An Inquiry into the Method of Penetrating the Chaotic Obscurity 鑽杳冥 in Li Xiyue’s Internal Alchemy Practice

Abstract

Li Xiyue 李西月, the founder of the Western Branch (Xipai 西派) of Internal Alchemy (neidan 內丹) during the mid-to-late Qing dynasty, explicitly identified the method of Penetrating the Chaotic Obscurity (zuan yaoming 鑽杳冥) as the primary and most challenging task in his alchemical system. However, contemporary scholarship often exhibits confusion regarding his methods of penetrating the chaotic obscurity and Unfolding the Cavities and Opening the Passes. This paper argues that what he termed penetrating the chaotic obscurity is a state achieved by cultivators after they have withdrawn their mental focus, harmonized their breath, established the Interdependence of Mind and Breath, and concentrated their Spirit within the Void. The state precipitated from this condition is what Li Xiyue’s internal alchemy theory describes as the emergence of the living Mysterious Pass (huo xuanguan 活玄關). He defined the living Mysterious Pass revealed through this practice as the Mysterious Pass within the Void (xuwu qiao 虛無竅), which serves as the Postnatal Furnace and Tripod (houtian ding 後天鼎)—the locus for the intercourse of spirit and qi. The true breath (zhenxi 真息) perceived within the state of the chaotic obscurity is gathered into this tripod, thereby generating the Primordial qi within the Postnatal Stage (houtian zhong xiantian qi 後天中先天氣). Once this qi is activated, the cavities open and the passes unlock spontaneously. Consequently, Li Xiyue’s method of penetrating the chaotic obscurity represents not only the culmination of the initial practices—such as concentrating the spirit and regulating breath—within his alchemical system, but also an essential prerequisite for initiating the Coagulation of the Jade Liquor to the Cinnabar Field (yuye jiedan 玉液結丹).

1. Introduction

Li Xiyue (李西月, 1806–1856), originally named Yuanzhi 元植 and styled Pingquan 平權/泉, was a native of Changyi Mountain, Lijiahe, Leshan, Sichuan. During this period, although Daoism as a whole gradually lost the support of the imperial court, it was nonetheless reinvigorated within popular society. This reinvigoration manifested significantly in the emergence of new forms of Daoist religious communities 新道教信仰团体 (Z. Li 2017, p. 220), organized as spirit-writing altars (fuji daotan 扶乩道壇). Composed of local elites and officials, these communities operated beyond the traditional institutions of temples and ordained clergy. Representing a developmental mode of literati Daoism1 (wenren daojiao 文人道教), they gathered social elites around the altar, compiled and printed Daoist texts through spirit-writing, and cultivated and disseminated Daoist teachings. In so doing, they emerged as an important force that propelled the tradition during a period of relative quiescence in the Qing dynasty. In other words, for Qing-era Daoism, these gentry-led popular societies played a crucial role in the transmission and preservation of Daoist scriptures and internal alchemical methods (Olles 2022, p. 102). Depending on the region and the community, spirit-writing altars focus on different gods. Among these canonized gods, Lüzu 呂祖 takes pride of place (Goossaert 2015, p. 93). The Sichuan region where Li Xiyue lived had a long-established Daoist tradition. After the Jiaqing edicts were issued in the mid-Qing period, government officials, local gentry, and wealthy migrant merchants united to promote the flourishing of Lüzu’s cult (Valussi 2015, p. 166); even earlier, in the early years of the Qing dynasty, the region had already witnessed the literatus Wang Xiling 汪錫齡 engaging in spirit-writing to commune with Zhang Sanfeng 張三豐. Against the backdrop of a mature tradition of internal alchemy and a society beset by internal and external crises, Li Xiyue transitioned from Confucianism to Daoism. Venerating Lü and Zhang as his patriarchs and centered in Leshan, he united a group of literati and gentry to establish a literati Daoist altar, and on this basis, founded the Western Branch (Xipai 西派) of internal alchemy. The literati altar he founded engaged in spirit-writing, alchemical cultivation, textual composition, and scriptural exposition, giving expression to a consciousness of “salvation” (jiuji 救濟) aimed at delivering all beings from suffering (Valussi 2024, p. 723). Through these activities, he became a representative figure of literati Daoism in the Sichuan region during the Jiaqing and Daoguang reigns. The alchemical teachings he expounded thus infused new vitality into the development of internal alchemy during the mid-to-late Qing period.

