《參同契闡幽》Vol. 3

The Can Tong Qi Chan You (Elucidation of the Join Together Book) is a classic now republished in the Dao Zang Ji Yao (Collected Essentials of the Daoist Canon). The Can Tong Qi is divided into three sections—upper, middle, and lower—and here we focus on the first part of the middle section, which specifically discusses "governing the self" (regulating body and mind as one governs a state), comprising four chapters.

This classic consists of fifteen chapters in its upper section, covering three volumes: governing the self, nurturing nature (cultivating the mind), and "subduing nourishment" (ingesting elixirs). These correspond to the three essential elements of the alchemical process: the medicinal ingredients, the furnace and cauldron (alchemical vessels), and the firing times (the timing of practice). Although the core principles of the Golden Elixir (Jindan) path are already complete, this section still elaborates in three volumes to prevent learners from misunderstanding and straying into error, thus complementing the content of the upper section.

Now, let us specifically explain Chapter Sixteen, "The Four Symbols Circling Within":

The transformations of heaven and earth operate like a cyclical system. The nature of Qian (Heaven) is firm and vigorous, while Kun (Earth) is yielding and receptive—the two harmonize and embrace one another. The active Yang energy gives forth, while the passive Yin energy receives, much like the pairing of male and female. Through this creative interaction, the subtle primordial Qi (vital energy) unfolds and circulates.

The trigrams Kan (Water) and Li (Fire) are the most crucial—their radiance illuminates all directions, yet their profound mystery is unfathomable and cannot be depicted in diagrams. Only sages can fathom their depths and penetrate the fundamental principles of the cosmos.

Qian, Kun, Kan, and Li merge indistinctly, ultimately returning to the realm of emptiness. Just as the sixty hexagrams cycle endlessly, like chariots and horses perfectly prepared, the enlightened ruler seizes the right moment to govern the state. When harmony prevails, all affairs proceed smoothly, and the path is level; but if one strays onto a deviant path, obstacles arise, leading to the collapse of the nation.

This passage primarily illustrates how Qian (Heaven) and Kun (Earth), through the interaction of Kan (Water) and Li (Fire), reveal the wondrous, ceaseless cycle of primordial creation. The firm and active Yang of Qian, like a father, gives forth, while the yielding and receptive Yin of Kun, like a mother, nurtures and conceives. Only through their union can the myriad things be born—this is the true meaning of "Qian firm and Kun yielding, matched and embracing one another."

This scripture elucidates the principle of mutual generation and transformation between Yin and Yang. The feminine Yin energy gestates the golden embryo (rudimentary form of the Golden Elixir), while masculine Yang energy receives from and depends upon Yin. These two complementary forces—symbolized as the female and male principles—must unite to accomplish the creative work of cosmic transformation. This transformative process encompasses both "creation" (bringing forth from nothingness) and "dissolution" (returning to nothingness): when manifesting from void, the formless absolute (zhenkong) appears as wondrous phenomena (miaoyou), with pure Yang (Qian) containing latent Yin (Kun); when dissolving back to void, phenomenal existence returns to the absolute, with Yin harboring Yang.

This mystical inversion—where Qian conceals Kun (called the Primordial Essence of Supreme Unity) and Kun contains Qian (called the Ancestral Primordial Qi)—reveals the profound mystery of cosmic transformation.

The text then explains the function of Kan (Water trigram) and Li (Fire trigram). These emerge from the interaction of Qian and Kun, just as the I Ching states: "When Heaven and Earth commune, all things are transformed." Kan represents supreme Yang Qi, while Li embodies supreme Yin Jing. Though formed after Heaven and Earth, their operation precedes cosmic creation. When cosmic transformation obtains Kan-Li, sun and moon (solar soul and lunar essence) take form; when the human body receives Kan-Li, it generates solar essence and lunar luminosity (cultivation energies). This primordial essence and energy are too subtle for visual representation—thus sages use the trigrams of Qian, Kun, Kan and Li as metaphors for the alchemical furnace (cultivation space) and medicinal ingredients (alchemical materials).

Practitioners who emulate Qian-Kun to establish their foundation and gather Kan-Li's energies—allowing solar essence and lunar radiance (Yin-Yang energies) to naturally coalesce in the ancestral cavity (upper Dantian) through chaotic fusion—can return to the primordial state of formless void, where the Great Medicine (Golden Elixir) takes shape. This mirrors the I Ching's teaching: "When male and female unite, all things are born."

Finally, the text references the sixty-four hexagrams' cyclical movement resembling chariots in motion. The enlightened ruler (practitioner) must seize the proper timing and maintain harmony, ensuring the path remains straight and true—a metaphor for cultivation requiring alignment with natural rhythms and precise fire regulation.

This scripture primarily elucidates the regulatory principles of fire times (huohou) in alchemical practice—the modulation of intention and breath during cultivation. It first notes that apart from the four hexagrams Qian (Heaven), Kun (Earth), Kan (Water), and Li (Fire)—which represent the furnace and cauldron (the physical foundation of cultivation) and the medicinal ingredients (Jing, Qi, and Shen)—the remaining sixty hexagrams are arranged in cyclical patterns corresponding to celestial movements. This manifests concretely in the four daily periods (midnight, noon, dawn, and dusk), the four lunar phases (new moon, full moon, first and last quarters), and the four seasons of the year, all following this perpetual cyclical rhythm.

The text employs the metaphor of charioteering to illustrate cultivation: the chariot symbolizes the human body, the horses represent intention, and the charioteer embodies the guiding Shen (spirit). Just as an enlightened ruler governs a nation with clear laws, during cultivation, the Shen must firmly regulate intention, ensuring the smooth and orderly movement of Jing and Qi like well-guided horses pulling a chariot. Improper control—akin to a tilted chariot overturning or a wayward ruler losing his kingdom—would damage one's vital nature (xing) and life (ming), ruining the alchemical elixir (the fruits of cultivation).

Particular emphasis is placed on the importance of "sovereign control": chariots require drivers, states need wise rulers, the Northern Dipper governs seasonal transitions, and alchemy must grasp the "Celestial Heart" (the core principle of cultivation). This aligns seamlessly with the earlier concept of the "Dipper's Handle" (Kuibing, symbolizing pivotal control).

The latter section highlights how this chapter resonates with preceding teachings: the dynamic Qian and yielding Kun correspond to the "Gateways of Qian and Kun" theory (the opening and closing of Yin-Yang); Kan and Li taking precedence reflects the "Framework of Kan and Li" doctrine (the structure of Water and Fire); while the sixty hexagrams' cycles mirror the "Axle Turning the Wheel" (like a hub regulating its periphery). Finally, citing the Zhouyi (Book of Changes), it clarifies that true adepts—even while dwelling quietly indoors—can resonate with Heaven and Earth through actions aligned with the Dao, much as rulers govern empires from their palaces. The crux lies in mastering the timing of movement and stillness.

This passage elucidates the crucial principles of fire regulation (referring to the modulation of intention and breath during cultivation) in Neidan (internal alchemy) practice. Just as a ruler issuing decrees from the palace depths must align with the shifts of Yin-Yang, the practitioner must strictly adhere to celestial timing.

Specifically, the Zhun hexagram (symbolizing nascent life) corresponds to the hours between midnight and late afternoon, while the Meng hexagram (symbolizing enlightenment) governs the hours from dawn to nightfall—with the remaining sixty hexagrams each having their designated temporal alignments. Cultivation should alternate between discipline and benevolence like establishing laws and enacting compassionate governance—violating these rhythms invites misfortune, whereas compliance brings auspicious results.

Three metaphors illustrate the criticality of fire regulation:

1. Like governing a kingdom: The "ruler of ten thousand chariots" (representing the human Shen/spirit) residing in the nine-layered palace (symbolizing the middle Dantian/energy center) must issue commands in harmony with seasonal nodes;

2. Like agricultural work: Storing tools while awaiting the proper moment (symbolizing how cultivation must observe the waxing and waning of Yin-Yang);

3. Like judicial administration: Establishing regulations and dispensing kindness must coordinate with celestial timing (symbolizing the balance of firmness and flexibility in practice).

Particular emphasis is placed on precise observation of:

• Daily temporal transitions (scrutinizing growth and decay)
• Seasonal turning points (such as the Yin-Yang reversal during winter and summer solstices)
• Natural omens (like unusual celestial phenomena)

The text reveals the principle of heaven-human resonance: the practitioner's internal movements and stillness can trigger external transformations—minor fluctuations affecting personal fortune, major ones influencing worldly order. Thus, intention must be as exact as a carpenter's ink line (adhering to its straightedge), breath must synchronize with seasonal Qi/vital energy (achieving harmonious interaction), and the Five Phases' energies must maintain their proper positions (without arbitrary expansion or contraction)—ultimately realizing the cyclical circulation of Qi within the body (curving and extending throughout).

The core insight concludes: The essence of fire regulation lies in maintaining constant rhythm between movement and stillness, as the Zhouyi states: "When the noble person in their chamber speaks words of goodness, responses come from a thousand miles away"—demonstrating how subtle cultivation adjustments yield profound consequences.

This passage elucidates the principles of Yin-Yang transformation during cultivation and the crucial importance of timing. When the mind achieves profound stillness—like the moon positioned at the "lunar cavity" (the zenith of Yin energy), corresponding to the Gou hexagram during the fifth lunar month—it represents the fullest Yin state. Conversely, when Yang energy begins to sprout—like residing at the "celestial root" (the nascent emergence of Yang), matching the Fu hexagram during the eleventh lunar month—it marks Yang's initial stirring. Practitioners must discern when to maintain tranquil patience and when to act decisively as opportunities arise.

The text employs the Zhun and Meng hexagrams to illustrate the cyclical rhythm of Yin-Yang waxing and waning: Zhun symbolizes the germination of all beings, corresponding to the hours from midnight to afternoon (like spring and summer when Yang expands), while Meng represents nature's withdrawal, aligning with dawn to dusk (like autumn and winter when Yin consolidates). These two hexagrams cycle like the alternation of day and night or the turning of four seasons.

Particular emphasis is placed on the pivotal solar terms of Spring Equinox (the third month) and Autumn Equinox (the ninth month). Though Spring Equinox belongs to Wood's generative phase, it secretly harbors Metal's austere energy; though Autumn Equinox governs Metal's retributive nature, it subtly contains Wood's gentle virtue. This mirrors statecraft requiring balanced benevolence and authority, just as cultivation demands skillful Yin-Yang harmonization.

Ultimately, the text warns that the finest miscalculation in Yin-Yang transitions brings consequences as grave as a ruler issuing untimely decrees—inviting calamity. Practitioners must strictly follow the calendrical solar terms, meticulously observing the subtle fluxes of Yin and Yang. Misjudging these temporal nodes may trigger anomalies: winter heatwaves or summer frosts manifest as cosmic dissonance mirroring cultivation errors.

This scripture elucidates the critical importance of fire regulation (referring to the control of intention and breath during cultivation) in Neidan (internal alchemy) practice. Just as natural disasters like floods, droughts, locust plagues, and earthquakes stem from imbalances in Yin-Yang, improper fire regulation during cultivation can lead to severe consequences.

The text employs seasonal transitions as metaphors: When Yang Qi first emerges at the winter solstice, one should "advance the fire" (intensify intention) as gently as nurturing tender sprouts. When Yin Qi begins its descent at the summer solstice, one must "retreat the fire" (diminish intention) as cautiously as guarding against early frost. Excessive heat when warmth is needed turns winter into scorching summer; excessive cold when cooling is required brings frost in midsummer. During the equinoxes when Yin-Yang achieve equilibrium, practitioners should "cease fire for bathing" (suspend intentional activity), allowing the genuine Qi in the cauldron to coalesce naturally.

Scattered or unfocused intention is like a malfunctioning water clock, causing Water and Fire to fall out of balance—excessive Water leads to flooding, excessive Fire brings drought, and wind and rain lose their seasonal rhythms. More gravely, it may disrupt the body's Jing-Qi (essence-energy) system (where locusts symbolize turbid Yin, and the jade furnace with golden cauldron represents bodily organs), or even cause primordial Qi to dissipate (the golden tiger and green dragon denoting Yin-Yang energies). These are all perilous omens of violating natural laws.

Conversely, maintaining focused inner observation (through the "turning the light inward" method) with the devotion of a filial child serving parents allows one to perceive the "Sovereign Pole" (the innate sovereign within the human body). This state of utmost sincerity in cultivation not only averts calamities but also attracts blessings—all hinging on the practitioner's state of mind in each moment.

This passage describes how our innate primordial spirit (Yuanshen)—the sovereign consciousness residing in the celestial valley of our being—remains naturally serene and unaffected by external influences, embodying the principle of Wuwei (non-action). However, once post-birth thoughts arise, this spirit immediately resonates with the external world. Just as a filial child’s concern for their parents transcends physical distance, creating a heart-to-heart connection, our words and actions ripple outward like water waves, affecting both near and far. Aligning with this resonance brings auspicious outcomes, while opposing it invites misfortune.

The pivot between fortune and calamity lies in how the mind employs this mechanism of resonance: a tranquil heart fosters harmony, while agitation breeds conflict. Often, the distinction between auspicious and inauspicious outcomes hinges on a single thought, demanding careful attunement to the rhythms of movement and stillness. In Neidan (internal alchemy) practice, one must follow nature’s cadence like the turning seasons: entering deep stillness when required and applying intention with precision when action is needed. Just as the equinoxes call for gentle nurturing and the solstices require careful modulation of "fire phases" (referring to the intensity of breath and focus), the practitioner must discern between "martial fire" (strong intention) and "civil fire" (gentle intention)—using the former to temper body and mind when they are unrefined, and the latter to nourish once Shen (spirit) and Qi (vital energy) harmonize.

The essence of cultivation lies in balancing the "four emblems" (symbolizing Wood, Fire, Metal, and Water energies) and the Five Phases (Metal, Wood, Water, Fire, Earth), ensuring each occupies its proper place. Like the Earth at the center governing the four directions, energetic movement must maintain clear boundaries without losing holistic unity. Mastering the interplay of movement-stillness and firmness-yielding requires the precision of a carpenter following an inked line—the slightest deviation risks undoing all progress.

The movement of the Five Phases (Metal, Wood, Water, Fire, Earth) operates within fixed boundaries—neither exceeding nor falling short. The natural flow of Yin and Yang energies gives rise to their respective qualities of firmness and yielding. The harmonious interplay between firmness and yielding creates the timing of movement and stillness in transformation. This mirrors the true principles of Yin-Yang transformation within our bodies—where genuine Qi (vital energy) circulates freely in flexion and extension, as naturally coordinated as a ruler's commands being carried out a thousand miles away.

This passage elaborates on the measured regulation of "fire times" (the control of intention and breath in Neidan/internal alchemy practice), corresponding with earlier discussions of the Zhun and Meng hexagrams (symbolizing the initiation of cultivation) and the solar terms of the four seasons. While previous sections outlined general principles, here we refine them into concrete operational guidelines—clarifying what practitioners should emulate and what to avoid.

At the juncture between the lunar month's end and beginning (the critical moment of Yin-Yang transition), the Kan (Water) and Li (Fire) hexagrams intersect and merge. Here Yin and Yang exist in undifferentiated chaos, akin to the primordial separation of heaven and earth, where feminine and masculine energies unite, nourishing fluids flow, and vital circulation emerges. Even celestial deities find this creative marvel unfathomable. Practitioners should stabilize body and mind during this phase, concealing the true Yang energy in the northeast quadrant corresponding to the Ji and Dou constellations (the Dantian/energy center region where primordial Qi is stored in Neidan practice).

Primordial Qi first rotates rightward like a wheel spurring germination, manifesting forms in deep pools while essence and luminous Qi radiate outward. When reaching the Mao and Bi constellation positions, the signs of Zhen (Thunder) hexagram begin to appear. Newborn Yang resembles a "hidden dragon" (the initial Yang line of Qian hexagram), with Yang establishing its foundation in three and Yin permeating through eight. The third-day moon displays Zhen hexagram's image, while the eighth-day moon reveals Dui (Joy) hexagram's form.

During the "appearing dragon" phase (the second Yang line where Yang becomes visible), Yin and Yang harmonize to generate illumination. At the full moon on the fifteenth day, the Qi of Five Phases becomes complete, forming the perfected body of Qian hexagram. The "evening vigilance" phase (the third Yang line where flourishing Yang requires caution) warns against essence dissipation. What reaches its zenith must decline—this natural law ultimately returns all to the source. When Xun (Wind) hexagram takes over governance, one must stabilize foundations and maintain careful vigilance. The "leaping" phase (the fourth Yang line where Yang ascends) presents dangers between advancement and retreat.

Gen (Mountain) hexagram governs movement and stillness—never miss the opportune moment. During the waning moon's twenty-third day, maintain equilibrium. The "flying dragon in heaven" (the fifth Yang line at Yang's zenith) represents the optimal alignment of celestial and terrestrial timing. The "Kun's receptivity" phase (the fifth Yin line where Yin dominates) nurtures all things like a mother gestating life. The "overreaching dragon's remorse" (the top Yang line where Yang becomes excessive) shows Yin and Yang contending beyond the borders. The "using nine" line reveals heaven's cyclical Dao—when Yang numbers exhaust themselves, renewal begins as Yin and Yang natures transform mutually.

This celestial circuit operates like the Big Dipper's rotation—rising, descending, floating, and sinking through six alternating phases in endless cycles, defying concrete observation. Precisely because of its constant mutability, it constitutes the fundamental principle of the Yijing (Book of Changes). This chapter discusses how the intersection of Kan and Li produces the elixir (Neidan), corresponding to the moon's phases of conjunction, crescents, and quarters—the essential formula for practicing the "small celestial cycle" fire times.

This passage elucidates the mystical moment of Yin-Yang convergence and the celestial union of sun and moon—the fundamental principle for cultivating the Golden Elixir (Jindan). The profound mystery of cosmic creation lies in the dynamic interplay of movement and stillness, an endless cyclical process. Just as there can be no expansion without gathering, no renewal without retreat, this principle manifests across different temporal scales:

In the grand cosmic cycles (Yuanhui), stillness (Zhen) gives rise to movement (Yuan);

In the annual cycle, winter precedes spring;

In the daily rhythm, the depth of Hai hour (9–11 PM) transitions into Zi hour (11 PM–1 AM), marking rebirth;

In the lunar month, the moon's complete obscuration (Hui) at month's end necessarily precedes its rebirth at the new moon (Shuo).

This perpetual cycle of endings birthing beginnings embodies the immutable law of cosmic operation.

Why is this called "Hui-Shuo"? The moon emits no light of its own—it shines by absorbing the solar essence (Sun Soul, Rihun). On the 30th night of the lunar month, when moonlight vanishes completely and the lunar body withdraws, this is "Hui." At this moment, sun and moon converge along the ecliptic. Within our bodies, the solar essence (heart-mind, Rijing) and lunar essence (kidney Jing, Yuejing) stand divided between south and north. Only through the guidance of true intention (innate awareness) can they meet in the middle Dantian (Central Yellow Divine Chamber), like fire and water harmonizing at the celestial junction marked by the Xu and Wei stars (symbolizing Yin-Yang convergence). When the mind achieves perfect stillness, spiritual illumination spontaneously arises—this fleeting union constitutes the "True Hui-Shuo" within the human body.

As spirit and Qi return to the Qi cavity (Dantian), one enters a state beyond heaven and earth, beyond sight and sound—as if celestial motion pauses, returning to the primordial chaos before creation. Within this undifferentiated state, true Yin and Yang naturally unite like mating phoenixes, the Mysterious Feminine (Xuanpin) coupling to gestate the primal Yuanqi. This twilight state resembles the sun releasing its essence while the moon receives and transforms it, allowing vital energies to flow unimpeded.

At the moment of sun-moon union, celestial Qi (Yang) descends into earthly depths (Yin), all sound ceases, and divine light hides within the cavity of chaos—undetectable even to ghosts and spirits. Here, Yang lies wrapped in Yin like dragons submerged in abyssal waters or pearls concealed in riverbeds. As Tang Dynasty Daoist Tan Jingsheng proclaimed: "Only by mastering the gateway to the vast Yuanqi can one return to the root; only by understanding the inner vessel of the primordial spirit can radiance be gathered." This is the supreme attainment of "concealing one's form and establishing life in stillness."

This passage elucidates the mysteries of Yin-Yang transformation and the esoteric principles of Neidan (internal alchemy) practice. When the moon reaches the position of the Ji and Dou constellations in the northeast, it begins its westward movement from the right, resembling a wheel's rotation sprouting tender buds, with faint light emerging from the depths of a dark pool. As the moon passes the Mao and Bi constellations, Yang Qi begins to stir, mirroring the "submerged dragon biding its time" state described in the first Yang line of the Qian hexagram in the Yijing (Book of Changes).

Here we witness the principle of the single Yang line in the Gen hexagram (representing mountain, Yang) transforming into the Zhen hexagram (representing thunder, Yang). Ordinary observers only notice the moon losing its radiance during the lunar waning phase, unaware these changes actually commence during the last quarter moon. This phase corresponds to the Gen hexagram, which occupies the northeast position in the Later Heaven Bagua arrangement, aligning with the Chou (1-3 AM) and Yin (3-5 AM) earthly branches, where the Ji and Dou constellations of the twenty-eight lunar mansions also reside.

Heavenly Dao follows a leftward rotation moving forward, beginning at Zi hour (midnight), while earthly Qi circulates rightward in reverse, starting between Chou and Yin. To comprehend the forward movement of Heavenly Dao, observe the sequence of four seasons: progressing from north to east, then south, before returning north via the west—this reflects the Five Phases' sequential movement in the Later Heaven Bagua. To understand earthly Qi's reverse flow, one must study the moon's Nayin system that correlates lunar phases with heavenly stems and earthly branches.

The Golden Elixir cultivation completely follows the prenatal Nayin principles, identical to the moon's cyclical patterns. The moon's true Yin-water begins generating at Wu hour (noon), developing from the single Yin line of the Xun hexagram on the 16th day to the two Yin lines of Gen hexagram by the 23rd, as Yin Qi gradually erodes Yang Qi. When reaching the Ji (water element) and Dou (wood element) constellations at the Chou-Yin transition in the northeast, even Gen's last Yang line vanishes, transforming completely into Kun hexagram (pure Yin). In human cultivation, this manifests as Shen (spirit) merging with Qi while all things return to their origin—precisely what the scripture describes as "turning eastward at Wu hour, losing companions in the northeast."

Yet extreme Yin inevitably births Yang. The sun's true Yang-fire begins stirring at Zi hour (midnight). In the northern region of Xu and Wei constellations where sun and moon conjoin, as the moon gradually turns from north to west, it reveals the first glimmer of light—the phenomenon described as "turning right to sprout buds," symbolizing the emergence of life's most refined primordial Qi.

This passage discusses the crucial timing of "living midnight" (huo zishi) in Daoist Neidan (internal alchemy) practice. When the body's true Qi (yang energy) first begins to stir, it resembles the crescent moon rising in the west (the Geng direction) during the third lunar day. At this stage, yang energy is still faint, corresponding to the Zhen hexagram in the Yijing (Book of Changes) where a single yang line stirs beneath two yin lines. Practitioners must nurture this energy gently, like tending new sprouts in early spring, avoiding the forceful application of intense heat.

By the eighth lunar day when the waxing half-moon appears in the south (the Ding direction), corresponding to the Dui hexagram (one yin line above two yang lines), the golden essence (primordial energy) within the crucible (referring to the Dantian or energy center) grows vigorous. Though this phase shows clear vitality, it also harbors hidden dangers, requiring the "bathing" stage (a fire-regulation technique) to harmonize yin and yang.

At the full moon on the fifteenth day when yang energy peaks, corresponding to the pure yang Qian hexagram, the Golden Elixir (jindan) manifests its medicinal potency like moonlight illuminating the void. Yet as things reach their extreme they reverse—when yang culminates, yin is born. Practitioners must remain vigilant as cautioned in the third line of the Qian hexagram: "The nobleman remains diligent throughout the day," for the yang energy will gradually decline and return to its initial state.

The terms "living midnight" (the critical juncture of yin-yang alternation within the body) and "sun-moon conjoining" (the fusion of yin and yang energies) are specialized Neidan terminology referring to optimal moments for harnessing the waxing and waning of these forces. Master Yin Xi (Laozi's disciple) emphasized recognizing this living midnight within oneself precisely for this reason—it marks the pivot point where cosmic and bodily cycles converge.

This scripture elucidates the principles of Yin-Yang transformation during the practice of cultivating the Golden Elixir (Jindan), using the hexagram imagery from the Book of Changes (Zhouyi) to metaphorize fire regulation techniques.

The first section describes the manifestation of the Xun hexagram (representing wind, belonging to Yin). When Yang energy reaches its peak, the single Yin line of the Xun hexagram is required to harmonize and consolidate it, demanding vigilance akin to guarding a fortress. At this stage, the "or leaping in the deep" state of the fourth Yang line (9-4) in the Qian hexagram transforms into the "tying the sack" state of the Kun hexagram, warning practitioners to remain cautious. This critical juncture marks both the retreat of the three Yang lines and the initial growth of the three Yin lines.

The second section explains the appearance of the Gen hexagram (representing mountain, belonging to Yang). Here, Yang energy resembles the solitary fruit remaining atop a mountain, requiring timely cessation. During the last quarter moon on the twenty-third day of the lunar month, when the energies of Water and Fire achieve equilibrium, the Yang energy within the cauldron (referring to the practitioner's body) begins to coalesce and store. The "flying dragon in heaven" state of the fifth Yang line (9-5) in the Qian hexagram transitions into Kun's "yellow skirt, supreme good fortune," symbolizing the gestation of vital force amid austerity. This phase, called "celestial position bringing joy," also represents the appropriate moment for "bathing" (regulating breath and quiet cultivation) in alchemical practice.

The third section reveals the transformation principle of extreme Yin generating Yang when the Kun hexagram (pure Yin) reaches its zenith. Although the six-fifth line nominally refers to Kun's fifth line, it actually encompasses the complete lunar cycle from new moon to full moon and then to dark moon. Within the eight trigrams, Qian (Heaven) and Kun (Earth) contain the beginning and end, while the other six trigrams (Zhen, Xun, Kan, Li, Gen, Dui) all depend on Qian's creative power and Kun's concluding function. The moon, being the embodiment of Supreme Yin (Taiyin), inherently lacks radiance—it shines only by receiving the essence of solar Yang. From new moon to full moon represents Qian's Yang temporarily residing within the lunar body, whereas from full moon to dark moon manifests Kun's Yin in its true form. Ultimately, moonlight always originates from the solar Yang essence of Qian, merely utilizing Kun's Yin body as its vessel for manifestation.

