《易外別傳》

The Supplementary Teachings on the Yi (Yi Wai Bie Zhuan) is a work composed by Yu Yan (styled as the Stone Stream Daoist) on the fifteenth day of the eighth month in the Zhiyuan reign period (1284) during the Yuan dynasty. It primarily elucidates the mysteries of the Diagram of Prior Heaven (Xiantian Tu), an important visual representation in Daoist cultivation. This text builds upon the ideas of Wei Boyang's Zhouyi Cantong Qi (The Seal of the Unity of the Three in Accordance with the Book of Changes), a foundational Daoist alchemical scripture from the Han dynasty, asserting that the human body resonates with the transformations of Yin-Yang in heaven and earth.

Key Concepts:

The human body functions as a microcosm: the head corresponds to heaven (represented by the Qian hexagram), the abdomen to earth (the Kun hexagram), and the breath mirrors the movements of the sun and moon, synchronizing with the cyclical shifts of Yin-Yang in the cosmos.

The profundity of the Diagram of Prior Heaven lies in the "transition between Kun and Fu" (Kun Fu Zhi Jiao), symbolizing the subtle interplay of Yin-Yang in motion and stillness. Yu Yan claimed to have received secret teachings on interpreting the Yi (Book of Changes) from a reclusive master, which enabled him to grasp its deeper significance.

The Yi within the body: Concepts such as the Taiji (Supreme Ultimate) and the "Celestial Root and Lunar Cavity" (Tian Gen Yue Ku), proposed by the Song dynasty scholar Shao Yong (Shao Kangjie), find their counterparts in the human form. The so-called "Thirty-Six Palaces" (referring to the sum of all line transformations in the eight trigrams) actually describe the cyclical movement of Qi within the body.

Important Terms Explained:

• Celestial Root and Lunar Cavity: The Celestial Root resides in the lower body (corresponding to the Fu hexagram), while the Lunar Cavity is located in the upper body (the Gou hexagram), with the Shen (spirit) traveling between them.
• Thirty-Six Palaces: Refers to the total permutations of the eight trigrams—Qian (1), Dui (2), Li (3), Zhen (4), Xun (5), Kan (6), Gen (7), and Kun (8)—through their line changes.
• "All is spring": A metaphor for the harmonious circulation of genuine Qi (Zhenqi) within the body.

Yu Yan emphasizes that while scholars like Shao Yong and Zhu Xi (Zhu Ziyang) understood these principles, most Confucian literati remained unaware. True cultivation does not lie in books but in personal practice.

(Note: This doctrine integrates profound theories of Daoist Neidan (internal alchemy) with the hexagrams of the Yi Jing, advocating for the guidance of health-preserving practices through observing natural laws.)

This passage discusses the relationship between the "Innate Diagram" (Xiantian tu) in Daoist cultivation and human respiration, along with the dynamics of Yin-Yang movement and stillness.

Shao Kangjie states in his Book of Supreme World Ordering Principles that the Innate Diagram resembles a circular ring. The author posits that the human body itself embodies this diagram, with the heart positioned at the body's center just as the Taiji (Supreme Ultimate) occupies the diagram's core. Zhu Xi remarked that the empty space at the center represents the Taiji. This diagram begins with the Fu hexagram and concludes with the Kun hexagram, forming an interconnected cycle. The sixty-four hexagrams encircle the periphery while the Taiji resides at the center. What the Yijing calls Taiji manifests in the human body as the heart. Only by recognizing the heart as Taiji can one truly comprehend the Dao.

The text further explains: The period after winter solstice corresponds to exhalation, while the time following summer solstice aligns with inhalation—these constitute heaven and earth's annual respiration. Zhu Xi observed that the cosmos contains but a single Qi, with each complete cycle from one winter solstice to the next representing one respiratory process. Exhalation belongs to Yang, inhalation to Yin. From Fu to Qian hexagrams after winter solstice belongs to Yang, hence exhalation; from Gou to Kun hexagrams after summer solstice pertains to Yin, thus inhalation. Exhalation signifies Qi's outward expansion, corresponding to post-winter solstice; inhalation denotes Qi's inward contraction, matching post-summer solstice. On the macrocosmic level, this manifests as heaven and earth's yearly breath; microscopically, it appears as human respiration. The Cantongqi employs metaphors like "the dragon exhales while the tiger inhales" and "respiration resembles marital union"—all its elaborate discourse ultimately revolves around these two characters: "breath."