Compared with earlier internal alchemists, Li Xiyue’s alchemical theory exhibits a more refined structure and greater clarity of detail. According to his own terminology, his system of internal alchemy can be broadly divided into the Postnatal Stage and the Prenatal Stage.2 The goal of the Postnatal Stage is the formation of the Coagulation of the Jade Liquor to the Cinnabar Field (yuye jiedan 玉液結丹). Upon its completion, cultivators advance to the Prenatal Stage, where the aim is to refine the Return of the Golden Liquor to the Cinnabar Field (jinye huandan 金液還丹). Li Xiyue provided a more detailed and nuanced analysis of the preliminary practices and sequential stages within the Postnatal Stage. He not only expanded the foundational practices of Laying the Foundation and Refining the Self (zhuji lianji 筑基煉己) into four major phases—Opening the Passes, Laying the Foundation, Gathering the Ingredients (yaowu 藥物), and Refining the Self—but also further subdivided these into nine distinct stages in his Houtian Chuanshu Wenzhong Jing 後天串述文終經 (The Final Classic on the Sequential Elucidation of the Postnatal): Withdrawing the Mind, Seeking the Qi, Concentering the Spirit, Unfolding the Cavity, Opening the Passes, Laying the Foundation, Gathering the Ingredients, Coagulating the Elixir, and Refining the Self.3 Among these, Withdrawing the Mind, Seeking the Qi, and Concentering the Spirit constitute the preliminary practices required for cultivators commencing the Postnatal Stage. Furthermore, the method of penetrating the chaotic obscurity—a novel term coined by Li Xiyue—occupies a central and pivotal position within his alchemical system. Encompassing its implied preliminary practices, this method can be regarded as both the gateway to internal alchemy and the key to success or failure in the Postnatal Stage. Li Xiyue explicitly identified it as the first difficult task in alchemical practice, for it represents not only the culmination of the initial practices within his Postnatal Stage but also an essential prerequisite for initiating the Coagulation of the Jade Liquor to the Cinnabar Field.

However, specialized studies on Li Xiyue’s practice of “penetrating the chaotic obscurity” remain scarce. To date, only one article has approached the topic through the lens of physiology and modern scientific discourse, proposing that this practice entails directing the mind deeply into a state of profound stillness and emptiness and describing its operational process. However, its analysis lacks depth (Lin 2007, pp. 21–22). Most other studies are subsumed within broader investigations of Li Xiyue’s alchemical thought. While these works acknowledge “penetrating the chaotic obscurity” as a distinctive feature of his alchemical theory, significant disagreements persist regarding its precise meaning and functional position within his system. The majority of studies equate this practice directly with “unfolding the cavities and opening the passes” (zhanqiao kaiguan 展竅開關) (Qing and Zhan 2019, p. 416; Y. Li 2014, p. 557). In contrast, some scholars argue that “penetrating the chaotic obscurity” belongs to the initial practices rather than to the preliminary work of opening the cavities and passes undertaken before foundation-laying (Ding 2021, pp. 81–82). Still others maintain that Li Xiyue’s foundational practice consists of concentrating on the Mysterious Pass within the Void (xuwu qiao 虛無竅), allowing spirit and breath to merge, and quietly awaiting the emergence of true breath (zhenxi 真息) or the Mysterious Pass (xuanguan 玄關)—precisely the method he termed “penetrating the chaotic obscurity”. This same scholarship further emphasizes that this practice underwent significant transformation in the collateral transmission branch of the Western School (Xiao 2012, pp. 309–11; Xiao 2015, pp. 198–207). Research on “concentrating the spirit within the void” (ningshen yu xu 凝神於虛)—a practice closely related to “penetrating the chaotic obscurity”—is particularly contentious. Some scholars associate it with the collateral branch’s concept of the “void outside the body” (shenwai xukong 身外虛空), maintaining that Li Xiyue’s concentrating the spirit within the void refers precisely to concentrating the spirit and regulating the breath in the void outside the body (Qing and Zhan 2019, p. 418; X. Zhang 1999, p. 116). One study even identifies the boundless cosmos as this external void while simultaneously locating the Mysterious Pass within the Void in the middle Cinnabar Field (zhong dantian 中丹田), classifying it as an internal bodily void (Huo 2007, p. 73). In opposition to these views, other scholars explicitly argue that there is no textual basis for regarding “concentrating the spirit within the void” as the essential method of the Western School’s foundational practice, nor for claiming that Xu Haiyin’s 徐海印 teaching of “concentrating the spirit and regulating the breath in the void outside the body” derives from Li Xiyue’s own thought (Ding 2021, pp. 82–84). In summary, although existing scholarship has touched upon several key issues concerning Li Xiyue’s practice of “penetrating the chaotic obscurity”, the overall level of inquiry remains insufficient. Core questions—including the precise definition of this practice, its sequential stages, its relationship to “unfolding the cavities and opening the passes”, and its theoretical evolution through different lines of transmission—await further systematic investigation. This paper aims to clarify the unique meaning of penetrating the chaotic obscurity and to explore its pivotal role within the alchemical system of the Western Branch, as well as its subsequent transformations in later transmissions.