This passage explains the principle of Yin-Yang transformation in Daoist Neidan (internal alchemy) cultivation, using the hexagram imagery from the Yijing (Book of Changes) to illustrate the alchemical process. At its core, it describes the mutually generative relationship between Yin and Yang, and the formation principle of the Golden Elixir (Jindan).

The Kun hexagram (representing Yin and the maternal principle) acts as a nurturing mother. The progression from its first to fifth lines symbolizes a complete cultivation cycle. The sixth-fifth line marks Kun's completion of gestation, yet all six offspring hexagrams (Zhen, Kan, and Gen as the three masculine hexagrams; Xun, Li, and Dui as the three feminine) remain within the domain of Qian and Kun. The Yang aspect of the Hun (ethereal soul) belongs to solar essence and is governed by the Qian hexagram (representing Yang and the paternal principle), while the Yin aspect of the Po (corporeal soul) belongs to lunar essence and is governed by Kun. However, the three Yin lines ultimately derive from the Qian origin (cosmic source), manifesting the paternal Dao; the three Yang lines are temporarily housed within Kun's form, embodying the maternal Dao.

The topmost Yang line (ninth-nine) of Qian represents the ancestral temple, father to all six offspring hexagrams; the topmost Yin line (six-six) of Kun serves as their mother. The Golden Elixir first emerges in the Kun furnace (lower Dantian), ascends to the Qian cauldron (upper Dantian), then descends to the Yellow Court (middle Dantian). Throughout this process, the nurturing maternal function remains indispensable, mirroring Kun's patient waiting for Yang's return.

When Qian's ninth-nine line reaches its extreme, it transforms into Kun's six-six line—yet Yang never fully vanishes. As the Huozhulin states, the top line symbolizes the eternal, unchanging ancestral temple. Kun's six-six line mentioning "dragons battling in the wild" actually refers to Qian's ninth-nine line's "overreaching dragon." When Yin reaches its limit, Yang comes to engage, and through their struggle achieves harmony. Kun represents the Wuji (limitless) state, hence called "the wild." In the Later Heaven Bagua arrangement, Qian occupies the northwest Yin position, thus termed "battling at Qian."

Through this Yin-Yang confrontation, primordial Qi (Yuanhuang) begins merging, gestating Yang essence to form the Zhen hexagram (symbolizing the first stirring of Yang). This resembles thunder within the earth, splitting chaos to transform into the returning Fu hexagram (symbolizing Yang's rebirth). Finally, the "using nine" line demonstrates the celestial cycle—when Yang numbers exhaust, they regenerate anew. The perpetual interaction of Kan and Li (representing water and fire) circulates through all six lines in endless transformations, embodying the fundamental principle of the Yijing.

This passage primarily elucidates the dynamic process of Golden Elixir formation through Yin-Yang interaction and water-fire balance in Neidan practice, using hexagram transformations to map the alchemical journey.

This scripture elucidates the core principles of cultivating the Golden Elixir (Jindan), employing the hexagrams of the Book of Changes (Yijing) to explain the transformations of Yin-Yang and the methods of spiritual practice.

The Qian hexagram represents pure Yang, while the Kun hexagram symbolizes pure Yin. The foundation of Golden Elixir cultivation lies in the nature of Qian (pure Yang essence), which can only be perfected through the ninefold cyclical refinement process. Here, the number "nine" represents the ultimate Yang number—when the sun reaches its zenith, it transforms into lesser Yin. The primordial Qian hexagram, through transformation, manifests in the later world as the Li hexagram (symbolizing fire). The numbers nine and one are fundamentally interconnected, cycling endlessly without termination—this illustrates how the Yang number, having reached its limit, begins anew.

Within the Kan hexagram (symbolizing water) lies the golden essence (the metal of the West), while the Li hexagram contains the wood nature (the wood of the East). Though East and West are originally separate, the rotation of the Big Dipper's handle is required to reunite the golden affection (metal of Kan) with the wood nature (wood of Li). The ancients used the celestial instrument "Xuanji Yuheng" to simulate the movement of heavenly bodies, essentially describing the interaction of these two elements: nature (wood) and affection (metal).

The movement of the sun and moon, along with the ascent and descent of Yin-Yang, forms the north-south (Zi-Wu) and east-west (Mao-You) axes. This celestial circuit, like the cyclical motion of Xuanji, is unpredictable in its beginning and end—this is the function of the Mao-You celestial cycle (a cultivation term referring to the circulation of true Qi along specific pathways in the body). From the Zhen hexagram to Qian, and from the Xun hexagram to Kun, the three Yang and three Yin lines wax and wane, seemingly leaving no place for the Kan and Li hexagrams. Yet the coming and going of the sun and moon are in fact the marvelous workings of Kan (water) and Li (fire).

The sun and moon govern the transformations of Qian and Kun, flowing ceaselessly through the six voids (the six directions of space)—this is the formless "Yi" (the Dao of change). This intangible transformation governs the celestial heart (the core of the cosmos) and serves as the root source of the sixty-four hexagrams and their 384 lines. The Qian origin (pure Yang source) governs the heavenly Dao, aligning with the ninefold refinement practice—hence "nine" is taken as the standard for Dao cultivation. The changes represented by the sun and moon inherently lack fixed positions, and the Golden Elixir path is the very foundation of this Dao of transformation.

This passage primarily explains the key to Golden Elixir cultivation: during the conjunction of the waning and new moons (when sun and moon unite at month's end), one must extract the true Yang within Kan (the metal within water) to replenish the emptiness within Li (the wood within fire). This process of returning affection (metal) to nature (wood) constitutes the essential formula of the Golden Elixir path.

This scripture explains the operational principles of "Great Celestial Cycle Fire Phases" (Dazhou Tian Huohou) in Daoist Neidan (internal alchemy) practice, using the waxing and waning of Yin-Yang throughout the twelve lunar months as a metaphor for the alchemical process.

"The birth of single Yang" refers to the initial emergence of pure Yang Qi (Zhen Yang) during early cultivation stages—the foundational energy for refining the Golden Elixir (Jindan). As practice deepens, this Yang energy ascends from the lower body (Kun position) to the upper regions (Qian position), forming a cyclical movement of rising and descending. When Yang accumulates to the "Three Yang" stage, practitioners enter the "Small Celestial Cycle" (Xiaozhou Tian) level of cultivation.

The text meticulously describes Yang Qi's transformations across twelve lunar months: beginning with its initial emergence in the eleventh month (Zi month), reaching peak intensity by the fourth month (Si month), witnessing Yin's first appearance in the fifth month (Wu month), and culminating with Yang's complete withdrawal by the tenth month (Hai month). This mirrors seasonal cycles where Yang energy germinates, flourishes, then recedes in perpetual rotation.

Practitioners must align with this natural rhythm—nurturing Yang during its ascendant phases while conserving Jing (essence) when Yin dominates. By observing these Yin-Yang fluctuations, one masters the optimal timing for cultivation. The ultimate achievement lies in balancing Yin-Yang to complete the celestial cycle—the essential method of Great Celestial Cycle Fire Phases.

Terms like "Yellow Bell establishing Zi" reference ancient musical correlations with lunar months, while natural phenomena such as "elm seeds falling" metaphorically represent Jing-Qi transformations. The entire process flows with the natural order of seasonal rotation, requiring practitioners to harmonize with this cosmic rhythm of the Dao.

This passage explains the critical moment of "the first stirring of Yang" (一阳初动) in Neidan (internal alchemy) practice. When Yang energy first begins to stir (known as the "Return Hexagram" 复卦 state), it marks the foundational stage of refining the Golden Elixir. As previously mentioned, when the Kan (Water) and Li (Fire) hexagrams intersect, they produce the "Great Medicine" (大药, a Neidan term referring to primordial Qi). This moment is called "Living Zi Hour" (活子时), a cultivation opportunity that can occur at any time of day.

After the Great Medicine emerges, practitioners use the Prenatal Celestial Stems method (先天纳甲法) to guide Yang Qi upward and Yin Qi downward—this process of fire regulation is termed the "Small Heavenly Cycle" (小周天). Only after completing the Small Heavenly Cycle and reaching "True Zi Hour" (正子时, the fixed midnight period) can one proceed to the "Grand Heavenly Cycle" (大周天) practice. What exactly is True Zi Hour? From the Zhen (Thunder) hexagram to the Qian (Heaven) hexagram represents movement reaching its peak and transitioning to stillness; from the Xun (Wind) hexagram to the Kun (Earth) hexagram signifies stillness culminating in renewed movement. When practitioners achieve a state of profound emptiness and stillness, that pure Yang Qi becomes deeply concealed within the body's innermost depths (the "ninth earth"), marking the transitional moment between Hai Hour (9-11 PM) and Zi Hour (11 PM-1 AM).

When the time ripens, being arises from non-being—like thunder suddenly sounding at midnight, creating the Heart of Heaven and Earth from primordial chaos. This corresponds to the celestial phenomena of the winter solstice and new moon. Hence the saying "the new moon dawns as Return," when Yang energy begins its stirring. This state of "first Yang stirring" represents the practitioner's internal True Zi Hour.

The newly restored Yang energy remains extremely subtle at this stage. Like a hidden dragon, it should be gently nurtured without hastily applying "martial fire" (intense heat regulation). Ancient sage-kings would enter seclusion during the winter solstice, cutting off all external contact precisely to protect this fragile Yang spark. Though minute, its vital force cannot be restrained—just as the Huangzhong pitch (the foundational musical tone among the twelve pitches) or the Big Dipper pointing due north at Zi Hour symbolize all things growing from insignificance to greatness.

At this phase, the Yang fire resides in the lower Dantian (丹田), where the "lead cauldron" (referring to the elixir field) maintains gentle warmth, naturally producing a soft, warm sensation. Amidst abundant Yin energies, everything depends on this single Yang essence as the sovereign. Like the hexagram showing five Yin lines surrounding one Yang line, within the human body it manifests as all vital essences being governed by this singular Yang essence. This constitutes the process of "Yang's return" establishing the foundation of the Great Elixir.

As Yang energy grows further into the "Approach Hexagram" (临卦, with two Yang lines), the furnace's fiery energy gradually circulates freely—like opening a path that emits light, with radiance steadily intensifying as daylight slowly lengthens. The Chou Hour (1-3 AM) corresponds to the Dalü musical pitch, when Yin and Yang energies achieve harmonious balance. This describes the scenery of Yang energy progressing to its second stage.

This passage describes the correspondence between the "advancing the fire" (Jinhuo) method in Daoist Neidan (internal alchemy) practice and seasonal celestial changes. Following the twelve lunar months and twenty-four solar terms, the process divides into six stages:

The first stage corresponds to the twelfth lunar month (Chou month), when the Big Dipper's handle points to the Chou position during the "Great Pitch" solar term. Practitioners should first lower then raise their focus, mirroring the initial interaction of Yin and Yang energies as Yang gradually strengthens. By the first lunar month (Yin month), when Yin and Yang achieve balance, it becomes an optimal time for cultivation.

The second stage occurs in the second lunar month (Mao month) during the Spring Equinox. Here Yang energy grows more vigorous, yet contains hidden dangers—like elm seeds maturing and falling back to their roots. Practitioners must maintain equilibrium, just as day and night reach perfect balance during the equinox.

The third stage in the third lunar month (Chen month) sees Yang energy dominating as Yin approaches exhaustion. Like the roc bird washing its feathers before soaring, practitioners must purify distracting thoughts as their internal Qi begins ascending.

The fourth stage arrives in the fourth lunar month (Si month) at Yang's zenith. Internal energy now shines like sunlight with the Golden Elixir (Jinye, the refined essence produced through alchemical practice) flowing freely. Yet within this peak, Yin energy begins emerging to disrupt Yang—marking both an endpoint and midpoint in the cultivation cycle.

The referenced hexagrams—Tai (Peace), Dazhuang (Great Strength), Guai (Resolution), and Qian (Heaven)—from the Yijing (Classic of Changes) represent these progressive Yin-Yang transformations. Practitioners must adapt their methods according to these natural cosmological patterns.

This passage describes the six stages of waxing and waning between Yin and Yang, corresponding to the Gou, Dun, Pi, Guan, and Bo hexagrams from the Zhouyi (Book of Changes). It uses natural phenomena and cultivation terminology to illustrate the transformation process of Yin and Yang energies.

The first stage (Gou hexagram) depicts the initial emergence of Yin energy when Yang reaches its peak. Like the height of summer (the fifth lunar month), while the earth's surface is scorching, well water turns cool. In cultivation, this is when one begins "retreating fire and entering water" (tuihuo jinshui), allowing Yin energy to gradually take the lead while Yang energy shifts to a supporting role. This resembles the musical note "Ruibin" (one of the ancient twelve pitch standards), where host and guest positions start reversing.

The second stage (Dun hexagram) describes Yin energy growing as Yang withdraws. Like the sixth lunar month (Wei month), Yang energy gradually hides itself, akin to sages retreating to mountain forests to accumulate strength while awaiting opportunities. Here, one should emulate trees during the "Linzhong" pitch (corresponding to the sixth month), gathering essence and concealing brilliance.

The third stage (Pi hexagram) represents the state of Yin and Yang separation. In the seventh month (Shen month), autumn's harsh energy withers all things, much like the damaging effect of the "Yize" pitch (seventh month's note). Yin energy expands while Yang contracts, suppressing vitality.

The fourth stage (Guan hexagram) discusses the equilibrium of the autumn equinox. Though the eighth month (You month) appears severe on the surface, it secretly harbors new life. Like the "Nanlü" pitch (eighth month's note), withered plants sprout fresh buds while shepherd's purse and wheat shoots begin growing. Here Yin and Yang are balanced equally, resembling the last quarter moon (visible on the 22nd-23rd of the lunar month), requiring careful maintenance of harmony.

The fifth stage (Bo hexagram) shows Yin energy at its zenith. During the ninth month (Xu month) under the "Wushe" pitch (ninth month's note), Yang energy is completely eroded by Yin—like trees shedding leaves and physical forms dissipating, until even the subtlest Shen (vital spirit) nears disappearance. This marks the period when Yin energy wholly dominates.

This passage elucidates the profound state of "Six Yins Returning to Kun" (liuyin fankun) in cultivation practice. When practice reaches its ultimate stage, the primordial Qi within the body gradually dissipates like withering vegetation, yet its most refined essence remains steadfast like fruit atop a tree. This is not true dissolution, but rather the pinnacle state of "returning to storage" (guicang), akin to winter's hibernation where all things secretly nurture new vitality.

The text employs celestial movements as metaphors for cultivation: human nature (xing) and life essence (ming) originate respectively from Qian (Heaven's origin) and Kun (Earth's origin). Initial practice establishes foundations through Kun-oriented life cultivation (minggong). As Yang Qi gradually strengthens to manifest the six Yang lines (Qian hexagram), life cultivation transforms into nature cultivation (xinggong). Subsequently, when Yin Qi develops to complete the six Yin lines (Kun hexagram), nature cultivation returns to life cultivation. This cyclical process mirrors cosmic operation: Heaven's Yang Qi descends while Earth's Yin Qi ascends. Though sky and abyss stand eighty-four thousand li apart, their essences interact like lodestone attracting iron.

Upon attaining "Six Yins Returning to Kun," the primordial spirit (Shen) becomes concealed within primordial Qi. Though appearing quiescent, it secretly gestates the "Great Medicine" (Golden Elixir). This Yin-dominated state actually heralds new Yang's birth, much like the winter solstice's hidden Yang impulse containing nature's endless generative mysteries. The text emphasizes this Yin-Yang transformation represents not annihilation, but rather shedding superficial layers to return to authenticity—ultimately achieving the dual cultivation of nature and life (xingming shuangxiu).

This scripture elucidates the profound state of "Great Celestial Cycle Fire Regulation" in Daoist cultivation. It begins by describing the primordial state of the universe—the Primal Ancestral Qi (the most original energy) gestating Yin-Yang, akin to the critical moment when a mother's womb is about to give birth. This transitional instant between the Hai hour (9-11 PM) and Zi hour (11 PM-1 AM) represents the most subtle operational pivot of the Three Powers (Heaven, Earth, and Humanity). Even sages find it difficult to fully comprehend this mysterious state of primal chaos and Yin-Yang interaction, which transcends accurate verbal description.

Using the Kun (Earth) and Fu (Return) hexagrams from the Yijing (Book of Changes) as metaphors, the text illustrates that the initial state resembles the chaos and obscurity of Kun, followed by the activation of the "Heavenly Root" (cosmic origin), much like the rebirth of the first Yang line in the Fu hexagram, where all things naturally return. This transformation between Yin and Yang operates in cycles like the alternation of day and night or the waxing and waning of the moon—without perpetual flatness (Yang), there would be no slopes (Yin), a fundamental law of nature. As Yin wanes, Yang waxes; when Kun (pure Yin) concludes, Fu (the return of Yang) begins, forming an endless, interconnected cycle.

Practitioners who master this rhythm of Fire Regulation (energy modulation during cultivation) can align themselves with cosmic movements above and harmonize body and mind below. Emperors who apply this principle in governance ensure enduring stability, while alchemists (cultivators) harness it to achieve an eternal Dharma body. The text concludes by connecting this to the preceding chapter on "Illuminated Hall Governance" (statecraft), completing the sequence of Great Celestial Cycle Fire Regulation cultivation: first, the fusion of Kan (Water) and Li (Fire) produces the "Great Medicine" (raw material for the Golden Elixir), followed by steps of gathering, refining in the furnace, and tempering—seamlessly linking to the "gathering" techniques discussed in the previous chapter.

This passage explains two crucial stages in Daoist Neidan (internal alchemy) practice—the cultivation methods for "Living Zi Hour" (huo zishi) and "True Zi Hour" (zheng zishi).

First, regarding the timing for "Living Zi Hour" practice: When gathering the medicinal essence (collecting vital Jing-Qi within the body), one must seize the "Living Zi Hour"—those spontaneous moments when the body naturally enters an optimal state for cultivation. Wait until the lunar month's end and beginning when Yin and Yang alternate, with the moon positioned in the Geng direction (west). Like metal forming within water, seek the "Primordial Pearl" (primordial Qi) in the twilight state between waking and sleeping (huanghu yaoming). At this time, employ Wuwei (non-action) consciousness to activate the True Fire (internal heat), continuing until the full moon when the Golden Elixir (jindan) crystallizes.

Next comes "True Zi Hour" practice: During the transition between Hai and Zi hours when Yang energy first stirs, apply the "fire emerging from water" method (generating Yang energy from kidney water). The specific technique involves: closing the Ren Channel and opening the Du Channel (regulating the meridians), using "Xun Wind" (gentle breathing) to stir the Qi like bellows stoking a flame. When the fire grows strong, propel the "River Cart" (Qi circulation) to make the Golden Fluid (refined essence) flow backward from the Taiyuan Pass (lower Dantian) up to the Tiangu point (crown of the head). This process manifests miraculous phenomena—all meridians returning to their source and golden essence penetrating the crown.

When Yin-Yang interaction completes and Yang energy peaks, immediately withdraw the fire (cease heating), allowing the Qi to descend gradually through the "Heavy Tower" (throat) before finally settling in the "Earthen Cauldron" (middle Dantian). This is called "Qian-Kun Copulation" (Yin-Yang union), where the Golden Elixir descends into the Yellow Court (middle Dantian). Subsequently, practice the Mao-You Heavenly Cycle (specific timed circulation) to consolidate the Sacred Embryo (primordial spirit embryo).

After the Sacred Embryo forms, it requires gentle nurturing until the "infant" (primordial spirit) matures and relocates to the Upper Field (upper Dantian). At this stage, the innate primordial spirit gains transformative freedom, achieving the sublime state where form and spirit become wondrously unified with the Dao—the highest accomplishment of "Nine-Cycle Golden Fluid Returned Elixir."

The author Wei Boyang specially notes these two methods differ fundamentally as internal and external practices, traditionally transmitted orally from master to disciple rather than fully recorded. Using moon phases to symbolize elixir refinement and annual Yin-Yang cycles to represent the nine transformations, his text conceals true fire regulation secrets. Those fortunate to encounter enlightened masters will naturally comprehend its profound meaning.

This passage elucidates the fundamental principles of subtle energy circulation within the human body and the essence of cultivation. Original Jing (primordial life essence) disperses throughout the body like clouds, carried by Qi (primordial vital energy). The interaction of Yin and Yang energies constitutes the law of life, with Hun (Yang spirit) and Po (Yin corporeal soul) each occupying their respective positions. The solar Hun represents the Yang spirit, while the lunar Po embodies the Yin spirit.

Hun and Po are interdependent like a house and its owner. Xing (innate nature) governs the interior as the structural framework, while Qing (acquired emotions) regulate the exterior like protective walls. Only when both aspects are complete can human life achieve stability. At this stage, emotions harmonize with Heaven and Earth—Qian (Heaven) governs movement and direct circulation, dispersing Qi's subtle essence; Kun (Earth) governs stillness and containment, becoming the dwelling place of the Dao. Strong energies dissipate after expression, while gentle energies nourish all things, forming the cultivation cycle described as "nine returns and seven reversions, eight homecomings and six dwellings."

Male energy corresponds to white (Metal phase), female to red (Fire phase), with Metal and Fire mutually restraining each other. Water stabilizes Fire's nature, and the Five Phases (Metal, Wood, Water, Fire, Earth) in their primordial state resemble perfectly clear water—flawless and pure. The true state of the Dao defies description; after transformation and distribution, each element exists independently, like the clear and turbid separation within an egg. Initially forming just one inch in size, it gradually develops limbs, five organs, bones and tendons over ten months of gestation before leaving the mother's body—at which stage bones remain soft enough to curl and muscles smooth as syrup.

This section primarily demonstrates that Xing (nature) and Ming (life) share the same origin, and only by establishing a stable life foundation can one nurture innate nature. To cultivate consciousness and prolong life, one must contemplate life's origins and transformations. The body humans initially receive is inherently complete and unified.

The subsequent explanation delves deeper into the cultivation work required to thoroughly investigate the roots of Xing and Ming. Xing refers to the lucid primordial awareness, akin to the Qian (Heaven) energy at cosmic inception; Ming denotes the vital primordial Qi that sustains life, resembling the Kun (Earth) energy that nurtures all things. Before parental conception, Xing and Ming existed as an undifferentiated whole—untainted and requiring no cultivation. After birth, the Taiji polarity divides, establishing distinct Xing and Ming that both require refinement. Innate nature has neither coming nor going, yet life has its limits—if Ming cannot be preserved, the luminous spirit suddenly disperses. Therefore, Daoist practitioners begin cultivation by strengthening Ming to nurture Xing. Ordinary people's lifespans follow predetermined measures, but adepts can attain self-mastery. When a truly stable life foundation is established, true nature spontaneously manifests. Regrettably, most people fail to recognize their original true nature.

This scripture explores the fundamental principles of dual cultivation of nature and life (xingming shuangxiu). At the inception of human life, the physical form emerges from the union of parental essence and blood, yet this constitutes merely the tangible flesh, not the true original substance. Our innate true nature is pristine and empty as the void. When the fetus completes its ten-month formation, a spark of primordial essence (innate Jing-Qi) from the great void enters the body, becoming the sovereign of life. At this moment, the celestial-mandated nature divides into the two energies of Yin and Yang.

Postnatal life activities require the governance of innate primordial essence to attain vitality, while the innate primordial essence also depends on postnatal Qi for its existence—demonstrating the inseparable unity of nature (xing) and life (ming). Within the dual energies of Yin and Yang, the Yang spirit is called hun (associated with Wood, governing clarity and lightness), while the Yin spirit is called po (associated with Metal, governing heaviness and turbidity). These two spirits respectively reside in the positions of Kan (Water) and Li (Fire) within the Eight Trigrams (Bagua).

Since human life belongs to the realm of postnatal creation, it inevitably carries emotional desires and consciousness. The originally pure true nature becomes mixed with karmic habits accumulated since time immemorial, forming the eight consciousnesses (a Buddhist term referring to the eight functions of mind), which in turn give rise to various delusions and attachments. These obscure the true nature, trapping beings in the cycle of rebirth. Thus, practitioners seeking to illuminate the mind and realize their true nature must first cultivate the work of life (minggong).

The Yang spirit resembles the soul of the sun, while the Yin spirit resembles the soul of the moon—the hun and po depend on each other. The true nature resides within like the core of a fortress, while emotional consciousness surrounds it like the outer walls. Only when inner and outer are harmonized can life attain stability. This passage primarily discusses how, in the postnatal cultivation of life, one must properly balance the relationship between hun and po, Yin and Yang.

This passage explains the principles of mutual transformation between Yin-Yang, the ethereal Hun and corporeal Po souls, and inner nature (xing) with life force (ming) in Daoist Neidan (internal alchemy) practice. At mao hour (5-7 AM) when the sun rises, the solar Hun within the Li trigram (symbolizing fire) represents the Yang spiritual force; at you hour (5-7 PM) when the moon appears, the lunar Po within the Kan trigram (symbolizing water) embodies the Yin spiritual force. Though sun and moon appear separate, sunlight actually contains lunar essence (Jade Rabbit), causing the solar Hun to transform into Yin spirit; moonlight inherently carries solar quintessence (Golden Crow), making the lunar Po transform into Yang spirit. Thus the souls mutually inhabit each other like dwelling in the other's residence.

Though the postnatally formed Hun and Po appear divided, the prenatal nature (xing) actually resides within postnatal destiny (ming). Once entering the fluctuations of Yin-Yang, both belong to the realm of ming. This destiny further transforms into emotional desires, because the interactions of Yin-Yang fundamentally operate through emotional forces. Precisely because xing resides within ming, the original essence (yuanjing) in the Li trigram and the primordial qi (yuanqi) in the Kan trigram are both called ming. And because ming transforms into emotions, the Wood soul in the sun and Metal Po in the moon are both termed emotions.

Only the drop of original spirit (yuanshen) in the ancestral cavity (upper Dantian between the eyebrows) constitutes true innate nature. The shen acts as sovereign, peacefully abiding within this cavity without venturing outward—this illustrates how nature governs internal preservation. The vital essences (jing and qi) serve as ministers, constructing external defenses against pathogenic influences—demonstrating how emotions manage external protection. When these defenses stabilize, the spirit can dwell undisturbed in its inner chamber. Thus just as intact city walls enable citizens' security, the inner nature sufficiently regulates emotions while external desires naturally return to their origin.