Finally, it addresses the principle of movement and stillness: The alternation between motion and stillness constitutes heaven and earth's most refined mechanism, with the transitional moment between them representing the supreme mystery uniting cosmos and humanity. Zhu Xi noted the diagram's left side belongs to Yang, the right to Yin. The author interprets the left progression from Fu to Qian as Yang movement, while the right sequence from Gou to Kun signifies Yin stillness. The transitional juncture occurs precisely at the intersection between Kun's end and Fu's beginning—the moment of Yin-Yang interaction. This corresponds to winter solstice in the annual cycle, the conjunction of old and new moons monthly, and the transition between Hai and Zi hours daily. At this critical point, Yin and Yang merge within the human body; stillness reaches its apex as vital energy stirs—perfectly synchronized with cosmic rhythms. This indeed constitutes the most profound moment uniting heaven, earth and humanity.

This scripture primarily discusses the profound principles of Yin-Yang transformation, which can be understood in modern terms as follows:

The text first describes the state of "absolute stillness without movement" as representing the pure Yin state of the Kun hexagram, while "response leading to penetration" signifies the initial movement of Yang energy in the Fu hexagram. The extreme of stillness manifests as the pure Yin Kun hexagram, while the beginning of movement appears as the nascent Yang in the Fu hexagram. The transition between stillness and response marks the critical moment of alternation between movement and stillness.

It further explains that before the Wuji (primordial undifferentiated state), Yin and Yang were not yet separated. Once forms and images emerged, Yang energy began to differentiate. Shao Yong (Master Shao) used hexagram cycles to illustrate this: from the Gou hexagram to Kun hexagram represents Yin containing Yang, while from Fu hexagram to Qian hexagram shows Yang separating from Yin. The transition between Kun and Fu represents the Wuji state. Zhu Xi (Master Zhu) considered this explanation profoundly insightful, describing it poetically as "the midnight thunderclap that stirs all things to life."

The text cites Shao Yong's "Winter Solstice Ode," noting that the midpoint of the midnight hour (11 PM to 1 AM) during winter solstice represents the initial stirring of Yang energy, when all things stand at the threshold of emergence—like the faintest wine or most delicate sound. This subtle state, though difficult to articulate in words, contains the fundamental mechanism of cosmic creation (zaohua zhi ji). Cheng Yi (Master Cheng) remarked that without comprehending this mystery, one cannot grasp the Dao of longevity.

Finally, the scripture quotes Shao Yong's "Hymn to the Indistinct," depicting the hazy, mysterious state when Yin and Yang first separate and heaven-earth begins to open. This secret of the "Heavenly Root" (tian gen, the origin of life) cannot be conveyed through language unless personally experienced. Zhu Xi regarded this poem as perfectly capturing the ultimate mystery of life's origin.

(Note: The mentioned Kun, Fu, Gou, and Qian are hexagram names from the Zhouyi [Book of Changes], representing different Yin-Yang states; "Heavenly Root" is a Daoist term referring to the origin of life or the universe; "mechanism of creation" denotes the fundamental laws governing natural creation and transformation.)

This passage explains the operational principles of the sixty-four hexagrams from the Book of Changes (Yijing) and their correspondences with heaven-earth and the human body.

First, the arrangement of the primal sixty-four hexagrams: Qian (Heaven) occupies the upper position and Kun (Earth) the lower, representing the fixed positions of heaven and earth. Kan (Water) and Li (Fire) reside between Qian and Kun, symbolizing the pivotal point where Yin and Yang converge. Shao Yong (Shao Kangjie) states in Huangji Jingshi Shu that the foundation of heaven and earth originates from the center—thus, no matter how Qian and Kun transform, they never depart from this central axis.

