging to Yang and the abdomen to Yin. The round head symbolizes odd numbers (Yang), while its seven orifices represent even numbers (Yin). The upper body corresponds to heaven, the lower to earth. The Governor Vessel (Du Mai) is the Yang meridian, ascending from the lower body along the spine to the brain; the Thrusting Vessel (Chong Mai) is the Yin meridian, rising from the Qichong point along the Shaoyin channel to the chest.

The Inner Canon states: The back belongs to Yang—the heart is Yang within Yang (corresponding to the Li trigram), the lungs are Yin within Yang (Dui trigram), with both located in the upper body. The abdomen belongs to Yin—the kidneys are Yin within Yin (Kan trigram), the liver is Yang within Yin (Zhen and Gen trigrams), with both in the lower body. The spleen occupies the center as Ultimate Yin within Yin. Though the Triple Burner (Sanjiao) has no physical form, the upper burner irrigates meridians like mist, the middle burner ferments food like a bubbling brew, and the lower burner eliminates waste like drainage ditches.

Finally, it emphasizes aligning with the Five Qi (Five Phase energies) for bodily cultivation. The entire passage embodies the Daoist concept of "cosmos-human resonance" (tianren xiangying), correlating human anatomy with celestial operational patterns.

This passage primarily discusses the correspondence between the human body and the natural world, as well as methods for achieving physical and mental well-being through cultivation.

It begins by stating that when humans harmonize the five flavors (pungent, sweet, salty, bland, sour, and bitter) to nourish the body, understand the five virtues (benevolence, righteousness, propriety, wisdom, and trustworthiness) to perfect moral character, and follow the five constants (benevolence, righteousness, propriety, wisdom, and trustworthiness) in conduct, they can participate in the transformative processes of heaven and earth. The text cites Cheng Yi's criticism of worldly people: many enthusiastically study the principles of all things in nature yet pay little attention to the concrete conditions of their own internal organs, hair, skin, and bones. Truly wise learners should observe the laws of heaven and earth by first examining themselves.

The explanation then proceeds through the Four Symbols and Eight Trigrams (Bagua) diagram to illustrate the correspondence between the human body and nature: the three weather conditions of summer heat, heat, and dryness belong to Yang, corresponding to fire; while dampness, cold, and wind belong to Yin, corresponding to water. Specifically:

• Summer heat corresponds to the Qian trigram (bright red, the color of fire)
• Heat corresponds to the Li trigram (the nature of fire)
• Dryness corresponds to the Zhen trigram (the nature of aridity)
• Dampness corresponds to the Kun trigram
• Cold corresponds to the Kan trigram (the nature of water)
• Wind corresponds to the Xun trigram

Regarding the human body, the heart, lungs, and pericardium in the upper body belong to the hand channels, where the six Yin energies circulate downward from noon to midnight (wu to hai hours). The liver, spleen, and kidneys in the lower body belong to the foot channels, where the six Yang energies circulate upward from midnight to noon (zi to si hours). When diagnosing illness, the pulse in the upper body reflects external conditions, with a floating pulse indicating Qi movement; the pulse in the lower body reflects internal conditions, with a deep pulse indicating blood circulation.

The passage concludes by explaining: summer heat, heat, dryness, dampness, cold, and wind are the six Qi of heaven; pungent, sweet, salty, bland, sour, and bitter are the six flavors of earth; while the three Yin and three Yang channels of the hands and feet are the six pulses of humans. Humans receive the harmonizing Qi of heaven and earth, embody forms generated by the Five Phases (Wood, Fire, Earth, Metal, Water), and gather both Yin and Yang, hardness and softness within one body. The vitality of life is rooted internally as the "divine mechanism" (Shenji). Only when external six Qi are harmonized, internal six flavors nourish properly, daily routines follow regularity, and dietary habits maintain moderation, can physical and mental harmony be preserved. If burdened by external matters or drained by emotional desires that consume internal Jing (essence) and Qi, the six Qi and six flavors will disrupt bodily equilibrium, leading to illness—particularly noting that cold and dampness belong to pathogenic Yin influences.

This passage elucidates the operation of Yin-Yang and Five Phases theory in both human physiology and cosmic order from medical and Yijing (Classic of Changes) perspectives.

The medical section explains: Cold Qi harms the blood vessels, with diseases originating from the lower body meridians; heat Qi damages Qi circulation, manifesting first in upper body meridians. Wind, being Yang within Yin, is changeable—wind pathogens attack the liver (which governs tendons), causing convulsions and spasms. Dryness, as Yin within Yang, has astringent properties—dryness pathogens injure the lungs (controlling skin and hair), leading to skin fissures. Treatment methods must differentiate upper/lower and deficiency/excess conditions: emesis for upper disorders, purgation for lower disorders, harmonization for middle disorders, tonification for deficiency, drainage for excess, and meridian regulation for balanced conditions.

The Yijing section employs the Four Symbols (Lesser Yang, Greater Yang, Lesser Yin, Greater Yin) and Bagua (Eight Trigrams) diagram to reveal cosmic patterns: After Heaven and Earth establish their positions, the movements of sun, moon and stars create Yin-Yang, four seasons and Five Phases—what sages call the "Dao." Sages institutionalized social systems (like administrative divisions, ruler-subject rituals, and calendars) by observing these patterns, while virtuous scholars comprehended human ethics through classics like the Book of Songs, Book of Documents, Yijing, and Spring and Autumn Annals. Key points include:

• Yijing reveals the foundation of Yin-Yang (source of ritual-music)
• Book of Documents records ritual-music's golden age
• Book of Songs reflects ritual-music's transformations
• Spring and Autumn Annals rectifies ritual-music's decline
• Divination and calendrics represent Yijing's practical applications
• Literary genres derive from Book of Songs' evolution

Finally, citing Shao Yong and Du Qingbi's views, the four classics correspond to seasons: Yijing as spring (Three Sovereigns era), Book of Documents as summer (Five Emperors), Book of Songs as autumn (Three Dynasties), and Spring and Autumn Annals as winter (Five Hegemons)—together forming a complete moral system.

