《周易參同契註(五)》

The Zhouyi Cantongqi (The Seal of the Unity of the Three) primarily elucidates the principles of Yin-Yang transformation in alchemical cultivation. It begins by explaining that Qian (Heaven) and Kun (Earth) represent the fundamental polarity of Yin-Yang, serving as the gateway to all changes in the Yijing (Book of Changes). All hexagrams emerge from this duality. The Kan (Water) and Li (Fire) hexagrams revolve between Qian and Kun like the axle of a wheel—Kan is concealed within Kun (Earth), while Li resides within Qian (Heaven), forming the basic framework of Yin-Yang dynamics.

Next, the text describes how these four hexagrams (Qian, Kun, Kan, Li) function like bellows, driving the transformations of Yin and Yang. Practitioners must grasp the laws of these changes, much like a charioteer controlling the reins, regulating external transformations from the core. The "medicinal substances" mentioned here refer to the essential Qi (vital energy) of Yin and Yang required for alchemical refinement.

The second section discusses temporal rhythms. The thirty days of a lunar month correspond to sixty hexagrams (two per day), while the twelve double-hours align with the twelve pitch-standards of music, the twelve months, and the twelve-year cycle. The sequence begins with the Zhun and Meng hexagrams and cycles through to Jiji and Weiji, mirroring the waxing and waning of the moon. This analogy illustrates the regulation of "fire times" (huohou) in alchemy.

The third section addresses the daily rhythm of fire regulation. The twelve double-hours correspond to the climatic phases of the twelve months. From Zi (midnight) to Si (mid-morning), the energy resembles spring and summer, with Yang Qi expanding; from Wu (noon) to Hai (late night), it shifts to autumn and winter, with Yin Qi contracting. Cultivation must follow the ebb and flow of Yin-Yang like the changing seasons, adjusting the rhythm of breath and energy circulation according to the time of day.

Finally, the text explains that once Heaven and Earth establish their Yin-Yang positions, the Kan and Li hexagrams (Water and Fire) circulate within them. Though Kan and Li have no fixed positions, they flow continuously through the six lines (yao) of the hexagrams—a dynamic described in the Yijing as "moving through the six voids." All of this underscores how alchemical practice must emulate the natural patterns of Heaven and Earth in their Yin-Yang transformations.

This passage explains the pivotal role of the "Kan-Li" (the Water ☵ and Fire ☷ trigrams from the Bagua) in spiritual cultivation as described in the Zhouyi Cantongqi. The central lines of these two trigrams are particularly significant, embodying the quintessential interaction of Qian (Heaven) and Kun (Earth). Just as humans are born through receiving the harmonized Qi of Heaven and Earth, these central lines serve as the pivot of Yin-Yang transformation.

The interplay between Kan (Water, ☵) and Li (Fire, ☷) through their central lines forms the fundamental principle of cultivation. The Yang line within Kan and the Yin line within Li undergo mutual transformation, mirroring the celestial dance of the sun and moon. When the Yin line of Li transforms into the Yang line of Kan, it creates the pure Yang Qian trigram (☰), causing the original forms of Kan and Li to dissolve. This metamorphosis reveals the profound function of the "central line."

The text mentions "Wu within Kan, Ji within Li" — Wu and Ji representing the central Earth element, symbolizing harmonized Qi. This balanced energy enables Kan and Li to intersect, just as the sun and moon conjoin. Like the orderly progression of seasons or the Five Phases (Wood, Fire, Metal, Water, and Earth) occupying their proper positions, all rely on the mediating function of the central Wu-Ji Earth element.

By observing celestial phenomena like the sun-moon conjunction, one comprehends the principle of Kan-Li interaction. The appearance of the Yang line in Zhen trigram's (Thunder, ☳) bottom position reveals the moment of Yang Qi's initial emergence. Kan symbolizes masculinity, containing Qian's Yang essence; Li represents femininity, holding Kun's Yin essence. When these two energies merge in primordial chaos — akin to the dawn of creation when Heaven and Earth first separated — all things come into being. This represents the foundation of cultivation.

Through these trigram transformations, the passage allegorizes the process of Yin-Yang convergence in Neidan (internal alchemy) practice. It emphasizes seizing the critical moments of cosmic change, harmonizing Kan-Li energies, and mastering central-line transformations to achieve spiritual refinement.

This passage elucidates the mysteries of Yin-Yang transformation and the regulation of fire times (huohou) in cultivation as described in the Zhouyi Cantongqi (The Kinship of the Three). The content is organized into several key sections:

The text first explains the principle of Yin-Yang interaction. While the feminine is associated with Yin (represented by the Kun hexagram), it contains latent Yang lines within. The yellow essence of Kun can transform into the pure Yang of Qian. This illustrates the critical moment of "advancing fire for intercourse" (jinhuo jiaogou) in cultivation, akin to Confucius' praise of the primordial state where Heaven (Qian) and Earth (Kun) energies first merged. Quoting the Book of Songs, it compares human marriage to cosmic union—the natural law of Yin-Yang attraction that gives birth to all things.

Next, it describes how sages observe celestial patterns to determine cultivation timing. By studying heavenly signs (tianfu), sages regulate the advance, retreat, flexion, and extension of fire practice, strictly following cosmic rhythms. The Fu hexagram symbolizes Yang's initial emergence, after which Yin-Yang waxing and waning must align with the twelve pitch-standards (lülü), while energy ascents and descents correspond to the Big Dipper's rotation. Detailed lunar phases are mapped to cultivation stages: the crescent moon on the third day (Zhen hexagram), first quarter moon on the eighth (Dui hexagram), and full moon on the fifteenth (Qian hexagram)—each celestial change marking distinct fire phases.

Particular emphasis is placed on the winter solstice's significance as Yang's rebirth (Fu hexagram). This moment of initial Yang sprouting reveals the fundamental heart of Heaven and Earth. The twelve Yang transformation stages mirror both the pitch-standards and the Dipper's seasonal rotations. When Kun's bottom line turns Yang, it becomes Zhen hexagram—demonstrating Fuxi's pre-heaven Bagua logic.

Finally, the text outlines Yin's cyclical operation. Celestial stems (壬癸甲乙) pair with trigrams (Qian/Kun), where numerical combinations (7+8, 9+6) always sum to fifteen—matching the moon's waxing-waning cycle. Four phases complete the thirty-day period, with Yang energy progressing from full expression to storage, all precisely aligned with the eight trigrams' movements. The pairings of Ren-Jia with Qian and Yi-Gui with Kun reflect Luoshu's Five Phase numerology, systematically embodying cosmic order.

This passage explains the principles of timing in Yin-Yang transformations during Neidan (internal alchemy) practice. At the fifteen-day mark, the three lines of the Kun trigram (symbolizing pure Yin) manifest; by thirty days, the sun and moon complete their conjunction cycle, repeating endlessly. The Eight Trigrams (Bagua) distribute across eight directions while the twenty-eight lunar mansions revolve with the Big Dipper—the waxing and waning of Yin and Yang Qi follow immutable rhythms that cannot be violated. Here, the "center" refers to the pivotal solar terms of winter solstice and summer solstice.

The core teaching demonstrates how celestial observations guide the "fire timing" (regulation of internal energy flow) in alchemical practice. Though the Dao of heaven is subtle and elusive, its patterns can be deduced and verified through the hexagrams of the Yijing (Book of Changes). During meditation, one must observe celestial changes and adjust one's state accordingly, mirroring how ancient sundials measured solar shadows to establish standards. Divination determines auspicious timing—actions must align with celestial cycles without missing critical moments of hexagram transitions. Above, observe stellar movements; below, comprehend earthly patterns; between them, discern human affairs—integrating the Three Powers (heaven, earth, and humanity). Movement follows hexagram rhythms; stillness contemplates their symbolic meanings. Only by harmonizing like the Qian (heaven) and Kun (earth) trigrams can body-mind unity be achieved.

Though the celestial Dao is profound, the Yijing's hexagrams reveal its manifestations. Sundials track heavenly movements precisely to capture the nascent stirring of Yang Qi. When the "return of single Yang" (winter solstice's first Yang emergence) arrives, one must promptly unite the Kan (water) and Li (fire) energies to forge the pure Yang body. The Big Dipper's advancing-retreating rotations display heaven's visible signs; tidal ebbs with lunar phases demonstrate earth's tangible rhythms; merchants suspending trade per solar terms reflect humanity's celestial attunement. Whether active or still, all must follow the Yijing's Dao—the essence lies in seizing the exquisite timing of changing hexagram lines.