2. Coining the Concept of Penetrating the Chaotic Obscurity

Since the rise of Internal Alchemy studies in the Tang and Song dynasties, Daoist scholars have elucidated practices such as quiet sitting, spirit concentration, and breath regulation with a central aim: to illuminate for the world a path of spiritual transformation known as “reversing to become an immortal” (ni ze chengxian 逆則成仙). This path takes the unification of spirit and qi as its pivotal mechanism, is driven by the primordial creativity inherent within emptiness and tranquility, and has as its ultimate purpose the complete mastery over one’s own life. It is within this theoretical context that Li Xiyue creatively introduced the concept of penetrating the chaotic obscurity, thereby deepening the practices of quiet sitting and spirit–breath concentration by directing them toward the more fundamental realm of the primordial.

In his Shouxinfa Zatan 收心法雜談 (Miscellaneous Discourses on the Work of Summoning the Scattered Spirit), Li Xiyue unequivocally states: “In all practical work, the method of penetrating the chaotic obscurity is the primary difficult task.” 凡做功夫, 鑽杳冥是第一桩難事 (X. Li 1994d, p. 631). This assertion underscores the paramount importance of this method within his alchemical theory. Yet, what precisely does penetrating the chaotic obscurity entail? Li Xiyue elaborates on this in his Shouxinfa Xiashou Gongfu 收心法下手功夫 (Foundational Practice in the Work of Summoning the Scattered Spirit) as follows:

The heart-mind is like empty space. Yet, with the breath clinging to it, it is not utterly void; with the breath following it, it is not completely vacant. In this state between not-void and not-vacant, one becomes ever more tranquil and ever more pure. The breath becomes continuous and subtle, the heart-mind silent and absorbed. At this point, it is essential to let go of all attachments and relinquish all distinctions between self and other. This is what is termed “penetrating the chaotic obscurity”. 心如虛空, 有息相依則不虛, 有息相隨則不空, 不虛不空之間, 靜而又靜, 清而又清. 氣息綿綿, 心神默默. 至此要一切放下, 人我皆忘. 此之謂“鑽杳冥”.

(X. Li 1994d, pp. 630–31)

To comprehend the meaning of “penetrating the chaotic obscurity” (zuan yaoming 鑽杳冥), one must first look beyond the literal interpretation of its characters. The verb “penetrating” (zuan 鑽) conveys the sense of deep, focused entry, while “chaotic obscurity” (yaoming 杳冥) originates from the Daode jing 道德經: “How remote it is and how dark, yet within it there is an essence.” 窈兮冥兮, 其中有精 (Chen 2016, p. 156). In this classical context, the term describes the profound, mysterious, and elusive nature of the Dao. Li Xiyue absorbed and refined this concept within his framework of internal alchemy. For him, “penetrating” does not denote forceful probing, but rather a dynamic process—active yet focused, deepening progressively through the interdependence of mind and breath (xinxi xiangyi 心息相依) and the continuous, subtle interplay of spirit and qi. Similarly, “chaotic obscurity” signifies not mere inert stillness, but rather the primordial, undifferentiated state in which Yin and Yang are blended and the Primordial qi (xiantian yiqi 先天一氣) is on the verge of manifesting.

The penetrating of the chaotic obscurity elucidated by Li Xiyue is neither a static adherence to quiescence nor a deliberate, contrived action. Rather, it is the state of profound dimness and vibrant potential that practitioners naturally enter after a specific process of cultivation. This process begins with dispersing desires and dissolving distracting thoughts, calming the mind through seated meditation, and turning the vision inward with eyes closed. Through these stages, mind and breath become interdependent and mutually safeguarding, gradually leading to a stabilized heart-mind and a continuous, subtle flow of breath. This state is fundamentally distinct from ordinary experience. Within it, the body feels as if suspended within a vast cosmic emptiness. In this clarified and tranquil void, only the continuous, subtle breath is perceived, circulating naturally alongside the spirit. All distinctions between person and thing, self and other, inner and outer dissolve, gradually drawing one closer to the undifferentiated, primordial state of unity with the Dao.