Through this mutual cooperation between host and guest, sovereign and minister unite—this constitutes the Kan-Li intersection (water-fire balance), the foundational stage of Golden Elixir cultivation. Establishing life cultivation practices serves precisely to nurture innate nature. When emotions harmonize with Qian-Kun (heaven-earth), Qian (heaven) governs dynamic expansion through unimpeded qi circulation, while Kun (earth) maintains quiescent receptivity as Dao's dwelling. The firm withdraws after giving, the yielding nurtures growth.

This describes the process of returning postnatal conditions to prenatal origins. The postnatal Kan-Li are essentially the prenatal Qian-Kun—only after heaven-earth's rupture did original nature transform into emotional desires, becoming driven by sensory pursuits that prevent return to the source. When reunited with complete defenses and stable abode, emotions revert to nature: the Yin essence in Li returns to Kun-earth, the Yang qi in Kan returns to Qian-heaven. Qian's nature is supremely dynamic—quiescent in concentration, active in unwavering integrity—where the single spark of spirit sovereignly commands the vital forces with ultimate strength and rectitude.

This scripture elucidates the principles of primordial spirit (Shen, the innate consciousness) formation and the cyclical movement of the Five Phases (Wuxing) in Daoist Neidan (internal alchemy) practice.

The primordial spirit is as vigorous and dynamic as Heaven (Qian), its energy flowing ceaselessly—this is the origin of all creation. At the same time, it is as gentle and receptive as Earth (Kun), capable of nurturing and containment—this is the foundation of life. When Qian (Yang) releases a spark of innate true Qi, Kun (Yin) receives and gestates it. This gathered Qi is gradually cultivated in the middle Dantian (the central earthen crucible), much like a mother carrying a child in her womb.

The numerical references such as "nine returns, seven reversions, eight homecomings, and six dwellings" describe the cyclical process of Five Phases energy transformation: Water (Kan trigram), belonging to Yin, has an intrinsic number of six, which transforms to seven with the addition of Yang Qi; Fire (Li trigram), belonging to Yang, has an intrinsic number of seven, which transforms to nine with the addition of Yin Qi. During cultivation, the Water energy of the North returns to Qian-Yang (seven reversions), while the Fire energy of the South returns to Kun-Yin (nine returns), thereby restoring the balance of Yin and Yang. The number eight represents the harmonization of Wood and Metal energies, while six signifies the stable state of Water.

In essence, the four symbols—Metal, Wood, Water, and Fire—along with the central Earth constitute the Five Phases, all of which are transformations of the fundamental Kan (Water) and Li (Fire) energies. Through this interplay of Yin-Yang and the Five Phases, the practitioner returns to the innate primordial state, ultimately forming the Golden Elixir (Jindan).

This passage explains the concept of "Nine Returns and Seven Reversions" (九还七返) in Daoist Neidan (internal alchemy) practice. When the two fundamental energies (referring to Yin and Yang Qi) undergo nine cycles of return and seven transformations, they naturally restore to their proper positions—the eight trigrams returning to their places and the six directions settling in their domains. The Wuzhen Pian (Awakening to Reality) particularly elucidates this principle of reversion, revealing the profound mystery of cosmic creation.

The pairing of two with seven represents the western metallic phase transforming to white, while one with six represents the southern fiery phase transforming to red. White corresponds to metal (金), red to fire (火). By combining western metal with southern fire in cultivation, we arrive at the saying: "The male is white, the female red—metal and fire mutually constrain each other."

The pre-celestial water (Heaven's primal water) emerges from the Qian palace (head region), embodying the true fire of the sun; the earthly fire arises from the Kun palace (abdominal region), embodying the true water of the moon. Only through repeated cycles of return can water revert to its watery nature and fire to its fiery essence, restoring their original states. The mystery of post-celestial creation lies precisely in the interaction of the Kan (water) and Li (fire) trigrams. Though manifested through various names—as water and fire in their fundamental positions, as metal and water in terms of Yin-Yang Qi, as metal and wood in practical cultivation, or as metal and fire in alchemical work—they ultimately represent transformations of water and fire.

The pre-celestial Qi (primordial cosmic energy) forms the foundation for refining the Golden Elixir (金丹). The Dao is fundamentally formless emptiness, giving birth to pre-celestial Qi—this undifferentiated chaotic state is the true primal water (not ordinary water). If practitioners can withdraw scattered thoughts to return to their original nature, uniting Yin and Yang Qi into oneness, they can restore this pre-celestial true water. At this stage, the water becomes supremely pure, with body and mind fused without impurity, internally and externally transparent like a vast crystalline lake. Hence the saying: "The highest virtue is like water—clear and flawless."

The Great Dao is inherently formless and imageless, yet when manifesting as Qi, it becomes provisionally describable. However, this pre-celestial true Qi remains profoundly subtle and elusive.

This scripture describes the process of forming the "Water of True Unity" (zhenyi zhi shui) and the "Sacred Embryo" (shengtai) in Daoist Neidan (internal alchemy) practice.

The "Water of True Unity" represents the fundamental basis of cultivation—formless and imageless, transcending conceptual understanding. This "True Unity" refers to the foundational point in the Central Palace (Dantian), known as the "Supreme Unity Embracing Genuine Qi" (Taiyi han zhenqi). When unified, it appears as a single mass of Qi; when divided, it separates into the two aspects of Yin and Yang, which further differentiate into the Four Symbols and Five Phases (Wood, Fire, Earth, Metal, Water). As the Five Phases interact, all transformations occur at the central position, yet ultimately each phase returns to its proper place—Wood, Fire, Metal, and Water each settling into their distinct positions. This is what the text means by "transforming and distributing, each dwelling independently."

If practitioners comprehend the essential principle of "gathering the Five and uniting the Four, converging the Two to return to One," they can establish their foundation and crystallize the Sacred Embryo. In its initial stage, the Sacred Embryo resembles an egg—black and white intermingled, about an inch in diameter. At this point, the Dharma Body (the realized spirit, or Shen) resides hidden within this "Divine Chamber," much like an infant growing in the womb. Through gradual nurturing, the Sacred Embryo takes form, with limbs, organs, and bones all developing—though these are metaphorical descriptions, not literal physical forms.

After ten months of cultivation (a symbolic gestation period), the Sacred Embryo matures, akin to an infant leaving its mother's body. The Dharma Body then ascends from the Kun Furnace (lower Dantian) to the Qian Cauldron (upper Dantian), ready to begin higher stages of practice. At this stage, the Dharma Body can commune with heaven and earth, merging with the Great Void (Taixu), and attains qualities described as "bones pliant enough to roll up, flesh smooth as maltose." This entire process illustrates the progressive stages of spiritual realization in Neidan practice.

The human physical form follows the same natural creative principles as when it was first conceived in the womb and received the primordial Qi (vital energy). However, following this natural course produces ordinary mortals, while cultivating in reverse can refine the Golden Elixir (the highest achievement of Neidan practice) — this marks the fundamental distinction between sages and common people. This chapter contains the essential formula for cultivating one's nature, resonating with the earlier discussion of "mutual interaction between the two apertures."

Chapter 21 explains the mutual resonance between Yin and Yang energies: The yangsui (ancient bronze mirror for fire-making) can produce fire, yet without sunlight no flame will emerge; the fangzhu (ancient shell vessel for water-gathering) can collect water, yet without moonlight no dew will form. Though these objects are distant from the sun and moon, they still interact through resonance — how much more should this apply to the intrinsic Yin-Yang energies within our bodies, existing right between our heart (fire) and kidneys (water)? The correspondence between Yin-Yang and sun-moon finds its clearest demonstration in the interplay of water and fire.

This passage describes how water and fire energies resonate during the moon's quarter phases (around the 7th and 23rd lunar days) through shared attributes. The previous chapter's discussion of the interdependent hun (Yang spirit) and po (Yin spirit) essentially describes this water-fire dynamic. The cultivation of the Golden Elixir takes the sun-moon cycles as its fundamental principle and water-fire interaction as its practical method — the principle requires concrete methods for realization, while methods depend on the principle for guidance. This truth remains consistent whether observing internal cultivation or external phenomena.

The yangsui fire-bead resembles a bronze mirror with a thick center, symbolizing the Yang line within the Kan trigram (water trigram of the Bagua). It contains the solar essence of fire, hence its ancient use for fire-making. Yet it must face the sun directly to obtain true fire, because the authentic Yang within the device is fundamentally condensed solar essence. The sun serves as the source of light, while the yangsui acts as its attracting medium — naturally effective when using fiery objects to gather fire. Similarly, the fangzhu water-gatherer, made from clam shell with a hollow center, symbolizes the Yin line within the Li trigram (fire trigram). It contains the lunar essence of water and must face moonlight to obtain true water, because the authentic Yin within the vessel is essentially condensed lunar essence. The moon serves as the reservoir of water essence, while the fangzhu acts as its collecting tool — naturally responsive when using watery objects to gather water. This reveals the profound mystery of mutual utilization between Kan (water) and Li (fire).

Though separated by tens of thousands of miles, the celestial sun-moon and earthly water-fire overcome spatial barriers to interact — much like a magnet attracting iron — precisely because shared attributes facilitate mutual attraction. If even lifeless objects can resonate across great distances, how much more should this apply to the authentic water and fire (kidney-water and heart-fire) truly existing within the human body, residing right in the square-inch heart (Dantian)?

This scripture elucidates the interaction of Yin and Yang energies within the human body and the principles of cultivation. It describes how the most subtle and numinous primordial Qi (至虚至灵) resonates within us, just as the lunar Yin and Yang energies (两弦真气) during the moon's waxing and waning phases naturally harmonize. The true Water within the Li trigram (symbolizing Fire) flows downward, while the true Fire within the Kan trigram (symbolizing Water) ascends and gathers. Through specific cultivation methods (假法象), one can collect the essence of the Great Yin (太阴) and establish the "cauldron vessel" (a metaphor for the Dantian) to condense the solar Yang energy.

Authentic Yin-Yang energies mutually contain each other (互藏其宅), mirroring the celestial movements of sun and moon within our bodies. The solar essence and lunar radiance coordinate like the interplay of Water and Fire within us. The crucial factor in this process of collection and resonance lies in the "Central Yellow True Intention" (中黄真意), referring to the regulatory function of conscious awareness. This operates with the same precision as ancient methods of using a yang-sui mirror to gather fire or a fangzhu vessel to collect dew. Thus, the coordination of Yin and Yang resembles the celestial dance of sun and moon, while the harmonious interaction of Water and Fire manifests as tangible efficacy.

The text later references principles from the Zhouyi (周易): the Upper Canon begins with Qian (Heaven) and Kun (Earth) to establish cosmic orientation, while the Lower Canon commences with Xian (Influence) and Heng (Constancy) to illustrate resonant interaction. The Xian hexagram (泽山咸), symbolizing the mutual influence of two energies, reflects how Heaven and Earth interact to generate all things. Practitioners reversely apply this principle through the Yin-Yang resonance of lunar phases (represented by the Dui and Gen trigrams), enabling return to the primordial Qian-Kun state. Like using yang-sui to gather fire or fangzhu to collect water, these methods represent innate cultivation techniques accessible to all.

Chapter 22 explains essential cultivation techniques: closing the "three treasures" of eyes, ears and mouth to allow deep submersion of true Qi. The practitioner (真人) must focus with the intensity of diving into deep abyss, while the spirit guards the Central Palace (中宫). Harmoniously regulating the opening and closing of sensory perception forms the pivotal mechanism of practice. The Li (Fire) energy should be channeled into the blood vessels (荣卫), while Kan (Water) energy requires no auditory attention. The Dui trigram (representing the mouth) must abstain from idle speech, aligning with primordial Qi (鸿蒙). When these three are properly restrained, body and mind relax into emptiness and stillness, allowing natural stabilization of willpower.

The essence of cultivation lies in returning to the state of emptiness and thoughtlessness, which represents the normal condition of practice. Attaining this state is profoundly difficult, requiring single-minded focus without distraction—maintaining the unity of spirit and mind whether asleep or awake. When one achieves this, the complexion gradually becomes radiant, and bones and joints grow increasingly robust. Only by first expelling the yin pathogenic Qi within can one establish pure yang's upright energy.

Through continuous practice, the body's true Qi will circulate naturally like clouds and rain—moistening the earth like spring showers, or melting ice and snow into flowing water. This Qi descends from the crown to the soles, then cycles upward again, flowing endlessly within. Such cyclical movement verifies the Great Dao (the Way), while yielding softness manifests De (Virtue/Power). Like hoeing weeds from a field, one must cleanse accumulated impurities within, harmonizing even the subtlest breath. Turbidity ultimately returns to clarity, just as prolonged darkness inevitably yields to light.

This passage reveals the key to the "Three Treasures" (Jing/essence, Qi/vital energy, Shen/spirit): the correspondence between inner truth and outer manifestation forms the foundational practice of nurturing one's nature.

The three external treasures—ears, eyes, and mouth—must be closed, preventing their indiscriminate dissipation. True practitioners should dwell like hidden dragons in deep abysses, allowing the spirit to move within the "Guizhong" (the Dantian/energy center or the source of one's nature). This constitutes the guiding principle for mastering the Three Treasures. Practitioners possess both internal Three Treasures (primordial Jing, Qi, and Shen) and external Three Treasures (ears, eyes, mouth). To preserve the internal treasures, one must prevent leakage through the external ones—as stated in the Yinfu Jing: "The evils of the nine orifices reside in these three essentials."

At cultivation's initial stage, one must shut down sensory perception and guard speech vigilantly to prevent true essence from dissipating. When external orifices cease leaking, internal spirit can be preserved. At the convergence point between front and back dwells a "true person" (zhenren) without fixed location, concealed in profound depths. This abyss refers to the Great Northern Polar Abyss (Beiji Taiyuan), the celestial heart's dwelling—also called the "Primordial Pass Single Cavity" (Yuanguan Yi Qiao). Situated between heaven and earth at the cosmic center, this suspended cavity can expand infinitely or contract to minuteness, known as "Guizhong." Its sovereign is called the "true person." Maintaining unbroken connection with it constitutes "embracing the One" (Baoyi).

The secret lies in neither excessive exertion nor laxity—neither forcing growth nor forgetting—maintaining a state of natural buoyancy. Hence the saying: "The true person lurks in deep abyss, floating freely while guarding Guizhong." These four lines encapsulate the essence of nature-nurturing practice and form this chapter's core.

During cultivation, sensory withdrawal must coordinate with unified opening and closing. Movement and stillness require balanced moderation, like an unceasingly rotating axle. Withdraw from worldly splendor (Li Qi absorbs nourishment), let ears hear less (Kan need not employ hearing), let mouth speak sparingly (Dui combines without chatter), and follow the Dao's natural flow through few words (Xi Yan follows cosmic chaos).

This section details concrete methods for Three Treasures cultivation: The Kan trigram (water) represents the gate of primordial Qi; the Li trigram (fire) symbolizes the gate of life.

This passage explains the Daoist practice of conserving vital energy (Qi) and focusing the spirit (Shen) by regulating three key bodily gateways: the mouth, ears, and eyes.

The text begins by associating the mouth with the Dui trigram (one of the Eight Trigrams/Bagua). When practitioners enter meditation, they should withdraw their outward gaze, reverse their auditory focus, and turn external awareness inward. This opening-and-closing movement resonates with the body’s internal pivotal cavity—the Mysterious Feminine Inner Gate (Yuanpin Neiqiao).

The Yin-Yang theory is then applied: within the Kan trigram (associated with Water), the Yang aspect of Earth (Wu Tu) governs movement, while in the Li trigram (associated with Fire), the Yin aspect of Earth (Ji Tu) governs stillness. However, though the Yin within Li is fundamentally tranquil, it tends toward agitation in practice and must be regulated by the true Yang within Kan. This dynamic is likened to a door hinge controlling the door’s swing or an axle governing a wheel’s rotation—ensuring balanced movement and stillness so that primordial Qi is not dissipated.

Originally, one’s innate Qi exists in an undifferentiated, chaotic state. But when the eyes (Li trigram) engage with visual stimuli, they deplete "clarity" (Ming); when the ears (Kan trigram) fixate on sounds, they exhaust "acuity" (Cong); and when the mouth (Dui trigram) speaks, it opens a gateway of expenditure. If these three are left unchecked, innate Qi scatters rapidly.

The crux of practice lies in:

• Lowering the eyelids to maintain silence and reversing auditory focus, preventing the outward leakage of Li’s Fire-Qi and Kan’s Water-Qi.
• Sealing the lips in wordless stillness and guarding internal chaos, ensuring the mouth’s Qi does not dissipate.

This is what Daoists call "closing the Three Treasures"—shutting the three portals (ears, eyes, mouth) that drain Qi.

A deeper insight is revealed about the character for "mouth" (口): it symbolizes the body’s pivotal Mysterious Pass (Yuanguan Yiqiao), capable of drawing in and releasing the energies of Heaven and Earth—not merely the physical mouth used for eating and speech. This esoteric principle requires a true master’s guidance to fully grasp.

Finally, the passage describes the meditative state: when the ears, eyes, and mouth are securely closed, the practitioner’s body relaxes as if in an empty chamber, the mind returns to emptiness, and thoughtless awareness is maintained. Whether asleep or awake, the spirit remains inwardly vigilant, attuned to the subtle shifts of Qi within. This "hidden abyss, guarding the center" practice allows the primordial Qi to arise spontaneously from the void.

The foundation of cultivation lies in maintaining inner tranquility, reaching a state of thoughtless awareness to resonate with the Dao. This "no-thought" state doesn't imply the dullness of wood or stone, but rather a mind naturally clear and pure - this luminous awareness constitutes true right mindfulness. Only when right mindfulness manifests continuously can one perceive the Primordial Qi (the cosmic source energy) and thereby obtain the "medicinal ingredients" (the foundational substances for transforming Jing, Qi and Shen).

Every person inherently possesses this potential, as straightforward as a shadow appearing when a pole is erected. What makes it seem difficult is our scattered minds entangled with distracting thoughts. If one can maintain unwavering focus during practice, severing all mental disturbances, enlightenment of the Great Dao can occur in an instant. The key lies in sustaining awareness throughout all twelve two-hour periods of the day - whether walking, standing, sitting or lying down - even maintaining a spark of the Original Shen (primordial consciousness) embracing the Original Qi during sleep, like keeping the furnace fire alive.

Particular vigilance is needed against drowsy states; one must maintain illuminating awareness, observing internal transformations and discerning the survival of the "true seed" (primordial energy). Through such practice, the Golden Elixir (symbol of cultivation achievement) will form naturally, and the state of a Zhenren (perfected being) will manifest spontaneously. This embodies the cultivation secret described in the Daode Jing: "The true person dives deep into the abyss, floating and wandering while guarding the center."

Successful cultivation yields tangible verification: complexion gradually glowing, bones growing stronger, yin-pathogenic energies dissipating while pure yang energy establishes itself. With continuous practice, the energy channels throughout the body will flow freely like spring rain nourishing the earth or snow melting away, with energy circulating from the crown to the soles and back again, filling every corner of the being. This manifests the movement of Primordial Qi within - all 360 joints and 84,000 pores become suffused with harmonious life energy.

The cultivation of true Qi (vital energy) flows within the body as naturally as rain nourishing the earth or ice melting effortlessly. Qi descends from the Kunlun (a Daoist term referring to the Baihui point at the crown of the head) down to the soles of the feet, then rises again from the Yongquan point at the feet to return to the crown, circulating endlessly through the body's vast and ethereal channels without obstruction.

Just as mountains, rivers, and rocks in nature may seem obstructive, the hollow valleys of the Grotto-Heavens and Blissful Realms (sacred abodes of immortals in Daoism) remain interconnected. Similarly, while muscles and bones appear to block the body, the innate energy passages (Yuanqiao) form a network of empty pathways that link together like the Grotto-Heavens in nature. Primordial Qi (Yuanqi) moves freely through these hollow channels, embodying the scripture's teaching: "Flowing through the boundless caverns, swirling gently within the valleys." This aligns with the earlier passage's description: "The Yellow Center gradually opens to principle, its moisture reaching skin and flesh"—both natural manifestations of Golden Elixir (Jindan) cultivation.

The paradoxical is proof of the Dao (the Way), and softness is the handle of De (Virtue). Just as weeding a field clears obstructions, removing accumulated impurities from the body allows subtle pathways to open naturally. Turbidity eventually clarifies; prolonged darkness gives way to light. Here, the extraordinary nature of the Golden Elixir path is summarized: cultivation proceeds counterintuitively, inverting the Yuanpin (Yin-Yang energies), holding fast to undivided purity to return to the root and restore life's mandate. Is this not the meaning of "Reversal is the test of the Dao"? Softness ensures survival—like an infant's concentrated breath yielding perfect pliancy—naturally grasping life's pivotal mechanism. Is this not the essence of "Weakness is the handle of De"?

Once Yin and malign energies are expelled, the body's accumulated filth is cleansed; once pure Yang energy is established, primordial Qi permeates every subtle crevice. When the Golden Elixir first coalesces, the pulse seems to pause as one returns to a state of primordial chaos, as if being reborn. This apparent turbidity and obscurity is actually the critical moment of bodily transformation. Through this silent passage, new life eventually emerges—one awakens to their original face, attaining a state of perfect purity and luminous wisdom, with body and mind crystallized into transparency. Hence the saying: "Turbidity is the path to clarity; prolonged obscurity yields radiant light."

The previous section revealed the marvels of physical cultivation; this passage unveils the mysteries of spiritual refinement. Only when both form and spirit reach sublime states can one truly unite with the Dao. This chapter specifically expounds the essentials of cultivating the Three Treasures (Jing, Qi, Shen)—the foundational practice of embracing the One and nurturing inner nature—echoing the earlier chapter on "Refining the Self to Establish the Foundation."

Baoyizi (a Daoist cultivation master) said: When the ears cease listening to external sounds, the Kan-water (kidney essence) within naturally becomes clear; when the eyes stop viewing external scenes, the Li-fire (heart fire) naturally regulates itself; when the mouth refrains from speech, the Dui-metal (lung metal) ceases restless movement. When these three gates are closed, the true primordial Qi circulates freely within.

He further explained: When the seven apertures (sensory gateways of eyes, ears, nose, tongue, body and mind) all turn inward, the practitioner enters a state of self-forgetfulness where all meridians become tranquil, form and breath dissolve into nothingness, the body grows weak as if boneless, and consciousness becomes drowsy like intoxication. This precisely verifies successful Dao cultivation and manifests the signs of De (virtue). What appears as drowsiness is actually the foundation of illumination; what seems turbid is in truth the source of purity. Continuing cultivation from this state gradually leads to perfect luminosity and penetrating insight - all experiences of spiritual clarity originate from this initial turbid condition.

Yu Yuwu (a Neidan master) elucidated: "Returning" means reverting to the original source. The crux of Golden Elixir (Neidan) cultivation lies in attaining extreme emptiness and stillness, merging with cosmic nature until the primordial Qi spontaneously arises like the first dawn of returning sunlight. "Weakness" refers to maintaining tender softness. The essential method requires holding the heart-mind steadfast without dispersing Qi, becoming pure and pliant like an infant, thereby returning to life's origin.

Chapter 23 specifically exposes the futility of heterodox practices. Ordinary people often delight in minor techniques without comprehending the Dao's profundity, abandoning the true path for deviant roads, seeking quick results yet blocking their own cultivation. This resembles blind men rejecting canes, deaf listeners craving music, diving to catch pheasants, climbing mountains for aquatic dragons, planting wheat to harvest millet, or using compasses to draw squares - exhausting one's spirit all year without achievement. The authentic cultivation method is supremely simple and uncomplicated.

This chapter clearly reveals the vanity of peripheral techniques. Dao practitioners must first understand the vast difference between the Great Dao and mere methods. The dual cultivation of nature and life (Xingming Shuangxiu) and return to Wuji (Dao's origin) constitute the Great Dao, while fragmented techniques count as minor skills. Though difficult to encounter, the Golden Elixir path (fundamental Neidan method) is easy to accomplish, whereas various heterodox methods, though readily available, prove ultimately fruitless. How lamentable that deluded people, their hearts blocked like overgrown paths, neither discern depths nor see clearly, constantly turning from light to darkness, abandoning orthodoxy for deviant arts - intending swift attainment, they sever their own cultivation path, forever losing the Dao's opportunity!

They fail to understand that the innate Dao of nature and life transcends physical form, mistakenly groping among postnatal Jing and Qi (corporeal energies), drifting aimlessly without true direction. This resembles the absurdity of blind men refusing canes or deaf listeners desiring music. Worse still, not recognizing that innate Yin-Yang (life's primordial energies) are inherently possessed within, they erroneously seek external sexual practices, sinking into licentious paths - nothing harms life and violates De more grievously than this.

This scripture primarily critiques those deviant cultivation methods that stray from the true path, emphasizing the supreme simplicity and essence of the authentic Golden Elixir (Jindan) tradition.

Attempting to catch pheasants in water or fish for dragons on mountains is as absurd as seeking the primordial lead and mercury (fundamental elements of cultivation) while fixating on material forms. Some burn straw, refine false mercury, or claim to transform copper into gold—deceiving the ignorant while ultimately harming both others and themselves. This resembles planting wheat yet expecting to harvest rice, or using a compass to draw squares—utterly misguided. These heterodox methods exhaust a lifetime’s effort, leaving practitioners empty-handed in old age, only to slander the ancestral masters as liars.

In truth, the method of "subduing and ingesting" (Fushi, a key Neidan practice) in the Golden Elixir tradition is profoundly simple: it begins with deliberate effort to lay the foundation, ultimately returning to the natural state of Wuwei (non-action), aligning with the creative power of heaven and earth. Even a dull-witted person, upon receiving the true transmission, can immediately transcend the ordinary and attain sagehood—how could these petty heterodox methods compare? Here, we merely outline the errors of deviant paths. In reality, Buddhism speaks of ninety-six heterodox schools, while Daoism identifies thirty-six hundred misguided branches—too numerous to count. Thus, Patriarch Zhengyang (Zhongli Quan) composed the "Song of the True Path," Master Cuixu (Chen Nan) wrote the "Chant of Luofu," and Li Qing’an’s "Discourse on Nine Grades" and Chen Guanwu’s "Song of Dispelling Delusion" all expose the fallacies of heterodoxy to awaken the world. Sadly, people remain stubbornly deluded, allowing false methods to spread ever wider—a profound tragedy.