The following section details cultivation essentials during Yang Qi's initial emergence—the foremost priority requiring governance-like precision. At Zi hour (midnight), when Yang Qi first stirs and Kan-Li energies begin intersecting, close sensory gates, cease external seeking, and protect this tender Yang sprout. Thus nourished, Yang naturally grows from the Fu hexagram (single Yang line) to the Tai hexagram (three Yang lines). Align practice hours with the Big Dipper's handle orientation—hence its title as the pivot of cosmic creation.

Subsequent teachings will specify "advancing the fire" (strengthening Yang Qi) methods. Hexagram transformations internally activate energy flow while externally manifesting omens. The five planets' (Wood, Fire, Earth, Metal, Water) motions influence bodily resonance; misaligned lunar mansions disrupt Yin-Yang balance. Like court officials fulfilling distinct duties, bodily components must maintain proper positions. When fire timing's line changes circulate internally, wondrous Qi-transformation phenomena manifest outwardly.

This scripture primarily discusses the regulation of fire times (the timing and intensity of cultivation) in Neidan (internal alchemy) practice, along with the principles of Yin-Yang interaction (the harmonization of Jing, Qi, and Shen within the body). Improper fire regulation would be like the disordered movements of the Five Planets (Wood, Fire, Earth, Metal, Water) or the disrupted sequence of the twenty-eight lunar mansions, leading to cultivation mishaps.

Proper fire regulation should follow celestial rhythms: the sun corresponds to the essence of the Five Phases, while the moon follows the six musical pitch standards, forming a thirty-day cycle that repeats continuously. Within a single day, the alternating movements of the Zhen trigram (representing Yang activation) and Xun trigram (representing Yin compliance) circulate endlessly. This mirrors the relationship between a ruler (symbolizing the Shen/spirit) and ministers (symbolizing Jing-essence and Qi): if the ruler becomes arrogant and ministers turn treacherous—like abnormal moon phases—disasters will follow. Imbalances between firmness and yielding, or mistimed movement and stillness, all stem from improper Yin-Yang interaction.

Conversely, one should emulate the North Star's unwavering centrality amid circling stars (symbolizing stabilized consciousness) and the orderly governance of the "bright hall" (referring to the Dantian). The method involves maintaining emptiness and stillness, closing the sensory portals ("blocking the openings" means sealing the mouth, nose and other orifices), stabilizing the foundation ("spiritual root" denotes the Dantian), and internalizing vital energies ("three lights submerging" refers to the inward illumination of sun, moon and stars). Spontaneous transformations then occur within—like the growth of "yellow sprouts" (the nascent form of the inner elixir)—with essence-energy permeating the skin. These internal changes manifest naturally externally.

The text further distinguishes "superior De (virtue)" and "inferior De": the former is the natural state of Wuwei (non-action) requiring no deliberate pursuit; the latter demands persistent effort. The key to cultivation lies in grasping the "One" (the origin of Dao), akin to the mutual generation of Metal (lung Qi) and Water (kidney Qi): Metal begets Water, yet Water contains Metal's essence ("the white signifies Metal's essence" denotes primordial lung Qi). Lead (kidney Jing), though black externally, harbors golden flowers (primordial Qi), like a true person "wearing coarse cloth yet holding jade." These subtle Qi movements flicker between presence and absence, like objects submerged in deep water—each must return to its proper position ("keeping to their domains"). The text concludes by revealing esoteric correspondences: Water's pre-heaven number is one, concealing Yang Qi within, while the golden (primordial Qi) hides within black lead (kidney Jing) as silver-white essence (primordial Jing)—a mystery seldom understood.

Note: "Openings" refer to orifices like mouth/nose; "spiritual root" metaphorizes the Dantian; "three lights" symbolize Jing-Qi-Shen; "yellow sprouts" denote the nascent elixir in Neidan terminology; "river chariot" describes the Qi circulation path along the Governing and Conception vessels.

This passage elucidates the essential principles of Daoist Neidan (internal alchemy) practice. It begins with the fundamental concept of "Kan and Li" - where Kan (representing water) symbolizes superior De (virtue/power), while Li (representing fire) embodies inferior De. During cultivation, one must maintain continuous awareness like the rhythm of breathing, achieving the harmonious union of water and fire (Yin-Yang balance). Just as mercury requires genuine Yang metal (lead) for transformation, true gold also needs Li fire to refine its essence - these elements exist in mutual dependence.

Practitioners must comprehend the principle of metal concealed within water. By preserving the kidney water (innate primordial Qi), true gold (the Golden Elixir) will naturally manifest. This process resembles fetal development during pregnancy - a natural unfolding. Water's numerical correspondence is one, and its color is black, hence the term "guarding the black," meaning to withdraw spiritual radiance and conceal one's brilliance. This describes the method of "gathering the medicinal substance" (collecting innate primordial Qi).

The text then depicts the manifestation of the Golden Elixir: initially white in appearance, it transforms to vermilion through refinement. Protected by defensive Qi externally and containing pure Yang essence within, though merely an inch in size, it encompasses the creative transformations of heaven and earth. Like the sacred Penglai immortal isles, it stands majestic and divine, guarded by passes that prevent perverse Qi from intruding. This emphasizes the need for careful nurturing after the "sacred embryo" (Golden Elixir) takes form.

Subsequent passages critique erroneous cultivation methods: forced inner vision, ritualistic stepping patterns (a ceremonial footwork), rigid adherence to auspicious hours, or sexual alchemy and other heterodox practices. These approaches cause practitioners to lose sleep, experience digestive disturbances, physical exhaustion, and mental confusion - ultimately disrupting the hundred meridians. Some establish altars to worship spirits, becoming self-satisfied with illusory visions in dreams, thereby violating natural principles and inevitably meeting mortal ends.

Those who truly comprehend the Dao can penetrate the essence of cultivation. After three years of diligent practice, one attains the state where fire cannot burn nor water wet them, capable of freely maintaining awareness or forgetting form, abiding in perpetual joy without worry. When merits reach perfection, the Great Unity Celestial Deity (a revered Daoist divinity) will guide their ascension to the celestial realms, where they take their place among the immortal ranks. This describes the ultimate realization of attaining the Dao and achieving perfection.

This passage primarily explains the principles of Yin-Yang harmonization and medicinal refinement in alchemical practice.

The text first mentions that in the "Crescent Moon Method" (a neidan technique), the White Tiger (representing Metal) serves as the pivotal axis of refinement, while Mercury flows like drifting pearls alongside the Azure Dragon (representing Wood). When the East (Azure Dragon) and West (White Tiger) unite, the Hun (Yang spirit) and Po (Yin soul) naturally merge. The first quarter moon (8th day) and last quarter moon (23rd day) each span eight days—their union symbolizes the blending of Yin and Yang, forming the complete embodiment of Qian (Heaven) and Kun (Earth). The phrase "two eights correspond to one jin" refers to the balanced firing process in alchemy where Yin and Yang reach equilibrium.

It further explains that Metal and Water share the northern position (Kan trigram), hence the moon and White Tiger jointly serve as the central axis. Wood and Fire reside together in the East, which is why flowing mercury accompanies the Azure Dragon. The union of East and West resembles Li Fire (South) receiving Kan Water (North), ultimately returning to the pure Yang form of Qian Heaven. From the new moon (1st day) to the first quarter moon, Yang waxes while Yin wanes; from the full moon (15th day) to the last quarter moon, Yin waxes while Yang wanes. This cyclical exchange of Yin and Yang constitutes the "two eights correspond to one jin" firing technique in elixir refinement.

A crucial point emphasizes that Metal (the true Yang medicinal agent), though tempered in fire, does not diminish—just as the sun and moon have remained unchanging since antiquity. Metal is born from the moon, receives the sun’s energy at the new moon, and ultimately returns to its origin. When the moon vanishes, Metal withdraws into emptiness, only to reappear later with undiminished radiance.

Later, the text states that the number of Zi (Water) is one, Wu (Fire) is two, and Wu-Ji (central Earth) is five—their sum is eight, corresponding to the eight foundational materials in alchemy. Breathing techniques should harmonize like the union of husband and wife. Yellow Earth generates Metal, while flowing Mercury (Water) requires Earth to restrain it; otherwise, excessive Water will extinguish the flame (Vermilion Bird). When the natures of Metal, Water, and Fire converge within Earth, they return to the most fundamental origin.

Finally, the perfected "Jusheng" (Golden Elixir) grants longevity because the nature of Metal never decays. By ingesting this elixir, practitioners attain enduring life, moving through the world as effortlessly as Earth pervades the four directions. This passage systematically elucidates the principles of refining the Golden Elixir through the harmonization of Yin-Yang and the Five Phases.