The subtle and mystical state of “chaotic obscurity” is the result of non-coercive action—an achievement not attainable overnight. It demands the practitioner’s long-term perseverance, progressing from the interdependence of mind and breath to the eventual forgetting of both mind and breath. It is precisely to express the difficulty of attaining this state that Li Xiyue employed the character “penetrating”. He drew upon his own experience to illustrate the arduousness of this accomplishment, stating: “In the past, within the cavern-heaven, I studied the method of penetrating the chaotic obscurity for seven or eight years before I gained a slight handle on it.” 昔我在洞天中, 學鑽杳冥七八年, 然後稍有把柄 (X. Li 1994d, p. 631).

However, he believed that for such practitioners, “the difficulty comes first, the attainment follows.”先難而後獲 (X. Li 1994d, p. 631). He analogized this process, stating: “The Primordial qi emerges from within the Void. There must be genuine chaotic obscurity before there can be genuine Void.” 先天一氣, 自虛無中來, 必有真杳冥, 乃有真虛無 (X. Li 1994d, p. 631). Once a practitioner enters the state of chaotic obscurity, they gain access to the authentic realm of the genuine Void and thereby perceive the presence of the Primordial qi. The Primordial qi generated through the process of penetrating the chaotic obscurity corresponds precisely to what Li Xiyue identified in his alchemical system as the Prenatal within the Postnatal (houtian zhong xiantian 後天中之先天). Consequently, this specific energy is also termed the Primordial qi within the Postnatal Stage (houtian zhong xiantian qi 後天中先天氣). According to Li Xiyue, “There must be such genuine gongfu before there can be true verification.” 必有此等真功夫, 然後有真效驗 (X. Li 1994d, p. 631). This principle directly corresponds to the subsequent physiological response, namely, a heart-permeating warmth and sublime exhilaration that manifests upon the generation of this qi.

3. Prerequiring the Method of Penetrating the Chaotic Obscurity: Establishing the Interdependence of Mind and Breath

Penetrating the chaotic obscurity constitutes a distinctive and crucial component of Li Xiyue’s internal cultivation method. But where precisely does it fit within his alchemical system? In his analysis of the foundational practices within the Postnatal Stage, Li Xiyue instructs: “In all practice, one must first eliminate the human mind and seek the spirit of the Dao; suppress the ordinary breath and seek the true breath; only then can one stabilize spirit and qi, and penetrate the chaotic obscurity. Each of these stages is indispensable.” 凡作功課, 必先去人心, 求道心; 屏凡息, 尋真息; 然後定神氣, 鑽杳冥. 如此諸境, 皆不可少 (X. Li 1994d, p. 631). This indicates that a practitioner, having just entered the Postnatal Stage, must first undertake the work of withdrawing the mind, seeking the qi, and concentrating the spirit. It is only after prolonged concentration of the spirit and regulation of the breath—when spirit and qi gradually tend toward unification—that the opportunity to enter the state of chaotic obscurity arises.

In other words, the prerequisite for a practitioner to engage in the work of “penetrating the chaotic obscurity” is to grasp the core of Postnatal Stage cultivation: Spirit and Qi. As Li Xiyue stated in his Discourses on the Daoqiao Tan 道竅談 (Discourses on the Subtleties of the Dao): “The Dao of the Postnatal stage is Spirit and Qi.” 後天之道, 神氣也 (X. Li 1994a, p. 615), and “One must use Spirit and Qi to complete the Postnatal stage.” 當以神氣了後天 (X. Li 1994a, p. 615). Thus, for Li Xiyue, although the Postnatal Stage of alchemical cultivation is divided into nine steps, the foundational practice must begin with these two elements: Spirit and Qi. Since, to a certain extent, the Heart-mind is equivalent to Spirit, and Qi is equivalent to Breath, the cultivation of Spirit and Qi can be further realized in practice as the cultivation of Mind and Breath—namely, the interdependence of mind and breath.