The movement of Yin-Yang follows this pattern: ascending from below signifies growth, while descending from above represents decline. Yang energy arises from below, and Yin energy emerges from above, which is why all things grow in reverse correspondence. Yin and Yang mutually transform—Yin gives birth to Yang, and Yang gives birth to Yin—in an endless cyclical motion.

The text emphasizes a crucial point: the Great Dao (Dao) is never distant from humanity—Qian and Kun are present within our bodies. Qian represents pure Yang (heaven) and thus resides in the upper center, while Kun embodies pure Yin (earth) and occupies the lower center. Kan (moon) contains Yang within Yin, and Li (sun) holds Yin within Yang, placing them between Qian and Kun. The remaining sixty hexagrams all begin with the first stirring of Yang within Kun, reaching their zenith at five Yang lines before culminating in the pure Yang of Qian—and vice versa.

This cycle of ascent and descent manifests not only in the operations of heaven and earth but also within the human body: during the Zi hour (11 PM–1 AM), Qi gathers at the coccyx (Weilü point); during the Chou and Yin hours (1–5 AM), it moves to the waist; from Mao to Si hours (5–11 AM), it ascends along the spine; at the Wu hour (11 AM–1 PM), it reaches the crown point (Muddy Pellet Palace, Niwan Gong), then gradually descends, returning to the abdomen during the Xu and Hai hours (7–11 PM). This pattern applies not only to daily cycles but even to each breath—inhaling draws Qi upward from below, while exhaling releases it downward from above.

Celestial bodies revolve around the celestial meridian (Zi-Wu axis), just as earthly tides follow the moon’s position along this line—Zi and Wu mark the center of heaven and earth. The Cantong Qi (Triple Unity) speaks of "aligning with the center in movement," "shifting without losing the center," and "floating while guarding the central rule," all emphasizing this law of centrality. If one comprehends the center within their body and aligns it with the center of heaven and earth, then the Great Dao of Qian-Kun is no longer external—it resides within us.

The Supplementary Commentary on the Yi elucidates the correspondence between the human body and the natural cosmos, as well as the principles of Neidan (internal alchemy) cultivation:

The Body's Correspondence with Heaven and Earth

The human abdomen resembles the earth (Kun), which nurtures all things by containing primordial Qi. When the Shen (spirit) descends to the abdomen (earth), it mirrors the celestial Qi descending to merge with terrestrial Qi. This harmonious interaction of heaven and earth—known as "heaven-earth communion"—generates life in nature and produces the "medicine" (Neidan) within the body. As the Taixuan Jing states, "Sink the Shen into the Dantian (abyss) to nourish the root of spiritual vitality," conveying this very principle.

The Metaphor of Shen and the Sun-Moon Dynamic

The moon (Taiyin) emits no light of its own but reflects the radiance of the sun (Taiyang). Similarly, the heart-mind is like the sun, while the sea of Qi in the kidneys resembles the moon. When the heart-mind stabilizes (Xin Ding), the Shen condenses (Shen Ning), causing Qi to gather. This state of "Shen entering Qi" parallels the moon illuminated by sunlight.

The Body's Triadic Structure (Heaven-Earth-Humanity)

The head corresponds to the Qian hexagram (heaven), the abdomen to Kun (earth), and the heart occupies the central "human" position, forming the triad of heaven-earth-humanity. The kidneys govern Qi (below), while the head governs form (above); these are inherently separate but harmonized by the mediating Shen. When the Shen resides in the kidneys, it embodies quiescent storage (Kun's Dao); when ascending to the head, it manifests active circulation (Qian's Dao). These states correspond to:

• Quiescence: The subtle fusion of Qi condenses into "medicine" (Neidan).
• Activity: The unceasing cyclical "fire phases" of Zhou Tian (celestial orbit) circulation.

The Pivotal Role of the Eyes

The Yinfu Jing identifies the eyes as crucial to cultivation, for wherever the gaze rests, the Shen follows. Thus, internal practice requires:

• Inward vision fixed on the nose tip.
• Nasal alignment directed toward the navel.
• Guiding the heart-fire downward to the Qi sea (Dantian).