This passage elucidates the fundamental principles of governance practiced by ancient sage-kings and explores the relationship between music and the natural order of heaven and earth.

The author first critiques the frequent dynastic changes since the late Spring and Autumn period, noting that none surpassed the four cardinal principles of "revering ritual, honoring music, dwelling in benevolence, and following righteousness." He asserts that following the teachings of ancient kings represents the true Dao (Way), while doctrines that defy natural principles and seek novelty are mere heterodoxies. During the golden age of the Three Dynasties when the teachings of the Six Classics flourished, such heresies found no foothold; they only proliferated when classical learning declined. Thus scholars should focus on fundamental principles rather than engage in fruitless debates.

The text then interprets the symbolism of the Yu hexagram: the thunder emerging from beneath the earth signifies how ancient kings created music to manifest virtue. When rulers achieved great accomplishments and brought peace to the world, they composed music to harmonize the eight directional winds (listing in detail the wind names corresponding to eight solar terms), thereby resonating with the Qi (vital energy) of heaven and earth to attain supreme harmony.

It meticulously records ancient methods of determining musical temperament: first establishing the fundamental pitch, then calculating through the "method of dividing and supplementing by thirds" (an ancient acoustical calculation system) to derive the twelve pitch standards. This embodies the principle of harmony between the three unities of heaven, earth and humanity:

• The celestial unity begins at the zi hour (11pm-1am), represented by the yang number nine, corresponding to the Yellow Bell pitch pipe of nine inches
• The earthly unity begins at the chou hour (1-3am), represented by the yin number six, corresponding to the Forest Bell pitch pipe of six inches
• The human unity begins at the yin hour (3-5am), the convergence of yin and yang, represented by the number eight, corresponding to the Great Regulator pitch pipe of eight inches

These musical temperaments were all formulated in resonance with the movements of heaven and earth, embodying the ancient cosmological view of "the unity of heaven and humanity."

Fuxi (one of the Three Sovereigns of ancient legend) created pitch pipes measuring eight inches and eight fen, using them as the foundation to delineate the Eight Trigrams (Bagua), thereby aligning with celestial patterns and communicating with divine forces. This illustrates the ancient correspondence between musical tones and the Yin-Yang principles of heaven and earth: three calendrical systems interpenetrated while three distinct epochal starting points (marking different dynastic calendars) alternated in usage. The yang pitch standards (representing masculine tones) resembled taking a wife, while the yin pitch standards (representing feminine tones) resembled bearing children—the six yang and six yin tones (twelve-note system) cycled through the twelve earthly branches, forming a complete tonal system containing inexhaustible mysteries.

Specifically, the six yang tones were: Huangzhong, Dacu, Guxian, Ruibin, Yize, and Wuyi; the six yin tones were: Dalü, Yingzhong, Nanlü, Linzhong, Xiaolü, and Jiazhuang. This mirrored how the sun and moon's passage through the twelve celestial stations (zodiacal mansions) rotated rightward, prompting sages to create the six yin tones in correspondence, while the Big Dipper's handle pointing through the twelve earthly branches rotated leftward, inspiring the six yang tones. The six yang tones rotated left to unite with yin, the six yin tones rotated right to unite with yang—tones in corresponding positions symbolized marital union, while those in alternating positions symbolized maternal relationships. Those derived from Qian (the pure yang hexagram) through line transformations became the six yang tones; those derived from Kun (the pure yin hexagram) became the six yin tones.

Yang tones governed the earthly branches from zi (midnight) to si (midday), when pitch pipes were longer; yin tones governed from wu (noon) to hai (midnight), when pipes were shorter. This principle regulated the five notes: long pipes produced deep tones while short pipes produced high tones—the deep tones being resonant and expansive, the high tones crisp and urgent. Among these, the gong note symbolized the sovereign, residing centrally to govern the four directions as the foundation for other tones. Their characteristics manifested as: gong—serene and substantial; shang—vigorous and distinct; jue—rounded and upright; zhi—modulated and flowing; yu—clear and lingering. Ancient sages held that hearing gong tones cultivated gentle magnanimity, while shang tones fostered integrity and resolve.

This passage explores the profound relationship between ancient music and the harmony of heaven, earth, and human ethics, along with the cosmological principles behind measurement standards. The five musical notes (Gong, Shang, Jue, Zhi, Yu) each correspond to distinct social functions and moral influences: the Gong note symbolizes the ruler, Shang represents ministers, Jue embodies the common people, Zhi signifies affairs of state, and Yu stands for all things in creation. Hearing the Jue note evokes compassion and love for others, the Zhi note inspires joy in performing good deeds and generosity, while the Yu note encourages adherence to rules and reverence for ritual propriety.

Music forms an integral system with the Five Phases (Wood, Fire, Earth, Metal, Water), the five standards (compass, square, weight, balance, and plumb line), the five human activities (appearance, speech, vision, hearing, and thought), the eight timbres (metal, stone, silk, bamboo, gourd, clay, leather, and wood), and the Eight Trigrams (Bagua). Together they constitute the complete framework governing celestial movements and human conduct.

The text meticulously records ancient measurement standards: the Huangzhong pitch pipe measures nine inches long, its interior capacity holding 1,200 black millet grains called a yue. Two yue make a ge, ten ge form a sheng, ten sheng equal a dou, and ten dou constitute a hu. For weight measurements, the millet filling one yue weighs twelve zhu (corresponding to the twenty-four lines of the Eight Trigrams), sixteen liang make one jin (reflecting the 384 lines of the sixty-four hexagrams), thirty jin equal a jun, and four jun form a dan. All these standards derive from the Huangzhong pitch pipe, embodying music's deep connection with yin-yang cosmology and human nature. Through moral education and musical cultivation, people naturally incline toward goodness.