3.1. Calming the Mind and Restraining Random Thoughts: The Foundation of the Interdependence of Mind and Breath

The fundamental purpose of the interdependence of mind and breath is to achieve, through the mutual reliance and gradual unification of the postcelestial spirit (shishen 識神) with oral-nasal breathing, the summoning, consolidation, and ultimate merging with the innate heart-mind—thereby attaining the primordial state of Spirit and Qi Unity. This dynamic process unfolds on the foundation of regulating the body and breath. Within the Quanzhen Daoist 全真道 tradition, it is embodied in the practice of sitting in meditation (dazuo 打坐). As Chongyang Lijiao Shiwulun 重陽立教十五論 (Chongyang’s Fifteen Discourses on Establishing the Teaching) states: “Those who practice sitting in meditation are not merely those whose physical form is upright, with eyes closed and shut—this is false sitting. True sitting requires that throughout the twelve two-hour periods (of the traditional Chinese day), in walking, standing, sitting, lying down, and amidst all activity and stillness, the mind be like Mount Tai, unmoving and unshaken, blocking the four gates (eyes, ears, mouth, nose), not allowing external scenes to enter within. If there is even the slightest stirring of thought, it cannot be called tranquil sitting.” 凡打坐者, 非言形體端然, 瞑目合眼, 此是假坐也. 真坐者, 須要十二時辰行住坐臥、一切動靜中間, 心如泰山, 不動不搖, 把斷四門眼耳口鼻, 不令外景入內. 但有絲毫動靜思念, 即不名靜坐 (C. Wang 1988, p. 153).

Informed by this tradition, Li Xiyue’s emphasis on “sitting in meditation deep into the night, tranquil and spontaneous,” 深宵打坐, 清靜自然 (X. Li 1994a, p. 609), serves to remind practitioners that before formally engaging in the work, they must first adjust their posture to ensure the body is centered, relaxed, and comfortable, allowing for the unimpeded flow of qi and blood. They should then breathe naturally and freely. As the mind turns inward, free from discursive thought, the coarse and heavy breath will gradually become gentle, subtle, long, and even. This stage is also referred to as cleansing the mind and purifying the self through concentration and individual practice (Pregadio 2008, p. 646).

Since humans are easily drawn to external stimuli, leading to internal clutter, restlessness, and an inability to sit in tranquility, the regulation of body and breath must be fundamentally grounded in calming the mind. To return the mind from agitation to stillness, Li Xiyue proposed beginning with the dispersal of desires and the relinquishment of mundane affairs. In his commentary on the Qingjing Jing 清靜經 (Scripture on Clarity and Quiescence), specifically the passage “If one can constantly disperse their desires, the mind will naturally become quiescent.” 若能常遣其欲, 而心自靜 (X. Li 2009, p. 144). He elaborated: “To disperse desires, one must first relinquish affairs. To calm the mind, one must first disperse desires.” 遣欲者, 必先舍事. 靜心者, 必先遣欲 (X. Li 2009, p. 144). “Relinquishing affairs” means setting aside external matters—those concerns unrelated to one’s inner state and spiritual cultivation. This practice aligns with what Sima Chengzhen 司馬承禎, in his Zuowang Lun 坐忘論 (Essay on Sitting-in-Forgetfulness), referred to as “simplifying affairs”4, thereby preventing the arising of a troubled mind. Dispersing desires entails eliminating random thoughts. Thoughts arise from the mind, often initiated by desires, which manifest in two primary forms: One is conscious attachments, such as those to fame and wealth. As Li Xiyue noted, “One who seeks to attain the state of a Daluo Immortal, the heart must be refined. Cherish no vain thoughts of merit or fame, nor be ensnared by profit and desire.” 欲造大羅仙, 須把心兒煉. 功名休亂想, 利欲莫牽纏 (X. Li 1994b, p. 634) and the other is unconscious inclinations, such as idle wandering thoughts. Practitioners must “eradicate these entirely, practicing diligently day and night without interruption.” 亦盡滅除, 晝夜勤行, 須臾不替 (X. Li 2009, p. 156). Through the disciplined work of relinquishing affairs and dispersing desires, the practitioner may eliminate illusion and return to authenticity, restoring the mind from a state of scattered agitation to its original, inherent clarity and quiescence.