This passage elucidates the principles and precautions of alchemical cultivation, addressing several key aspects:

First, it describes the miraculous effects of ingesting the Golden Elixir (Jindan): When the elixir enters the five viscera, it spreads through the body like wind and rain, restoring rosy complexion, turning white hair black, regrowing lost teeth, transforming old men back to their prime and elderly women to their youth. Thus one transcends worldly calamities to become a "Perfected Person" (Zhenren, realized Daoist adept). The "medicine of true yang" mentioned here refers precisely to the Golden Elixir.

The text then explains alchemical principles through natural phenomena: Just as lead white (hufen) reverts to lead when smelted, or ice and snow melt into water when heated, elchemy follows the law of "like begets like." Cinnabar serves as the primary ingredient, with mercury assisting the transformative process—each stage interconnected like links in a chain. As farming requires millet seeds and hatching needs hen's eggs, violating natural law leads to failure—fish eyes cannot become pearls, nor wormwood grow into catalpa trees.

A stern warning is given to misguided immortality seekers: Many talented individuals, lacking proper guidance from enlightened masters, recklessly experiment with incompatible materials like qiangshidan minerals, mica, alum stones, magnetite, sulfur, or even attempt to blend them with five-mineral copper. These conflicting substances can never properly fuse, resulting in countless failed attempts where intelligence becomes folly—youth wasted until white-haired without achievement.

The conclusion emphasizes: While the human body inherently contains yin and yang energies (Yin-Yang), true transformation requires the catalyst of genuine yang (the Golden Elixir). External mineral substances can only be utilized through correct methods. The author venerates the wisdom of the Three Sages—Fuxi who drew the Eight Trigrams (Bagua), King Wen who developed the Zhouyi, and Confucius who composed the Ten Wings—for progressively revealing cosmic patterns. As stated in the 600-chapter alchemical classic Huoji ("Fire Records"), cultivation must follow established cosmic laws rather than subjective speculation.

People often fail to delve deeply into the fundamental origins of things, not understanding that yin and yang (the hidden and manifest) share the same source and coexist. Though I wish to explain this to the wise, how dare I casually compose texts? If I remain silent, I fear losing the transmission of the great Dao and incurring blame; if I express the true meaning in writing, I worry about revealing celestial secrets. After much hesitation, I can only sigh, and in this brief moment, I set down these rough insights. The path of cultivation has strict methods, which I cannot fully elaborate—only outline the essentials.

The three sages—Fu Xi, King Wen of Zhou, and Confucius—all understood that this principle originates from the hexagrams of the Yijing and the Hetu (River Chart) and Luoshu (Luo Writing), ancient mystical diagrams. The Zhen hexagram (representing thunder) moving forward corresponds to the number eight; the Xun hexagram (representing wind) moving forward corresponds to three; the Li hexagram (representing fire) moving forward corresponds to seven; the Kan hexagram (representing water) moving forward corresponds to one and six. The Qian hexagram (representing heaven) moving backward corresponds to four, as does the Dui hexagram (representing marsh). The Kun hexagram (representing earth) and Gen hexagram (representing mountain), one moving forward and the other backward, combine to form the fifteen of the "Imperial Ultimate" (the fundamental cosmic pattern).

Master Wei Boyang (a Han dynasty alchemist) said: Heaven bestowed the Hetu upon Fu Xi, who combined it with the numerical arrangement of the Luoshu to create the "Earlier Heaven" (innate) Bagua. By aligning the Earlier Heaven Bagua with the Hetu, one can clearly discern the "medicinal substances" (referring to yin and yang qi) and the "firing times" (critical moments in cultivation) of alchemy. This is the key by which sages comprehend the Dao of Heaven and master the mysteries of creation. Specifically: the union of the Qian and Li hexagrams forms the "yang furnace" (the yang vessel of alchemy), with Li occupying the position of Qian; the union of the Kun and Kan hexagrams forms the "yin cauldron" (the yin vessel of alchemy), with Kan occupying the position of Kun. The meeting of Zhen and Li is like a dragon born from fire; the meeting of Dui and Kan is like a tiger emerging from water. These embody the profound principle of "the child generating the mother." As for the moon waning in the Zhen position, waxing full in the Qian position, diminishing in the Xun position, and disappearing in the Kun position—these correspond to the subtle applications of firing times during key moments like the winter and summer solstices.

The Dao of Heaven is vast; without the Yijing's hexagrams, it cannot be illuminated. The principles of the Yi are profound; only sages can elucidate them. This truth was pioneered by the three sages of antiquity and clarified by Wei Boyang later—all indeed stem from the wisdom of the Hetu.

Using "metal" (true lead) as a dike to control "water" (true mercury) allows their harmonious fusion. The number of metal is fifteen, as is the number of water. When precisely measured in the alchemical furnace, water exceeds by five parts: two parts represent pure metal, equal in weight to the original material, while the third part does not enter the fire, allowing the two and three to mutually contain one another. Their transformations are mysteriously unpredictable: below, the solar true qi steams upward, first liquefying and then solidifying in an instant, forming what is called the "Yellow Chariot" (the embryonic form of the Golden Elixir). If cultivation goes awry and the elixir is ruined, not only is lifespan harmed, but the body turns to ashes like dust on a window lattice.

Metal and water are originally one substance—when metal is lifted, water naturally follows. The number of metal (nine) and the number of water (six) sum to fifteen, corresponding to the central number of the Hetu (fifteen at its core). This is the natural union of heaven-earth and yin-yang.

This passage explains the principles of Yin-Yang transformation and specific operational methods during the Neidan (internal alchemy) practice.

Within the Five Phases (Wood, Fire, Earth, Metal, Water), water corresponds to the number six and metal to five—these two elements serve as the "true medicine" in alchemy. Wood nature requires metal's support, while water nature needs metal's guidance, much like a child relying on its mother. The dynamic interplay among water, metal, and fire manifests as: using metal to restrain wood, employing water to guide metal, and applying fire to refine metal—wood remains indirectly involved in this process. When Yang Qi reaches its zenith, it liquefies; when Yin Qi emerges, it condenses—this state is called the "Yellow Chariot" (symbolizing heaven-earth communion where Kun/earth represents the great vehicle). At this cultivation stage, Yang Qi peaks while Yin Qi begins to germinate, marking the transition from Qian (pure Yang) to Kun (pure Yin) hexagrams.

The concrete Neidan method involves: grinding and mixing medicinal substances before placing them in the crimson-gated furnace, then sealing its opening. Begin with gentle "civil fire" (wenhuo) for gradual tempering, switching to intense "martial fire" (wuhuo) when the time ripens. Carefully monitor the fire phases while adjusting temperature through twelve two-hour periods (shichen). When the furnace's Qi approaches exhaustion, the medicine turns purple, ultimately forming the returned elixir (huandan). Using an ancient spoon (daogui) to measure one pellet yields this most miraculous elixir.

During the convergence of the Four Symbols (lesser Yang, greater Yang, lesser Yin, greater Yin), practitioners must close sensory gates (Dui/hexagram representing mouth as closure), maintaining a thoughtless state. As transformation progresses from Kun (pure Yin) to Qian (pure Yang), Qian's crimson attributes manifest—hence termed "entering the crimson gate." Fire regulation divides into three phases: initial gentle Gou-hexagram fire ("field combat"), intermediate civil fire nourishment ("irrigation"), and final intense fire completion ("culinary refining"). Purple symbolizes Qian's ultimate crimson, corresponding to changes in Yi-hexagram's third line and Zhen-hexagram's top line, ultimately achieving pure Yang Qian state. The Kan (water) and Li (fire) hexagrams achieve union through the mediating function of central earth (Wuji).

This passage explains the principle of Yin-Yang transformation in Daoist alchemy. When two earth elements combine, they form the shape of the Qian trigram (representing pure Yang), which is why the character "圭" (guī) is composed of two "土" (earth) characters. When the firing process reaches sufficient intensity, the Kun trigram (representing pure Yin) transforms into the Qian trigram. This process involves transitions through three celestial positions (Rest, Death, and Extinction), refining the hun and po souls—a crucial phenomenon in the alchemical process.

Here, the principle of "Yang emerging from the extreme of Yin" is expounded. Through the cyclical patterns of mutual generation and restraint among the Five Phases (Wood, Fire, Earth, Metal, Water), water is used to stimulate fire, much like how the sun and moon interact during the moonless periods (new moon). When water's influence is strong, it suppresses Yang energy; when fire weakens, daylight dims. Yin and Yang wax and wane yet depend on each other—this dynamic interaction aligns with the natural Dao.