This passage mainly discusses two subjects: first, the relationship between music and the cultivation of human nature; second, the evolution of the ancient official system.

The first part says that people are born endowed with the harmonious Qi of Heaven and Earth, and all possess the essence of the Five Phases (Wood, Fire, Earth, Metal, Water) and the virtues of the Five Constants (benevolence, righteousness, propriety, wisdom, and trustworthiness). Music can harmonize human temperament: the gong tone can stimulate an honest heart, the zhi tone can cultivate respectful propriety, the shang tone can awaken a sense of shame and righteousness, the yu tone can clarify the wisdom of right and wrong, and the jue tone can evoke compassionate benevolence. In this way, cultivating both inner and outer aspects can make social customs honest and simple and bring peace to the world.

The second part records in detail the development of the official system from high antiquity to the Zhou dynasty. The earliest was Emperor Zhuanxu’s establishment of the Southern Rectifier, an astronomical official, and the Northern Rectifier, a geographical official; during the times of Yao and Shun this developed into the system of the Six Ministers. King Cheng of Zhou, referring to the Yin-Shang system, established in the Rites of Zhou a system of Six Officials framed by Heaven, Earth, and the four seasons: the Heavenly Official, the Grand Steward, oversaw court administration; the Earthly Official, the Minister of Education, was in charge of moral transformation; the Spring Official, the Minister of Rites, was responsible for ritual and ceremony; the Summer Official, the Minister of War, commanded military affairs; the Autumn Official, the Minister of Justice, supervised punishments; and the Winter Official, the Minister of Works, managed land. Each of the Six Officials performed its duties and together governed the realm. The Zhou dynasty also established the Three Dukes—the Grand Preceptor, Grand Tutor, and Grand Guardian—as the highest advisers.

These institutions all emulated the patterns of movement of Heaven and Earth; for example, the Six Officials corresponded to the 360 degrees of the celestial circuit, embodying the idea of correspondence between Heaven and humanity. The establishment of offices, from the earliest simple division of labor to the complete system formed in the Zhou dynasty, reflects the gradual improvement of the ancient political system.

This passage primarily discusses two aspects: the ancient official system and military formations. The first half explains the Zhou Dynasty's bureaucratic structure: the Grand Preceptor (Taishi), Grand Mentor (Taifu), and Grand Guardian (Taibao) were collectively known as the "Three Dukes" (Sangong), responsible for assisting the ruler in governance and harmonizing Yin-Yang. The Junior Preceptor (Shaoshi), Junior Mentor (Shaofu), and Junior Guardian (Shaobao), termed the "Three Solitaries" (Sangu), aided the Three Dukes in educating the people and venerating Heaven and Earth. These positions weren't administrative roles but were established according to the patterns of cosmic Yin-Yang movement and seasonal transitions. After the Zhou's decline, this system deteriorated until the Qin Dynasty abolished the feudal system, establishing new offices like the Chancellor (Chengxiang), Imperial Secretary (Yushi Dafu), and Grand Commandant (Taiwei), which the Han Dynasty inherited unchanged, resulting in bureaucratic confusion. The author considers the Six Ministries system recorded in Zhou's Rites of Zhou as exemplary for later rulers—like lifting a fishing net by its main cord or straightening a fur coat by its collar—capable of governing myriad affairs.

The latter half interprets ancient military formations through Bagua (Eight Trigrams) symbolism. Ancient military organization (five soldiers forming a "squad," a hundred forming a "company") and the Son of Heaven's six armies or major states' three armies all originated from the Xiangshu (image-number) principles in the Book of Changes. Zhuge Liang (Marquis Wu) accordingly created the Eight Formation Arrays: Heaven, Earth, Wind, and Cloud corresponded to the four diagonal directions (northwest, southwest, southeast, northeast) in the Later Heaven Bagua arrangement, while Dragon, Tiger, Bird, and Snake aligned with the four cardinal directions (north, east, south, west). The formations emphasized regular troops maintaining structure while special forces adapted flexibly, combining movement and stillness like cosmic operation—when stationary, deeply concealed as the "Nine Earths"; when mobile, unstoppable as the "Nine Heavens." The eight formation characteristics mirrored natural elements: flowing like water, steadfast as mountains, sharp as metal (Dui trigram), awe-inspiring like fire (Li trigram), swift as thunder, and rapid as wind. At the core, the commander held position at the central "Grasping the Pivot" point, with all directions flexibly transforming to form a tactical system of coordinated offense and defense, where vanguard and rearguard supported each other.

This passage explains the mathematical principles and practical applications of ancient military formations. The ancients used the numbers "five" and "eight" as the foundation for military organization. Five soldiers formed a "Wu" squad, and five Wu units (25 men) composed a "Dui" platoon, which served as the basic combat unit.

Army sizes were categorized into three levels: small formations consisted of eight Dui (200 men), medium formations sixty-four Dui (1,600 men), and the largest formations five hundred twelve Dui (12,800 men). This organizational method not only aligned with Zhou dynasty military systems (five men per Wu, one hundred per Zu) but also secretly corresponded with the generative cycle of the Five Phases (Wuxing).

For battlefield deployment, the "Eight Formations" arrangement was employed, mirroring the eight directions of the Bagua (Eight Trigrams). The commander positioned himself at the center, with eight directional formations encircling him, creating a nine-square grid pattern (though called "Eight Formations," there were actually nine command points). This formation operated like a door's pivot—appearing static yet capable of fluid movement.

When encamped, the troops formed a garrison; when mobilized, they transformed into battle arrays. The four cardinal directions (east, south, west, north) deployed main forces, while the four corners (southeast, southwest, northwest, northeast) positioned special troops, symbolizing the celestial creatures—dragon, tiger, bird, and serpent. The formations of heaven, earth, wind, and cloud occupied the four dimensional spaces, with regular and special troops coordinating to create infinite variations.