The fundamental path for individuals to relinquish affairs and disperse desires lies in the daily practice of restraining their random thoughts. According to Li Xiyue’s description, “Those who begin learning the Dao must restrain their thoughts and return to quiescence; in walking, standing, sitting, and lying down, the mind must always remain within the cavity.” 下手學道者, 必須攝念歸靜, 行、住、坐、臥, 皆在腔子裏 (X. Li 1994a, p. 623). For those newly embarked on the Daoist path, it is crucial to gather distracting thoughts during everyday activities, thereby Summoning the Scattered Spirit to a state of tranquility and clarity. Yet, there is a specific method for restraining thoughts. On this matter, Li Xiyue observed:

If one waits until thoughts triggered by external affairs, social interactions, human transactions, conversation, or food and drink have already stirred the mind’s mechanism, and only then attempts to restrain them, the inner mind will already be agitated and random thoughts will have arisen. If I stop them and they cease immediately, that is fortunate. But if, after stopping them, they arise again, or after driving them away, they return, growing more numerous the more they are pursued—like encountering a rampant enemy, closing one’s eyes to engage in a battle between heaven and man, and finding one’s innermost self becoming a battlefield of chaos—then the mind has been defeated. 如待有事物交接人我應酬笑言飲食之念觸動心機, 而乃從而克制之, 則內心浮動, 雜念已生, 吾止之而即止, 幸也. 苟或止之而複起, 麾之而又來, 愈逐愈多, 如逢勃敵, 閉目作天人之戰, 撫衷為糜爛之場, 心敗矣.

(X. Li 1994a, p. 622)

The deeper implication of this passage is to guide practitioners away from the inefficient and even harmful approach of restraining thoughts, directing them toward a higher level of cultivation. This is achieved through the ordinary, nurturing practice of relinquishing affairs and dispersing desires, as well as the immediate, on-the-spot transformation fostered by the interdependence of mind and breath. By these means, the mind is freed from its entanglement with thoughts and returns to its original source of clarity and quiescence. It is precisely here that Li Xiyue’s thought aligns with and inherits the tradition of the Qingjing Jing and Quanzhen Daoist. This progression manifests in the following aspects. First is the maxim that restraining thoughts is inferior, while forgetting thoughts is superior. If one waits until thoughts have already taken shape—specifically, until they have stirred the mind’s mechanism—before dealing with them, this already belongs to a lower level of practice. Alchemical cultivation lies in the ordinary practice of relinquishing affairs and dispersing desires, allowing the mind itself to abide in a state of emptiness and tranquility. When the mind is empty, although it may respond to external stimuli as they arise, it leaves no trace, like a mirror reflecting objects, and thus no entangled thoughts can take root. Second, the principle of transformation rather than confrontation. When thoughts first begin to stir, one neither welcomes nor resists them, neither pursues nor chases after them. Instead, one gently withdraws attention and harmonizes the breath. This method effectively refines the discriminating postcelestial spirit into the fuel for manifesting the primordial state. The process resembles removing firewood from beneath a cauldron—the fire of the heart naturally subsides, and the pneuma of the kidneys (shenqi 腎氣) naturally ascends. By contrast, if one forcibly restrains thoughts, obsessively fixating on their elimination, the thoughts will be merely suppressed, only to arise again, leading to endless psychological affliction over time. Ultimately, the authentic path of alchemical cultivation involves constructing within oneself a pure, quiescent, and natural realm of peace. Through the interdependence of mind and breath, the wandering postcelestial mind unites with the continuous, subtle breath—like a wandering child returning home, naturally abiding in peace, no longer entangled with the turbulent waves of the external world.

3.2. Concentrating the Spirit and Regulating Breath: The Dialectical Unity of Mind and Breath Cultivation

Li Xiyue emphasized that the cultivation of the mind and breath must be conducted concurrently, holding that individuals can regulate their breath by first calming their mind. Prior to Li Xiyue 李西月, Lu Xixing 陸西星 had explicitly stated: “Once the ordinary breath ceases, the true breath will naturally stir.” 凡息既停, 則真息自動 (Lu 1992, p. 365). The ordinary breath refers to oral-nasal respiration, while the true breath is embryonic breathing. The cessation of oral-nasal breathing is not achieved through deliberate restraint; rather, it occurs naturally when the mind reaches a state of utmost emptiness and quiescence, at which point oral-nasal breathing becomes slow and seemingly ceases. When the oral-nasal breathing approaches cessation, the embryonic breathing spontaneously activates.