The earlier-mentioned state where form turns to ashes and breath nears extinction resembles the eclipse of sun and moon, where darkness prevails because Kan-water (Yin) overwhelms Li-fire (Yang). Names define nature, and characters express inherent qualities. When Metal's nature (Yang) returns to its original state, it is called the "Reverted Elixir" (Huandan, a term for the cyclical sublimation of the alchemical process). This is no empty claim but follows the records of ancient sages.

The text cites renowned alchemists: the Yellow Emperor refined Golden Flowers (an alchemical term), the King of Huainan produced Autumn Stone (mineral elixir), and Wang Yang added Yellow Sprouts (alchemical ingredient). The worthy persevere in practice, while the incapable fail to attain. The principles of cultivation remain constant across ages—seekers should diligently study and contemplate deeply. These key teachings are straightforward and truthful, never deceptive.

When Metal's nature (Yang) returns to Water's nature (Yin), it resembles returning to the root. Emotion arises from innate nature, and nature reverts to its origin—hence the term "Reverted Elixir," consistent with the middle chapter's concept of "harmonizing emotion with nature." This section elucidates the alchemical principle of Yin-Yang union culminating in elixir formation.

This passage explains the principle of "Kan-Li coupling" (the meditative state of water-fire interaction) in Daoist Neidan (internal alchemy) practice, which involves cultivating Jing (essence), Qi (vital energy), and Shen (spirit) through breath regulation and mental focus. Qian represents strength while Kun embodies receptivity—these Yin-Yang forces complement and contain each other. The active Yang gives while the passive Yin receives, like the indispensable pairing of female and male. Practitioners must comprehend the creative patterns of heaven and earth to allow vital energies to flow naturally.

Kan (water trigram) and Li (fire trigram) are pivotal in cultivation—their radiance mutually illuminates. Their profundity defies visual representation, accessible only to sages. When the four primary elements (metal, wood, water, fire) blend into emptiness, they mirror the cyclical movement of the sixty hexagrams (from the Yijing system). Practitioners must seize opportunities like wise rulers governing a state: advance smoothly on open roads, but faltering at obstacles jeopardizes progress.

Here, Qian and Kun are metaphorically termed the "medicinal ingredients" (referring to vital essences). The Kan trigram delivers Yang energy to Li, which absorbs it—demonstrating Yin-Yang synergy. Mastering Kan-Li interaction requires applying the six Yang lines (within hexagrams) as "fire phases" (refinement control) to facilitate natural energy circulation.

"Primordial Qi" denotes the most original energy—the first among the Three Qi of the Dao (Mysterious, Origin, Beginning). When the four symbolic animals (lesser Yang, greater Yang, lesser Yin, greater Yin) converge, they replenish the emptiness of the "Li palace" (heart center). Following the sixty hexagrams' rhythm during celestial cycle refinement ensures unimpeded harmony. "Dragon-horse harnessing" symbolizes Zhen (thunder) as dragon and Qian as horse—each Yang line from first to sixth marks a refinement phase.

From "Kan-Li leading" to "ordering mystical foundations" describes refining the medicinal essences; "four elements merging into emptiness" refers to gentle cultivation (wenhuo tempering), while post-"sixty hexagram cycles" discusses fire-phase mastery. Practitioners time their refinement like emperors harmonizing governance with cosmic patterns—aligning the Three Lights (sun, moon, stars) to achieve cosmic peace. Applied to statecraft, it becomes imperial wisdom; applied to self-cultivation, it transforms into alchemical method.

The noble practitioner, cultivating in seclusion, projects intention across vast distances—akin to an emperor decreeing policies from the palace in accordance with Yin-Yang shifts. Practice resembles sheathing weapons awaiting auspicious moments, never contradicting monthly hexagram indications. Zhun hexagram uses midnight hours, Meng hexagram dawn hours—each of the sixty hexagrams has corresponding temporal alignments. Only two examples are cited here to illustrate the principle of synchronizing practice with celestial timing.

This passage explains how ancient alchemical practices (Neidan/internal alchemy) adapt cultivation methods according to seasonal solar terms. The core principle revolves around aligning with the natural rhythms of the "Two Solstices and Two Equinoxes" (winter solstice, summer solstice, spring equinox, autumn equinox).

Practitioners must strictly follow these solar terms as if obeying immutable laws: the winter solstice corresponds to the Fu hexagram (Earth over Thunder), while the summer solstice aligns with the Meng hexagram (Mountain over Water). Specifically:

• At winter solstice, when Yang Qi first emerges, the initial line of the Tun hexagram (Gengzi) marks this pivotal moment
• During spring equinox, as Yang Qi flourishes, the fourth line of Tun hexagram (Wushen) corresponds to the equinox, requiring "muyu" (an alchemical term for refining the fire intensity)
• At summer solstice, when Yin Qi begins to arise, the initial line of Meng hexagram (Wuyin) represents this transition
• During autumn equinox, as Yin Qi dominates, the fourth line of Meng hexagram (Bingxu) matches the equinox, again necessitating "muyu"

Violating these rhythms brings consequences as severe as breaking cosmic laws. The text employs natural disasters as metaphors: scorching heat in winter, sudden frost in summer, or chaotic weather patterns—all manifestations of disrupted Yin-Yang balance.

Governing a nation and cultivating the self follow identical principles. When rulers disregard cosmic patterns, calamities befall the state; when adepts ignore seasonal transitions, disorders arise in the body. The key lies in mastering the timing of "Yang fire and Yin talisman" (the application of Yang and Yin energies), precisely adjusting the rhythm of "generation, restraint, and purification" during these four cardinal solar points.

The conclusion emphasizes adhering to natural laws with the precision of a craftsman following his plumb line: seasonal cycles must match climatic characteristics, the Five Phases (Wood, Fire, Earth, Metal, Water) must maintain their proper positions, movement and stillness must occur at their appointed times. In the primal state, one merges with heavenly patterns; in cultivated practice, one harmonizes with celestial timing—achieving the natural Yin-Yang fusion seen in the moon's dark and new phases.

This passage explains the correspondence between "fire timing" (huohou, the regulation of intention and breathing during cultivation) in Daoist Neidan (internal alchemy) practice and the lunar phases, as well as the operation of the Bagua (Eight Trigrams). The moon's gradual illumination beginning from the northeast mirrors the process of Yang Qi (vital energy) transitioning from latent concealment to visible manifestation in cultivation.

During the moonless phases of the lunar month's end and beginning (huishuo), the moon disappears completely, just as practitioners must initially conceal their form and nourish the Yin Po (yin life force). On the third day, when faint moonlight appears in the northeast, it corresponds to the Zhen trigram (symbolizing thunder), marking the initial emergence of Yang Qi—like the "hidden dragon" (first Yang line) beginning to stir. The half-moon on the eighth day aligns with the Dui trigram (symbolizing lake), showing strengthened Yang energy. The full moon on the fifteenth day matches the Qian trigram (symbolizing heaven), representing Yang Qi at its peak.

Thereafter begins the Yin Fu phase (the cultivation period dominated by yin energy): the waning moon corresponds to the Xun trigram (symbolizing wind), requiring careful regulation of advance and retreat in practice. The last quarter moon on the twenty-third day aligns with the Gen trigram (symbolizing mountain), when cultivation rhythm must be controlled. The moonless end of the month corresponds to the Kun trigram (symbolizing earth), as yin energy completes its gestation, preparing for a new cycle.

The text emphasizes that these trigram transformations synchronize with the celestial movements of the "Xuanji" (heavenly mechanism's ascent and descent), rather than being fixed to specific solar terms or hours. The lunar phases illustrate the waxing and waning patterns of Yin-Yang. For example, the dawn of the new moon (shuodan) corresponds to the Fu hexagram, when nascent Yang Qi stirs—like the "Yellow Bell" (first musical pitch) activating at midnight (zi hour), as warm energy begins nourishing all things. As time progresses, Yang Qi gradually strengthens until the yin-yang intersection at the tiger hour (yin hour, 3-5 AM), when all beings flourish. By the rabbit hour (mao hour, sunrise), flourishing Yang energy manifests as depicted in the Dazhuang hexagram—plants shed leaves to return to their roots, and day-night balance begins.

This passage elucidates the relationship between Yin-Yang transformations and the regulation of inner fire (huohou) in cultivation, as well as the significance of sovereigns practicing the Dao.