This military strategy drew wisdom from the Yijing (Book of Changes), achieving the effects of defeating larger forces with smaller numbers and controlling movement through stillness via numerical combinations and directional transformations. As Sunzi said: "Managing a great army is like managing a small troop—the key lies in organizational structure." With clear organization, even vast numbers could be commanded effectively.

This passage is a Qing dynasty scholar Zhang Li’s (courtesy name Zhongchun) interpretation of the astronomical and calendrical content in the Yijing. It mainly discusses how calendars were formulated by observing the movements of the sun, moon, and stars, and how the pattern of the changing four seasons was elucidated.

The text mentions the image of the Ge hexagram (Revolution) in the Yijing, “fire in the marsh,” and uses it to illustrate the importance of calendrical reform. The Li hexagram represents fire and the sun, while the Dui hexagram represents the marsh and the moon (here citing Shao Yong’s Huangji Jingshi Shu). The sun and moon push each other along and produce light; cold and heat alternate and form the year. These are all bases for formulating a calendar through observing celestial phenomena.

Ancient observers found that the sun and moon meet in the twelve stellar stations (called chen) over the course of a year—for example, in the first month they meet in Xuanxiao, in the second in Zouzi, and so on. These stellar stations correspond to the twenty-eight lunar mansions, which are divided into four groups, such as the seven mansions of the Azure Dragon in the east and the seven mansions of the Dark Warrior in the north.

The author points out that because the paths of the sun and moon have already changed, the ancient method of determining months by the direction of the Dipper’s handle (for example, in the first month the handle points to yin) no longer fully agrees with modern observations. Therefore, it may not be entirely appropriate to formulate calendars or make musical instruments strictly according to ancient methods. This reflects the pursuit of astronomical and calendrical precision among ancient scholars.

This passage explains how ancient people calculated time through celestial patterns and trigram correspondences. The heavens were divided into twenty-eight lunar mansions (ancient constellations grouped into twenty-eight sectors), distributed across four directions—east, north, west, and south—with seven mansions in each. The eastern mansions span 75 degrees, the northern 98 degrees, the western 80 degrees, and the southern 112 degrees, totaling precisely 365¼ degrees, which corresponds to the number of days in a solar year.

Using these celestial markers, the ancients delineated the four seasons, eight solar terms (major seasonal nodes like Spring Begins and Spring Equinox), twelve months, twenty-four solar terms, and seventy-two pentads (five-day micro-seasons), ultimately defining the year as 365¼ days. The Yijing (Book of Changes) system mirrors these astronomical phenomena: the four images (Lesser Yang, Greater Yang, Lesser Yin, Greater Yin) correspond to the four seasons, while the eight trigrams (Bagua) align with the eight solar terms (e.g., the Gen trigram for Spring Begins, Zhen for Spring Equinox, etc.).

The twelve sovereign hexagrams (Fu, Lin, Tai, etc.) represent the twelve months, the twenty-four lines of the eight trigrams match the twenty-four solar terms, and the seventy-two lines correspond to the seventy-two pentads. The twenty-eight inverted-change hexagrams reflect the twenty-eight lunar mansions, while the 384 lines of the sixty-four hexagrams symbolize the days of the year. Through this meticulous correspondence system, the ancients could precisely track time, including inserting intercalary months to reconcile discrepancies between lunar and solar calendars.

The text concludes with a quote from the Shangshu (Book of Documents): "The sun and moon's movements create the alternation of cold and heat—when the sun reaches its northern extreme at the winter solstice, cold prevails; at its southern extreme during the summer solstice, heat dominates." This encapsulates the foundational principle behind ancient calendar-making through celestial observation.

The movement of the sun correlates closely with seasonal changes: when the sun travels over southern land, it brings the heat of summer; its western path marks autumn, while its eastern course lengthens daylight hours. Both the duration of day/night and temperature variations follow observable patterns, which is why ancient astronomers like Feng Xiangshi (officials in charge of celestial observation) determined seasonal transitions by measuring solar shadows.

The specific measurement method involved erecting an eight-chi tall gnomon (called "yi") with eight ropes extending to the four cardinal directions (north, south, east, west) and four intercardinal points (northeast, northwest, southeast, southwest). At summer solstice, the shadow measured shortest at just 1.5 chi, coinciding with the longest daylight; winter solstice produced the longest shadow of 13 chi during the shortest day. The difference between these extremes measured precisely 11.5 chi.

After winter solstice, the sun gradually shifted northward, shortening shadows until spring equinox when they measured 5 chi 7.5 cun shorter than at winter solstice, with equal day and night. The shadows continued diminishing to reach exactly 1.5 chi at summer solstice. Thereafter, the sun moved southward, lengthening shadows to autumn equinox where they grew 5 chi 7.5 cun longer than summer solstice, again balancing daylight. By winter solstice, shadows returned to 13 chi. Agricultural prosperity was predicted when shadow lengths matched this pattern, whereas deviations foretold poor harvests.

Abnormally long shadows indicated floods, while short shadows signaled drought. When shadow variations exceeded 1 chi 2 cun: elongation predicted lunar eclipses, shortening solar eclipses. These phenomena occurred when the sun deviated from the ecliptic (its apparent celestial path)—northern deviation caused longer shadows with excessive yin leading to floods, while southern shifts brought shorter shadows with excessive yang causing drought.

Lunar observation methods were recorded in astronomical texts: the moon follows nine orbital paths. Among these, two black paths lie north of the ecliptic, two red paths south, two white paths west, and two blue paths east. The red and blue paths belong to yang channels, while black paths correspond to yin channels. Lunar deviations manifested as: yang path aberrations causing drought and wind, yin path deviations bringing rain and clouds. All nine orbits were defined relative to the ecliptic.