Li Xiyue developed Lu’s concept further by elaborating on how the mind, in its active and quiescent states, differentially affects the breath. He states: “Qi is precisely the qi within the mind; when the mind moves, qi moves.” 氣即心中之氣, 心動則氣動 (X. Li 2009, p. 157). This reveals the direct functional correlation between mind and qi—once the postcelestial discriminating consciousness becomes agitated, the corresponding postcelestial qi inevitably follows suit and becomes unsettled. Conversely, “When the mind is quiescent, qi becomes calm, and the supreme regulation of the breath is that which requires no deliberate effort.” 心靜則氣平, 不調之調為上 (X. Li 1994d, p. 631). When the mind returns to stillness, qi naturally becomes harmonious and smooth. At this point, the regulation of breath is no longer a matter of deliberate striving but enters a natural state of regulation without regulating—the supreme level of breath regulation. On this basis, Li Xiyue further deepens the dialectical relationship between mind stillness and subtlety of breath. He points out: “When the mind is still, breath is also easy to regulate. The more subtle the mind, the more subtle the breath.” 心之靜者, 息亦易調. 心愈細, 而息愈微也 (X. Li 1994a, p. 623). This indicates that the more still and subtle the cultivator’s mind becomes, the stronger is their capacity to regulate breath, and the breath accordingly becomes increasingly subtle, continuous, and prolonged. A subtle mind enables refined awareness, allowing one to perceive the rising and falling of breath without being disturbed by it; subtle breath leads to the inward gathering of spirit and qi, gradually approaching the primordial state of chaos. Ultimately, Li Xiyue, like previous internal alchemists, referred to this heart-mind—one that delights in stillness and remains unaffected by external conditions—as the True Mind (zhenxin 真心)5, considering it the central focus of Daoist cultivation (Esposito 2001, p. 198). Correspondingly, he refers to the qi that emerges from the state of chaotic obscurity as the True Breath (X. Li 1994d, pp. 630–31). He maintains that when cultivators are able to act from the True Mind, no longer governed by the postcelestial discriminating consciousness, the oral-nasal ordinary breath is naturally and deeply suppressed, and the innate True Breath—embryonic breathing—spontaneously activates without any forceful striving. Thus, the complete sequence of cultivation—from mind stillness to breath regulation, and from breath regulation to the manifestation of True Breath—is fully realized.

Moreover, individuals can also concentrate their spirit by calming the mind. Li Xiyue believed that the mind, in a state of utmost quiescence, becomes one with the spirit. As elucidated by Zhang Bodua 張伯端: “Concentrating the spirit involves ceasing discursive thought and returning the spirit to the heart-mind.” 凝神者, 蓋息念．而返神於心 (B. Zhang 1988, p. 365). Li Xiyue elaborated:

The heart-mind resides in the Crimson Palace (jianggong 絳宮). When it is active and left unrestrained, it transforms into random thoughts and desires. Conversely, when the scattered mind is withdrawn and returned to quiescence, it can be called spirit. 蓋心在絳宮, 動以紛之則為念, 靜以收之則為心, 即靜心而返乎神室則為神.

(X. Li 1994a, p. 623)

In other words, when the mind is in a state of agitation, it gives rise to random thoughts. When desires arise from these thoughts, and the mind becomes captivated and obscured by them, it manifests as the human mind—the deluded mind. The true spirit, which by nature delights in tranquility, is thus disturbed by this deluded mind. Consequently, in this state, the mind and spirit are separate. Conversely, when the mind is in a state of quiescence, it becomes clear and pure, untainted and unattached, restored to its original state of inherent clarity and stillness. Upon reaching a state free of mundane knowledge and sensory discrimination, the primordial mind—the innately primordial, pure, and undivided true mind—manifests. When practitioners seal the three treasures (ears, eyes, and mouth), becoming like an infant, wholly oblivious to external things, the postcelestial spirit remains inactive, allowing the true spirit to radiate forth. Thus, in this state, the mind and spirit are one. Therefore, after curbing desires, restraining random thoughts, eliminating delusion, and returning to authenticity, if practitioners daily and steadfastly embrace and maintain this true mind, abiding in a prolonged state of unwavering purity and tranquility, the true spirit will be revealed.