These methods all employ ocular regulation to direct the flow of internal Qi.

This scripture primarily discusses the correspondences between Yin-Yang, the Five Phases (Wood, Fire, Earth, Metal, Water), the Bagua (Eight Trigrams) directions, and the human body in Daoist cultivation practices.

Regarding the "Diagram of Qian-Kun-Kan-Li" and "Diagram of Heaven-Earth-Sun-Moon":

The Yijing (Book of Changes) states that Qian represents heaven, Kun represents earth, Li represents the sun, and Kan represents the moon. It further notes that Qian symbolizes the head while Kun symbolizes the abdomen. The Taixuan Jing mentions that Yang Qi subtly germinates within the Yellow Palace (referring to the Dantian). The Huangting Jing (Scripture of the Yellow Court) teaches that longevity requires cultivating Kunlun (the crown of the head) and that breathing exercises should follow the rhythmic regularity of sunrise and moonset. The author posits that the head, being round and positioned at the body's apex where Yang Qi gathers, corresponds to Qian-as-heaven—hence the Yijing using Qian to represent the head. Since Kunlun aligns with the northwest (Qian's direction), the Huangting Jing employs Qian to denote Kunlun. The abdomen, being hollow and positioned below where the eight meridians converge, corresponds to Kun-as-earth. The cosmic colors of heaven (black) and earth (yellow) explain why the Taixuan Jing uses Kun to represent the Yellow Palace. The sun rises in the east while the moon emerges from the west, thus the Yijing assigns Li to the sun and Kan to the moon. The ceaseless cyclical movement of breath mirrors celestial motion, which is why the Huangting Jing compares respiration to the sun-moon cycle. The notion that eyes symbolize the sun and moon is incorrect—while eyes may resemble them in form, they lack their celestial functions.

Regarding the "Diagram of Eight-Seven-Nine-Six" and "Diagram of Wood-Fire-Metal-Water":

The Cantongqi (Triple Unity) speaks of nine requiring return, seven requiring reversion, eight requiring homecoming, and six requiring peaceful dwelling. It further states that seven plus eight makes fifteen, as does nine plus six. Additionally, it describes metal-water merging and wood-fire pairing, with these four elements chaotically arranged as dragon and tiger. The author explains that six, seven, eight, and nine represent the mature numbers of water, fire, wood, and metal respectively: Wood's number eight belongs to the east, fire's seven to the south—when wood rises eastward it pairs with fire in the south; metal's nine belongs to the west, water's six to the north—when metal descends westward it merges with water in the north. Alchemists refer to the crimson dragon and black tiger: when the eastern Azure Dragon constellation moves south it becomes crimson, while the western White Tiger constellation moving north turns black. These all metaphorically describe the body's internal respiratory cycles. Ultimately, there are no literal dragons/tigers, metal-water/wood-fire, or seven-eight-nine-six distinctions—all are merely symbolic representations. Some question why nine-seven-eight involve "return-reversion-homecoming" while six alone "peacefully dwells." This is because six resides motionless in the north, while the other three directions' cyclical movements all gather there—hence "peaceful dwelling."

Notes:

1. Qian-Kun-Kan-Li are four trigrams representing heaven, earth, water, and fire respectively

2. Huangting (Yellow Court) refers to the middle Dantian among the three energy centers

3. Cantongqi (full title Zhouyi Cantongqi) is a pivotal Daoist alchemical scripture

4. "Seven returns and nine reversions" refer to firing process variations in alchemy

5. Dragon-tiger in internal alchemy typically represent lead-mercury, Yin-Yang, or heart-mind/kidney Qi

This scripture passage explains the use of the sixty-four hexagrams from the Book of Changes (Zhouyi) as metaphors for the movement patterns of Qi (vital energy) in Daoist Neidan (internal alchemy) practice. It can be divided into several key sections:

The first section discusses "the transformation of Qian and Kun." The Qian (Heaven) hexagram above and Kun (Earth) hexagram below symbolize the human body as a microcosm. The Tai (Peace) hexagram on the left and Pi (Stagnation) hexagram on the right represent the ascending and descending movements of Yin-Yang energies within the body. The references to "Zi hour" and "Wu hour" here don't denote actual time periods but rather critical junctures in the body's internal energetic rhythms.