Seasonal correspondences were: summer moons on the ecliptic's southern red path (chidao), deviating northward to black paths (heidao); spring moons on eastern blue paths (qingdao), shifting westward to white paths (baidao); winter moons on northern black paths, veering southward to red paths; autumn moons on western white paths, straying eastward to blue paths. Though named differently, all these paths represent lunar trajectories relative to the ecliptic.

This scripture primarily describes ancient methods for predicting weather patterns and determining solar terms through celestial observation. The text mentions the "Yang path" and "Yin path," which represent the sun's northern and southern trajectories respectively. When the sun moves predominantly northward (Yang path), drought conditions prevail, while southward movement (Yin path) brings increased rainfall. The most balanced state occurs when the sun follows the central ecliptic path—its apparent motion across the celestial sphere.

Zheng Kangcheng (a Han dynasty classical scholar) noted that during the Spring Equinox, the sun aligns with the Lou constellation, while during the Autumn Equinox it aligns with the Jiao constellation. By observing the moon's position during the first quarter (around the 8th lunar day) and last quarter (around the 23rd lunar day), one could assess the balance of Yin and Yang energies. For instance, during Spring Equinox, the first quarter moon appears in the Jing constellation and the last quarter in the Niu constellation—a pattern that reverses during Autumn Equinox.

The text meticulously records the sun's stellar positions and sunrise/sunset times for all twenty-four solar terms. At Winter Solstice, the sun resides at the eighth degree of the Ji constellation, rising at the beginning of the Chen hour (approximately 7:15 AM) and setting at the third mark of the Shen hour (around 4:45 PM). During Spring Equinox, the sun occupies the eighth degree of the Bi constellation, rising at the fourth mark of the Mao hour (about 6:00 AM) and setting at the beginning of the You hour (around 6:00 PM). Minor discrepancies in these measurements account for the effects of precession—the gradual shift in Earth's rotational axis that causes long-term astronomical variations.

These observational techniques demonstrate the ancients' wisdom in correlating celestial phenomena with natural laws, using stellar patterns to forecast weather and guide agricultural activities.

This scripture primarily elucidates the patterns of celestial movements and the transformations of Yin-Yang. It first records the sun's positions among the twenty-eight lunar mansions (such as Liu, Xing, and Zhang) from the Beginning of Autumn (Liqiu) to Major Snow (Daxue), along with the shifting times of sunrise and sunset. These observations reflect the seasonal variations in day and night lengths.

The text then expounds on the cyclical principle of Heaven and Earth's Qi: the alternating movements of the sun and moon, and the mutual succession of cold and warm seasons. In the previously mentioned circular and square diagrams, the arranged Eight Trigrams (Bagua) intersect in complementary patterns (one clockwise, one counterclockwise), with Yin and Yang mutually propelling each other (advancing and retreating). Yang represents daylight, warmth, and heat, while Yin symbolizes night, coolness, and cold. The alternation of day and night drives the growth of all things, and the cycle of cold and heat forms the four seasons.

Ancient scholars divided time as follows: five days constitute a hou (small climatic period), three hou form a qi (15 days), six qi make a shi (90 days, one season), and four shi complete a year (360 days). The year contains twenty-four solar terms, corresponding to the twenty-four lines (yao) of the Eight Trigrams (six lines per trigram), with each line matching a solar term. The lower trigram (zhen gua, "steadfast hexagram") and upper trigram (hui gua, "changing hexagram") have corresponding line positions: the first line pairs with the fourth, the second with the fifth, and the third with the sixth.

The Winter Solstice (Dongzhi) begins with the initial yang line (9th line) of the Fu hexagram (Zhen below, Kun above), where a single yang line stirs beneath layers of yin lines. When yin energy peaks and yang is faint—measured by a ten-part division—yang occupies just one part while yin claims nine (considering the five solar terms surrounding Dongzhi: Minor Snow, Major Snow, Minor Cold, Major Cold, and the solstice itself, totaling ten lines). Thus, this period has the longest nights and shortest days, with the coldest weather. The 6/2 and 6/3 yin lines correspond to Minor Cold and Major Cold, where yin's frigidity culminates before spring's energy begins stirring. The Beginning of Spring (Lichun) emerges through the initial yang line of the Bi hexagram (Li below, Gen above).

(Note: The "zhen gua" refers to the lower trigram, representing a phenomenon's essence, while the "hui gua" denotes the upper trigram, symbolizing its transformations—ancient divination terminology.)

This passage uses the hexagrams of the Yijing (Book of Changes) to explain the cyclical patterns of seasonal climate changes. It correlates the twenty-four solar terms with transformations among the sixty-four hexagrams, revealing natural rhythms through the waxing and waning of Yin-Yang.

At spring's commencement, Yang qi dominates three parts while Yin qi holds seven, as temperatures gradually warm. From the Rain Water and Waking of Insects solar terms until the Spring Equinox, Yin and Yang achieve equilibrium—each occupying five parts—bringing mild weather with equal day and night duration. During Clear Brightness and Grain Rain periods, temperatures continue rising as summer's influence emerges.

At Summer Commencement, Yang qi ascends to seven parts against Yin's three, marking the shift toward heat. During Grain Full and Grain in Ear, midsummer peaks. Though the Summer Solstice represents Yang's zenith (nine parts Yang to one part Yin, with long days and short nights), Yin qi already begins germinating beneath (symbolized by the first Yin line beneath multiple Yang lines in the Gou hexagram's structure).

When Autumn Commencement arrives, Yin qi grows to three parts against Yang's seven, bringing cooler weather. From End of Heat and White Dew until the Autumn Equinox, Yin and Yang balance again (five parts each), creating refreshing temperatures. Cold Dew and Frost Descent deepen the chill as winter approaches.