The alternation of Yin and Yang resembles a bird shaking dust from its wings. When Yang Qi reaches its zenith, it shines like sunlight illuminating all directions, peaking during the Si hour (9-11 AM), resonating with the Zhonglü musical pitch. The nascent emergence of Yin Qi is like treading on thin frost, with well waters turning cold. At the noon hour (11 AM-1 PM), Yang Qi begins to decline while Yin gradually strengthens.

Practitioners must understand the wisdom of withdrawal and containment, accumulating Jing (essence) while awaiting opportune moments. When Yin and Yang fall out of balance and vitality wanes, one should observe autumn's harvest cycles to comprehend the principles of growth and decline in all things. Just as withered plants sprout anew, this reflects nature's cyclical patterns.

The twelve-month fire regulation practice requires repeated contemplation of the Zhun and Meng hexagrams (from the Yijing, representing the birth of all phenomena). Beginning from the Yin position in the northeast (3-5 AM), like the newborn crescent moon, Yang Qi does not peak at the Zi hour (11 PM-1 AM). These chapters focus on essential techniques for fire regulation.

Yin-Yang transformations appear mysteriously unpredictable, yet follow cyclical patterns. Sovereigns who master these principles and align with celestial Dao can achieve enduring governance. The Yellow Emperor attained ascension precisely through this understanding. Conversely, violating celestial patterns brings calamities and national decline—a truth applicable from emperors to commoners, where those aligned with Dao prosper while those opposing it perish.

The text concludes by emphasizing that profound contemplation and understanding of developmental sequences are essential for self-cultivation and longevity. This passage primarily expounds the crucial methods for sovereigns to cultivate Dao and govern states.

The original human body is composed of the most primordial prenatal Qi (vital energy), which disperses like clouds, forming the foundation of life through the agency of Qi (life force). The interaction of the dual energies of Yin and Yang creates the dwelling place of the soul—the positive spiritual energy (sun soul) and the negative spiritual energy (moon soul) rely on each other, much like mutual abodes.

Human nature (Xing) governs the inner self, establishing a core, while emotions (Qing) govern the outer self, like building walls. Only when both inner and outer aspects are complete can the body and mind find stability. In this state, emotions align with the laws of heaven and earth: the nature of Qian (Heaven) is movement and directness, facilitating the flow of Jing (essence); the nature of Kun (Earth) is stillness and receptivity, serving as the dwelling place of the Dao. The vigorous Qi disperses and recedes, while the gentle Qi nourishes all things, forming the cyclical practice of "nine rotations and seven returns, eight reversions and six abidings" (referring to the specific pathways of Jing and Qi circulation in Neidan, or internal alchemy).

Men correspond to white (Metal nature), while women correspond to red (Fire nature). Metal and Fire restrain each other, just as water stabilizes fire. The original state of the Five Phases (Wood, Fire, Earth, Metal, Water) is as pure and flawless as the highest form of water. The true essence of the Dao is indescribable; once transformed, it disperses into various independent forms.

Before birth, humans exist in a state of pure "True Oneness," emerging from nothingness and taking form through the transformations of Qi. The body becomes the dwelling place of the soul: the sun soul is fundamentally Yang Shen (spirit), while the moon soul is fundamentally Yin Shen (spirit). Just as the sun hare (a celestial symbol) resides in the moon and the moon crow resides in the sun, the central lines of the Kan (Water) and Li (Fire) trigrams also contain each other. Nature is the soul, emotions are the spirit, and nature requires the protection of emotions to remain authentic.

The Kan trigram represents men, receiving the vigorous Yang Qi of the Qian trigram to release essence; the Li trigram represents women, receiving the gentle Yin Qi of the Kun trigram to nurture life. This naturally forms the alchemical process of "nine fires and seven metals returning to the source, eight woods and six waters reverting to the root" (referring to the circulation of Jing and Qi in Neidan). This is explained using the perfected numbers of the Luoshu (an ancient mystical diagram) to interpret the Four Symbols (Lesser Yang, Greater Yang, Lesser Yin, Greater Yin). Metal is white, and Fire is red, hence the term "red and white"—Metal represents the true Yang within Kan, while Fire represents the true Yin within Li, illustrating the dual functions of Metal and Fire. The earlier mention of the numbers seven, eight, nine, and six for the Four Symbols, while later only Metal, Fire, and Water are mentioned, aligns with the principle of the "three substances intermingling" (referring to the fusion of Jing, Qi, and Shen). When the Four Symbols unite, they form the ineffable state of "True Oneness"; when dispersed, they become the Five Phases occupying their respective domains.

This passage describes the practitioner's specific method: just as the black and white (yolk and egg white) within an egg rely on each other, the embryo initially forms as a square inch, developing over ten months until limbs, organs, bones, and muscles are fully formed. At birth, the bones are soft enough to curl, and the flesh is smooth as lead (describing the newborn state).

Using a yangsui (ancient fire mirror) to gather fire, without the sun, there would be no flame; using a fangzhu (ancient water vessel) to collect water, without the stars and moon, no water would be obtained. Though the dual energies of Yin and Yang are mysterious and elusive, they still interact and transform—how much more so for the Jing and Qi within one's own body?

This passage elucidates the methods and principles of Daoist Neidan (internal alchemy) practice. The essence of cultivation lies in harmonizing the body's Yin and Yang energies (the two opposing vital forces within the human body), mirroring the natural interplay of sun and moon or the mutual nourishment of water and fire. The human body inherently possesses true Yin and true Yang (the primordial Yin-Yang Qi). By emulating the cyclical patterns of celestial bodies, balancing Kan (kidney water) and Li (heart fire) becomes attainable.

During practice, one must seal the three sensory gates—ears, eyes, and mouth—that commonly dissipate Jing (essence) and Qi, maintaining stillness like an immortal (perfected being) diving into deep waters. The breath should circulate internally with measured rhythm, balancing opening and closing, movement and stillness. The Li fire (heart fire) moves protectively within, while the Kan water (kidney water) remains tranquil. Speech should be minimal, aligning with natural rhythms to unify Jing, Qi, and Shen (spirit) harmoniously.

Practitioners relax their bodies, eliminate distracting thoughts, and preserve a state of empty serenity. The mind remains undistracted, maintaining awareness even during sleep. With persistent practice, the complexion gradually brightens, sinews and bones strengthen, Yin-pathogenic energies are expelled, and pure Yang Qi is nurtured. Continued cultivation allows internal Qi to flow like spring rain nourishing earth or melting ice permeating the body—descending from the crown to the soles before rising again in unimpeded circulation.

Progress may appear regressive yet signifies advancement; apparent weakness embodies the foundation of cultivating De (virtue). Like weeding a garden, impurities are cleared internally. Subtle adjustments eventually transform turbidity into clarity, as prolonged darkness inevitably yields to light.

When the sacred embryo (the fruition of Neidan) forms, one must guard it steadfastly, abiding in Wuwei (non-action). Unwavering perseverance leads naturally from obscurity to illumination, from murkiness to purity—transitioning gradually from the Kun hexagram (pure Yin) toward the Qian hexagram (pure Yang).

The text cautions against worldly pursuits of quick techniques while neglecting the profound depths of the Dao. Straying from the true path resembles a blind man discarding his cane, a deaf person listening to music, hunting pheasants underwater, or fishing for dragons on mountains—as futile as expecting millet from wheat seeds. Authentic practice is inherently simple, its principles self-evident without excessive explanation.

The passage references "the sun's flowing pearl" (heart fire) that tends to scatter outward, requiring "golden splendor" (kidney Jing) for transformation. Their union generates a white liquid (the refined substance of the inner elixir) that gradually solidifies. This process unfolds with the natural order of a nurturing mother, a filial child's devotion, or a stern father's command.

This passage elucidates the principles and process of Kan-Li (water-fire) interaction in Daoist Neidan (internal alchemy) practice.

Within the mutual generation and restraint of the Five Phases (Wuxing), fire can melt metal (fire restrains metal), while metal can fell wood (metal restrains wood). The harmony of three and five (referring to Yin-Yang balance) represents the most profound principle between heaven and earth—it can be transmitted through oral formulas but is difficult to fully express in writing.

The "flowing pearl" (referring to mercury in the Li trigram, symbolizing the original spirit, Yuanshen) inherently tends to ascend and must be subdued by "yang metal" (lead in the Kan trigram, symbolizing original essence, Yuanjing) combined with water. When these two are skillfully united, they congeal. When metal and fire merge, fire melts metal and transforms it into water—this is the principle of "fire's nature dissolving metal." When Yin and Yang Qi naturally harmonize, the breath returns to the Dantian (the "sea of origin"), and all distracting thoughts naturally cease.