Next comes "the transformation of Kan and Li." The Kan (Water) hexagram in the north and Li (Fire) hexagram in the south symbolize the water-fire energies within the body. The Ji Ji (After Completion) hexagram in the east and Wei Ji (Before Completion) hexagram in the west depict the rising and falling of these water-fire energies. The Tun (Difficulty) and Meng (Youthful Folly) hexagrams represent the "fire timing" (the crucial moments and intensity in practice), where references to "Yin hour" and "Xu hour" similarly indicate internal energetic states rather than literal time.

The passage then cites the Zhouyi Cantongqi (The Kinship of the Three), comparing Qian and Kun to the alchemical cauldron, Kan and Li to the medicinal ingredients, and the remaining sixty hexagrams to the regulation of fire timing. The twelve two-hour periods of the day correspond to two hexagrams with twelve lines—for example, using Tun hexagram in the morning and Meng hexagram in the evening, cycling through them accordingly. The Tun hexagram inverted becomes the Meng hexagram, one symbolizing ascent (like daytime and spring/summer) while the other represents descent (like nighttime and autumn/winter).

Finally, the text clarifies that this method of matching sixty hexagrams to thirty days is purely metaphorical, not to be taken as strict correspondence. Using it to count breaths would be unnecessarily complicated, violating the Daoist principle of supreme simplicity. The core message is this: despite the vast diversity of alchemical terminology, the fundamental principles remain universally consistent.

(Note: The term "fire timing" refers to the crucial moments and intensity control in Neidan practice, while references to "Zi, Wu, Yin, Xu" hours all metaphorically represent specific states in the body's energetic circulation.)

This scripture expounds the cultivation principle of the correspondence between heaven and humanity, which can be understood as follows:

This exquisite practice method is genuine and unfailing, remaining clearly traceable through myriad generations. It operates as naturally as stars traversing the Milky Way or rivers returning to the ocean. One must contemplate it repeatedly, studying it thousands of times until suddenly comprehending its profound mysteries and finding the correct gateway to cultivation. The Dao of Heaven shows no partiality—it is transmitted only to virtuous sages.

(Detailed explanation follows):

1. Heaven's ceaseless movement: The celestial sphere resembles an inclined pestle, with its north and south poles each tilted 36 degrees from the horizon. Covering over 900,000 li in a single day-night cycle, Heaven travels more than 80 li during just one human breath—demonstrating its perpetual motion without rest.

2. Human vitality follows the same principle: When Shen (spirit) and Qi (vital energy) gather, life flourishes; when they scatter, death ensues. Just as Heaven endures through constant yang-powered movement, so too must humans maintain this dynamic.

3. The human body as microcosm: Our physical form mirrors celestial movement, with the "Heavenly Pass" (crown of the head) above and "Earthly Axis" (perineum) below. By activating these pivotal points, one complete Zhou Tian (celestial cycle) circulation can be achieved in a single breath.

4. The heart as pivot: Just as the Northern Dipper serves as the celestial pivot, the heart functions as the body's central hub. The heart's internal rotations mirror the Dipper's heavenly revolutions.

5. Heaven-human unity: The essential cultivation method lies in observing celestial patterns and emulating Heaven's movements. Through neiguan (inner observation) and fan ting (inward listening), one quiets mental activity and regulates breath into continuous circulation—thus achieving harmony with the Heavenly Dao.

(Note: "Zhou Tian" refers to the Qi circulation pathway within the body; "Xuanji" denotes the Northern Dipper constellation; the "Yinfu Jing" is a foundational Daoist classic.)

The operation of the Great Dao aligns with the patterns of celestial Dao, and I can grasp its essential principles. However, though the celestial Dao can be understood by observing celestial phenomena, truly mastering it is not easy. Only those with a mind of serene emptiness can achieve this.