At Winter Commencement, Yin qi dominates seven parts with Yang reduced to three, bringing cold weather. During Minor Snow and Major Snow, Yin reaches its peak—yet Yang already stirs anew at the foundation (symbolized by the first line of the Fu hexagram). Like a circle without endpoints, the cycle perpetually renews. Through the mutual stimulation of the eight trigrams, the sixty-four hexagrams emerge completely, manifesting the Dao's celestial patterns.

The mentioned hexagrams—Fu, Gou, Jie, Lü, Bi, Xiao Xu, Kun, and Yu—all belong to the "first generation transformations" in the eight-trigram palace system: Fu and Gou correspond to winter and summer solstices (initial line changes in Qian and Kun hexagrams), while Jie and Lü align with spring and autumn equinoxes (initial line changes in Kan and Li hexagrams). This hexagram-qi theory perfectly integrates astronomical calendars with Yijing principles, demonstrating the ancient wisdom of "observing celestial phenomena to establish calendars."

This passage discusses two main components: first, the correspondence between the Eight Trigrams (Bagua) — Qian, Kun, Kan, Li, Gen, Xun, Dui, and Zhen — and the cyclical patterns of the twenty-four solar terms; second, the feudal system and territorial organization of the Zhou Dynasty.

The first part explains the relationship between the trigrams and the solar terms. At the beginning of spring (Lichun), the initial line change of the Gen trigram corresponds to the Xiaoxu hexagram; at the start of summer (Lixia), the initial line change of the Xun trigram aligns with the Kun hexagram; at the onset of autumn (Liqiu), the initial line change of the Dui trigram matches the Yu hexagram; and at the beginning of winter (Lidong), the initial line change of the Zhen trigram takes effect. The four cardinal solar terms — winter solstice, summer solstice, spring equinox, and autumn equinox — are governed by the four primary trigrams (Qian, Kun, Kan, and Li), which remain unchanged. Meanwhile, the four "beginning" solar terms (the starts of each season) are governed by the four secondary trigrams (Gen, Xun, Dui, and Zhen), which undergo transformations. Among the Eight Trigrams, only these eight exhibit corresponding Yin-Yang relationships between their first and fourth lines, while the other lines do not interact. Thus, although there are twenty-four solar terms in a year, the principal seasonal transitions are reflected in these eight trigrams.

The second part describes the feudal system of the Zhou Dynasty. The Zhou king divided the realm into ten thousand states, enfeoffing lords to safeguard the royal house. According to the Rites of Zhou (Zhouli), the Zhou established a comprehensive territorial system: the royal domain (directly ruled by the Son of Heaven) spanned a thousand li in radius, surrounded by concentric administrative zones — the xiang (rural districts), sui (outer districts), du (cities), and bi (borderlands). The enfeoffed lords were ranked into five grades — duke (gong), marquis (hou), earl (bo), viscount (zi), and baron (nan) — with fiefs ranging from five hundred to one hundred li in size. Smaller vassal states were subordinate to these lords. During times of prosperity, the realm could extend ten thousand li, with the Central States occupying seven thousand li; in middling eras, including the Yi and Qiu regions, it covered seven thousand li, with the Central States comprising five thousand li; in decline, including the Yi and Di peoples, it spanned five thousand li, with the Central States reduced to three thousand li. Mencius's reference to "nine domains of a thousand li within the seas" alludes to this feudal system, which originated in the Xia and Shang periods, was maintained in early Zhou, and expanded under the Duke of Zhou's regency for King Cheng, with additional enfeoffments for meritorious officials.

Finally, the Rites of Zhou records that the Minister of Lands (Da Situ) determined the earth's center by measuring shadows cast by a gnomon: short shadows indicated southern regions with hot climates, while long shadows marked northern areas with cold climates. This was an essential method of geographical measurement in antiquity.

The ancient Chinese used jade sundials (known as tugui) to determine the geographical center of the land. The standard tugui measured one chi five cun (approx. 35 cm). At high noon during the summer solstice, if an eight-chi tall gnomon cast a shadow of exactly one chi five cun, this location was considered the "center of earth" (dizhong) - the pivotal point between heaven and earth. This spot represented perfect yin-yang harmony, seasonal equilibrium, and the convergence of wind and rain, making it the ideal site for establishing a royal capital.

The Duke of Zhou during the Zhou dynasty conducted such measurements at Yangcheng in Yingchuan (modern Dengfeng, Henan). Using Yangcheng as the central reference point, they erected markers: a southern gnomon placed a thousand li to the south cast a shadow one cun shorter, indicating hotter climate; a northern gnomen a thousand li north showed one cun longer shadow, marking colder regions; an eastern gnomon a thousand li east revealed westward-leaning shadows, signifying windy conditions; while a western marker a thousand li west produced eastward shadows, denoting cloudy weather. Only at Yangcheng did all natural conditions achieve perfect balance.

Ancient scholars formulated the "one cun per thousand li" rule: every cun difference in shadow length corresponded to a thousand li (approx. 500 km) in actual distance. This measurement method aligned with astronomical calculations.

For capital city construction, builders first leveled the ground using weighted plumb lines. Solar observations determined orientation: morning measurements of sunrise shadows, evening readings of sunset shadows, noon solar positions, and nighttime Polaris observations all helped calibrate directions. The ideal capital formed a square measuring nine li (approx. 4.5 km) per side, with three gates on each wall. The grid pattern featured nine north-south and nine east-west avenues, each wide enough for nine chariots abreast. The ancestral temple stood to the left (east), the altar of soil and grain to the right (west), with the imperial court facing south and markets occupying the northern sector - each public space covering one hundred mu (approx. 6.7 hectares).

These standardized methods for establishing ancient capitals embodied the cosmological principle of harmony between heaven and humanity (tianren heyi) in urban planning.