During practice, one must carefully regulate the "fire timing" (ensuring fire does not flare upward) to prevent the arising of deluded thoughts (blocking the "path of ghosts"). Metal restrains wood, preventing excessive wood-generated fire that could lead to calamity. The Li trigram (fire) receives nourishment from the Kun trigram (motherly nature), nurturing all things like a compassionate mother; the Kan trigram (water) embodies the authority of the Qian trigram (fatherly nature), using sternness to foster growth.

At the hour of Zi (north), the energy turns right; at the hour of Wu (south), it rotates left, with Mao (east) and You (west) serving as boundaries. The dragon (original spirit) and tiger (original essence) naturally attract each other, much like a cat stalking a mouse or a sparrow fearing a hawk. When Mars reaches the west and Venus crosses the zenith (symbolizing the optimal moment for Yin-Yang union), it marks the ideal time for cultivation. From mutual attraction to complete fusion, the practice progresses from shallow to profound, naturally achieving the state of Kan-Li intercourse. During summer, when Yang Qi is at its peak, one must restrain the fire timing; in winter, when Yin Qi is strongest, one must seize the opportunity for Yin-Yang convergence.

This passage elucidates the principles of Yin-Yang harmonization and Five Phases mutual restraint in Daoist Neidan (internal alchemy) practice. Practitioners must comprehend the cyclical transformations between the Yin hour (midnight) and Yang hour (noon), akin to using the Metal Tiger (Metal phase) to subdue the Wood Dragon (Wood phase), preventing its escape. This dynamic mirrors how dogs guard against rats or small birds fear birds of prey—each element exhibits natural cycles of generation and restraint.

The text cautions that without understanding the subtle workings of Yin-Yang and the proper application of inner fire, blind cultivation will only deplete one's resources, leaving family members destitute. Throughout history, countless seekers pursued this path, yet genuine attainment remains exceedingly rare. Many exhaust themselves chasing rare medicinal ingredients while fundamentally misunderstanding the true Dao. Those with authentic realization perceive the subtle signs of transformation and grasp the Five Phases' mutual relationships—how Metal generates Water which in turn nourishes Metal, or Wood produces Fire that subsequently sustains Wood. The union of Yin and Yang resembles parental conception—only through concentrated Jing (essence) and Qi (vital energy) can one embody the Dao, with effects manifesting immediately.

A potent analogy warns: when deadly poisons like wild aconite or croton seeds are ingested, not even King Wen's divinations, Confucius' calculations, Bian Que's medical skills, or Wu Xian's ritual drumming could revive the victim. This underscores how cultivation must align with natural laws.

The "Riverbank Maiden" (symbolizing the fiery nature within the Li trigram) proves elusive and scatters when exposed to flame. To stabilize it requires "Yellow Sprouts" (the metallic nature within the Kan trigram) as foundation. Like mercury in cinnabar that vaporizes with heat, the body's vital essences behave similarly—this section reveals the alchemical pharmacology underlying the practice.

The conclusion emphasizes universal reliance on Yin-Yang conjunction, just as a solitary hen cannot hatch eggs alone. Without this cosmic intercourse—when the Five Phases (three and five) fail to merge and hardness/softness remain divided—no creation or transformation can occur.

The natural order of heaven and earth operates like flames rising upward and water flowing downward—these patterns require no human instruction to function. Such principles were established from the very beginning of creation and cannot be arbitrarily altered.

When yin and yang (the Daoist concept of complementary cosmic forces) unite, hardness and softness merge into an inseparable whole. This union is not the result of human manipulation. Just as males are inherently active and females naturally receptive—physical traits determined by primordial qi (the foundational life-energy) at conception—these characteristics cannot be altered through postnatal education. These innate qualities persist not only in life but after death, proving that the fundamental laws of yin-yang interaction are established at the moment life takes form.

Neither solitary yin nor isolated yang can accomplish anything substantial. The natural pairing of the Kan trigram (representing moon/water/yin) and Li trigram (representing sun/fire/yang) follows cosmic law, beyond human interference. In celestial motion, the sun emits light while the moon reflects it. When the moon fully receives sunlight, its form becomes complete; any imbalance between yin and yang manifests as an eclipse—a warning symbol for practitioners about losing control of "fire times" (huohou) during alchemical practice.

When metal melts into flowing liquid (the alchemical transformation of "metal generating water"), water naturally seeks to restrain Li-fire (symbolizing the heart-mind). Yet Li-fire generates earth (representing focused intention), which in turn stabilizes water. This mirrors the innate dynamic where masculine energy actively gives while feminine energy quietly receives. Just as the hun (yang soul) requires the po (yin soul) for equilibrium, mutual regulation prevents excessive depletion. Practitioners must maintain the "firing temperature" with precision, advancing and retreating in harmony with yin-yang cycles to achieve perfect attunement.

The essence of elixir refinement lies in the coordination of four elements: Cinnabar (symbolizing fire) contains wood's essence and requires metal for completion. Metal and water engender each other, while wood and fire form partnerships. These four intermingle chaotically to create dragon (yang, odd-numbered) and tiger (yin, even-numbered) phenomena, corresponding to the body's organs—the liver (wood, azure) as father, lungs (metal, white) as mother, kidneys (water, black) as child, and spleen (earth, yellow) as foundation. Ultimately, all elements return to the central earth of Wuji (symbolizing focused concentration in the middle dantian), completing the refinement of the Golden Elixir.

This passage explains the cultivation principle of Yin-Yang union and the meeting of dragon and tiger. Yin and Yang are like two forces—one firm, one yielding—that wax and wane in an endless cycle. The positions of the Azure Dragon of the East (representing Yang) and the White Tiger of the West (representing Yin) interchange, just as the directions of Mao (east) and You (west) correspond to each other. Mao symbolizes vitality (De, Virtue), while You represents austerity (punishment), yet life and death are mutually contained.

To elaborate: when elm trees wither in the second lunar month, the Xin Metal (associated with the northwest, Xu position) suppresses Yi Wood; when wheat flourishes in the eighth month, Yi Wood (linked to the southeast, Chen position) overcomes Xin Metal. This directional shift mirrors how Zi (north) and Wu (south) govern each other, and how the Xu and Wei constellations (two stars of the northern mansions) resonate with the Xing and Zhang constellations (southern stars). Master Zhang Ziyang (a Neidan, or internal alchemy, adept of the Northern Song Dynasty) once wrote in a poem: "On the fifteenth of the eighth month, when moonlight is brightest, the Metal Qi is at its peak." This is because, during the Mid-Autumn Festival at midnight, the Xu and Wei stars dominate the sky—a time when the energies of Metal and Water are abundant, making it ideal for alchemical refinement.

The numbers nine and one (in the pre-heaven Bagua, Kan ☵ represents one, Li ☲ represents nine) cycle endlessly: Kan Water (kidney essence, Jing) and Li Fire (heart spirit, Shen) merge, much like Wu Fire (heart) gestates within Zi Water (kidneys), while Kan Water in turn nourishes Li Fire with its essence. This state of Yin-Yang coupling is what Neidan practitioners call the "medicine-body of pure Qian" (the pristine condition of the nascent Golden Elixir).

Finally, the passage draws an analogy from the Book of Songs's ospreys: just as the male bird never dwells alone nor the female nests in solitude, cultivation requires the mutual support of the Dark Warrior (Xuanwu, the entwined turtle-and-snake deity symbolizing the harmony of Water and Fire) to maintain Yin-Yang equilibrium. All of this illustrates the core Neidan principle of Yin-Yang interaction and the dragon-tiger confluence.

This passage vividly illustrates the principle of Yin-Yang harmony through metaphorical examples. It states that just as female and male must complement each other (like the pairing of mare and stallion), if two women were forced to live together in the same chamber—no matter how beautiful they might be, even with the most eloquent matchmakers like Su Qin or Zhang Yi attempting to arrange their union—their forced "marriage" would ultimately fail, leaving them gray-haired and toothless without achieving true union. This mirrors the futility of using incorrect ingredients in alchemical practices: even if the Yellow Emperor himself presided over the furnace, the Daoist deity Taiyi Zhenren descended, the Eight Immortals (legendary transcendents) pounded herbs, or Prince Huainan (a Han dynasty alchemist) tended the flames—even with elevated altars, jade steps, offerings of qilin meat and phoenix jerky, or kneeling recitations of prayers with sincere fasting and purification—it would be as absurd as patching a pot with glue or treating wounds with sal ammoniac (a mineral drug). Such efforts would only intensify the problem: adding ice to dispel cold, using boiling water to reduce fever, or expecting tortoises and snakes to dance—all would create greater disorder.