The middle section focuses on Fushi (the pivotal stage of Neidan cultivation), which inherently encompasses the principles of "governing" (regulating body and mind) and "nurturing nature." Chapter 24, "The Convergence of Nature and Emotion," depicts the harmonious interplay of Yin-Yang during cultivation: the "flowing pearl of the sun" (the spirit, Shen) tends to scatter and must be anchored by the "golden splendor" (vital essence, Jing). Their fusion transforms into the "white liquid" (the material basis of the Golden Elixir). Just as the Five Phases (Wood, Fire, Earth, Metal, Water) mutually generate and restrain one another, the "three fives" (essence, Qi, and spirit) unite into one—this is the supreme principle of heaven and earth’s refined essence. Such profundities can only be transmitted orally and grasped intuitively, defying full expression in writing. Practitioners must attune to the transitions of Zi, Wu, Mao, and You (key temporal and directional markers), allowing the "dragon" (Shen) and "tiger" (Jing) to resonate, merge, and ultimately become one.

This passage elucidates the core principle of "metal and wood merging" (jinmu jiaobing) in Daoist Neidan (internal alchemy) practice. It begins with natural metaphors: just as when Mars (Yinghuo) moves westward and Venus (Taibai) traverses the sky, creating an atmosphere of stern restraint; or like a cat catching mice or an eagle seizing small birds, all things follow their inherent natures of mutual generation and restraint.

The crux of cultivation lies in harmonizing "wood nature" (associated with the liver's Hun soul) with "metal emotion" (linked to the lungs' Po soul). The "flowing pearl" (liuzhu, referring to the heart-mind) within the sun (Li trigram) tends to scatter outward and must be gathered by the "golden splendor" (jinhua, the primordial Jing from the Kan trigram). In their primal state, Qian (pure yang) and Kun (pure yin) later differentiate into Kan (water) and Li (fire). The practice aims to reunite Kan and Li, returning them to their original Qian-Kun unity.

Specifically: the true nature from the Qian trigram (pure yang) descends into Kun (pure yin), becoming the "wood mercury" (mugong, conscious mind) in Li, while Kun receives a spark of yang from Qian to form the "gold lead" (jinqian, primordial Jing) in Kan. Practitioners use the true lead (primordial Jing) from Kan to subdue the true mercury (conscious mind) from Li, much like containing liquid mercury in a metal vessel. When lead (Jing) and mercury (mind) fuse in the Dantian (yellow chamber), they first transform into white liquid (metal generating water), ultimately solidifying into the indestructible Golden Elixir (metal's enduring nature). Here, metal nature (Jing) actively guides while water nature (primordial Shen) naturally responds, achieving spontaneous harmony between essence and emotion.

The phrase "horse-teeth jade" (machi lang'an) symbolizes the Elixir's crystalline purity, while "two crescents' Qi" denotes the waxing and waning of yin-yang energies during the moon's phases. The entire process reverses the later Kan-Li division to return to the primordial Qian-Kun state—the source of original nature and life.

This passage describes the process of Yin-Yang energy interaction in Daoist Neidan (internal alchemy) practice. The metallic nature within the Kan trigram (representing the true Yang within kidney water) actively ascends, while the wooden nature within the Li trigram (representing the true Yin within heart fire) responds accordingly. When the true Yang (golden essence/Jing) within Kan rises, it resembles metal being refined in a furnace—suddenly manifesting when the timing is right. This liquid transformed from golden essence becomes the "water of true unity," initially flowing like mist before gradually condensing into solid matter resembling horse teeth or fine jade.

Though the Yin-Yang substances (metal and wood) from the eastern and western regions remain separated for long periods, they ultimately unite through the mediation of true intention (the practitioner's guided awareness). Like the natural attraction between metal and wood, this fusion occurs spontaneously without artificial coercion. The "flowing pearl of the sun" (essence of heart fire), yang in appearance but yin in nature, tends to dissipate easily. Only when combined with the true Yang of golden essence does it stabilize, transforming into true Yin and creating the wondrous state of inverted Yin-Yang.

The text then explains how to consolidate this "true seed" (embryo of the internal elixir) produced by Yin-Yang fusion. When the Qi of Kan and Li converges at the Xuwei point (Dantian region), practitioners must seize the precise moment, using true intention to facilitate their union while sealing all bodily energy portals (forbidden gates) to prevent essence leakage. Nurtured in the central palace of the Yellow Court (Dantian), this true seed resembles an infant cared for by a loving mother—requiring constant incubation. Initially demanding hen-like attentiveness during incubation, it later develops mutual dependence like crows feeding their parents. Simultaneously, practitioners must guard it with strict fatherly discipline, shutting the eight bodily gates (sensory organs like eyes and ears) to prevent energy dissipation. Throughout this process, cultivating the true seed requires both tender nourishment and rigorous protection.

This scripture reveals the profound mysteries of mutual generation and restraint among the Five Phases (Wood, Fire, Earth, Metal, Water) in alchemical practice. Conventional understanding holds that the Five Phases follow a sequential generative cycle—Metal begets Water, Wood begets Fire, and so forth. Yet this forward movement ultimately leads to the exhaustion of Jing (essence) and Qi (vital energy), culminating in death—a principle encapsulated in the phrase "the root of life becomes the root of death."

The Dao of alchemy operates inversely, employing a reverse cycle of the Five Phases. Take "Flowing Pearls" (the Wood Dragon's essence), which inherently belongs to the Wood phase but must be extracted from Li Fire (the southern Fire trigram), or "Golden Splendor" (the Metal Tiger's essence), which is fundamentally Metal yet must be drawn from Kan Water (the northern Water trigram). Only through such paradoxical unions—Fire and Water intermingling, Metal and Wood inverting—can life return to its primordial source and achieve longevity. This embodies the principle that "the root of death becomes the root of life."

In practice: First, use the Fire within southern Wood to refine the Metal concealed in northern Water, purging impurities to reveal Metal's pure nature. Then employ the Metal within western Water to regulate the Wood within eastern Fire, dispelling Yin energies to invigorate Wood's vitality. This process is captured in the phrase "Fire's nature dissolves Metal, while Metal's restraint makes Wood flourish."

Ultimately, merge the eastern Three (Wood) and southern Two (Fire) to form Five; combine the northern One (Water) and western Four (Metal) to form another Five; while the central Earth inherently constitutes its own Five. These "Three Fives" converge in the central Earth, uniting as one—a fusion containing the universe's most sublime creative principles. However, the precise cultivation methods must be transmitted orally from master to disciple, as they transcend written expression.

(Note: "Flowing Pearls" denotes the essence of the Wood Dragon, "Golden Splendor" the essence of the Metal Tiger—both specialized alchemical terms. "Li Fire," "Kan Water," etc., refer to the Five Phase attributes corresponding to the eight trigrams' directional associations.)

This scripture reveals the profound mystery of "inverting the Five Phases (Wuxing)" in Daoist internal alchemy (Neidan) practice. The most subtle principles between heaven and earth can be transmitted through oral formulas, yet remain difficult to fully express in written words.

The key to cultivation lies in returning the Qi of the Five Phases—Wood, Fire, Earth, Metal, and Water—back to their unified origin. Specifically: In the normal cycle of the Five Phases, Wood (represented by the Dragon) is born from Water, and Metal (the Tiger) is born from Fire. But in alchemical practice, this process is reversed—Metal Qi (Tiger) must be generated from Water, while Wood Qi (Dragon) arises from Fire. This is akin to the moon's waxing (Metal Qi) and waning (Wood Qi) phases, which must transform and merge with one another.

When the positions of Zi hour (North, Water) and Wu hour (South, Fire) are inverted, the Metal and Wood Qi exchange their roles as host and guest. Normally, the East (Wood) is host and the West (Metal) is guest; after inversion, Metal Qi becomes host while Wood Qi becomes guest. At this stage, the practitioner must employ the "bathing" technique (a method of purifying body and mind), letting go of all distracting thoughts and maintaining balanced true intention, allowing Metal and Wood Qi to harmonize and blend.

The relationship between Metal and Wood Qi can be understood from multiple perspectives: like husband and wife complementing each other, mother and child nurturing one another, father and son restraining and supporting, or host and guest shifting roles. This ever-changing dynamic embodies the most profound principle of heaven and earth.

Finally, the scripture describes the mutual attraction of Dragon and Tiger: once Metal and Wood Qi complete their role reversal, it is as if the Dragon calls to the Tiger, and the Tiger draws in the Dragon's essence (Jing), merging and nourishing each other until they become one. This vivid metaphor of "devouring and consuming" illustrates the perfect fusion of Yin and Yang Qi within the body.

This scripture elucidates the principles of interaction and mutual restraint between Yin and Yang Qi in Daoist Neidan (internal alchemy) practice. It first depicts the phenomenon of "dragon-tiger copulation": when the Western Qi (represented by the metal tiger) and the Eastern Jing (essence, represented by the crimson dragon) become mutually attracted, it resembles a dragon summoning the tiger while the tiger draws in the dragon's vital essence. Their intrinsic natures resonate, merging into unity. During this union, the two energies swallow and absorb each other, eventually condensing in the mouth to form a golden elixir no larger than a millet grain—the initial achievement in Neidan cultivation.

The text then employs celestial phenomena as metaphors: when Mars (Yinghuo) moves into the Western metal position, or Venus (Taibai) traverses the Eastern wood position, these astronomical configurations correspond to the restraining energies of the Five Phases' mutual conquest. Just as fire melts metal and metal chops wood, or as cats catch mice and sparrows fear hawks in nature, these interactions follow the innate patterns of mutual generation and restraint. This natural regulation isn't forced suppression but rather an expression of intrinsic qualities.

The core revelation concerns the profound meaning of "restraint and assimilation" (fushi): while Yin and Yang Qi must harmoniously merge (assimilation), they must also mutually regulate (restraint). This resembles how the cycle of conquest among the Five Phases conceals regenerative potential—within destructive mechanisms lie seeds of vitality. Authentic Neidan practice (huandan, returning elixir) involves mastering this subtle equilibrium of mutual generation and restraint, fundamentally distinct from the mundane understanding of ingesting alchemical substances.

In the appended commentary, Baoyizi further explains: human life force (mingbao, life-treasure) resembles the vital essence at sunrise, yet this energy tends to scatter easily. To preserve this golden luminosity (jinhua), one must employ metal's nature to restrain it—directly echoing the earlier principle of the metal tiger regulating the crimson dragon. The entire cultivation process achieves the dual cultivation of nature and life (xingming shuangxiu) precisely through this mutual regulation of Yin and Yang.

This chapter discusses the distinction between true and false paths of cultivation, emphasizing the need to discern counterfeit practices while preserving authentic Dao.

Without understanding the true principles of cultivation, proper practice becomes impossible. Many exhaust their family fortunes pursuing longevity, only to leave their wives and children hungry and impoverished. Throughout history, countless seekers have pursued the Dao, yet few ever encounter genuine transmission or achieve realization. Some wander searching for so-called "precious medicinal ingredients," which in truth runs counter to authentic Daoist practice. The key lies in discerning truth from falsehood and perceiving the essence of things.

Particular emphasis is placed on distinguishing authentic from inauthentic elixir practices—cultivators must recognize this early. The true path of the Golden Elixir (Neidan/internal alchemy) encompasses the principles of heaven, earth, and all creation, containing the profound mysteries of the Yijing (Book of Changes). Its principles are supremely vast and subtle. One must thoroughly comprehend the transformations of Yin-Yang and deeply grasp the wondrous mechanisms of creation to truly understand its mysteries. Those who discuss or practice recklessly without this understanding often stray onto wrong paths, becoming obsessed with Waidan (external alchemy) furnace techniques. Tragically, they exhaust their resources and bring suffering to their families without realizing their error.

Since ancient times, Daoist practitioners have been as numerous as hairs on an ox, yet few encounter authentic transmission, and fewer still achieve realization. Many abandon the innate great Dao of their own nature and life (Xingming Shuangxiu), instead chasing mercury in mountains or digging for lead ore, collecting minerals as immortality elixirs—completely deviating from true cultivation.

When seeking teachers and the Dao, practitioners must first cultivate discernment. Upon meeting someone claiming to transmit Daoist methods, one must examine whether their teachings are authentic. A true enlightened master will thoroughly understand Yin-Yang transformations and the profound mechanisms of creation. By inquiring about the roots of nature and life, the mutual generation and restraint of the Five Phases, and the principle of "like seeking like" (referring to the harmony of Yin and Yang), one can distinguish truth from falsehood.

This passage elucidates the profound interplay of mutual conquest and generation among the Five Phases (Wood, Fire, Earth, Metal, Water) in Neidan (internal alchemy) practice. While conventional understanding emphasizes their generative sequence, Daoist alchemy paradoxically achieves regeneration through conquest—without restraint, there can be no renewal, as the seed of life lies hidden within destructive forces.

Take Metal conquering Wood: when Metal Qi stirs, it generates Water. Enticed by this nourishing Water, Wood forgets Metal's conquering force. Here, the conquering element is called the "Father," while the element that generates new life through conquest is termed the "Mother." This principle applies universally among the Five Phases, hence the saying: "In mutual conquest, the Five Phases serve as each other's Father and Mother."

The Mother's path belongs to Kun (the Earth hexagram), symbolizing nurturing growth through silent receptivity. During the union of Yin and Yang, she receives the "true seed" (primordial Qi) from the Qian (Heaven hexagram) Father, incubating it in the central palace (Dantian) until it matures into the "infant" (the inner elixir). This is the meaning of "the Mother harbors nourishing fluids," embodying maternal care.

The Father's path belongs to Qian (the Heaven hexagram), representing dynamic initiation through steadfast vigor. At the first meeting of Yin and Yang, the flow of Jing (essence) delivers the generative force to the Kun Mother—this is the true seed. The phrase "the Father governs bestowal" reflects the stern paternal principle of creating life through restraint.

Between generation and conquest, the Qian Father condenses primordial Jing, while the Kun Mother disseminates formative vitality. Their mystical union gives birth to the "true embryo" (inner elixir). Persisting in this practice refines the Dharmic Body (Shen/spirit) into indestructible permanence, like gold or stone. The key lies in unwavering focus and guarding against Qi leakage—only then can the supreme Dao be realized.

Throughout this process, the mystery of "generation through conquest" unfolds, revealing the inverted workings of the Five Phases. Understanding this principle brings the Great Elixir (highest Neidan attainment) to instantaneous fruition—as swift as a shadow following a pole or an echo in a valley. Such is the wondrous law governing heaven and earth.

These are genuine verifications of Daoist cultivation, whose traces can be clearly discerned—how could the fraudulent arts of heretical paths possibly infiltrate them? Just as with deadly poisons like wild aconite or croton seeds, consuming even an inch or an ounce will immediately induce fatal toxicity, leaving the victim paralyzed. At that point, even if King Wen of Zhou were to divine with yarrow stalks, Confucius were to interpret the hexagrams, Bian Que were to apply his healing needles, or the shaman Xian were to perform drum rituals, none could restore the dead to life or make them walk again.

This passage uses metaphor to illustrate the miraculous effects of ingesting the Golden Elixir (Jindan). Ordinary people only understand that poison brings certain death, yet remain oblivious to how the Golden Elixir grants immortality. Once poison enters the mouth, not even immortals can reverse its effects; but once the Golden Elixir is ingested, not even the Creator can make one die again. Alas, the world recognizes the lethality of poison but remains ignorant of the wondrous efficacy of the Golden Elixir. Moreover, after consuming it, even ingesting deadly poisons like wild aconite or croton seeds will cause no harm. Clearly, the method of refining and ingesting the Golden Elixir—where the Five Phases (Wuxing) mutually generate and restrain, and essence (Jing) and Qi coalesce into form—produces effects as immediate as a shadow cast by sunlight or an echo in a valley. How could the fraudulent practices of heretical paths ever compare?

This chapter specifically distinguishes the authenticity of Golden Elixir ingestion, guiding later cultivators to avoid being misled by ignorant teachers.

Chapter 26 explains the principle of lead-mercury union: The "Radiant Maiden of the River" (referring to true mercury) is ethereal and elusive, scattering like mist upon encountering fire, leaving neither ghosts nor divine dragons able to trace it. To subdue it, one must rely on "Yellow Sprouts" (true lead) as the foundation. All things in existence possess Yin and Yang aspects—to violate this heavenly principle is like a hen attempting to hatch eggs alone, which will never yield chicks. Why? Because Yin and Yang fail to couple, the Five Phases do not intermingle, and hardness and softness remain divided. Such is the natural Dao of creation: Fire’s nature is to blaze upward, water’s to moisten downward—this requires no human instruction. These are laws established at the very inception of heaven and earth, immutable.

Observe the union of male and female: hardness and softness merge inseparably. This is natural law, not something artificial techniques can contrive. The posture of the male above and female below has existed since conception—it is not learned after birth. Even in death, this posture is maintained during burial. This is not taught by parents but originates from the fundamental principle of Yin-Yang interaction, determined from the very beginning.

This chapter elucidates the mutual restraint and harmonious application of true lead and true mercury.

This passage explains the core principle of "lead and mercury restraining each other" in Daoist Neidan (internal alchemy) practice. The River Goddess (referring to the true mercury within the Li trigram, symbolizing the primordial Shen/spirit) possesses boundless agility—once exposed to fire (representing post-heaven conscious activity), it scatters like mist, becoming as elusive as hidden ghosts or submerged dragons. To subdue it, one must use Yellow Sprout (the true lead within the Kan trigram, symbolizing primordial Jing/essence) as the foundation.

The Li trigram (symbolizing fire) originates from the purely yang Qian trigram, representing our innate nature, yet contains a hidden yin element (the true mercury)—like masculinity containing femininity, hence its name "Goddess." Conversely, the Kan trigram (symbolizing water) stems from the purely yin Kun trigram, representing our innate vitality, yet conceals a yang element (the true lead)—like gold emerging from water, thus called "Yellow Sprout." The human mind possesses innate spirituality, but when influenced by post-heaven emotional desires, it behaves like volatile quicksilver—thoughts become uncontrollable and ever-changing.

To tame this restless consciousness, one must employ the true lead from the Kan trigram. Because the yang-metal within Kan shares the same origin as the Qian trigram: following desires leads to ordinary emotions, while practicing reverse cultivation returns one to original nature. When true lead and mercury unite, it resembles a ruler governing subjects or a husband guiding a wife—natural harmony is restored. This is what Master Zhang Boduan meant by "one must find the Golden Duke (true lead) to achieve mastery," echoing the earlier concept of flowing pearl (true mercury) and golden splendor (true lead) mutually restraining each other.

All things that lack the harmonious union of Yin and Yang defy the Dao of heaven and stray from their origin. It is like a hen attempting to hatch eggs alone—the chicks cannot form. Why? Because the complementary interplay of Yin and Yang is missing. When the numbers of Three and Five (referring to the generative and controlling relationships of the Five Phases) fail to merge, and hardness and softness remain separate, they contradict the natural law of creation, which is rooted in the spontaneous union of Yin and Yang.

This passage discusses the pitfalls of one-sided cultivation. The Great Dao lies in the harmonious balance of Yin and Yang. Any phenomenon that leans excessively toward Yin without Yang, or Yang without Yin, violates the fundamental principles of Qian (the creative force of Yang) and Kun (the nurturing force of Yin). Just as hatching an egg requires the infusion of true Yang Qi from a rooster—without it, the chick cannot develop—so too does the art of alchemy demand the convergence of the Four Symbols: Wood (Three) of the East, Fire (Two) of the South, Water (One) of the North, and Metal (Four) of the West, all gathering in the central True Earth (Five). Only when these forces unite in mutual resonance, forming the Three-Five harmony, can the Sacred Embryo (Neidan, or internal elixir) be perfected. If the Qi of Three and Five does not interact, it remains solitary Yin and isolated Yang, with rigidity and softness forever apart—how then can the true embryo be formed?

Yang governs the release of Jing (essence) and Qi, while Yin governs reception and gestation. This is the natural Dao of Yin and Yang in heaven and earth. Whether forming an ordinary body or a sacred one, this law of creation must be followed—one cannot cultivate only a single aspect. The true path of the Golden Elixir (Jindan) requires the dual cultivation of Qian’s true nature (Shen, spirit) and Kun’s true life (the physical body). To cultivate life (body) without nature (spirit), or nature without life, is to stray into heretical paths that defy the Dao. Sadly, some fail to grasp this principle and mistakenly pursue harmful techniques, like fleeing floodwaters only to leap into a fire—truly lamentable.

Fire naturally rises, and water naturally flows downward—this is not taught to them. From the moment of creation, they have maintained this intrinsic nature, never changing. This passage describes the innate tendencies of Yin and Yang Qi to return to their original states. Nothing exemplifies the qualities of true Yin and Yang better than fire and water: fire, belonging to Yang and active, inevitably ascends; water, belonging to Yin and still, inevitably descends. This is mirrored in the human body, where the true fire within the Kan trigram (kidney water) always rises (manifesting the Yang nature of Qian), while the true water within the Li trigram (heart fire) always descends (manifesting the Yin nature of Kun). This intrinsic nature was determined at the moment of creation and will never alter. By observing the patterns of nature, we can understand the workings of our own bodies.

This scripture employs the natural phenomenon of sexual union between man and woman as a metaphor for the principle of "Kan-Li coupling" (the harmonious interaction of water and fire) in Daoist Neidan (internal alchemy) practice. It explains that water possesses moistening and descending qualities (the nature of the Kun Mother), while fire exhibits flaming and ascending characteristics. Just as in sexual union where the strong male naturally assumes the upper position and the yielding female the lower, this configuration arises spontaneously without artificial manipulation.

From the perspective of life formation, males are naturally prone to lying prone (indicating introverted disposition), while females naturally lie supine (suggesting extroverted temperament) - these differences are determined from the moment of conception. Remarkably, even in death by drowning, corpses maintain this gendered positioning with males face-down and females face-up, demonstrating that Yin-Yang attributes are innate.

The text uses "Qian Father and Kun Mother" (pure Yang and pure Yin from the Prenatal Bagua) to symbolize the fundamental Yin-Yang energies within the human body, while "Kan Male and Li Female" (the water and fire trigrams from the Postnatal Bagua) represent the concrete expressions of water and fire Qi within the body. Just as water naturally flows downward and fire rises upward in nature, the water and fire Qi within the human body follow the same principles. The crux of cultivation lies in returning Li fire (the heart's Shen/spirit) and Kan water (the kidneys' Jing/essence) to their original states, much like children naturally returning to their parents.

The line from the Mirror for Compounding the Medicine stating "water can flow, fire can flame" precisely describes this natural energetic movement within the human body. By observing the natural postures during sexual union, practitioners can comprehend how Yin and Yang Qi naturally intermingle within themselves. This coupling requires no artificial interference - just as a fetus naturally develops gendered characteristics in the womb, it is preordained and unalterable.

This scripture elucidates the principle of Kan (Water) and Li (Fire) intercourse in Daoist Neidan (internal alchemy) practice, representing the interaction of Yin and Yang. The Kan trigram symbolizes the moon, masculinity, and water, while the Li trigram represents the sun, femininity, and fire. Although Qian (Heaven) and Kun (Earth) originally belong above and below respectively, their union causes the positional exchange of Kan and Li while preserving their intrinsic natures—the fire within Kan still ascends, and the water within Li still descends, both yearning to return to their origins.

Just as the union of male and female restores innate nature and life (Xingming), the reunion of Kan and Li returns them to their original Qian-Kun state. This mirrors how humans enter life through the complementary motions of bending and stretching, maintaining this posture even in death—demonstrating the unalterable fundamental pattern.

Chapter 27 explains refining the Golden Elixir (Jindan) by harmonizing the Hun (solar soul) and Po (lunar soul). The moon achieves fullness by receiving the sun’s radiance, just as Yin and Yang must cooperate in cultivation. Imbalance between them manifests as anomalies like lunar eclipses. Men and women must balance movement and stillness, akin to the mutual nourishment of Metal and Water or the transformative union of Fire and Earth. The Hun must avoid excessive indulgence, maintaining temperate harmony—neither too cold nor too hot.

The crux of practice lies in mutual regulation between the solar Hun and lunar Po. Though Kan represents the moon, it contains true Yang; though Li symbolizes the sun, it harbors true Yin. Just as sun and moon illuminate each other in nature, the body must achieve the perfect interaction of water and fire (Jishui Jihuo), blending solar and lunar essences. The preceding chapter’s analogy of complementary male-female postures precisely reveals Kan and Li’s profound mystery—their inverted dynamics (Kan outwardly positioned yet inwardly oriented, Li inwardly positioned yet outwardly directed) embody the essential alchemical secret.

The moon belongs to the Great Yin (yin energy), embodying the essence of water and symbolizing the Kun trigram (Earth Mother), which by nature should be purely yin. Yet within the moon lies the solar true fire of the Qian trigram (Heaven Father), much like the Jade Rabbit (the yang energy within the moon) hidden within the lunar essence (po), revealing its latent yang qualities.

The sun belongs to the Qian trigram (Heaven Father), embodying the essence of fire and thus seemingly purely yang. However, within the sun resides the lunar true water of the Kun trigram (Earth Mother), akin to the Golden Crow (the yin energy within the sun) concealed within the solar essence (hun), manifesting its hidden yin nature. This is the profound mystery of "inverted yin-yang" described in the Wuzhen Pian (Awakening to Reality).

The Li trigram (fire) originates from the Qian trigram (Heaven Father) and should naturally radiate outward, yet it transforms into the inwardly attuned Li Maiden (yin energy). Conversely, the Kan trigram (water) stems from the Kun trigram (Earth Mother) and should naturally condense inward, yet it transforms into the outwardly directed Kan Male (yang energy). Though the sun governs outward illumination, it constantly interacts with the moon’s reflection; though the moon governs inward absorption, it ceaselessly draws upon the sun’s qi.

At the new moon (hui) and full moon (shuo), when the sun and moon meet along the ecliptic, yin and yang merge into primordial chaos. The solar essence (hun) enters the lunar body (po), much like the union of yin and yang forming an embryonic state. This fusion does not deplete the sun or moon, just as the moon absorbs sunlight without diminishing its own substance.