This passage describes ancient methods for surveying directions and planning cities. It first explains a technique for measuring方位 using vertical poles: Erect pillars at the four corners and level the ground with a water-level instrument. Set up an eight-foot central gnomon (nie) in the middle, suspending eight plumb lines from its four corners and midpoints to fix the pillars vertically. Then determine east-west orientation by observing the shadows cast by the pillars at sunrise and sunset, while north-south orientation is established by observing the sun's shadow during daytime and the North Star at night.

The city planning system is then detailed: A square measuring one li (about 500 meters) forms a basic unit called a "well-field" (jing), with nine such units creating a three-by-three li area. North-south roads are called "warp" (jing) and east-west roads "weft" (wei), totaling nine in each direction to form a grid. The city walls have three gates on each side, making twelve gates corresponding to the twelve earthly branches. Road widths follow the standard of nine "tracks" (one track equals the width of wheel ruts—six chi six cun for the carriage plus seven cun on each side totaling eight chi), with nine tracks amounting to seventy-two chi, or twelve paces wide. Each city gate has three passageways: men walk on the left, women on the right, and vehicles pass through the center.

The urban layout observes Yin-Yang principles: Ancestral temples (yang) are placed on the left, altars of soil and grain (yin) on the right; the three administrative courts (yang) are positioned at the front, while the three marketplaces for trade and executions (yin) are located at the rear. All districts follow the "one husband, one hundred mu" land division standard.

The final section explains land allocation systems: The "Field Master" (zaishi) distributes land according to its nature. Urban areas house merchants, garden plots are for cultivation, suburban zones contain residential fields (for scholars, officials, and merchants), while outer suburbs hold palace fields, cattle fields, reward fields, and pasturelands. More distant territories—dian, shao, xian, and jiang lands—are designated as fiefdoms for ducal estates, noble houses, minor capitals, and major capitals respectively.

A supplementary note clarifies that this was the planning system for the royal domain (wangji) during the Zhou dynasty, covering a thousand-li radius with the capital at its center extending five hundred li in all directions. Measurements follow hundred-li units, with the inner fifty li as near suburbs and the full hundred li as far suburbs. This area accommodated seventy-five thousand households in six districts (xiang), with remaining lands allocated as described above.

This passage primarily discusses the land system and administrative divisions of the ancient Zhou dynasty. Based on their distance from the royal capital, lands were classified into different graded zones:

The area closest to the capital was called the "suburban land" (jiao di), covering four "tong" (an ancient unit of measurement) and capable of accommodating 10,000 well-fields (jing) and 30,000 households. Among these, 75,000 people formed the "six districts" (liu xiang), while the remaining 45,000 were responsible for cultivating nine grades of land.

Beyond the suburban land lay the "outlying land" (dian di), covering twelve tong and accommodating 360,000 households. Here, 75,000 people formed the "six outer districts" (liu sui), while the remaining 285,000 cultivated fields in public estates managed by the "land officers" (sui ren).

Further outward were:

• "Marginal land" (shao di), twenty tong, responsible for fields of noble estates
• "County land" (xian di), twenty-eight tong, responsible for fields of minor capitals
• "Border land" (jiang di), thirty-six tong, responsible for fields of major capitals

These outer regions employed the "well-pasture system" (jing mu zhi), a farming method similar to the well-field system, managed by the "minor minister of education" (xiao situ).

According to the Sima Fa, the zones around the capital were measured as:

• Hundred li radius: suburban land
• Two hundred li: prefectures
• Three hundred li: wilderness
• Four hundred li: counties
• Five hundred li: capitals

The "grand minister of education" (da situ) was responsible for land and population statistics, establishing grassroots administrative units:

• Five households formed a "mutual guarantee group" (bi)
• Five bi formed a "neighborhood" (lü) for mutual aid
• Four lü formed a "clan" (zu) for joint funeral arrangements
• Five zu formed a "community" (dang) for mutual relief
• Five dang formed a "district" (zhou) for mutual support
• Five zhou formed a "region" (xiang) for mutual courtesy

For noble fiefdoms:

• Dukes received major capitals (da du), spanning 100 li
• Ministers received minor capitals (xiao du), spanning 50 li
• Officials received noble estates (jia yi), spanning 25 li
• Royal descendants received benefits according to their degree of kinship

The "minor minister of education" (xiao situ) oversaw military organization:

• Five men formed a "squad" (wu)
• Five wu formed a "platoon" (liang)
• Four liang formed a "company" (zu)
• Five zu formed a "battalion" (lü)
• Five lü formed a "regiment" (shi)
• Five shi formed an "army" (jun)

This structure was used for military campaigns, hunting expeditions, labor services, and pursuing bandits.

This passage describes the military organization and land distribution system of ancient China, divided into two main parts:

Military Organization:

The population was organized with five households as the basic unit (bi), providing five men to form the smallest military unit (wu). This structure expanded progressively: 25 households formed a lü (with 25 men constituting a "liang"), 100 households formed a zu (100 men as a "zu"), 500 households formed a dang (500 men as a "lü"), 2,500 households formed a zhou (2,500 men as a "shi"), and 12,500 households formed a xiang (12,500 men as a "jun"). This system served both military conscription and organized activities like hunting and apprehending bandits. Here, "gong" referred to grain and mountain forest product tributes, while "fu" denoted providing vehicles and labor services.

Land Distribution:

The official position of "suiren" managed rural land allocation. Land was categorized into three grades (upper, middle, lower) for distribution: Upper-grade land allotted 100 mu of arable land plus 50 mu of fallow land per household; middle-grade land gave 100 mu arable plus 100 mu fallow; lower-grade land provided 100 mu arable plus 200 mu fallow. The term "vegetable fields" (caitian) referred to rotational fallow land—for instance, middle-grade land involved cultivating 100 mu while resting another 100 mu, alternating annually.

Note: One ancient mu equals approximately 0.066 modern hectares. This system tightly integrated military organization with agricultural production, embodying the ancient principle of "unifying soldiers and farmers."