The Book of Changes states: The noble person should maintain the central and upright path (Huangzhong), comprehend the principles of things, and rectify their position. Inner virtue will naturally extend to the limbs and manifest in one's endeavors—this is the most sublime state.

Xu Jinzhai remarked: Alchemists also draw upon this principle. Wei Boyang's Cantong Qi mentions, "Through Huangzhong, one gradually comprehends the principles, and moistening vitality reaches the skin," though their applications differ. Here, it refers to the cultivation of mind and nature, belonging to the realm of celestial Dao, while alchemists focus on consolidating Jing (essence) and Qi (vital energy), which pertains to personal cultivation.

I believe the Cantong Qi borrows the principles of the Book of Changes to elucidate its own ideas, and the cited passages may not fully align with their original meanings. Since the Book of Changes resonates with the patterns of heaven and earth, and the human body mirrors them, Wei Boyang used the Book of Changes as a framework for the Cantong Qi. Here, "Huangzhong" refers to the central channel (Yellow Path) within the human body.

The Book of Changes states: Returning from straying not far brings no great regret—this is supremely auspicious.

Zhu Xi explains: Laozi said, "In governing human affairs and following the celestial Dao, nothing surpasses frugality." "Early preparation" means awakening in time and returning before straying too far. "Accumulating virtue abundantly" refers to building upon existing foundations through frugal cultivation, further enriching one's virtue. Like those who nurture life, preserving health before decline is called "early preparation and abundant accumulation." If one waits until already weakened to recuperate, it can only mend losses, not count as "abundant accumulation." Thus, the value lies in "early preparation"—frugal preservation before decline. As for someone like me, whose body is already depleted and frail like a crumbling house, attempts at restoration are futile.

This year, I received a letter from Cai Jitong, who said he had recently grasped the principles of life cultivation thoroughly and mastered the methods, but his physical foundation was already weak, leaving no room to apply them. This indeed seems true.

Zeng Zhiyou records in Biographies of the Gathered Immortals: Zhou Cong was from Sizhou. Xu Shenweng held him in high regard, saying, "I married young, yet this man attained the Dao in his youth."

The Yiwai Biezhuan (Alternative Transmission Beyond the Changes) primarily discusses two aspects: the physiological transformation cycles of the human body and the principles of life cultivation.

Regarding physiological changes, the text cites the Huangdi Neijing (Yellow Emperor's Inner Canon) stating that males experience eight-year physiological cycles. At age 8, when kidney Qi (vital energy) becomes substantial, children begin losing baby teeth. By 16, abundant kidney Qi enables reproductive capacity. Physical maturation completes at 24, peak vitality arrives at 32, then kidney Qi starts declining at 40. Facial aging appears at 48, liver Qi weakens causing sluggish movement at 56, and basic physiological functions largely diminish by 64. This demonstrates the natural decline of bodily functions with aging.

Concerning life cultivation, ancient adepts who understood these principles would harmonize with natural laws (following Yin-Yang), adopt appropriate cultivation methods (aligning with numerical correspondences), maintain dietary moderation, regular routines, and avoid overexertion—thus achieving centenarian longevity. Modern people, by contrast, indulge in alcohol and desires, deplete their Jing (essence) and Qi, and live chaotically, resulting in premature decline.

The author raises a crucial question: When elderly individuals experience memory loss, mental cloudiness, and chronic fatigue—all signs of declining Jing-Qi—what foundation remains for Neidan (internal alchemy) practice that fundamentally relies on Shen (spirit) and Qi? How can cultivation proceed when these vital substrates deteriorate?

Finally, the text quotes the Yijing (Book of Changes) hexagram image "water repeatedly flowing through dangerous places" and integrates the Lingshu Jing (Divine Pivot Classic) to illustrate how human meridian cycles mirror celestial patterns: the body's 28 meridians correspond to 28 lunar mansions, with 2,700 daily respirations and 50 Qi-blood circulations synchronizing with water-clock measurements. This exemplifies the Daoist worldview of "cosmic-human resonance" in life cultivation.