Neidan (internal alchemy) cultivation follows the same principle: within the human body, the solar essence (jing) and lunar essence (hua) continuously circulate and merge. When the state of "sun and moon uniting as one" (yin-yang balance) is achieved, the Toad Light (the nascent form of the Golden Elixir) emerges. However, if yin and yang fall into imbalance—like during solar or lunar eclipses, where yin qi overwhelms yang qi—calamity may ensue. This aligns with the earlier discussion on "excessive water weakening fire": during the convergence of hui and shuo, if yang qi fails to subdue yin qi, though yin and yang unite, the light may still be lost.

The nature of the sun is inherently eternally radiant, yet if it cannot maintain self-mastery and becomes submerged in the northern water abyss (symbolized by the yin energy of the Kan trigram), unable to rise, it loses the natural harmony of yin-yang interaction. When the balance between yin and yang is disrupted, the sun is eroded by yin energy, resulting in diminished radiance. This is why it is said that when yang energy fails to uphold its covenant, yin energy encroaches upon the light.

When yang is overtaken by yin, phenomena such as solar and lunar eclipses occur. Particularly during the dark and new moon phases (the end and beginning of the lunar month), that spark of yang essence sinks into emptiness, the fire's power weakens, and water's influence grows dominant. As yin strengthens, it obscures yang; as water's force swells, it suppresses fire. In this struggle, even the sun's daylight can turn dim. The sun's luminous nature originates from the perfected radiance of the metal phase (one of the Five Phases), meant to shine eternally. But once infiltrated by yin, its form temporarily vanishes, manifesting as the calamity of eclipses.

This passage describes how the abnormal convergence of the sun and moon immediately triggers disasters. The same principle applies to internal cultivation (the union of Kan and Li): the nascent yang energy sinks to the ocean floor of the dantian (lower energy center). If the regulation of movement and stillness is even slightly imbalanced, the true fire becomes trapped in the kidney water (symbolizing yin) and fails to ascend—mirroring celestial eclipses.

Man and woman (symbolized by the Kan and Li trigrams) depend on each other, nourished through the rhythm of inhalation and exhalation. Feminine and masculine (yin and yang) intertwine, each seeking its counterpart. Metal transforms into the fluidity of water, while fire transforms into earth, preventing water from flowing unchecked. The masculine (yang) actively radiates outward, while the feminine (yin) quietly gathers inward. If one exceeds proper measure, they become bound by yin's softness. The po (yin spirit) restrains the hun (yang spirit); neither should be indulged excessively. Neither too cold nor too hot, advance and retreat in due time—each maintains harmony, jointly verifying the rhythm (cultivation's firing process) through breath.

This passage explains that the interaction of yin and yang must follow the correct path. The Kan trigram (representing kidney water) is male, while the Li trigram (representing heart fire) is female—they complement each other: the moon's po absorbs the sun's essence from without, while the sun's hun exhales the moon's brilliance from within. Host and guest reverse roles, swallowing and spitting, giving rise to the "true seed" (primordial qi). The Qian trigram, originally the elder yang, transforms into the middle daughter within Li; the Kun trigram, originally the elder yin, transforms into the middle son within Kan. Once the original forms of Qian and Kun are disrupted, the imagery of yin and yang intermingling emerges. Yet the true fire within Kan still seeks to return to Qian's position, just as the true water within Li yearns to return to Kun's place. Through cultivation, the fragmented form is refined into pure yang—illustrating how water flows to dampness and fire burns toward dryness, each returning to its kind.

This passage explains the alchemical principle of mutual transformation between Yin-Yang and the Five Phases (Wood, Fire, Earth, Metal, Water) within the human body. Just as metal (Jin) melts into flowing water, the body's Yang energy (represented by the Qian trigram's solar metal) transforms into supple Yin energy (water). This metamorphosis resembles the shifting radiance of sunlight—inherently fluid and difficult to restrain—hence termed "metal transforming into water."

When Yin-water energy becomes excessive, it suppresses the genuine fire within the Kan trigram (the original Yang Qi of the Dantian). This requires relying on Wu-earth energy (earth-phase power) generated in the Dantian to restrain the flooding water, much like using dikes to control a deluge. This regulatory relationship is called "yellow sprouts as the root." The Wu-earth in Kan and Si-earth in Li trigrams cooperate like a central dam system, effectively managing water energy's excess.

The text employs conjugal union as a metaphor for Yin-Yang interaction: the masculine (Yang) actively releases energy while the feminine (Yin) receptively stores it. This mirrors how the sun (solar Hun-soul) emits light while the moon (lunar Po-soul) absorbs it. However, uncontrolled Yin-Yang communion—like excessive intercourse—damages Yang Qi, allowing Yin-water to erode true fire, creating a "waning eclipse" (energy depletion).

A crucial insight reveals: the Yin energy within the Li trigram (heart fire) is actually the Yang spirit (solar Hun), while the Yang energy in the Kan trigram (kidney water) paradoxically contains the lunar Po. This demonstrates how Hun-Po (spiritual energies) are interdependent dwellings. When fire transforms into earth-phase energy, the Po (Yin force) can restrain the Hun (Yang force), preventing excessive dissipation.

The ultimate state achieves balanced Yin-Yang and harmonized water-fire: Yang energy activates upward movement while Yin energy nourishes downward settling—neither excessively dry nor cold, maintaining Middle Path equilibrium. This embodies Daoist cultivation's core philosophy of harmonizing opposites through dual cultivation of nature (Xing) and life (Ming).

This passage elucidates the essential methods for cultivating the Golden Elixir (Jindan). It first emphasizes the crucial balance between water and fire in the alchemical process: the fire must not be too intense, nor the water too cold—perfect equilibrium is required. When water and fire harmonize to achieve Yin-Yang balance, like the sun and moon illuminating each other, golden essence light emerges in the western direction (associated with the celestial stem Geng). This marks the successful refinement of the supreme Golden Elixir medicine. The term "verification tally" (zhengfu) refers to confirming that one's cultivation aligns with the patterns of celestial Dao.

The text then explains the profound mystery of refining the hun (ethereal soul) and po (corporeal soul) while harmonizing Yin-Yang. The "meeting of three families" describes the unification of a person's essence (Jing), vital energy (Qi), and spirit (Shen). The human body mirrors the cosmos—from conception, it contains primordial Qi (Yuangi). This energy divides into three aspects: the celestial gate above houses the original spirit (Yuanshen), the earthly axis below contains the original life force (Yuanming), while the central void valley preserves true intention. These three further differentiate into four manifestations: the Qian nature transforms into the postnatal heart (represented by the Li trigram), while the Kun life force becomes the postnatal body (Kan trigram). Within the heart's fire resides the wood-natured hun soul (Zhen trigram), and within the body's water dwells the metal-natured po soul (Dui trigram). The cultivation process aims to reunite these dispersed energies.

The passage outlines Five Phase (Wuxing) correspondences: the liver (wood/green), lungs (metal/white), heart (fire/red), kidneys (water/black), and spleen (earth/yellow). The Qi from these organs ultimately returns to the central palace of earth (represented by the celestial stems Wu-Ji), achieving the unification of essence, energy, and spirit.

This scripture elucidates the interrelationships of the Five Phases (Wuxing) and Four Symbols in Daoist Neidan (internal alchemy) practice. The Four Symbols (Azure Dragon, White Tiger, Vermilion Bird, and Black Tortoise) correspond to the four cardinal directions: East belongs to Wood and South to Fire, both Yang in nature; West belongs to Metal and North to Water, both Yin in nature. The Li trigram (Fire) of the South symbolizes red cinnabar, containing true mercury (the essence of Wood); the Kan trigram (Water) of the North symbolizes black lead, containing the essence of Metal.

Most people recognize that Fire harbors Wood, but few realize that Wood conceals Metal. Wood Qi (vital energy) peaks at the Mao hour (5-7 AM), when Metal Qi is already gestating. Similarly, Metal Qi peaks at the You hour (5-7 PM), when Wood Qi begins to sprout. Though Metal and Wood appear separate, their Hun (ethereal soul) and Po (corporeal soul) are intertwined—just as cinnabar (Wood essence) requires Metal to achieve completion.

The number one (Heavenly One) generates Water, corresponding to the Black Tortoise and, in humans, the kidneys. Jing (essence) manifests through the ears. The number four (Earthly Four) generates Metal, corresponding to the White Tiger and, in humans, the lungs. Po Qi manifests through the nose. Since essence and Po Qi belong to the physical body, it is said that "Metal and Water unite in one place." The number two (Earthly Two) generates Fire, corresponding to the Vermilion Bird and, in humans, the heart. Shen (spirit) manifests through the tongue. The number three (Heavenly Three) generates Wood, corresponding to the Azure Dragon and, in humans, the liver. Hun Qi manifests through the eyes. As spirit and Hun Qi belong to the heart-mind, it is said that "Wood and Fire are companions."

Ordinary people experience a separation of body and mind, where Water and Fire do not harmonize, and Metal and Wood remain apart—thus drifting ever further from the Dao. Practitioners must, throughout the twelve double-hours of the day: withdraw the gaze, focus the ears, regulate breathing, and refrain from speech, gathering spirit, Hun, and Po in the central palace (Dantian). This allows Water, Fire, Metal, and Wood to intersect along the Yellow Path (the Governing and Conception Vessels), achieving the primordial state of chaos. In this condition, the Four Symbols can both merge into unity and differentiate into four distinct manifestations.

Wood and Fire mutually generate each other—from the Li trigram (Fire) emerges the liquid of Wood, called "the Dragon emerges from Fire." Metal and Water unite—from the Kan trigram (Water) emerges the essence of Metal, called "the Tiger is born from Water." This is the phenomenon of the Dragon-Tiger congress. As Zhang Pingshu (a renowned Song Dynasty Daoist) stated, "The Four Symbols never depart from their two roots." The Dragon originates from Heavenly Three's Wood, its odd-numbered three belonging to Yang; the Tiger originates from Earthly Four's Metal, its even-numbered four belonging to Yin.

This passage explores the mysteries of "Dragon-Tiger" and the Five Phases in Daoist Neidan (internal alchemy) practice. The Yin Tiger (representing kidney water) and Yang Dragon (representing heart fire) undergo mutual transformation—when the sequence of the Five Phases (Wood, Fire, Earth, Metal, Water) reverses, the originally Yang Dragon turns to Yin, while the Yin Tiger conversely shifts to Yang.

Wei Boyang (Master Wei), concerned about revealing celestial secrets, did not explicitly state the correspondence between the alchemical Five Phases and the five organs. Instead, he employed conventional Five Phase mutual generation theory to explain: the liver (Wood) corresponds to the father (associated with green), and the lungs (Metal) to the mother (associated with white)—this reflects Yin-Yang pairing. Similarly, the heart (Fire) corresponds to the daughter (associated with red), and the kidneys (Water) to the son (associated with black), also embodying Yin-Yang harmony. Water (one) and Fire (two) likewise manifest the Dao of Yin-Yang.

Water is the source of the Five Phases, as the formation of heaven and earth begins at the hour of Zi (northern Water position), followed sequentially by Wood, Fire, Earth, and Metal. The spleen (Earth, associated with yellow) is called the "Ancestor" because it harbors the innate ancestral Qi (primordial energy), the root of Metal, Wood, Water, and Fire. Here, the "Ancestral Cavity" refers to the Dantian (energy center) in the human body—both the origin of the Five Phases (Water as source) and their culmination (Earth as mother), embodying the cultivation principle of returning to the root and restoring life.

Specifically, in the human body: the liver (Wood) houses the Hun (ethereal soul), and the heart (Fire) houses the Shen (spirit), both originating from the innate "true emptiness and wondrous existence" within the Li trigram (heart). The lungs (Metal) house the Po (corporeal soul), and the kidneys (Water) house the Jing (essence), both stemming from the innate "wondrous existence and true emptiness" within the Kan trigram (kidneys). These two groups of Yin-Yang substances are harmonized by the true intention of the central spleen Earth (represented by the innate ancestral Qi of Wu-Ji Earth), ultimately fusing in the Dantian (central yellow earthen cauldron) to form the Golden Elixir. This is the process of "three families meeting to conceive the infant"—the unification of Jing, Qi, and Shen (essence, energy, and spirit) to return to the original innate state. The entire system emphasizes the cultivation essentials of Yin-Yang union, Five Phase reversal, and returning to the root to restore life.

This chapter of Unveiling the Secrets of the Triplex Unity reveals the core mysteries of cultivation. The postnatal state (referring to human existence after birth) of body and mind is in fact the manifestation of the prenatal (cosmic origin) nature and life-force, much like the symbolism of Yin-Yang. Specifically: the postnatal body, breath, and consciousness correspond to the prenatal Original Jing (vital essence), Original Qi (primordial energy), and Original Shen (primordial consciousness), representing the triad of Heaven, Earth, and Humanity; the postnatal "True Earth" (spleen-stomach function) corresponds to the prenatal "Floating Li Ancestral Earth" (cosmic origin), symbolizing the Taiji (Supreme Ultimate). When these three unite as one, the state of Taiji encompassing the Three Powers is achieved. Cultivation to this level enables complete fusion with the Heart of Heaven and Earth.

The author further points out that if one can break through limitations and trace back to the original state prior to birth, one may realize that eternal existence which transcends the destruction of Heaven-Earth and the dissolution of emptiness. This is an exceedingly profound mystery requiring the reader's sincere contemplation—do not miss this rare opportunity.

Chapter 29, The Alternation of Punishment and Virtue, discusses the Yin-Yang transformation principles in alchemy. The alternation of hardness and softness resembles the dragon (Yang) in the west and the tiger (Yin) in the east, with the Mao (east) and You (west) directions forming the warp and weft. Punishment (restraint) and Virtue (growth) cooperate: when elm leaves wither in the second month, the Big Dipper’s handle points to Mao; when wheat sprouts grow in the eighth month, the Heavenly Stem occupies You. Zi (north) and Wu (south) form the north-south axis, cycling through nine and one in perpetual recurrence. Primordial Qi circulates between the Xu and Wei constellations (northern stars), while its essence gathers at the Zi position.

This passage unveils the principle of using Water-Fire as the foundation and Metal-Wood as the function in alchemy. Zi-Wu determines north-south, Mao-You determines east-west, harmonizing with celestial movements. Heaven’s Dao has Yin-Yang, Earth’s Dao has hardness-softness, forming the four directional symbols: Water in the north (Zi), Fire in the south (Wu), Wood in the east (Mao), and Metal in the west (You). Yang Qi flows from Zi to Si (southeast), while Yin Qi circulates from Wu to Hai (northwest). The celestial cycle divides into twelve time periods and twenty-eight lunar mansions, yet when the Big Dipper rotates, Yin-Yang and hardness-softness transform each other, transcending conventional spatiotemporal order. This is the core law of Heaven-Human resonance in alchemical practice.

This passage reveals the profound mysteries of Yin-Yang and Five Phases transformations in Daoist Neidan (internal alchemy) practice. The Dragon (Zhen, representing Wood) originally belongs to the Mao position in the East, symbolizing vital energy, while the Tiger (Dui, representing Metal) naturally resides in the You position in the West, embodying austere restraint. However, during specific cultivation stages, their positions reverse—the Dragon moves westward while the Tiger shifts eastward.

This spatial inversion triggers an essential transformation: the Wood Qi (vital energy) of the East, originally representing growth, converts into Metal De (virtue/power) with restraining qualities, while the Western Metal Qi of restraint paradoxically transforms into Wood De with generative properties. This Metal-Wood interchange often occurs abruptly, like elm seeds suddenly falling in the second month or shepherd's purse unexpectedly sprouting in the eighth month—seemingly anomalous phenomena that actually conceal the mutual transformation between generative and destructive forces.

Practitioners must comprehend that destructive potential lurks within vitality, just as life force hides within restraint. Consider how during the flourishing of vegetation in the second month (when Mao Wood peaks), elm seeds abruptly fall—this occurs because Xu (the River Chief Star of the West) combines with Mao, embedding destruction within generation. Conversely, when plants wither in the eighth month (You Metal's ascendancy), shepherd's purse suddenly grows due to Chen (the Heavenly Gang Star of the East) uniting with You, concealing vitality within austerity.

True Dao cultivators, at the critical juncture of Yin-Yang Qi convergence (when the two lunar crescents merge), must harness the power of the Heavenly Gang Star to reverse heaven and earth. The method involves externally guarding the six senses (eyes, ears, nose, tongue, body, and mind) while internally sealing the Dantian (energy center) in serene purification. Through this practice, restraint transforms into vitality, unifying the dual energies.

The entire process resembles inverting cosmic orientations: conventional directions like Zi-Wu (north-south) and Mao-You (east-west) must operate in reverse. For instance, while True Fire naturally arises from the South, in alchemical practice it gestates from the northern Zi position (fire embryo in Zi)—precisely embodying the esoteric principle of attaining immortality through the inverted cultivation of the Golden Elixir.

This passage elucidates the Daoist Neidan (internal alchemy) principle of water-fire interaction and Yin-Yang transformation. The phrase "Zi in the south and Wu in the north" refers to inverting the acquired Bagua (Eight Trigrams) arrangement, exchanging positions between the Kan trigram (representing water at the northern Zi position) and the Li trigram (representing fire at the southern Wu position).

The northern Kan trigram belongs to water and holds the first position in the Luoshu numerical system, secretly containing the Yang energy of the Qian trigram. The southern Li trigram belongs to fire and occupies the ninth position, embodying the Yin energy of the Kun trigram. During cultivation, practitioners guide the Li fire (Shen/spirit of the heart) to descend and illuminate the Kan water (Jing/essence of the kidneys), causing them to merge at the "Xu-Wei point" near the coccyx where the Ren and Du meridians intersect. This location corresponds astronomically to the Xu and Wei constellations, the celestial meeting place of the sun and moon.

When practitioners achieve profound stillness, the interaction between Kan and Li generates "true Yang," miraculously producing fire from water. This energy forms the foundation for refining the Golden Elixir. The entire process shares the same essence as the metal-wood interaction technique—both employ Yin-Yang inversion and directional shifts to activate primordial Qi. The east-west dragon-tiger energies (liver and lung Qi) coordinate with the north-south Zi-Wu energies (heart and kidney Qi), forming a celestial cycle that ultimately achieves the alchemical goal of ninefold reversion.

Master Ziyang (Zhang Boduan) described this mystical process as "the silent creation of fire within water," emphasizing the Xu-Wei point as the crucial locus for water-fire harmony. By reversing conventional Five Phase relationships, practitioners reconstruct the pre-heaven Bagua order within their bodies, thereby attaining the cultivation state of returning to the primordial origin.

This scripture elucidates the core principle of cultivating the Golden Elixir (Jindan) — the harmonious union of Yin and Yang. Just as the ospreys in the Book of Songs are always depicted in pairs, or as beautiful maidens naturally attract noble suitors, the masculine never exists in isolation, nor does the feminine dwell alone. The Black Tortoise of the North (one of Daoism's Four Symbols) embodies this truth through its intertwined serpent-and-turtle form, perfectly illustrating how male and female complement each other, how Yin and Yang mutually complete one another.

If one were to force two women to share a chamber, no matter how exquisite their beauty, even with silver-tongued persuaders like Su Qin or Zhang Yi advocating their case, they could never become true spouses. This mirrors the futility of alchemical practice with mismatched ingredients — when the substances are of wrong kinds or imprecise measures, even if the Yellow Emperor himself tended the furnace, the Great Unity Perfected Lord (Taiyi Zhenren) controlled the fire, the Eight Immortals (Bagong) pounded herbs, or Prince Huainan prepared the elixir atop jade altars with offerings of qilin meat and phoenix liver, all such efforts would prove vain. Such errors resemble using glue to mend a cauldron or applying brine to heal wounds — they inevitably backfire.

The scripture particularly emphasizes that true cultivation requires pairing substances of "authentic Yin and authentic Yang" that share fundamental affinity. The Book of Changes begins with the cosmic interplay of Qian (Heaven) and Kun (Earth), just as the Book of Songs opens with ospreys symbolizing Yin-Yang union. Within our bodies, the harmonious interaction between Water (Kidneys) and Fire (Heart), like the natural entwining of tortoise and serpent or the pairing of ospreys, follows this universal principle. To comprehend the Yin-Yang complementarity permeating all creation is to grasp the very secret of attaining immortality.

This scripture employs metaphorical language to illustrate how cultivating only one aspect (solitary Yin or solitary Yang) violates the great Dao. Just as the Book of Changes teaches: Kun (Earth, Yin) must pair with Qian (Heaven, Yang), Li (Fire) with Kan (Water), Xun (Wind) with Zhen (Thunder), and Dui (Marsh) with Gen (Mountain)—only through Yin-Yang pairing can resonant interaction occur. If fire ascends while marsh descends (the Li trigram meeting Dui), two Yin forces combine to form the "Kuai Hexagram" (symbolizing divergence). Confucius remarks in the Commentaries: "When two women dwell together, their purposes differ"—like two women attempting marriage. Even with silver-tongued matchmakers like Su Qin or Zhang Yi, true harmony remains unattainable. Such are the pitfalls of one-sided cultivation.

The text then elucidates alchemical principles: When incorrect ingredients or imprecise measurements are used, no amount of divine assistance—whether the Yellow Emperor tending the furnace, Perfected Lord Taiyi (a Daoist immortal) stoking the flames, the Eight Lords (Liu An’s alchemical advisors) preparing herbs, or the Prince of Huainan compounding elixirs—can succeed. Building jade altars or offering unicorn flesh and phoenix jerky as sacrifices, kneeling in supplication to spirits, or observing fasts and ablutions—all prove futile. Such efforts resemble patching a cauldron with glue, treating wounds with brine, adding ice to cool fever, or using boiling water to reduce heat—as absurd as expecting turtles to fly or snakes to dance.

Authentic alchemy requires pairing substances of corresponding natures. What constitutes correspondence? The stem of life (mingdi) within the Li trigram and the root of innate nature (xinggen) within Kan—one Yin, one Yang—form true lead and mercury (Neidan terminology symbolizing Yin-Yang). Most mistake postnatally tangible materials (like orpiment, realgar, sulfur, metals, and minerals) for genuine lead-mercury, unaware these primordial forces originate from formless cosmic origins. Even with proper ingredients, lacking correct refinement methods renders efforts void. Some eschew enlightened masters, deludedly pursuing furnace-fire techniques, exhausting family fortunes year after year—building altars to implore ghosts and gods, hoping for divine intervention. They fail to realize: were immortals themselves to conduct such practices, failure would still ensue. For Waidan (external alchemy) employs counterfeit seeds and discordant methods—precisely the folly described earlier.

Using glue to mend a pot or applying brine to heal a wound—these substances are fundamentally incapable of repair or treatment. Everyone knows that ice represents the coldest substance, while boiling water embodies the utmost heat, just as turtles cannot fly and snakes cannot dance. Yet some people absurdly try to drive out cold by adding ice, dispel heat with boiling water, or force turtles to fly and snakes to dance. Such actions blatantly violate the natural principle of water and fire complementing each other and fail to grasp the profound mechanism underlying the turtle and snake's mutual restraint. The result is nothing but increasing chaos and grave error. How do these misguided practices differ from the absurdities of heretical paths?

The essence of the Great Dao (Daodejing) lies in the interplay of Yin and Yang, which manifests as the relationship between one's innate nature (Xing) and vital life (Ming). Though called by different names, these two share the same origin and are fundamentally one. In Fu Xi's "Book of Changes" (Yijing), they appear as the Kan (Water) and Li (Fire) trigrams; in Laozi's "Classic of the Way and Virtue" (Daodejing), they are expressed through the concepts of "Non-being" (Wu) and "Being" (You). In truth, the fundamental principle of the Great Dao can be conveyed in a single sentence. Unfortunately, later alchemical scriptures (Danjing) employed excessive metaphors, opening the floodgates of misunderstanding and leading many astray into heterodox practices.

In alchemical cultivation (Neidan), references to male and female symbolize the Qian (Heavenly) principle that forms masculine qualities and the Kun (Earthly) principle that shapes feminine traits—representing the spiritual parents (Original Spirit [Yuanshen] and Original Essence [Yuanjing]) within the human body, not literal men and women. When lead and mercury are mentioned, they signify the Original Essence (Yuanjing) in the Li trigram and the Original Qi (Yuanqi) in the Kan trigram—denoting the true Jing, Qi, and Shen within the body, not actual metallic substances. Yet worldly people, driven by greed and lust, either indulge in perverse techniques of "harvesting Yin to supplement Yang" or superstitiously pursue external alchemy (Waidan).

Those practicing licentious arts mistakenly equate real men and women with Yin-Yang, using the Dao as pretext for carnal indulgence. Those obsessed with external elixirs erroneously take cinnabar and mercury as the Golden Elixir (Jindan), masking avarice with spiritual pursuit. These heterodox paths not only slander the sages' teachings but sever the authentic practice for future generations. Under the guise of cultivation, they commit grave sins, condemning themselves to hellish rebirths.

Some seekers, though possessing slightly clearer insight and nobler aspirations—avoiding the aforementioned heresies—turn inward to seek the Dao through body and mind. Yet they mistakenly identify the physical body as a mere temporary aggregation of earth, water, fire, and wind (the Four Elements), unaware that the true body is the wondrous existence within emptiness. They wrongly perceive the heart as the physical organ, failing to recognize the true heart as the emptiness within wondrous existence. In reality, body and mind are originally one, provisionally called the "Elixir." Regrettably, without guidance from enlightened masters, these practitioners inevitably mistake the illusory physical form for their true self.

Those who cling to illusory forms often rigidly adhere to methods of circulating Qi and Jing (vital energy and essence), overemphasizing deliberate cultivation. Their error lies in seeking the body externally, unaware that true emptiness is the body itself—even the form they cling to is illusory. Those obsessed with deluded thoughts stubbornly fixate on seated meditation and trance states, overemphasizing Wuwei (non-action) practice. Their mistake is seeking the true mind externally, ignorant that wondrous existence is the genuine heart-mind—even the thoughts they grasp are false.

They fail to realize that cultivating only life-force (命功) without understanding mind-nature (心性), even with a lifespan matching heaven and earth, still leaves one a fool. Conversely, contemplating only mind-nature without life-force cultivation leaves the yin-spirit trapped through countless kalpas, never attaining sagehood. How much more misguided are those clinging to both illusory forms and deluded thoughts—they’ve mistaken the very object of practice! Generally, fixating on one extreme without achieving synthesis stems from imbalances of Yin and Yang, far from the great Dao of harmonious unity.