The passage primarily discusses the land distribution and irrigation systems of the ancient well-field system. Land was categorized into three types based on fertility: the poorest land (requiring biennial or triennial fallow rotation) had only one hundred mu cultivated out of three hundred, with the remaining two hundred mu left fallow in rotation for two years; medium-quality land required periodic fallowing; while the most fertile upper-grade land needed no fallow rotation.

The text details the hierarchical structure of the agricultural irrigation network: the smallest unit was the "fu" (approximately one hundred mu), with small field ditches (sui); ten "fu" formed a "ten-fu" unit, served by larger ditches (gou); a hundred fu had broader channels (xu); a thousand fu featured major canals (kuai); while ten thousand fu connected to natural rivers (chuan). Each waterway was accompanied by roads of corresponding widths: narrow paths for oxen and horses, zhen roads for carts, tu roads accommodating one chariot, dao roads for two chariots, and grand roads allowing three chariots to travel abreast.

The author cites the Rites of Zhou and Mencius to illustrate how this system aligned with both natural patterns ("water within earth" as symbolized by the Shi hexagram) and governance principles where benevolent rule begins with demarcating field boundaries. Through the well-field system, rational utilization of water and land resources was achieved while organizing the populace and managing military forces, fulfilling the purpose of "nourishing and gathering the people." Finally, the passage notes that this system's design drew upon concepts from the Classic of Changes (Yijing), integrating farmland planning with natural principles.

(Note: Terms like "xu" and "kuai" are specialized vocabulary for ancient irrigation systems, referring to different grades of canals; "fu" was an ancient land measurement unit equivalent to about one hundred mu; the "Shi hexagram" is one of the sixty-four hexagrams in the Yijing, symbolizing gathering people and military affairs)

This passage explains the specific division methods of the ancient well-field system. The ancients divided land into regular square plots to manage land taxes and labor obligations.

A ten-li square area was designated as a "cheng" unit. If a hundred-li square area is considered as a whole, the hierarchical units convert as follows: a "yi" corresponds to a "dian," a "qiu" to a "xian," a "dian" to a "du," a "gou" to a "kuai" (a larger irrigation ditch), and a "xu" to a river.

The specific measurement standards were: a plowshare (farm tool) was five inches wide, and two plowshares side by side formed a "cou." Digging a "cou" produced a furrow one chi deep and one chi wide, called a "mu." The headlands of fields required wider and deeper ditches—those two chi wide and two chi deep were called "sui."

Nine households shared one well, and between wells, ditches four chi wide and four chi deep, called "gou," were dug. A ten-li square area formed one "cheng," and between cheng units, ditches eight chi wide and eight chi deep, called "xu," were dug. A hundred-li square area formed one "tong," and between tong units, ditches two xun (approximately sixteen chi) wide and two ren (approximately sixteen chi) deep, called "kuai," were excavated.

Land management followed this hierarchical division: nine households formed one well, four wells formed one yi, four yi formed one qiu, four qiu formed one dian, four dian formed one xian, and four xian formed one du. This multi-layered division was used to administer land and collect taxes.

In detail: a one-li square area was divided into nine sections, each containing one hundred mu. One household was allocated one hundred mu, and nine households formed one well. Four wells formed a two-li square yi, four yi formed a four-li square qiu, and four qiu formed an eight-li square dian. Adding an additional li around it created a ten-li square "cheng," containing one hundred wells and nine hundred households. Of these, sixty-four wells (576 households) were responsible for tax payments, while thirty-six wells (324 households) maintained the irrigation ditches.

Four cheng formed one xian (twenty-li square), four xian formed one du (forty-li square), and four du formed an eighty-li square area. Adding an additional ten li around it created a hundred-li square "tong." One tong contained ninety thousand wells and ninety thousand households, of which sixty-four hundred wells (56,700 households) paid taxes, while thirty-six hundred wells (32,400 households) maintained the waterworks. The complete system of the well-field system was established within the scope of one "tong."

This passage describes the land division and military organization system under ancient feudal institutions, primarily structured in three tiers: states of one hundred li, fifty li, and twenty-five li, each obligated to pay taxes to the sovereign.

The land measurement units are converted as follows: 6 chi (feet) make 1 bu (pace), 100 bu make 1 mu (approximately 0.165 acre), and 100 mu make 1 fu (a unit of land for one household). Three fu form 1 wu, and three wu form 1 jing (the well-field unit). Ten jing make up 1 tong (a complete administrative district, measuring one li in radius). One tong encompasses 30 households and must provide 1 horse, 1 soldier, and 2 attendants.

Ten tong form 1 cheng (measuring ten li in radius), containing 100 jing and 300 households, and must equip 1 war chariot, 10 soldiers, and 20 attendants. Ten cheng form 1 zhong, containing 1,000 jing and 3,000 households, equipped with 10 war chariots, 100 soldiers, and 200 attendants.

Ten zhong form 1 tong (measuring one hundred li in radius), containing 10,000 jing and 30,000 households, equipped with 100 war chariots, 1,000 soldiers, and 2,000 attendants. Ten tong form 1 feng, containing 100,000 jing and 300,000 households, equipped with 1,000 war chariots, 10,000 soldiers, and 20,000 attendants.

Ten feng form 1 ji (measuring one thousand li in radius), containing 1,000,000 jing and 3,000,000 households, equipped with 10,000 war chariots, 100,000 soldiers, and 200,000 attendants. The passage concludes by citing the "Lu Song," which records that the state of Lu possessed a thousand war chariots and thirty thousand troops—a figure that includes both soldiers and attendants.

(Note: This describes an idealized ancient administrative-military system, where "war chariots" (geche) refer to combat vehicles, and "attendants" (tu) denote support personnel. This military organization under the well-field system reflects the ancient principle of integrating military service with agricultural life.)