This scripture elucidates the principles of Qi-blood circulation within the human body and the essential techniques for Neidan (internal alchemy) cultivation:

The movement of Qi and blood within the body flows ceaselessly like water currents and the revolutions of sun and moon. The Yin meridians nourish the five solid organs, while the Yang meridians sustain the six hollow organs, cycling endlessly without termination. When Qi-blood flows smoothly, health prevails; when obstructed, illness arises. During Neidan practice, one must regulate breathing to resemble an unbroken stream of water, allowing genuine Qi to circulate unimpeded throughout the body.

The Yijing (Book of Changes) teaches that the Kan trigram represents water and the moon, while the Li trigram symbolizes fire and the sun. Though the heart belongs to fire (Li trigram), it should take water's tranquility as its foundation (with Kan as substance). Though the kidneys belong to water (Kan trigram), they should employ fire's warmth as function (with Li as application). The crucial practice involves descending the heart's fire to the Dantian (the energy center behind the navel and before the kidneys), achieving the harmonious fusion of water and fire.

The text particularly emphasizes: Some alchemists avoid discussing heart and kidneys, speaking only of breathing as representing Kan-Li. Yet breathing is merely the function, while heart and kidneys constitute the fundamental basis. The heart is fire, the kidneys are water - when fire enters water it resembles the moon and sun conjoining during the new moon (when both luminaries occupy the same celestial palace). This constitutes the state of "water and fire in perfect harmony."

Finally, quoting the Zhouyi Cantongqi (The Kinship of the Three): Just as mountains and marshes exchange Qi to form clouds and rain, when the body's Yin-Yang energies merge within the Dantian, the clear Qi ascends to the Niwan (crown of the head). This follows the natural Dao and is no empty theory. Cultivation must accord with this spontaneous resonance, allowing the Yin and Yang energies to intermingle and mutually generate.

This passage elucidates the Daoist cultivation principles concerning breath regulation and the transformations of Yin-Yang:

Just as clouds transform into dew, Chen Xiyi (Patriarch Chen Tuan) describes in his poetry the sudden boiling of terrestrial Qi (Diqi) and the gushing forth of mountain springs. This mirrors the Liezi's teaching that the Qi of mountains and marshes can interconnect precisely because of their internal emptiness. Only by maintaining this emptiness can the two energies of Yin and Yang resonate with each other. The essence of Neidan (internal alchemy) practice lies in preserving mental emptiness, allowing the Shen (spirit) to concentrate and genuine Qi to gather, as naturally as clouds becoming rain or mountains exchanging Qi with marshes.

The "Far Roaming" chapter of Li Sao states: The great Dao (the Way) can be apprehended but not fully articulated—it is so minute it has no core, yet so vast it has no bounds. Do not disturb your Hun and Po (ethereal and corporeal souls), but let them move spontaneously. The most refined Qi will manifest at midnight; await it with a mind of emptiness and stillness, without forced seeking. Zhu Xi's commentary notes this is essentially the same immortality technique Guangchengzi taught the Yellow Emperor.

The Yijing (Book of Changes) states that opening and closing constitute transformation, while continuous coming and going constitutes penetration. Cheng Yi (Cheng Yichuan) maintained that the path of cultivation lies precisely in this opening-closing mechanism of respiration. Zhang Zai (Zhang Hengqu) observed that human breathing resembles the cosmic interaction of heaven and earth where firmness and yielding rub together, with Qian (Heaven) and Kun (Earth) opening and closing. In his "Admonition on Breath Regulation," Zhu Xi points out the profound mystery of respiratory opening and closing—this is the natural Dao in operation.

The Cantong Qi (Seal of the Unity of the Three) uses the six-line transformations of hexagrams to metaphorize breathing: exhalation represents Yang Qi emerging (opening), while inhalation represents Yin Qi entering (closing). The human body's Yin-Yang connects with cosmic Yin-Yang—if one can regulate breathing to make it circulate ceaselessly, then the mysteries of celestial and terrestrial opening-closing are fully present within us. Whether in grand cycles or fleeting moments, every respiratory opening and closing contains the operating principles of cosmic movement.