The Zhenren (Perfected Person) Wei Boyang (famous Eastern Han alchemist) composed the Zhouyi Cantong Qi (The Kinship of the Three), probing the Yijing’s fundamental principles through alchemical metaphors to verify the cultivation essence of Huangdi (Yellow Emperor) and Laozi. His aim was simply to reveal the "two things with different names but shared origin" (referring to nature and life), enabling all beings to reach the other shore through perfecting mind-nature and refining life-force. Yet fearing heterodox paths would obscure the true Dharma, he had to clarify distinctions; concerned petty practices would deviate from truth, he had to correct errors. Though the "Nourishing Nature" chapter repeatedly explains this, worried the world might still not comprehend, he here again elucidates the authentic transmission to dispel all side paths—guiding later seekers to abandon false views for the true path, transcend delusion, and realize suchness. Thus, his merit equals Fuxi, King Wen, and Confucius in unfolding the Yi, and Huangdi and Laozi in composing classics.

Chapter 31 discusses the essentials of successful "Fu Shi" (the inner alchemical process of gathering and refining the medicinal elixir): The ancient sages embraced profound mystery and held the true Dao, transforming their substance through the Ninefold Reverted Golden Elixir (the nine stages of Neidan practice), concealing their traces to withdraw from the world. They nurtured Shen (spirit) to commune with the Three Luminaries (sun, moon, stars), filled skin and pores with refined Qi, and solidified bones and joints until all pathogenic Qi dispersed, leaving only pure Yang energy. Through sustained accumulation, they shed their mortal form to attain immortality.

Observing later seekers often following deviant paths, Wei Boyang used diagrams and texts to point to the ancient sages’ true transmission. While revealing some branch methods, he concealed the root secrets. These teachings, wrapped in complex terminology, instead bewildered many students. Those receiving the true transmission treasured it as a lifelong secret, yet father-to-son transmission bred increasing confusion until the genuine art was lost. This caused officials to neglect governance, farmers to delay plowing, merchants to abandon goods, and aspirants to impoverish households—truly heartbreaking. Thus, he resolved to record these true formulas in concise words for contemplation, with straightforward methods for easy practice.

This passage elucidates the process and principles of attaining transcendental states through cultivation. Ancient sages achieved the Great Dao (Daodejing) through nine years of "fushi" (a Neidan/internal alchemy practice involving ingestion of elixirs or refining essence-energy).

The cultivation hinges on three key aspects: First, "embracing mystery and holding truth" (maintaining mental stillness to preserve the primordial Qi of authentic unity), which constitutes the work of nurturing one's innate nature. Second, undertaking the "nine-cauldron refinement process" (the complete alchemical procedure of ninefold golden elixir transformation), achieving metamorphosis as exemplified by the Yellow Emperor's ascension at Dinghu Lake and Laozi's western journey through Hangu Pass. Finally, aligning the body's fundamental energies—original essence (Yuanjing), primordial Qi (Yuanqi), and innate spirit (Yuanshen)—with the celestial triad of sun, moon, and stars (the Three Radiances).

Tangible cultivation effects manifest as: abundant essence-energy (Jing-Qi) producing radiant skin and robust sinews, while nurtured upright Qi dispels pathogenic influences—demonstrating the physical marvels. Through prolonged accumulation, practitioners ultimately transcend corporeal constraints to become "perfected beings" (Zhenren), attaining the sublime state where form and spirit achieve dual perfection.

The author compassionately records these mysteries through diagrams and texts to guide future seekers, particularly emphasizing persistent practice—three years of uninterrupted day-night cultivation yields the supernatural ability to "traverse fire unburned and enter water unwetted." At ultimate merit completion, the Supreme Unity deity (Taiyi) summons the adept to immortal isles to confer the celestial register (Xianlu), the official credential of transcendence.

Note: "Receiving registers and talismans" (Yinglu Shoufu) denotes celestial bureaucracy conferring official transcendence credentials; the "Three Radiances" (Sanguang) represent sun-moon-star essences symbolizing heaven-earth quintessence in alchemical practice.

The ancient sages wrote texts to awaken humanity, yet later generations often misunderstood their true intent. These sages, with their vast compassion, sought not only their own enlightenment but also to help others awaken. Thus, they reluctantly composed these classics. Take, for instance, the Yellow Emperor’s Yinfu Jing (Scripture of the Hidden Talisman) in three hundred characters, Laozi’s Daode Jing (Classic of the Way and Virtue) in five thousand words, and the alchemical scriptures transmitted by various perfected beings—all were written out of pity for future seekers who might struggle to find the path, explicitly pointing to the fundamental methods of cultivating xingming (nature and life, referring to the refinement of body and mind).

Yet the sages, fearing the disclosure of celestial secrets, expressed themselves through veiled language: they concealed the core principles between the lines, like revealing branches while hiding the roots. They used terms such as "three thefts and five bandits" or "mysterious female and bellows" (referring to the subtle mechanisms of Yin-Yang transformation), along with symbolic names like "dragon and tiger," "yellow sprout," and "golden flower" (Neidan, or internal alchemy terminology), to obscure the true meaning. This was actually to encourage seekers to study deeply, eventually grasping the essence while forgetting the surface expressions.

Sadly, most learners remain stubbornly unenlightened, unwilling to humbly seek a master’s guidance for the true teachings. It’s as if they lock away luminous pearls and treasures in a chest, never seeing the light of day—generation after generation lost in confusion. Officials lose their posts, farmers neglect their fields, merchants discard their goods, and aspiring adepts remain trapped in poverty. This resembles the story from the Lengyan Jing (Śūraṅgama Sūtra) of a poor man who unknowingly carried a priceless pearl sewn into his robe while begging for alms.

Yet this is not the fault of the sages. They composed these texts intending to awaken the world—who could have foreseen that they would instead be blamed? It’s like rivers and lakes that never hinder anyone; it is people themselves who fail to cross. The patriarchs never deceived the world; it is people who, unable to penetrate the teachings, turn around and accuse them. To avoid being misled by appearances, one must seek genuine guidance from an enlightened master.

I grieve that later students struggle to comprehend the Great Dao, hence I compose these words striving for clarity and accessibility, sparing readers from convoluted contemplation. The text presents systematic reasoning, authentic content with balanced weight, where sections echo one another. Though employing some arcane expressions, discerning minds through careful reflection can penetrate their profound meaning.

This passage conveys the author's original intent to inherit ancient sages' wisdom and educate through writing. The reason later learners fail to grasp the Great Dao often lies in lacking proper entry methods. Wei Boyang (Immortal Elder), moved by compassion for future students, composed the "Cantong Qi," employing the hexagrams of Qian, Kun, Kan, and Li from the "Yijing" (Book of Changes), borrowing alchemical terminology like dragon-tiger and lead-mercury, ultimately returning to the fundamental principles of self-cultivation and heavenly mandate found in Huang-Lao teachings. The diction pursues conciseness, thus using refined yet comprehensible language; as the core teaching remains unified, the content maintains simplicity without redundancy.

The enumerated sections divide the Great Dao into three systems (referring to the Zhouyi, Huang-Lao Daoism, and alchemy), like revealing tree branches, while the essence-exposing portions demonstrate their underlying unity, akin to hidden roots. The author's rhetorical brilliance manifests in partial revelation without complete disclosure, intentional concealment without total obscurity. Each section's relative emphasis has been carefully calibrated against ancient sages' classics for scholars' study. Complete explicitness might risk revealing celestial secrets, hence symbolic language; excessive concealment could obstruct the Dao's path, thus clues remain.

Should perceptive individuals emerge in this world, diligently studying these three sections to uncover their pivotal points, they would realize the Great Dao lies close at hand. Like treasures in a cabinet, all possess it equally without disparity. Wei Boyang's compassionate intention for later students truly continues the lineage of Huangdi (Yellow Emperor), Laozi, and other ancient sages. Compared to the 300 characters of the "Yinfu Jing" or Laozi's 5,000-word "Daode Jing," the "Cantong Qi" provides more detailed and concrete descriptions of cultivation processes.

Through diligent practice without ceasing day or night, after three years of "fushi" (ingesting one's vital essences in Neidan practice), the body becomes light enough to roam heaven and earth, unharmed by fire or wet by water, capable of vanishing or appearing at will, eternally joyful and carefree. When merit and virtue reach perfection, one naturally awaits the destined moment—then the Great Unity Celestial Deity (Taiyi) will summon the adept to the immortal realms (Central Continent), culminating in complete achievement, ascension to heaven, and reception of the immortal official's talismanic mandate (proof of Dao-realization).

This section describes the realm attained by scholars who penetrate the "Cantong Qi's" profundities and achieve immortality through cultivation. The Dao-seeking path requires unity of knowledge and practice, just as walking needs both feet and eyes. Initial obstacles stem from ignorant confusion; after comprehending principles, fear arises about lacking practice; following practice, concerns emerge about perseverance.

Those who lack diligence in practice, even if they receive guidance from a true master and comprehend the essentials of refining the Golden Elixir (referring to Neidan practice), should still enter the cultivation space (the alchemical chamber) with companions, concentrating wholeheartedly on their training. Laozi said: Those of superior capacity, upon hearing the Dao, will diligently practice it. Ma Danyang (a patriarch of the Quanzhen school) also said: The master's kindness is profound and difficult to repay; the only way is to vow to retreat into seclusion and cultivate the ultimate truth unto death. Thus, only by working tirelessly day and night can one be called truly diligent in the art of the Golden Elixir.

Although the achievement of the Golden Elixir occurs in an instant, laying the foundation (zhuji) generally takes about a hundred days, forming the elixir (jietai) about ten months, and the nurturing and maturation stage requires roughly three years. Chen Cuixu said: The Golden Elixir can be attained in a moment, but to reach full maturity, three years are necessary. However, one need not rigidly adhere to the three-year timeframe—the key lies in the degree of diligence in practice. When nurturing is sufficient and the sacred embryo (shengtai) is perfected, one may lightly ascend and wander freely in distant realms. From then on, the dharma body transcends all constraints, impervious to water and fire, appearing and vanishing at will. When arriving, one manifests a visible form; when departing, one becomes formless and untraceable—coming and going without hindrance, eternally enjoying boundless freedom.

Embracing the primordial Qi (yuanqi) is called "Dao," while accumulating virtuous deeds is called "De." Only when both are complete can one roam the human world while awaiting the moment of ascension. Thus it is said: Once the Dao is achieved and virtue perfected, one should live in seclusion, awaiting the opportune time. Beyond the mundane world lie the Four Seas, within which are three immortal islands (the upper islands: Penglai, Fangzhang, and Yingzhou; the middle islands: Furong, Langyuan, and Yaochi; the lower islands: Chicheng, Yuanguan, and Taoyuan). Among them, the Purple Mansion Isle (Zifu Zhou) is where the Supreme Unity Primordial Lord (Taiji Yuanjun, the highest Daoist deity) resides and examines the merits of immortals. If practitioners wish to shed their mortal shells and ascend, they must first undergo evaluation by the Primordial Lord before gradually rising through the celestial realms. With three thousand merits, one becomes a Great Luo Heavenly Immortal; with eight hundred virtuous deeds, one may serve as a Great Luo guest—ultimately receiving celestial talismans (tianshu fulu) and attaining the supreme rank of a perfected being (zhenren).

However, these descriptions are merely metaphorical devices to guide ordinary practitioners and prevent them from falling into nihilistic views. Ultimately, the so-called "central isle" is none other than one's own Dantian, the "Primordial Lord" is one's own original spirit (yuanshen), "ascension" means returning to one's true nature, and "receiving the talisman" signifies the restoration of one's primordial essence (the original face of Qian). It is liberation from the cycle of birth and death.

This passage summarizes the core content of the middle section of the Cantongqi (参同契) and outlines the structure and key concepts of its final section.

The conclusion of the middle section explains that when cultivation reaches profound levels, one's Shen (spirit) merges with the void, ultimately becoming one with the Dao. This transcendent state resembles clouds floating freely across the sky—a profound implication left partially unstated by Wei Boyang (Master Wei). While this chapter ostensibly discusses the essentials of successful Fushi (伏食, the Neidan practice of ingesting the elixir), it actually serves as the comprehensive conclusion to the entire middle section. Earlier chapters on "governing principles" (御政) only addressed the patterns of cosmic creation without touching upon the mysteries of nature-life cultivation (性命双修). The "nourishing nature" (养性) chapters, while addressing crucial aspects of nature and life, didn't fully explain the concrete methods of alchemical practice. Only through the seven chapters beginning with "the sun's flowing pearls" (太阳流珠) do we find complete instructions for Fushi practice—including gathering medicinal ingredients (药材采取), harmonizing Yin-Yang (阴阳配合), and the firing process (火候烹炼)—topics not fully developed in the first section.

The author clarifies his purpose in writing this text: to transmit the authentic teachings of ancient sages while guiding future practitioners. Following these methods faithfully leads directly to immortal attainment. This echoes the statement concluding the first section—"I dare not speak recklessly, but merely emulate the literary style of sages"—confirming this indeed serves as the middle section's conclusion. Current editions mistakenly place this passage at the beginning of the final section.

The final section, alternatively titled Sanxianglei (三相类, Three Corresponding Categories) or Buse Yituo (补塞遗脱, Supplementing Omissions), primarily integrates the three components from previous sections: "governing principles," "nourishing nature," and "Fushi." Chapter One explains the wondrous function of the cauldron and furnace (鼎炉, metaphors for the body's alchemical vessels). Chapter Two reveals the complete method of fire regulation (火候, mental control during practice). Chapter Three demonstrates how three cultivation paths ultimately return to the Dao. Chapter Four directly points out how "the four manifestations return to emptiness" (四象还虚, reverting essence, Qi, and spirit to their primordial state) aligns with supreme Daoist principles. The final chapter presents the author's writing intention while concealing his true name. These five chapters form a coherent exposition of the "three correspondences" core philosophy, supplementing omissions from the first two sections.

The concluding "Chapter on the Wondrous Use of Cauldron and Furnace" details the elixir vessel's specifications: circular shape, three-and-a-half-inch diameter, eight-inch circumference, two-inch-wide mouth, twelve-inch-long rim with even thickness, and a belly featuring three raised ridges—all maintained in a warm, moist state. These concrete measurements metaphorically represent key bodily locations and states during internal cultivation.

This passage elucidates the core principles of the "cauldron and furnace" (metaphorical sites for cultivating energy within the body) in Daoist Neidan (internal alchemy) practice. The Yin and Yang energies circulate within the body—Yin qi flowing above and Yang qi below—forming an interconnected cycle. The complete cultivation period spans 260 days, beginning with 70-day cycles and concluding with 30-day intervals, requiring meticulous harmonization.

The term "Yin fire, white yellow sprouts, and lead" refers to two essential substances generated during practice: Yin fire (internal energy produced during cultivation) and lead-mercury (alchemical terms symbolizing the body's vital essences). These substances accumulate at specific acupoints, aiding practitioners in stabilizing Shen (spirit) and elevating primordial qi, ultimately achieving physical-mental equilibrium.

During cultivation, energy circulates internally without dissipation, moving like a traveler passing through gateways. As practice deepens, one's temperament becomes purified, returning to the origin of life. Practitioners must maintain the reverent vigilance of ruler and minister, remaining diligent throughout the cycle to avoid losing direction. This path is both profound and distant—mastering its mysteries enables communion with heaven and earth.

The "knife-guǐ" (an ancient medicinal measure, metaphor for微量精华) purifies the ethereal and corporeal souls, granting longevity and celestial abodes. True Dao devotees investigate fundamental principles, meticulously studying the precise ratios of the Five Phases (Wood, Fire, Earth, Metal, Water). Such profound truths require silent contemplation rather than casual discussion, and must be deeply guarded. At advanced stages, practitioners ride white cranes and dragon-scales through the Taixu (Great Void) paradise, paying homage to immortal lords, receiving celestial registers, and attaining genuine transcendence.

The latter section details the cauldron-furnace structure. There are two types: The small cauldron-furnace uses Li trigram (symbolizing fire) as the "hanging-embryo cauldron" and Kan trigram (water) as the "crescent-moon furnace," with the central palace's divine chamber as the human position. The large version employs Qian trigram (heaven) above as cauldron and Kun trigram (earth) below as furnace, with the central Huangting (Yellow Court) as human position. Both feature upper/middle/lower tiers corresponding to heaven-human-earth triads. Once established, cosmic patterns manifest within them: the Two Forms (Yin-Yang), Four Symbols, Five Phases, Eight Trigrams, twelve earthly branches, twenty-eight lunar mansions, and the celestial 365-degree cycle. Modeled after Qian-Kun (heaven-earth), the round cauldron mirrors celestial rotation (diameter 1, circumference 3, per Hetu numerology), while the square furnace embodies earthly form.

This scripture elucidates the mysteries of the "furnace and cauldron" (referring to key energy centers in the body) and fire regulation in Daoist Neidan (internal alchemy) practice. It employs cosmological numerology to illustrate the principles of internal energy circulation:

The number three of the East (Wood) combines with two of the South (Fire) to make five, while one of the North (Water) joins four of the West (Metal) to likewise form five. The central Earth phase of Wuji naturally constitutes another five. These three fives encircle the center, creating a complete energetic matrix. Though this central void occupies merely one Cun (a traditional Chinese inch), it houses the "Celestial Heart" (the body's energetic core), from which the dual energies of Qian and Kun (Yin-Yang) differentiate—much like Shao Yong's cosmological principle that "the transformations of heaven and earth emerge from the primordial One."

The text employs geometric symbolism: the circle represents heaven (three-five Cun with one division), while the square symbolizes earth (Fangcun, the "square inch"). This square inch divides according to the Luoshu (ancient mystical diagram) into four cardinal directions (east, south, west, north) and four intercardinal directions (southeast, southwest, etc.), corresponding to the Four Symbols and Eight Trigrams. Within the body, the central aperture of this square inch resembles a mouth, with its upper and lower boundaries forming lips, while the surrounding energies correspond to the four seasons and eight solar terms (major nodes of the twenty-four seasonal divisions).

The movement of Yin-Yang energies follows celestial rhythms: from Zi hour (midnight) to Si hour (mid-morning) comprises six Yang hours corresponding to spring and summer—optimal for advancing the fire (strengthening energy); from Wu hour (noon) to Hai hour (late night) forms six Yin hours matching autumn and winter—suitable for withdrawing the fire (conserving energy). The annual cycle of solar terms thus mirrors the monthly and daily practice rhythms.

Authentic cultivation requires aligning with natural patterns by locating this internal "furnace and cauldron" rather than seeking external solutions. When the Water and Fire energies (Yin-Yang forces) converge in the Central Palace (abdominal region), practitioners must maintain serene stillness—neither forcing progress nor neglecting the process—awaiting the spontaneous manifestation of Shen (spirit). The text concludes by emphasizing balanced fire regulation to maintain Yin-Yang harmony, noting that successful integration requires specific cultivation cycles (either seventy or thirty-day periods totaling 260 days).

This passage explains the principles of fire regulation (the control of intention and breathing during practice) in Daoist Neidan (internal alchemy) when achieving the state of "water and fire in perfect harmony" (the balance of Yin and Yang).

The Li fire (heart fire) naturally ascends, yet the true Yin (true water within Li) within it naturally descends. The Kan water (kidney water) naturally descends, yet the true Yang (true fire within Kan) within it naturally rises. This dynamic relies entirely on the true earth of the central palace (the Qi of the spleen and stomach) to harmonize and balance them. When Yin and Yang unite and the great medicine (Neidan) is about to form, it is like refining elixir in a furnace, requiring the alternating use of martial fire (intense focus) and civil fire (gentle focus).

During the Zi hour (11 PM–1 AM), when Yin exhausts and Yang begins to emerge, martial fire is used to advance Yang and retreat Yin. During the Wu hour (11 AM–1 PM), when Yang exhausts and Yin begins to emerge, martial fire is also used to advance Yin and retreat Yang. However, during the Mao hour (5–7 AM) and You hour (5–7 PM), civil fire is needed for gentle bathing and nurturing. This is akin to the winter solstice, where the first stirring of Yang marks the beginning of the six Yang phases, and the summer solstice, where the first stillness of Yin marks the end of the six Yin phases—both requiring martial fire. Meanwhile, the equinoxes of spring and autumn correspond to the gentle bathing of civil fire.

The entire cultivation cycle spans 360 days, corresponding to the celestial degrees of the Zhou Tian (Heavenly Circuit). Excluding the initial and final 100-day martial fire stages, the remaining 260 days must be evenly balanced between Yin and Yang. Of these, 200 days are devoted to Zi-Wu cultivation, while the remaining 60 days are for Mao-You bathing, totaling 300 days—the exact duration of the "ten-month gestation" (the formation of the internal elixir). The key lies in mastering the precise application of fire regulation: martial fire is used for the intense refinement during the north-south (Zi-Wu) convergence, while civil fire is employed for the peaceful stillness of nurturing in the central palace (Dantian).

Master Ziyang (Zhang Boduan, a Northern Song dynasty Neidan master) reminds us: true fire regulation is not merely about observing the hours. The Yang Qi at the winter solstice does not manifest superficially at the Zi hour, and the bathing method emphasizes seizing the right moment during Mao and You. Practitioners must maintain unwavering focus at all times, avoiding distraction, for the most subtle fire regulation often occurs in mere fleeting instants.

This passage describes the initial nurturing process of the Golden Elixir (Jindan, the core concept of Daoist Neidan/internal alchemy) within the alchemical furnace. The true mercury (a Neidan term referring to the original spirit) within the Li trigram (one of the Eight Trigrams/Bagua, symbolizing fire) is called yin-fire. It manifests from the framework of Qian-metal (the Qian trigram belongs to metal), appearing as a white substance tinged with black. The true lead (a Neidan term referring to original qi) within the Kan trigram (one of the Bagua, symbolizing water) is called the yellow sprout, which bursts forth from the maternal body of Kun-earth (the Kun trigram belongs to earth), revealing the phenomenon of lead producing gold.

The number seven represents fire's completion number. The flowing pearl (referring to the original spirit) of the Li trigram is called yin-fire, while the yellow sprout of the Kan trigram is called yang-fire. These two fire phases converge and blend within the divine chamber (referring to the Dantian/energy center), like having supporting wings. The great medicine (the refined essence produced in Neidan practice) initially emerges from the Kun furnace (lower Dantian), and when the time is ripe, it ascends to the Qian cauldron (upper Dantian, located near the Baihui point at the crown of the head). At this stage, one must guide it with true intention (focused awareness), directing the medicinal force straight up to the Tiangu point at the head's summit before returning it to the Yellow Court (middle Dantian). This process resembles an infant (chizi) resting peacefully within the Yellow Court, completely at ease.

Initially, the medicinal force is only the size of a millet grain, but through gradual nurturing it expands, and its nature (referring to the medicine's quality) becomes purified. This true seed (primordial qi) originally comes from the Supreme Ultimate (Taiji), having differentiated into yin-yang, the Three Powers (heaven-earth-human), the Four Symbols, and all phenomena. Through cultivation, these dispersed energies are now reunited into oneness—this constitutes the path of returning to the origin in elixir formation. Throughout the entire practice, though the energy rises, descends, and circulates, it never departs from the gate of the original feminine (referring to the Dantian as the crucial focal point).

This passage elucidates the core principle of "guarding the One" (shouyi) in Daoist cultivation. The character "One" (yi) encapsulates the essence of Confucian, Buddhist, and Daoist traditions. Laozi proclaimed, "Attaining the One enables all things to flourish," while the Yellow Court Scripture (Huangting Jing) states that the cyclical movement of the Five Phases ultimately returns to the One. Confucius' "thread running through it all" and the Buddha's "all dharmas return to One" all point to this fundamental truth. Here, the focus lies in maintaining the unity of body and mind to establish a solid foundation for practice—much like precious substances in an alchemical crucible require the crucial process of gentle nurturing.

During cultivation, the relationship between innate primordial Qi (ancestral Qi, zuqi) and acquired vital essence (jing) should harmonize like the mutual respect between ruler and subject. The innate Qi acts as the sovereign (ruler), while the acquired essence serves as the supporting minister—both must coexist in perfect balance. The entire alchemical process demands nine cyclical transformations (jiuzhuan), requiring meticulous care comparable to ten months of gestation and three years of nursing, without the slightest negligence. When the primordial spirit (yuanshen, innate consciousness) resides in the dantian, it must be ceaselessly guarded by true intention (zhenyi, purified awareness), as momentary distraction could undo all progress.

The primordial spirit manifests unpredictably, capable of traversing heaven and earth in an instant, yet remaining elusive to grasp. Golden Elixir (jindan) cultivation unfolds in two stages: the initial phase involves the intercourse of Kan (Water) and Li (Fire)—the yin-yang polarity—to generate the "true seed"; the deeper stage requires refining essence into Qi (lianjing huaqi) and Qi into spirit (lianqi huashen), thereby reconstructing one's foundation. The most crucial element is a mystical elixir called "knife-measure" (daogui, metaphor for cultivated essence), which purifies the ethereal and earthly souls (hunpo), transcending life and death. At this stage, one's true nature becomes self-sustaining and impervious to external influences—though the physical body remains in the mundane world, the spirit merges with the Great Void (taixu, cosmic origin).

This passage elucidates the core principles and ultimate attainments of cultivating the Golden Elixir (Jindan) path. It first emphasizes that Daoist practice must grasp the fundamental root, just as Laozi taught "returning to the origin and restoring one's innate nature" (guigen fuming). Ordinary people often seek the Dao through trivial details, thereby drifting ever further from the essential truth.

True practitioners must comprehend the mysteries of the Five Phases (Wuxing - Metal, Wood, Water, Fire, Earth). While the sequential movement of these phases governs ordinary human life, their reverse operation holds the key to immortal attainment. However, this method of phase inversion contains profound subtleties - the slightest deviation in timing or intensity (huohou) during practice will prevent the successful formation of the elixir. Hence the text particularly stresses the need to "precisely determine the measurements of the Five Phases" (shen wuxing ding zhufen), requiring exact control over their generative and restrictive interactions.

The entire secret of the Golden Elixir path lies in mastering huohou - the proper timing and degree of practice. This constitutes the orally transmitted secret knowledge passed down through generations of patriarchs. Practitioners can only comprehend this through personal realization, never through casual discussion or written explanations. When the practice reaches perfect maturity and the Sacred Embryo (shengtai, the crystallized product of spirit condensation) becomes complete, the practitioner undergoes complete physical and spiritual transformation. At this stage, visions appear of riding white cranes or fire dragons through the Great Void (taixu, the highest celestial realm), paying homage to the supreme immortals, receiving celestial charts of immortality, attaining the status of Great Luo Heaven Immortal, and being granted the title of "Perfected Being" (zhenren).