The passage culminates by reaffirming the core truth: Yin must always rely on Yang (阴必资阳), echoing the profound meaning of Yin-Yang union first expressed in the "Guanju" poem from the Classic of Poetry. This text originates from the middle scroll of the Zhouyi Cantongqi (The Kinship of the Three), using both everyday analogies and alchemical metaphors to emphasize the fundamental cosmic law that all things require proper Yin-Yang pairing to achieve completion.

The ancient sages who attained perfection through cultivation embraced the profound mysteries of the Dao (the Way) within their hearts. By ingesting the elixir refined through the Nine Cauldrons (referring to the ninefold-cycled Golden Elixir), they withdrew their traces from the mundane world. Nourishing their Shen (spirit) and cultivating Qi (vital energy), they harmonized the three fundamental elements of Jing (essence), Qi, and Shen in Daoist practice. Their sinews and bones grew robust and dense, all pathogenic energies were expelled, and pure primordial Qi permanently resided within them. Through such prolonged accumulation of cultivation, they ultimately achieved the transformation of shedding their mortal form to become immortals.

Out of compassion for later generations seeking the Dao, these sages followed the examples of ancient worthies by annotating classical scriptures and compiling illustrated manuals to illuminate the path of cultivation for posterity. Yet these transmissions often revealed only branches while concealing the root, employing various pseudonyms and elaborate language to obscure the true essence. Scholars who obtained these texts treasured them like rare jewels, passing them down through family lineages, yet none ever grasped their true meaning. This led officials to neglect governance, farmers to delay planting, merchants to abandon their goods, and aspiring practitioners to impoverish their households. Deeply pained by this situation, I resolved to record these genuine methods.

These writings are straightforward and comprehensible, their content essential without being verbose, systematically organized with verifiable sources, moderate in scope yet internally coherent. Though seemingly disordered, they secretly contain profound mysteries. Those with wisdom who contemplate carefully will naturally comprehend their meaning.

The so-called "Nine Cauldrons" actually refer to the golden cauldron (alchemical vessel). In the Luo Shu (an ancient numerological diagram), nine represents the completed number of Metal, while the Qian trigram (one of the Eight Trigrams) also corresponds to Metal. Nine symbolizes the number of yang Metal, and the cauldron serves as the container that holds this Metal.

This passage primarily explains the symbolic system (fǎxiàng) of alchemical practice. Heaven and Earth constitute the grandest symbolic framework, with the boundary between Yin and Yang resembling the joining point of cauldron vessels. Metal and Wood remain separated by tens of thousands of li—only through the Dao's methods can they be united. The phrase "River Drum approaching the Stellar Chronogram" indicates the Fire phase (Li trigram) occupying the Metal position and oppressing the Metal phase, just as the Li trigram, which should reside below, instead usurps the upper position. The upward-tending nature of Li Fire causes Water and Fire to fail in mutual nourishment, making it impossible to extract the Qian Metal from the Kan trigram. This violates the crucial principle of "Dragon low, Tiger high" (the essential formula for Yin-Yang harmonization), resulting in rigid and yielding forces opposing rather than merging, ultimately causing the dissipation of the true medicine (the essence of alchemical refinement).

This passage elucidates the essential principles of alchemical practice (the Daoist method of Neidan/internal alchemy). The phrase "the people are all startled and terrified" metaphorically depicts the chaotic, uncontrolled dispersal of medicinal substances (referring to the vital essences of Jing, Qi, and Shen required for cultivation) during alchemical refinement, much like panicked crowds in disarray.

Regarding the mastery of fire times (the regulation of heat intensity and timing in alchemy): The tiger symbolizes the mountain peak while the dragon represents the ocean depths, illustrating how fire resides below while metal (referring to primordial Qi) ascends above. Earlier passages mention "blazing fire spread beneath" and "below lies the solar Qi's energy"—both describing clear indicators of rising and falling fire phases. The "gnomon's shadow" here symbolizes the timing for advancing or retreating the fire. If these movements lack rhythmic harmony—advancing when one shouldn't or forcing retreat at improper moments—it brings calamity like the nine-year floods. This mirrors how disrupted solar terms (summer/winter solstices) or imbalanced yin-yang at equinoxes lead to droughts, floods, and geological disasters. A ruler who understands this principle rectifies promptly, ensuring the Five Phases' energies flow smoothly, whereupon pathogenic influences naturally dissipate.

The natural flow of Yangtze and Huai River waters returning to the sea symbolizes the alchemical substances (essence and Qi) returning to their primordial source of emptiness. Heaven and earth's yin-yang cycle between midnight and noon (Kan trigram as male, Li trigram as female), while the hours of Yin and Shen mark yin-yang's inception (the yin tally and yang fire originate at Yin-Shen). According to the Nayin diagram (a chart depicting yin-yang transformations), when the moon appears at the Zhen trigram (Geng position), the yang line first stirs, marking yang fire's commencement; when the moon withdraws to the Xun trigram (Xin position), the yin line begins shifting, signaling the yin tally's start. In the pre-heaven Bagua arrangement, Zhen occupies the Yin position and Xun the Shen position, hence using Yin-Shen to determine yin-yang's transformative origin. The moon rises from Yin and sets at Shen, cycling endlessly like the Big Dipper's rotation governing Nayin fire phases—thus "holding the celestial balance to fix primordial order."

"River Drum nearing stellar chronicles, the people are all startled and terrified" describes how improper fire control leads to scattered medicinal substances; "gnomon shadows recklessly advance and retreat, nine years bring dire misfortunes" refers to disregarding fire phases like water losing its nature; "the pivot has its rises and falls" signifies timely correction of errors to harmonize the Five Phases, where calamities naturally cease; "Yangtze and Huai run dry yet streams pour to sea" metaphorizes how following fire phases returns substances to their origin. Midnight-noon concerns the movement of medicinal substances (essence-Qi), while Yin-Shen governs fire phase regulation—all requiring alignment with the Big Dipper's revolutions to discern auspicious and inauspicious shifts at Yin-Shen, demanding careful contemplation.

Finally, "raising the crucible atop Mount Zeng, blazing fire arrays below" depicts fire phase arrangement during alchemy: refining as if in a steaming vessel, with raging flames beneath; "the White Tiger leads the vanguard" signifies the western White Tiger constellation guiding the cultivation process. This section primarily details the laws of yin-yang interaction and the pivotal art of fire phase control.

This scripture depicts the interactions of Yin-Yang and the Five Phases during the alchemical process. It primarily describes how the elemental forces (Metal, Wood, Water, Fire, and Earth) mutually constrain and transform one another during elixir refinement.

The text employs four celestial creatures to symbolize the directional elements: the Azure Dragon (eastern Wood), White Tiger (western Metal), Vermilion Bird (southern Fire), and Black Tortoise (northern Water). When the Vermilion Bird encounters the Metal-Water opposition, it becomes ensnared as if trapped in a net, unable to take flight. The convergence of the Azure Dragon, White Tiger, and Vermilion Bird resembles a family reunion. The foundation of alchemy lies in the two primal energies of Yin and Yang (the two substances), ultimately achieving harmonious unity through the Five Phases (the three fives).

During the alchemical process, the coordination of fire regulation (temperature control) and medicinal ingredients (raw materials) proves crucial. The firing cycles must follow the "three fives" rhythm (fifteen days constituting a Yang fire phase), while the ingredients must observe the generative and restrictive relationships of the Five Phases. When the Dragon (Wood) and Tiger (Metal) energies merge, supplemented by Water and Fire, they ultimately fuse into unity at the central position of Earth (Wuji).

The scripture further describes various phenomena witnessed during refinement: liquids boiling and churning within the cauldron like interlocking icicles in winter; shimmering transformations of five-colored radiance—all these serve as omens of successful elixir production. The perfected elixir first appears white, then transforms to yellow, glowing red throughout, earning the designation "First Cauldron."

This passage actually employs symbolic language to describe the Neidan (internal alchemy) practice—a Daoist method of health cultivation involving the circulation of vital Qi (energy) and harmonization of Yin-Yang within the body. Through breath regulation and focused intention, the practitioner balances the Five Phase energies within, ultimately crystallizing the internal elixir.

This passage elucidates the transformative principles and patterns in the alchemical process. Just as substances in nature undergo spontaneous transformations—mountain and marsh qi (vital energy) evaporating to form clouds and rain, parched earth turning to dust, flames extinguishing into ashes—so too does alchemy follow natural laws. Using phellodendron bark dyes cloth yellow, while indigo plants yield green; boiling leather produces glue, and fermenting yeast creates wine. Substances of the same kind readily produce effects, whereas dissimilar types prove ineffective.