This scripture elucidates the principle of Yin-Yang circulation and the flow of Qi (vital energy) and blood.

First, it describes the patterns of celestial movement: The moon's monthly cycle of waxing and waning mirrors the seasonal changes of a year; the rise and fall of dynasties reflects the eternal cycles of the cosmos—all follow the same underlying principle. The Book of Changes (Yijing) states that the alternation of sun and moon generates light, while the rotation of cold and heat forms the year, both speaking of this cyclical movement.

Cheng Yi (known as Master Yichuan) observed that the core teaching of the Book of Changes is the law of "returning and recurring." The author argues that although alchemical and Daoist texts employ many metaphors, they fundamentally express this same principle of cyclical transformation. Any claims deviating from this are considered heterodox.

The author cites two ancient sages to illustrate this:

1. Wenzi (a disciple of Laozi) said: "Flowing water never stagnates because it moves; a door hinge never rots because it turns." Similarly, the Qi and blood in the human body must circulate freely. Blockages lead to minor ailments like boils (caused by obstructed Qi and blood at the joints) or severe conditions like abscesses (where "Yong" results from congested Qi and blood, and "Ju" from complete blockage).

2. Master Zihuazi (a sage Confucius once conversed with) remarked: "Ancient cultivators built walls to ward off harmful influences and cleared their sources to nurture true Qi (Zhenqi). They practiced stillness, undisturbed by external matters, harmonizing breath with spirit in each inhalation and exhalation. By maintaining focused awareness, their Qi flowed unimpeded, like ceaseless streams or the motion of sun and moon. Yin nourished the five organs, while Yang fortified the six bowels, ensuring abundant but balanced Qi and blood."

The body's Qi and blood resemble river water: superficially, it flows east to the sea, but underground currents circulate in interconnected loops (e.g., Mount Lu’s perpetual waterfall stems from this subterranean cycle). Likewise, the sun and moon follow the celestial sphere’s rotation in their cyclical paths. In truth, each person embodies this very "sun-moon cycle"—the secret lies within, not beyond.

(Note: "Opening and closing" (Hepi) refers to Yin-Yang expansion and contraction; "alchemists" (Danjia) denotes practitioners of internal alchemy (Neidan); "nurturing truth" (Yuzhen) means cultivating genuine Qi; "inhaling and exhaling" (Churu) describes breath regulation.)

This passage from the "Supplementary Transmission Beyond the Yi" discusses two crucial meridians in the human body—the Conception Vessel (Renmai) and the Governing Vessel (Dumai).

The Conception Vessel originates from the Zhongji point (four finger-widths below the navel) in the lower abdomen, ascends along the midline of the abdomen past the Guanyuan point (three finger-widths below the navel), and continues upward to the throat. It serves as the convergence of all Yin meridians. The Governing Vessel begins at the Changqiang point below the coccyx, runs upward along the spine through the Fengfu point (below the occipital bone), enters the brain, then follows the forehead down to the nasal bridge, constituting the convergence of all Yang meridians.

Why is it called the "Conception Vessel"? Because women rely on this meridian for pregnancy and nurturing the fetus. The "Governing Vessel" derives its name from its role in governing all bodily meridians. The text illustrates with animal examples: deer frequently sway their tails, indicating their Governing Vessel remains unobstructed; turtles breathe slowly through their noses, demonstrating their Conception Vessel flows freely.

When a practitioner successfully unblocks these two meridians, all bodily channels become unobstructed. The "Yellow Court Scripture" states: The key lies in internally circulating the "Celestial Pathway" (referring to the Qi movement routes within the body), and maintaining this state day and night naturally leads to longevity. Here, the "Celestial Pathway" precisely denotes the Conception and Governing Vessels—the primary channels for the movement of breath and vital energy in the human body.

(The notation "Supplementary Transmission Beyond the Yi (End)" marks the conclusion of this classic.)