Yet the scripture reminds us these miraculous visions are ultimately symbolic representations of internal cultivation: the white crane and fire dragon symbolize one's primordial Qi (yuanqi), the Great Void represents the mysterious pass (xuanguan) within the body, the immortal lords correspond to one's original spirit (yuanshen), the celestial charts signify the primordial Dao, and the Perfected Being refers to one's true innate nature. As Buddhist scriptures state, "All phenomena are illusory" - these external manifestations are provisional appearances, with the essential point being the recognition of one's original face.

Finally, the text explains the dual meaning of "zhenren": for ordinary people, it denotes the Dharma Body (fashen, the primordial nature inherent in all beings); for realized adepts, it refers to the Reward Body (baoshen, the perfected fruition of cultivation). This passage thoroughly explains the cultivation principles, huohou secrets, and verification stages of the Golden Elixir path, emphasizing the need to grasp fundamentals, precisely regulate practice, and ultimately realize one's true nature.

This passage elucidates the essence of spiritual realization. The perfected reward-body (the sublime fruition of cultivation) attained by sages is none other than the Dharma-body (the innate Buddha-nature) inherently possessed by all ordinary people. Though everyone is endowed with this fundamental nature, most fail to recognize and embrace it in the present moment, thus wasting their lives in the six realms (heavens, humans, asuras, hells, hungry ghosts, animals) of cyclic suffering. How can one blame heaven for this?

While this chapter primarily discusses the mysterious functions of the cauldron and furnace (metaphors for the body in Neidan/internal alchemy practice), it actually encompasses all key aspects of the medicinal ingredients (Jing, Qi, and Shen) and firing times (cultivation timing), serving as a comprehensive summary of the three essential elements of the Golden Elixir. However, one must read it in conjunction with the next chapter to fully grasp the profound interplay of these three components.

Chapter 33 details the complete practice of fire-phase application:

The celestial patterns of heaven and earth operate on the grandest scale, with the mysterious channel (the governing and conception vessels) of Yin-Yang interaction spanning endlessly. When the Altair star reaches its celestial position, people instinctively perceive astronomical changes. Should sundial measurements deviate, disasters may persist for nine years. When heaven observes such anomalies, rulers naturally correct their ways. As the pivotal mechanism (the body's Qi dynamics) undergoes ascent and descent, pathogenic energies disperse. Like the Yangtze and Huai rivers eventually returning to the sea after drying up.

The Yin and Yang energies of heaven and earth interact during the Zi (midnight) and Wu (noon) hours, while the Yin and Yang transitions fundamentally occur during the Yin (dawn) and Shen (dusk) hours. This cyclical movement resembles the rotation of the Big Dipper, which governs celestial balance and calendar systems. The medicinal ingredients (essence and Qi) are steamed atop the Zengkong mountain (the crown of the head), with true fire blazing below. The White Tiger (lung metal Qi) leads the way, while the Azure Dragon (liver wood fluid) harmonizes from behind. The Vermilion Bird (heart fire) spirals and dances, radiating five-colored brilliance.

When encountering obstacles and constraints—like a bird trapped in nets unable to soar—one may cry like an infant longing for its mother. Though the inverted immersion in the cauldron's refining fire may cause surface damage, it resembles how dragon scales regain their luster before half a ke (an ancient time unit). The five-colored lights shimmer unpredictably as the cauldron boils like a surging spring. Layer upon layer accumulates like interlocking teeth, forming shapes resembling winter icicles or stalactites.

Perfect Yin-Yang harmony enables serene mutual nourishment. The Azure Dragon resides in the Fang constellation (east), blossoming like spring in the Zhen position; the White Tiger dwells in the Mao constellation (west), manifesting autumn's austerity in the Dui position; the Vermilion Bird occupies the Zhang constellation (south), shining like midday sun in the Li position. When these three gather in assembly, it resembles a family reunion. Fundamentally, they are but two substances (Yin and Yang) that ultimately fuse into three fields and five energies, returning to oneness. The cultivation method follows established principles with fixed temporal cycles. First appearing white then turning yellow, with red permeating throughout—this is called the "First Cauldron," producing elixir grains the size of millet seeds. All this follows natural transformations, never deviant paths. Just as mountain and marsh vapors rise and merge, clouds and rain form spontaneously.

This passage discusses the control of firing times (huohou, referring to the technique of regulating furnace temperature and duration) in alchemical practice, using natural phenomena as metaphors. Just as clouds accumulate to form rain, dried earth turns to dust, extinguished flames become ashes, the amur cork tree yields yellow dye, and indigo plants produce green—these are all natural transformations within the same category of substances. Leather boils into glue, yeast ferments into wine; substances of the same kind readily interact, while different categories resist transformation.

The author emphasizes that this exquisite alchemical art is genuine and can be verified through the ages. Like stars traversing the Milky Way or rivers inevitably flowing to the sea, its profundity requires repeated contemplation to grasp. When cultivation reaches a certain stage, spiritual insight (shen) will suddenly bestow revelation, and the mind will naturally awaken. However, to find the entry point, one must patiently explore the thread of understanding. The Dao of Heaven (natural law) shows no partiality—it is transmitted only to those with genuine wisdom.

The text then explains this passage's placement and function within the Cantongqi (The Seal of the Unity of the Three). Originally misplaced before the "Perfecting the Three Fives" chapter, it has now been restored to its correct sequence. Using celestial movements as metaphor, it comprehensively illustrates alchemical firing cycles. While focusing on huohou, it actually encompasses alchemy's three core elements: the furnace-vessel (equipment), medicinal ingredients (materials), and firing regulation.

The book's first two sections separately address state governance, life cultivation, and alchemy—each implicitly containing these three elements, though scattered. Thus, Wei Boyang (the author) composed the "Perfecting the Three Fives" chapter as summation. However, that chapter primarily discusses the nurturing and preservation of the Golden Elixir (jindan, the advanced stage of neidan practice), leaving the fusion and refinement of the Reverted Elixir (huandan, the preliminary stage) insufficiently described. This passage follows to complete the explanation.

Finally, celestial phenomena serve as warnings about huohou's critical importance. When the Heavenly Drum star (Altair) moves to the Stellar Chronogram (one of twelve celestial sectors), spanning tens of thousands of miles across the Milky Way, earthly anomalies appear. Should sundials cast disordered shadows, nine consecutive years of calamity will follow—even emperors must repent upon witnessing such omens. Similarly, regulating alchemical fire resembles managing river levels: neither excessive nor deficient, success comes only through emulating rivers that ultimately return to the ocean—by aligning with nature's flow.

This passage explores the correspondence between celestial movements and human cultivation. Just as irregularities in heavenly phenomena can trigger natural disasters, improper circulation of Qi (vital energy) within the body leads to physical and mental disorders.

The text describes how the celestial mechanism (the cosmic system of heavenly bodies) mirrors human physiology. The eight-thousand-four-hundred-mile span between the Celestial Pivot and Earth's Axis finds its counterpart in the body's energy channels. The Yuan Trench (an energetic dividing line) separates the human form into upper and lower regions, mirroring the heaven-earth structure divided by the Metal-Wood polarity. The River Drum constellation (a three-star formation symbolizing military commanders) normally resides outside the Chou position (one of the twelve Earthly Branches directions). Its aberrant appearance in the corresponding celestial sector portends impending floods.

During cultivation, the Zi to Chou hours (11 PM to 3 AM) mark the critical period of Yang energy's initial emergence. Forcing Jing (essence) and Qi activation prematurely disrupts the body's energy flow like panicked crowds witnessing celestial omens. The sundial's shadow here symbolizes the "fire times" (the rhythmic regulation of internal energy) where every advance or retreat must be precisely measured. Just as untimely seasonal transitions cause floods or droughts, a single misstep in energy modulation can ruin an entire nine-cycle refinement process (the nine transformations of energy sublimation).

The text employs imperial metaphors: the "August Sovereign" represents our innate nature (humanity's original pure essence), while the "Regent" symbolizes acquired consciousness. The sovereign abides in stillness within the Divine Chamber (upper Dantian), whereas the regent actively governs the Celestial Meridian (the body's energy circulation). Only through their harmonious interaction can the fire times be properly regulated. Like ancient emperors rectifying their governance upon observing celestial warnings, cultivators must promptly correct deviations to align their inner energy movements with cosmic patterns.

This passage discusses the relationship between "fire timing" (huohou, the regulation of intention and breathing in cultivation) and the natural rhythms of heaven and earth in Daoist practice. It begins with an astronomical metaphor: The North Star rises 36 degrees above the horizon while the South Star dips 36 degrees below, forming the celestial pivot of cosmic rotation. Just as the orderly movement of stars never falters, practitioners must coordinate the "heavenly gate" (upper dantian) and "earthly axis" (lower dantian) during cultivation.

When intention becomes focused and breathing properly regulated (the "pivotal seal" secured), the body’s turbid yin energies naturally dissipate. Like rivers requiring the ocean as their destination to avoid flooding, the body’s vital essence (qi) must gather in the "primordial sea" (dantian). By harmonizing breath and awareness (the two polar pivots), one guides internal energies toward the dantian, mirroring how all waterways ultimately return to the sea.

The text then uses solar and lunar cycles to illustrate fire timing: The hour of Zi (midnight) symbolizes yang’s initial emergence, corresponding to the winter solstice; the hour of Wu (noon) marks yin’s birth, aligning with the summer solstice. These transitional moments resemble the sun’s brief pause at its zenith (ancients called this "lingering noon"). In practice, when true fire (kidney yang) ascends from the lower dantian—still fragile at first—one should close the eyes in stillness, emulating winter’s dormant quietude.

Throughout, the passage emphasizes modeling cultivation on celestial patterns, seizing the critical junctures of yin-yang flux. Through disciplined breath and intention, practitioners orchestrate their vital essence into harmonious flow, ultimately dispelling turbidity to crystallize authentic yang.

This passage explains the principle of Yin-Yang energy circulation in Daoist Neidan (internal alchemy) practice and its correspondence with celestial phenomena. During cultivation, one must grasp the timing of Yin-Yang waxing and waning, just as there are discernible patterns in celestial movements.

Practitioners should pay attention to the germination periods of Yin and Yang energies. Yang Qi (symbolized by the "hidden dragon") begins stirring at midnight (the Zi hour), while Yin Qi starts emerging at noon (the Wu hour). The Yin hour (3-5 AM) marks the true birth of Yang energy, and the Shen hour (3-5 PM) signifies the genuine growth of Yin energy. These Yin-Shen periods serve as both the source and gateway for the emergence and retreat of these dual energies.

The text emphasizes the importance of the fifth star "Heng" (the handle) in the Big Dipper constellation, which functions like a celestial compass needle indicating seasonal changes and directions. Though the nearby Yao star flickers irregularly, by following the Dipper's handle movement, one aligns with heavenly rhythms—a principle equally applicable to spiritual cultivation.

The crux of Neidan practice lies in the immobility of the "Celestial Heart" (Polaris) while the Dipper's handle rotates. When the handle points to Zi-Wu directions, it symbolizes the mutual transformation of Water and Fire energies; when oriented toward Yin-Shen positions, it represents the harmonious blending of Metal and Wood energies. Just as the Yao star follows the Dipper's rotation, cultivation must adhere to these cosmic patterns.

Finally, the text describes how the initial conjunction of Kan (Water) and Li (Fire) trigrams generates the "true seed"—the fundamental substance of alchemical practice. When Yang energy first stirs and the Dipper handle points to the Zi position, formal elixir refinement may commence. The process resembles kindling fire on Zeng Mountain (a symbolic alchemical site), where the White Tiger (representing Metal Qi) leads the way while the Vermilion Bird (symbolizing Fire Qi) follows to harmonize all elemental interactions.

This passage describes the process of fire regulation during the "Heaven-Earth copulation" (Qian-Kun jiaogou) in Daoist Neidan (internal alchemy) practice, using vivid metaphors to depict the energy transformations during elixir refinement.

Like a brilliantly colored Vermilion Bird (symbolizing the heart-mind) soaring through the sky only to be suddenly ensnared in a net, or like fledglings crying mournfully for their mother, the practitioner must employ the "inhaling, licking, gathering, and closing" techniques (four specialized breathing methods) during the crucial Zi hour (11 PM to 1 AM). This is when the "Golden Liquor" (elixir energy) produced by the union of kidney water (Kan trigram) and heart fire (Li trigram) is propelled upward from the lower Dantian (the Kun furnace).

At this stage, the energy moves like a boiling cauldron, shimmering unpredictably like dragon scales. As it ascends along the spinal pathway (the River Cart route) from the coccyx (Weilü point) to the crown of the head (Baihui point, the Kunlun summit), it resembles steam surging over an ancient steamer mountain—precisely the Zi-hour energy movement described in the Cuixu Pian (Jade Void Treatise).

The Western metallic essence (lung Qi) transforms into the White Tiger, while the Eastern wood-liquid (liver Qi) becomes the Azure Dragon. Under normal circumstances, the Azure Dragon (Yang) dominates the White Tiger (Yin), but in alchemical practice, this dynamic is reversed—the White Tiger leads while the Azure Dragon follows, creating the unique state of the Five Phases moving counter to their usual order.

The Southern Vermilion Bird (heart-mind) is inherently restless and difficult to control, yet it stabilizes only upon encountering the Northern Dark Warrior (kidney essence). During the grand energy convergence, the practitioner must shut the eyes and block the ears ("closing the openings and sealing the gates"), using specific breathing techniques ("blowing sounds and absorbing spirit") to make the heart fire descend and the kidney water rise. This differs fundamentally from the initial heart-kidney interaction (Kan-Li copulation). Through the interplay of the Four Symbols (Azure Dragon, White Tiger, Vermilion Bird, Dark Warrior), this passage vividly illustrates the profound mystery of energy reversal in Neidan cultivation.

This passage depicts the mystical phenomenon of "water and fire in mutual nourishment, dragon and tiger coupling" during Daoist Neidan (internal alchemy) practice. The Vermilion Bird (symbolizing heart fire) and the Dark Warrior (symbolizing kidney water) restrain each other, like birds trapped in a net unable to fly. Fire's nature should ascend, yet it's suppressed by water's power, emitting plaintive cries like an infant longing for its mother. This inverted water-fire dynamic resembles throwing birds into boiling soup—their feathers break and flight becomes impossible.

When water and fire achieve mutual balance, the four symbols—metal (lungs), wood (liver), water and fire—converge within the cauldron (referring to the human Dantian, energy center). In mere moments, these energies coalesce to form the elixir. The Qi (vital energy) of the Five Phases (Wood, Fire, Earth, Metal, Water) begins wondrous transformations within the cauldron, shimmering like a divine dragon's scales mid-flight, radiating indescribable iridescence. At the critical moment of refinement, the dragon (Yang energy) and tiger (Yin energy) clash, shaking heaven and earth—golden energy surges through the crown while silver currents roll like tidal waves, resembling steam bursting forth when rice nears completion.

When the fire reaches sufficient intensity, the cauldron fills with Zhenqi (true energy) interlocking like canine teeth. After the coupling completes, the golden cauldron (upper Dantian) maintains ideal warmth while the jade furnace (lower Dantian) disperses its heat. The refined essence descends into the Yellow Court (middle Dantian), first liquefying then solidifying, gradually hardening like winter icicles or crystalline stalactites. The clear, light Qi ascends to congeal at the Niwan Palace (crown of the head), while the turbid, heavy Qi sinks back to the Qi cavity (lower Dantian), creating distinct layers. When the true seed (embryonic Golden Elixir) forms, formless Qi begins materializing into tangible substance, supporting each other like pillars.

This scripture describes the key stages in Daoist alchemical practice. When the cosmic Yin-Yang (Qian-Kun) fully intermingles and true Yin perfectly matches true Yang, signs of successful elixir formation appear. At this point, one must cease vigorous fire regulation and instead employ gentle fire (wenhuo) to quietly nurture the process, akin to sealing the completed elixir within the earthen crucible (tufu) for preservation. This represents the state described as "Yin and Yang in perfect harmony, abiding in serene detachment."

The text then depicts how the Four Symbols (Green Dragon, White Tiger, Vermilion Bird, Black Tortoise) and Five Phases unite to form the Golden Elixir (Jindan). During the grand communion of Yin-Yang, the originally inverted movements of the Green Dragon, White Tiger and Vermilion Bird return to their proper positions:

The Wood-phase Green Dragon corresponds to the eastern constellation Fang (one of the 28 lunar mansions). While its numerical value should be eight, the text mentions "Fang six" because six represents water's completion number. Symbolizing spring with the Zhen trigram and the mao hour (5-7 AM), this period witnesses flourishing vegetation in bloom - hence "The Green Dragon dwells in Fang six while spring blossoms vibrate east at mao."

The Metal-phase White Tiger aligns with the western constellation Mao. Though its number should be nine, "Mao seven" appears as seven marks fire's completion. Representing autumn through the Dui trigram at the you hour (5-7 PM), this phase sees grain ripening - thus "The White Tiger resides in Mao seven while autumn harvests gather west at you."

The Fire-phase Vermilion Bird corresponds to the southern constellation Zhang, embodying noonday Yang energy. When these three celestial creatures gather in audience, it resembles a family reunion. What began as merely two substances (Yin-Yang) now achieves the perfect unity of three-five (referring to the Five Phases), ultimately merging into singular perfection. The refining process follows strict protocols, observing the elixir's chromatic transformation from white to yellow then crimson - known as the "First Crucible" - yielding golden pellets the size of millet grains.

This scripture elucidates the principle of mutual generation and restraint among the Five Phases in Daoist Neidan (internal alchemy) practice. Fire (represented by the Vermilion Bird) corresponds to the southern direction, the summer season, the Li trigram, and the noon hour. At midday, fire energy reaches its peak potency—capable of consuming wood (as wood generates fire) and melting metal (as fire overcomes metal). The phrase "the Vermilion Bird at Zhang-Er" refers to its position among the lunar mansions.

The harmonious interaction of wood, metal, and fire resembles a family reunion. Though the text doesn't explicitly mention the northern Black Tortoise (symbolizing water), its presence is implied since all three elements orient toward the North Star (symbolizing the Celestial Heart). This corresponds to the Neidan principle of "nine cycles returning, sevenfold reversal, eightfold homecoming, and sixfold abiding."

At its core, this process embodies the union of True Yin and True Yang: the Azure Dragon (wood) represents True Yang, the White Tiger (metal) signifies True Yin, and their combination with the Vermilion Bird (fire) forms the Three Families. With the inclusion of central earth, the complete Five Phases system emerges. Though seemingly complex, all ultimately derive from the differentiation of primordial Yin and Yang Qi.

The cultivation process follows both sequential and reverse paths: sequentially, it progresses from the One (Taiji, the Supreme Ultimate) to Yin-Yang, then to the Five Phases; reversely, through practice, the Five Phases consolidate into Three, Three into Two, and Two into One—ultimately returning to the prenatal primordial Qi (the "true seed"). This "One" refers to the original vital energy that ultimately settles in the body's central Huangting (Yellow Court) region.

This method descends from ancient sages and must be followed precisely. Mastery isn't achieved overnight but requires sustained dedication. Particular emphasis lies on nurturing the initial "true seed" (primordial Qi)—the foundation of the entire practice. Typically, three years are needed to complete the "fushi" (refining essence and Qi) process, beginning with elixir formation in the Qian Palace (head region) and culminating in the Huangting (middle Dantian).

This passage elucidates the natural process of forming the "Returned Elixir" (Golden Elixir) in Daoist Neidan (internal alchemy) practice. It first describes how the alchemical vessel known as the "earthen cauldron," nurtured by the Qi (vital energy) of the Earth Mother (Kun), gradually turns yellow. Through refinement by the pure Yang fire of the southern Li trigram (symbolizing ultimate Yang heat), it ultimately transforms into a crimson-red Golden Elixir. The entire progression—from white to yellow and finally to red—symbolizes the layered transformations of the elixir.

The text explains the principle behind the "Ninefold Refined Golden Elixir": though divided into nine transformative stages, the first crucible (initial refinement) already contains the essence of all nine transformations. As recorded in the Scripture on Salvation (Duren Jing), the millet-sized pearl suspended by the Celestial Worthy of Primordial Beginning symbolizes precisely this concentrated essence of the Golden Elixir. The crux of alchemy lies in the nurturing process after the "copulation of Qian and Kun" (harmonization of Yin and Yang), during which the elixir naturally coalesces into form.

The latter portion employs natural phenomena as metaphors for alchemical principles: the vapors of mountains and marshes rise to form clouds and rain; parched earth crumbles into dust; extinguished flames return to soil—just as yellow dye comes from amur cork trees and blue dye from indigo plants, all being natural transformations of kindred substances. Similarly, alchemy requires the natural pairing of true Yin and true Yang (primordial Qi), returning to the primal Qi of emptiness, rather than relying on artificial manipulation or external supplementation through heterodox methods. Like leather boiling into glue or ferment turning into wine, only kindred substances undergo natural transformation—this embodies Laozi's teaching that "the Dao follows what is natural." Though the alchemical process appears man-made, it wholly conforms to nature's laws.

This passage elucidates the core principles of alchemical cultivation—the Dao of "natural spontaneity" and "resonance between kindred elements."

Just as yellow and blue pigments naturally blend into green, as gelatin naturally seeps from animal hides, and as yeast naturally ferments wine—all these transformations occur spontaneously between substances of the same nature. The same principle applies to alchemy: The True Fire (Zhenhuo) within the Kan trigram (representing water) originates from the Qian trigram (representing heaven), for heavenly nature ascends to return to its source; the True Water (Zhenshui) within the Li trigram (representing fire) stems from the Kun trigram (representing earth), for earthly nature descends to reunite with its origin. Like clouds gathering at a dragon's roar or winds rising at a tiger's growl, the Yin and Yang energies resonate spontaneously, each returning to its kindred element.

Cultivation must adhere to the principle of "resonance between kindred elements." Attempts with isolated Yin or Yang, or mixtures of incompatible elements, are bound to fail. This is why the text states: "Kindred elements facilitate achievement; alien seeds defy skillful manipulation." The true mystery of alchemy (Neidan) lies in this natural resonance, which must be rooted in the "true seed" (Zhenzhong)—the shared origin of kindred elements.

The passage concludes by emphasizing that this principle has been verified through actual practice by generations of Daoist masters—it is no empty theory. Timeless as the stars coursing through the Milky Way or rivers flowing to the sea, its truth remains constant. Through repeated contemplation—a thousand or ten thousand readings—one may gradually grasp its profundity. Yet the Dao transmits its secrets only to virtuous adepts; sincere dedication is the key to unlocking its gate.

(Note: The Kan, Li, Qian, and Kun trigrams belong to the Bagua (Eight Trigrams) of the Yijing, symbolizing water, fire, heaven, and earth in alchemical practice. "True Fire" and "True Water" denote the refined essences of Yin and Yang energies within the body, while "dragon and tiger" metaphorically represent the heart's Shen (spirit) and the kidneys' Jing (essence).)

This scripture expounds the subtle art of fire regulation (huohou) in Neidan (internal alchemy) practice. Phrases like "the Dipper marking time as rivers pour into seas" are actually metaphorical descriptions of Qi (vital energy) circulation within the body. Practitioners must not merely recite these words, but deeply contemplate them; beyond contemplation, they must embody them through practice. Within the body, Yang Qi (yang fire) and Yin Qi (yin talisman) perpetually cycle—rising and descending in ceaseless flow. The key lies not in physical sight, but in perceiving through the inner Shen (spirit).

The text emphasizes repetitive cultivation: from one cycle to a thousand, from one repetition to ten thousand, maintaining this unbroken circulatory motion. As Guanzi advised: "Ponder and ponder again, until sudden comprehension dawns." Such focused dedication becomes even more crucial when practicing these esoteric fire regulation methods. After countless repetitions, the mind achieves sudden awakening—wisdom shines forth naturally, illuminating both worldly and transcendental truths as if divinely inspired.

The Golden Elixir (Jindan) path follows discernible principles: the mutual resonance of true Yin and Yang forms the foundation (initial thread); the interaction of Kan (Water) and Li (Fire) generates the medicinal elixir, while the union of Qian (Heaven) and Kun (Earth) crystallizes the golden pill—these constitute the dual aspects (gateways) of internal and external practice. Those who discover these essentials may glimpse the threshold of the Dao.

The scripture concludes by noting that while all inherently possess the Dao, transmission demands utmost discernment. Only those embodying loyalty, filial piety, purity, compassion and integrity—while relinquishing worldly attachments—can truly bear this Dharma. As the saying goes: "A sage's heart is required to accomplish immortal deeds." The Heavenly Dao shows no partiality, transmitting solely to worthy vessels. The Immortal Elder's repeated emphasis on fire regulation's crucial techniques underscores their paramount importance.

This passage elucidates the core teachings of the Zhouyi Cantongqi (The Kinship of the Three), a foundational Daoist scripture. Its author Wei Boyang (revered as Lord Wei) expounds the essential principle of "the unity of three paths" in spiritual cultivation.

The text begins by emphasizing the need for prudence in transmitting Daoist methods, reflecting the all-encompassing yet meticulous nature of the great Dao. While ostensibly discussing the timing of alchemical processes (crucial in Neidan/internal alchemy practice), this section actually synthesizes the entire work's essence. Serving as the epilogue following the main summary, it presents the three cardinal principles of state governance (administration), self-cultivation (nurturing one's nature), and alchemical practice (subduing nourishment), demonstrating their mutual verification—the so-called "threefold correspondence."

Originally, the Cantongqi contained only general discussions without systematic completeness, leaving certain subtleties unexplained. Therefore, the author reorganizes and supplements the content to create coherent connections between sections while maintaining unified, non-contradictory principles. Through this "threefold correspondence," the text fully reveals the fundamental doctrines of the Great Changes (Zhouyi).

Specifically: the Yin-Yang transformations in the Zhouyi, the statecraft and self-cultivation methods of the Huang-Lao tradition, and the timing techniques in alchemical practice—though manifested differently—all originate from the same root principle. Just as branches, flowers, and fruits differ while growing from the same tree, sincere contemplation leads to understanding their shared truth.