This exquisite alchemical art is genuine and enduring, passed down through generations with clarity, like the orderly arrangement of stars or rivers ultimately flowing to the sea. It demands repeated contemplation and refinement, requiring thousands of trials to grasp its profound mysteries. The Dao of heaven shows no partiality, always transmitting its truths to virtuous sages.

The crux of alchemy lies in harmonizing yin and yang: The yin fire within the Li trigram (symbolizing fire) is originally white. When lead is added, it turns yellow; with sufficient firing, the elixir matures to crimson and ultimately transforms into purple. This chromatic progression from white to purple corresponds precisely to the symbolic meaning of "the Qian trigram's great crimson." When a millet-sized pearl-like elixir forms, it marks the successful completion of the first cauldron's refinement. The discourses of sages all adhere to rigorous methods and sequences.

Although the Zhouyi Cantongqi (The Seal of the Unity of the Three) outlines the framework of alchemy, its explanations remain incomplete. Thus, supplementary elaboration is needed to ensure coherent meaning and unified intent. Through the "five mutual correspondences" system (i.e., the generative and controlling relationships of the Five Phases), the essence of yin-yang transformations in the Yijing (Book of Changes) can be fully expressed.

Specifically: The pairing of Yi Wood (pumice), Ding Fire (gentle fire), Ji Earth, Xin Metal (mundane silver), and Gui Water (true lead) forms one group; Jia Wood (sinking stone), Bing Fire (fierce fire), Wu Earth (medicine), Geng Metal (mundane gold), and Ren Water (true mercury) constitute another—both derived from the pre-heaven numerological system of the Luoshu. The Yijing's yin-yang natures each follow their own laws, while the teachings of the Yellow Emperor and Laozi originate from the Yijing, and alchemy in turn builds upon Huang-Lao thought. These three share a common source, all exploring the fundamental nature of heaven, earth, and the myriad things.

The flourishing of a tree's branches, flowers, leaves, and fruits depends entirely on its roots maintaining their original vitality. Similarly, matters of the heart can only be free from error when carefully examined.

This mirrors the growth process of fruit trees: in spring, they sprout new branches; in summer, they bloom with flowers and unfurl leaves; by autumn, they bear fruit. Yet the source of all this growth lies in the tree's roots. Thus, the key is ensuring the foundation never loses its innate nature. From the Tai hexagram (symbolizing harmony) to the Qian hexagram (symbolizing pure Yang), the root lies in the Fu hexagram (symbolizing the nascent Yang energy) established at the winter solstice. The wondrous cyclical workings all stem from this initial Yang energy.

Practitioners of the Dao (sages and perfected beings) place particular emphasis on the Zi hour (the time of Yang's first stirring). Scholars who comprehend the subtle function of this nascent Yang energy will naturally progress through the stages represented by the Lin, Tai, Zhuang, and Guai hexagrams—all without forced effort. Therefore, the imagery of midwinter (the winter solstice) is specifically used to illuminate this principle.

Here, the roots of a tree serve as a metaphor for the winter solstice. Though bamboo and trees may appear withered in winter, it is precisely this period of dormancy that allows them to sprout branches in spring, flourish with leaves in summer, and bear fruit in autumn. The primordial Qi (the foundational life energy) lies hidden in the roots, awaiting the return of the Fu hexagram's moment—the stirring of Yang's rebirth.

At the winter solstice, all things lie dormant, much like merchants halting their travels or rulers withdrawing from public life. At this time, one should align with the season, maintaining silence and refraining from reckless discussions of the Dao (for the Dao's vastness defies words). The state of emptiness and stillness is beyond description—external forms have all receded, and any forced explanation would only lead to error. Here, the principles of the Four Symbols (Lesser Yang, Greater Yang, Lesser Yin, Greater Yin) are specially outlined to enlighten future generations.

These two chapters focus on the cultivation timing (fire phases) of the first stirring of Yang (the winter solstice's awakening of Yang energy). Lead (symbolizing original essence, Jing) and mercury (symbolizing spirit, Shen) are both concealed within the Ren and Gui (two Heavenly Stems associated with Water): Ren corresponds to the Li fire within the Qian hexagram, while Gui corresponds to the Kan water within the Kun hexagram—profound meaning lies within this.

Finally, it is mentioned that I, a humble man of lowly origins, dwell in secluded valleys, embracing the simple Dao, free from worldly desires, content with a tranquil and unadorned life. In moments of leisure, I composed these words to elucidate the essential teachings of the Three Sages of the Yijing, unifying their principles. Where the meaning is easily understood, no further commentary is added.

This passage expounds the principles of cultivating body-mind and governing states by following natural laws. The first half discusses the "Huang-Lao techniques" (the Yellow Emperor and Laozi's methods for health preservation and statecraft), whose core lies in returning to original authenticity and maintaining mind-body unity.

The essence of practice involves "embracing the One" (maintaining mind-body unity) and "returning to the root and reverting to the origin" (going back to life's source). Just as trees must take root to grow, humans must preserve their foundation. Specific methods include ingesting elixirs (the "female and male" refer to medicines harmonizing Yin-Yang) and abandoning worldly distractions (the "Eight Minerals of Wudu" symbolize external complexities). Though these approaches appear different, they all stem from the same fundamental principle.

The middle section mentions that the classic Cantongqi (The Seal of the Unity of the Three), despite its concise text, contains profound meanings worthy of later generations' adherence. The subsequent "cauldron-vessel" metaphor illustrates: the cauldron (symbolized by the Kun trigram) and vessel (symbolized by the Qian trigram) separate represent heaven and earth, while combined they form complete alchemical apparatus. The measurement "three-fives and one-tenth of an inch" signifies Yin-Yang fusion (three plus five equals eight, representing the Bagua; one symbolizes the Dao's origin).

The "four-eight mouth" refers to the cauldron's opening representing the "Mysterious Feminine Gate" (the Daoist concept of creation's source), encompassing the transformational principles of the Four Symbols and Eight Trigrams. Each part corresponds to Yin-Yang: the cauldron belongs to Yin yet contains three Yang lines, the vessel belongs to Yang yet contains three Yin lines. The two-inch rim symbolizes the Yin-Yang boundary, while the twelve-inch length corresponds to the twelve earthly branches, embodying Yin-Yang balance.

Finally, Wei Boyang (author of Cantongqi) used four-character esoteric phrases like "withdrawing timely to avoid harm" to hint that practitioners should retreat from worldly clamor to ultimately achieve immortal ascension. Through the precise specifications of cauldron construction, the entire passage metaphorically conveys that alchemy requires exact harmonization of Yin-Yang principles.

This passage elucidates key stages and principles of Daoist Neidan (internal alchemy) practice. It begins by explaining the "Three Powers" (Heaven, Earth, and Humanity) each possess a central pivot—in the cosmos this represents the generative source of all things, while within the human body it manifests as the crucial gateway for cultivation (known as the Mysterious Feminine Gate).

Practitioners must maintain Yin-Yang harmony through the "fire advancement method," facilitating the mutual nourishment of water and fire. The text employs alchemical furnace imagery: the lower crucible (symbolized by the Kun hexagram representing yin) cooperates with the upper crucible (symbolized by the Qian hexagram representing yang). The process requires precise regulation of "fire times"—beginning and ending with intense heat (martial fire), while maintaining moderate warmth (civil fire) during intermediate stages.

The passage references the "White Tiger" (seven western constellations, associated with Metal) and "Azure Dragon" (seven eastern constellations, associated with Wood), each possessing seven orifices. Their union gives birth to the "sacred embryo" (internal elixir). Once formed, this embryo must be elevated to the upper Dantian (brain region) for nurturing, requiring meticulous care akin to tending an infant. Advanced practitioners achieve "spiritual metamorphosis," attaining the ability to ride white cranes or dragon-scaled steeds through the Great Void to commune with immortals.

The concluding verses summarize Yin-Yang dynamics: Qian (Heaven) contains Li (Fire), Kun (Earth) contains Kan (Water), with sun and moon conjoining through the pivotal Earth phases (Wu and Ji). It honors the teachings of Wei Boyang (Master Wei), the alchemical sage, emphasizing that fire-times mastery requires oral transmission from master to disciple. Devotees who practice faithfully may ultimately ascend as Jade Pond immortals.

Technical terms like "lead," "mercury," and "yellow sprout" metaphorically represent internal energy transformations through external alchemical imagery. "Two sevens" denotes the numerical values of Metal and Wood, while the "River Chart and Luo Writings"—ancient mystical diagrams—provide cosmological frameworks for alchemical theory.