The passage concludes by explaining Lord Wei's rationale for this supplemental section. The previous two chapters discussed the three paths separately, potentially creating a fragmented impression. Through integrating the chapters on "the wondrous function of the furnace and cauldron" and "the complete achievement of fire phases," the ultimate truth of "three paths sharing one origin" is fully revealed. Earlier passages merely outlined this concept, while this section systematically presents its fundamental tenets.

This passage elucidates how the "three correspondences" (governing affairs, nurturing nature, and subduing nourishment) in the Cantongqi ultimately converge upon the fundamental principle of "the disposition of the Great Change (Dayi)."

The author observes that many mistakenly divide the Cantongqi into three separate sections: interpreting the "Great Change" as mere Yin-Yang transformations, even erroneously applying it to sexual cultivation techniques; limiting "nurturing nature" to physical cultivation; and misconstruing "furnace fire" as external alchemy (Waidan). In truth, these three aspects are interconnected—their essence lies in the dynamic interaction of "Kan and Li" (symbolizing Yin and Yang), which is fundamentally the harmonization of body and mind.

The key lies in using the "True Intention of the Central Yellow" (Zhonghuang zhenyi—a core Neidan concept referring to the primordial Qi of true unity) to reconcile body and mind. The cultivation methods of the Yellow Emperor and Laozi, as well as alchemical practice, are essentially engaged in this same process. Just as a tree's roots, trunk, branches, leaves, flowers, and fruits may differ in form, they all originate from the same source.

The text emphasizes that genuine cultivation must grasp the profound meaning of "the sun and moon constituting the Yi (Change)"—the character Yi (易) combines the radicals for sun (日) and moon (月), symbolizing Yin-Yang. One must recognize that opposing concepts like metal and wood, water and fire, hun and po souls, dragon and tiger, male and female, ultimately return to the unity of body and mind. This insight dispels millennia of misinterpretations of the Cantongqi, revealing its authentic cultivation essence.

This passage elucidates the core principles of Daoist Neidan (internal alchemy) practice. When human consciousness (Shen) and physical form achieve complete integration, this unified state becomes the essential "medicine" required for refining the Golden Elixir (the highest attainment in internal alchemy cultivation).

The text references the health preservation methods of Huangdi (Yellow Emperor) and Laozi, which emphasize stillness and Wuwei (non-action). This subtly points to the Nine Palaces in the head (the Daoist concept dividing the brain into nine functional regions), where the Yellow Court (middle Dantian) serves as the dwelling place of the Central Yellow Elder Lord, also called the Hall of Light. This location bears multiple names: Central Yellow Position, Abode of Divine Virtue, Furnace of the Dao's Dwelling, Great Abyss, or Compass Center—all referring to the primordial ancestral cavity (the fundamental energy center of the human body). Only by recognizing this ancestral cavity can the original spirit (Yuanshen) find its true abode, which constitutes the essence of nurturing one's innate nature.

The core of cultivation lies in employing "true intention" (primordial consciousness) to harmonize body and mind. Using alchemical metaphors: after placing the "medicine" (integrated body-mind) into the "furnace-vessel" (ancestral cavity), one must apply "fire times" (cultivation methods) for refinement. Though the text mentions various terms like dragon-tiger, mercury-lead, flowing pearl, and golden flower, these all symbolize the dynamic interaction between body and mind—their mutual restraint called "subjugation," their fusion termed "consumption," all fundamentally describing the harmonization of body-mind through true intention.

The three cultivation elements (medicine, furnace-vessel, and fire times) are ultimately one: the medicine being the unified body-mind state, the furnace-vessel being the ancestral cavity's location, and fire times representing the timing and methods of practice. Understanding this reveals that all life shares the same essence (one substance), heaven and earth coexist in a single space (one place), and temporal flow converges in the present moment (one time). This realization of "three returning to one" constitutes the state of attaining the Dao.

The passage repeatedly emphasizes that despite employing diverse terminology, the fundamental principle remains unifying body and mind through specific states, harmonized by true intention, ultimately achieving complete integration with the Dao.

All things originate from the same fundamental principle, yet manifest through three distinct pathways. Consider the growth cycle of plants: in spring they sprout branches and buds, in summer bloom with flowers and leaves, and in autumn bear ripened fruit. Yet when we trace their life source, all ultimately stem from the same root. Only when winter comes—when leaves wither and return to the root—does the profound mystery of life's cyclical nature reveal itself.

This "root-stock" represents the primordial origin (taisu), the essence of returning to one's original nature. Just as branches and fruits diverge from a plant's root, the three pathways emerge from the fundamental principle; and just as vegetation returns to its roots, these paths ultimately converge. Though the preceding text presents three seemingly separate sections—like diverging branches—the underlying principle remains interconnected throughout. The author composed this with utmost sincerity, and readers must contemplate it repeatedly until sudden awakening reveals how these three pathways share a single source, preventing misguidance by heretical teachings.

The Perfected Wei Boyang (author of the Cantong Qi) particularly emphasizes in this chapter: one must neither mistake the fundamental principle for three separate paths, nor regard the three pathways as unrelated. The key lies in grasping the "root-stock" core—it resembles that first stirring of yang energy at winter solstice (the returning yang), containing the profound mechanism of cosmic creation. This explains why the three cultivation paths (governing affairs, nurturing nature, and refining substances), though methodologically distinct, ultimately lead to the same destination.

Later generations attempted explanations using the "Five Correspondences Diagram," forcibly aligning them with the Five Phase directions—a misinterpretation originating from Peng Xiao and others. Careful examination of Wei Gong's original intent clearly indicates three co-emergent pathways, not five. Just as the eastern three and southern two combine as one category, the northern one and western four form another, while the central five and ten stand independently—these three categories already encompass the generative and controlling dynamics of the Five Phases. Why add legs to a snake? This doctrine of three co-emergent paths not only connects all chapters but represents the essential marrow of the entire text.

The commentary on the Cantongqi's "Return of the Four Symbols to the Root" chapter begins by critiquing the Tang dynasty Daoist Peng Xiao's unauthorized additions of alchemical terms like "floating left and sinking right" or "worldly gold and silver." These forced interpretations contradict the original furnace-fire cultivation theory in the Cantongqi. Textual research confirms these passages weren't part of Wei Boyang's (author of the Cantongqi) original work and should be excised.

The "Return of the Four Symbols" chapter uses natural phenomena to elucidate cultivation essentials. Just as plants in midwinter shed leaves while preserving their roots, practitioners should withdraw the manifested "Four Symbols" (the yin-yang transformations represented by Qian, Kun, Kan, and Li trigrams) to return to the primordial source. The postnatal Four Symbols (nameable yin-yang phenomena) resemble a plant's branches and flowers that can be described, while the prenatal Four Symbols (formless original state) are like hidden roots that transcend verbal expression.

Wei Boyang meticulously detailed the postnatal Four Symbols in the Cantongqi, yet cautioned practitioners against fixating on phenomena at the expense of fundamentals. The text's concluding analogy reminds us: as plants withdraw vitality to their roots in winter's depth, cultivators must return to life's origin during the "first stirring of Yang" (that subtle moment when yang qi awakens). This transitional state between movement and stillness represents existence's most refined mystery - what Song dynasty Yijing master Shao Yong called "the supreme wonder connecting Heaven, Earth and Humanity."

Through seasonal metaphors, this passage emphasizes transcending postnatal manifestations to return to prenatal emptiness. The concept of "returning to the root of original life" lies at the heart of Daoist Neidan (internal alchemy) practice - achieving life's transcendence through concentrated spirit and reversion to the primordial state.

The cultivation of the heart should be as tightly sealed as the depths of a nine-layered abyss, ensuring that the inner essence (Jing, Qi, and Shen) does not leak outward, while external distractions (random thoughts and desires) cannot intrude. It resembles the state of seclusion and stillness during the winter solstice, where merchants cease their travels and rulers refrain from touring their domains. Here, the bustling activity of merchants symbolizes ordinary people indulging their sensory desires, while the ruler sitting in stillness (Wuwei) represents the practitioner’s inward focus and restraint.

A true cultivator must dwell like one hidden in the abyss, severing all outward-chasing thoughts, just as merchants are forbidden from traveling—completely halting restless movement. This practice of seclusion corresponds precisely to the characteristics of the winter solstice: though there appears to be movement (the first stirrings of Yang energy), one remains in deep stillness, wholly aligned with the rhythms of nature. At this time, the most crucial task is to close the senses (symbolized by the Dui trigram, representing the mouth, ears, and other senses) and focus on guarding the inner core, avoiding excessive speech that depletes the spirit (Shen).

The operating principles of the Golden Elixir (Jindan) align perfectly with the Dao of Heaven. The Dao of Heaven cycles endlessly through the four phases of "Yuan, Heng, Li, Zhen" (growth, flourishing, harvest, and storage), vast and profound beyond measure. Among these, "Yuan" and "Heng" govern expansion and manifestation (expressed in benevolence and virtue), while "Li" and "Zhen" govern withdrawal and storage (hidden in function). When entering the storage phase, one sees neither celestial phenomena above nor the abyss below—it is without beginning or end, like the dark and unfathomable realm that cannot be depicted in images.

Heaven and Earth are like embryos nurtured by the Great Void (Taixu, the cosmic origin), while the sun and moon are its breath. At the transition between the midwinter months of Hai and Zi, Heaven and Earth unite, and the sun and moon merge. Their movements temporarily cease, returning to a state of chaos (Hundun). Here, there is no distinction between Heaven and Earth, nor between sun and moon; the images of Qian (Heaven), Kun (Earth), Kan (Water), and Li (Fire) dissolve entirely into the realm of the Great Void. This is the wondrous state of "true emptiness and marvelous existence" (Zhenkong Miaoyou): it is the pre-cosmic principle before Fuxi drew the trigrams, the nameless Dao spoken of by Laozi; it is the soundless and formless state described in the Book of Songs, and the original face before the "Buddha of Majestic Sound" in Buddhism.

The chaos of Heaven and Earth is the source of the Qian and Kun trigrams, and the chaos of the sun and moon is the root of the Kan and Li images. The "image" without form is the true image, and the "word" beyond speech is the ultimate truth. Those who understand this principle can perceive the true pivot of creation within what appears to be dissolution—the chaos itself.

The path of cultivation reveals that those who truly comprehend the innate heart-method (referring to the formless cosmic origin) can directly penetrate the essence without relying on any images or words. Yet this realm is only instantly grasped by those of exceptional natural endowment. Ordinary practitioners often only understand the tangible principles of the Yijing (Book of Changes)—how could they perceive its formless, imageless true meaning? They recognize the concrete symbols of Qian (Heaven), Kun (Earth), Kan (Water), and Li (Fire) (four trigrams from the Bagua), but remain unaware of the nameless, formless origin behind these symbols.

Yet remaining completely silent risks being too vague, leaving cultivators unable to distinguish crucial differences or grasp practical methods, ultimately leading them astray. Conversely, overly detailed explanations become like "adding a head on top of a head" or "riding a donkey to search for a donkey"—forcing scholars into unnecessary complexities that harm fundamental practice. Thus, misguided explanations cause missed opportunities, while inappropriate words injure cultivation itself.

After careful deliberation, I’ve structured the content into three major sections, each subdivided: The first explains how Qian and Kun serve as the gateway to the Dao; the second describes how Kan and Li form the framework of practice; the third illustrates Qian and Kun as the cauldron and furnace, Kan and Li as the medicinal ingredients (referring to foundational elements of Neidan, or internal alchemy). These are all rooted in the core principles of the Yijing. Seen holistically, the health-preserving methods of the Yellow Emperor and Laozi, as well as the fire-timing in alchemy, are essentially applications of Qian, Kun, Kan, and Li. Such elaborate explanations are like laboriously directing the blind—those with clear vision need no such distinctions.

Though the Four Images (Shaoyang, Taiyang, Shaoyin, and Taiyin—four symbolic phases of the trigrams) are used to instruct later learners, note this: once the Four Images are employed for explanation, one has already strayed from the fundamental; once classifications are made, it’s like reducing a tree’s roots to scattered branches. How could this compare to the supreme state of undifferentiated chaos, where understanding transcends words?

This is the crucial message repeatedly emphasized in the final sections of the Cantongqi (Triple Concordance), often misunderstood throughout history. Chen Xianwei’s commentary relocated this passage to the "Flowing Pearl of the Great Yang" chapter, while Yu Yu’s version moved it to "Confucius Praising Primordial Chaos." Both interpreted the Four Images through the earthly branches (Zi, Wu, Mao, You) or the numbers 7, 8, 9, and 6 (Yijing numerology). Unaware that these belong to the realm of tangible, post-heaven phenomena, they missed the scripture’s true intent of "deep concealment, sealed lips—dissolving all frameworks" (pointing to the return to the formless origin).

This passage discusses the core philosophy of the Cantongqi (参同契), a foundational Daoist scripture. The author observes that many misinterpret the chapter divisions and meanings of the text, mistakenly conflating the "Three Ways" with the "Four Symbols." In truth, the entire Cantongqi expounds on the principle of the "Four Symbols" (referring to the four hexagram images: Lesser Yang, Greater Yang, Lesser Yin, and Greater Yin). However, Wei Boyang (known as Lord Wei) emphasizes in the concluding sections the need to return to the root—transcending specific forms to directly point toward the supreme teaching of "returning to primordial chaos."

The text describes the process of returning from concrete phenomena to the source: first, from the Four Symbols back to the Two Modes (Yin-Yang), then from the Two Modes back to the Taiji (Supreme Ultimate), ultimately arriving at the beginningless and endless state of "Wuji" (the Limitless). Terms such as "Great Origin" (太元), "emptiness and stillness" (虚寂), and "profound concealment" (深藏) all describe this return to the primordial source. The author suggests that truly grasping this principle reveals how these truths existed within heaven and earth even before the Cantongqi was composed—just as the Daode Jing states, "There was something formless yet complete, existing before heaven and earth."

The passage further cites Confucius' remark, "I wish to speak no more," and the Buddha's teaching, "I have not spoken a single word," illustrating how the highest truth transcends verbal expression. It critiques later misunderstandings of the Cantongqi: some wrongly interpret it as techniques of "harvesting and supplementing" (sexual practices), others oversimplify it as mere health cultivation, while still others mistake it for external alchemical practices (waidan). These misinterpretations are likened to the blind leading the blind, dragging people into peril. Even when encountering genuine masters who point out the truth, many remain unable to awaken to it.

The True Man Wei Boyang reveals his innermost thoughts in the final chapter of the Cantongqi: How lamentable that our patriarch, even in his final brushstrokes, remained deeply concerned and wished to seal his writing in silence, foreseeing how few in later generations would grasp the true meaning. These ultimate revelations of the Dao in the Cantongqi—how many can truly comprehend them? Truly, the Heavenly Dao does not lightly disclose its mysteries. May readers possess discerning vision, lest this profound effort be wasted.

This recluse from the state of Kuai (Wei Boyang's self-reference) was originally an unknown cultivator dwelling in secluded valleys, his heart preserving simple genuineness, unmoved by power or glory. He withdrew to remote mountains and wilds, indifferent to fame and wealth, steadfast in a life of purity and Wuwei (non-action), seeking only tranquil peace. It was precisely in such leisurely seclusion that he composed the Cantongqi, synthesizing the essential teachings of the Yijing from the three sages—Fu Xi, King Wen, and Confucius—exploring their true meaning and unifying them into a complete theory. At its core lies alignment with the Heavenly Dao, awakening the primordial Shen (spirit, the innate spiritual essence). When the Shen flows unimpeded, it resonates with Heaven and Earth, bringing harmony to all under heaven.

This scripture is worthy of transmission for ten thousand generations, serving as a guiding principle for governing the state and cultivating the self—its practice is not cumbersome. The inner cultivation of nature and life follows the natural Dao of the Yellow Emperor and Laozi, emphasizing the nurturing of profound De (Virtue) and returning to the origin of life. The key to this practice lies not afar but within one's own heart: simply hold fast to "embracing the origin and guarding the One" (a core Daoist meditation method) without wavering, and one may attain longevity and clear vision. As for the outer alchemical methods, it rejects vulgar materials like the "Eight Minerals of Wudu" (common mineral ingredients in alchemy), advocating instead careful selection of truly efficacious substances.

The three main threads of the text (the Great Change, the teachings of the Yellow Emperor and Laozi, and furnace-fire alchemy) are like interconnected branches of a tree—though named differently, they share a single source. These words are not mere ornate phrases but contain the true Dao, as solid as metal and stone. Wei Boyang states that he has discarded falsehoods, eliminated redundancies, and condensed the essence of the classics into the Cantongqi. Though concise in language, its principles are vast, and he hopes later generations will follow its true meaning. He foretells that he will cast off worldly fetters, withdraw to mountain forests, roam the Great Void, and ultimately ascend in feather-flight (Daoist term for achieving immortality). Even a hundred generations hence, his spirit will still manifest as a crane soaring among mortals. Just as trees wither in drought, only those who cultivate the Dao may ride the righteous Qi of Heaven and Earth, attaining enduring life and clarity.

Finally, he reiterates: This recluse from Kuai (Wei Boyang's self-reference), with his simple and genuine heart, untouched by glory, willingly dwelled in obscurity, indifferent to fame, composing this scripture in serene seclusion. According to the Liexian Zhuan (Biographies of Immortals), the True Man Wei Boyang was originally from Shangyu in Kuaiji, born into an official family yet unwilling to serve in government. He devoted himself to refining truth and nurturing his nature, embodying the Dao in stillness and Wuwei.

This passage discusses the origins and core teachings of the Zhouyi Cantongqi (The Kinship of the Three), a foundational Daoist classic. Its author, Wei Boyang (revered as Lord Wei), was originally from Kuaiji but attributed his work to the ancient state of Kuai—a common practice among Daoist adepts to conceal their identity. Having studied the Great Dao of the Golden Elixir (Jindan, a form of Neidan internal alchemy) under the immortal Yin Changsheng, he later composed the Cantongqi in three sections based on the Zhouyi (Book of Changes).

The text synthesizes the wisdom of the Zhouyi's three sages (Fuxi who created the trigrams, King Wen who composed the judgments, and Confucius who wrote the commentaries). Its essence lies in comprehending natural laws to harmonize Shen (spirit) and Qi. By mastering the application of "Kan and Li" (the water and fire trigrams symbolizing Yin-Yang), one penetrates the principles of "dual cultivation of nature and life" (Xingming Shuangxiu). Internal cultivation regulates body and mind, while external application governs the world—embodying the Daoist ideal of "inner sageliness and outer kingliness."

The text elaborates on concepts like the "Zi-Nan Wu-Bei" meridian (symbolizing Yin-Yang cycles) and "Mao-You" (cardinal directions), which serve both as calendrical foundations and alchemical formulae. Governing a state, it suggests, should emulate the ruler's Wuwei (non-action), allowing ministers to fulfill their roles naturally for societal harmony.

The ultimate cultivation method advocates following the natural Dao of Huang-Lao (Yellow Emperor and Laozi), maintaining inner purity to deepen De (virtue/power) spontaneously. The key is returning to primordial unity—holding fast to the "One" (the Dao) within oneself to attain longevity and vision. Simply put: preserve innate nature, return to simplicity. This truth resides within every heart, requiring no external search.

The Yellow Emperor (Huangdi) and Laozi (the two revered progenitors of Daoism) used the inner landscape of the human body to expound the principles of cultivation. Within the body are the Nine Palaces (the Daoist division of the body into nine energy centers), among which the Yellow Court (Huangting, located in the middle Dantian region) serves as the central pivot, governed by the Lord of Yellow and Lao (Huanglaojun, the body's primordial spirit). Here resides humanity's innate pure and genuine nature—what is called "nurturing one's nature" in cultivation refers precisely to preserving this inborn essence.

Thus, the phrase "drawing inward to nourish one's nature" means following the natural Dao of the Yellow Emperor and Laozi. This innate nature is the highest De (Virtue/Power), inherently complete, neither increasing nor decreasing. If practitioners can fully realize this nature, they can instantly return to the source of life. This state is called "embracing the depth of De"—a return to the root, a restoration of the original.

Humanity's innate nature is originally one, yet it divides into two functions: the heart-mind and the body. Here, the "heart" does not refer to the physical organ but to the inherently present luminous awareness, while the "body" is not the fleshly form composed of the four elements (earth, water, fire, wind) but the Dharmakāya—the wondrous existence of true emptiness. Both are fully present within every individual; all cultivation and realization are inseparable from one's immediate self. Hence it is said, "It is close to my heart, never leaving my own body."

The Ancestral Cavity (Zuqiao, the upper or middle Dantian) is the pivot where heart-mind and body unite. When these two merge in the Ancestral Cavity, the true self is revealed. If one can sustain this state of unity without interruption, even for a moment, they grasp the essential method of "long life and enduring vision" in cultivation. Thus it is said, "Embrace the One without letting go, and you may endure eternally."

This passage primarily elucidates the fundamental purpose of cultivating one's nature—the core principle explored and applied by the Yellow Emperor and Laozi.

Next, the essential meaning of alchemical refinement and ingestion is explained. From the perspective of inner cultivation, this concerns the great Dao of harmonizing true nature (the primordial spirit, Yuanshen) and true life (primordial Qi, Yuanqi) as Yin and Yang. As an external metaphor, it resembles the pairing of true lead (Yuanjing, primordial essence) and true mercury (Yuanshen, primordial spirit)—two complementary substances of Yin and Yang. In terms of restraining the Hun (ethereal soul) and Po (corporeal soul), it is called "subduing"; in terms of the dragon and tiger devouring one another, it is called "ingestion." These are all methods of refining the Golden Elixir (Jinye Huandan, the advanced stage of Neidan practice), entirely distinct from the Waidan (external alchemy) tradition of ingesting minerals.

When ordinary people hear of a "furnace and fire," they assume it refers to smelting metals and minerals; when they hear of "male and female," they think of orpiment and realgar. In truth, these are all dross of the conditioned, tangible world, which genuine practitioners discard. Since ancient times, there have indeed been techniques for transforming copper into gold, prized by the worldly.

The passage elucidates the essential principles of Daoist Golden Elixir (Jindan) cultivation, the core concept of internal alchemy (Neidan). The author observes that worldly people most value material wealth like gold and silver (literally "yellow and white substances"), while ancient masters skillfully employed these metaphors to reveal the profound mysteries of elixir cultivation—an approach that makes the teachings more convincing to ordinary seekers.

The mentioned orpiment (female yellow) and realgar (male yellow), two mineral substances, do not refer to actual materials but symbolize the yin-yang principles in cultivation. As the Awakening to Reality (Wuzhen Pian) states: "Cease refining the three yellows and four divinities"—a reminder not to become attached to external substances. True Golden Elixir practice (the furnace-fire work) follows internal principles rather than mere physical smelting.

The author emphasizes that cultivation fundamentally requires the "union of three paths": First, the hidden principles of yin-yang transformation (the medicinal substances of Kan and Li) from the Book of Changes (Yijing); second, the health-preserving Dao of the Yellow Emperor and Laozi (the central yellow furnace and cauldron); and finally, the fire regulation techniques (tempering through fire phases) in alchemical practice. Though these appear different superficially, they share the same essence—just as essence (Jing), vital energy (Qi), and spirit (Shen) are ultimately one.

When body, heart, and intention unite, the sacred embryo (cultivation achievement) can be formed; when essence, energy, and spirit fuse, one returns to the primordial Taiji source. These three paths seem separate yet are fundamentally interconnected—each containing the others and all converging into one. This perfectly illustrates Laozi's profound teaching about "the mysterious gate of shared origin with different names."

While the text appears elaborate, its complexity isn't artificial ornamentation but conveys profound truth. These theories correspond with cosmic creation, align with body-mind cultivation, and everywhere manifest the principle of heaven-human unity. Like uncarved jade hidden within stone, splitting it open reveals the truth. Fabricating false teachings to deceive later learners would be like growing useless tumors on one's body—inviting celestial retribution instead.

This passage explains the naming origin of the Cantongqi (The Seal of the Unity of the Three) and the ingenious method its author used to conceal his identity. The title "Cantongqi" refers to the integration of three major cultivation systems (likely Neidan [internal alchemy], Waidan [external alchemy], and Fulu [talismans and registers]) into perfect harmony with the supreme truth of the Dao. The author emphasizes that although this scripture is concise in wording, it contains the complete path of dual cultivation of nature and life (Xingming Shuangxiu), which later practitioners should follow.

The text particularly highlights how Wei Boyang (a renowned Daoist alchemist) embedded his name cryptically in the concluding verses. By deciphering four sets of sixteen-line poems, one can piece together the characters "Wei Boyang Zao" (Wei Boyang composed):

• The four lines beginning with "委时去害" conceal the character "魏" (Wei)
• The four lines starting with "化形而仙" hide the character "伯" (Bo)
• The four lines opening with "敷陈羽翮" contain the character "阳" (Yang)
• The four lines initiating with "柯叶萎黄" encode the character "造" (Zao)

This recluse scholar neither wished to sign openly nor desired complete anonymity, adopting instead this half-concealed approach—much like hiding fundamental principles within the foliage of three textual sections, awaiting discovery by destined readers. Such name-concealing technique aligns with the cultivation attitude of "keeping silent without unnecessary speech" mentioned earlier. Only genuine understanding reveals the secret; others would miss it even when facing the text directly.

The conclusion notes that while all three chapters (upper, middle, and lower) emphasize the scripture's purpose of transmitting the Dao through writing, the final section's closing chapter stands as the most comprehensive. It not only summarizes the essence of the "three correspondences" but also serves as the scripture's grand conclusion, establishing the standards for comprehending celestial principles and exhaustively investigating the Dao of nature and life.

The Cantongqi (Triple Concordance Scripture) stands as one of the most challenging texts to comprehend. It begins by splitting a single teaching into three distinct sections, only to ultimately reunite them into one profound statement that transcends literal interpretation. Within this process of division and synthesis lies wondrous transformation—even someone with the legendary vision of Li Zhu (ancient China's fabled sharp-eyed figure) would grow dizzy trying to follow it; even a listener with the acute hearing of Shi Kuang (renowned musician of the Spring and Autumn period) would often find themselves bewildered.

Now, having received my master's illuminating explanation of its mysteries, it feels like suddenly lighting a lamp in a chamber darkened for a thousand years, revealing everything with crystalline clarity. Is this not the compass for understanding the Yijing (Book of Changes), the torch of wisdom for studying the Cantongqi?