Fundamentally, Li Xiyue regarded the concentration of spirit and the regulation of breath not as two separate practices but as an indivisible whole. Regulating the breath without concentrating the spirit results in sterile sitting and stagnant emptiness; concentrating the spirit without regulating the breath causes deviant fire to flare up, readily leading to deviation. Furthermore, when the mind is tranquil, the breath naturally becomes regulated; when the breath is calm and harmonious, the mind can inwardly illuminate the bodily form. Only through the interdependence of spirit and breath can practitioners steadily enter the gate of Internal Alchemy. He expounded on this as follows: “When the breath is tranquil, the spirit returns, the method for concentrating the spirit indeed relies on regulating the breath. When the spirit is stable, the breath settles, the method for regulating the breath likewise relies on concentrating the spirit. … The wind, fanned by the fire, grows in intensity. The fire, stoked by the wind, burns more fiercely. The two sustain and bind one another in mutual dependence, to the point where one no longer distinguishes whether the wind comes from the fire or the fire from the wind.” 息靜則神歸, 凝神之法, 固賴調息. 神定則息住, 調息之法, 亦賴乎凝神也. ……風得火而煽, 火得風而灼. 相維相系, 又不知風之為火, 火之為風也 (X. Li 1994a, p. 623). In this passage, wind and fire correspond to spirit and breath, respectively: “Spirit is fire; breath is wind.” 神者, 火也; 息者, 風也 (X. Li 1994a, p. 623). Through this analogy of wind and fire, he illustrates the reciprocal action between breath regulation and spirit concentration from two perspectives. On one hand, wind is intensified by the heat of fire, corresponding to the practitioner concentrating the spirit within the void, which then generates the true breath. On the other hand, fire is intensified by the assistance of wind, corresponding to the practitioner’s calm breath pacifying the mind. As the true breath emerges, the true spirit manifests accordingly. Therefore, concentrating the spirit cannot be separated from regulating the breath, and regulating the breath cannot be separated from concentrating the spirit.

3.3. Neither Forgetting nor Assisting: The Core Principle of the Interdependence of Mind and Breath

In addition, Li Xiyue emphasized that the essence of the interdependence of mind and breath lies in “Neither Forgetting nor Assisting” (wuwang wuzhu 勿忘勿助). The phrase Neither Forgetting nor Assisting originates from Mengzi 孟子 (Mencius): “You must attend to it and do not presume to fix it. Do not forget it, and do not try to hurry its growth.” 必有事焉而勿正, 心勿忘, 勿助長也 (X. Zhu 2017, p. 216). Li Xiyue, applying it to the context of concentrating the spirit and regulating the breath, explained: “When spirit and breath are interdependent, maintaining their clarity and naturalness is not forgetting. Following their clarity and naturalness is not helping.” 神息相依, 守其清淨自然, 曰勿忘; 順其清淨自然, 曰勿助 (X. Li 1994d, p. 631). Li Xiyue established Neither Forgetting nor Assisting as the fundamental principle for regulating breath and concentrating spirit. He asserted that practitioners seeking to settle the spirit and pacify the breath must never use the mind to chase after or manipulate the breath. He explicitly stated: “Chasing the breath scatters the spirit; manipulating the breath agitates the spirit.” 逐息則神散, 運息則神搖 (X. Li 1994a, p. 623). This is because any deliberate use of the mind to pursue or control the breath inevitably leads to mental dissipation and instability. The specific manifestations are as follows: If the discriminating postcelestial spirit predominates, the breath becomes rapid and hurried, resulting in scattered spirit and disordered qi. If the practitioner falls into drowsiness and lethargy, they may even sink into inert emptiness. In contrast, when practitioners neither cling to purposeful action nor cling to inaction, but instead achieve emptiness and preserve stillness, conforming to the natural rhythm of respiration and allowing it to follow its spontaneous course, the spirit and breath will naturally stabilize and commune, no longer manifesting states of agitation or dullness.

In summary, when practitioners achieve the interdependence of mind and breath, their spirit and qi can merge into a state of profound unity, ultimately undergoing a qualitative transformation. As the oral-nasal breathing through the mouth and nose grows increasingly subtle, even to the point of apparent cessation, the embryonic breathing begins to emerge. Random thoughts settle, and one enters a state of tranquility where distinctions between inner and outer dissolve, thereby attaining the realization of chaotic obscurity.

4. Enacting the Method of Penetrating the Chaotic Obscurity: Concentrating the Spirit Within the Void

As elucidated in the previous section, practitioners, through concentrating the spirit and regulating the breath, can gradually enter the state of chaotic obscurity after prolonged interdependence of mind and breath. However, Li Xiyue posited that concentrating the spirit itself follows a sequence: the first stage manifests as concentrating the spirit and entering the cavity of pneuma (qixue 氣穴), while the second stage involves concentrating the spirit within the void. It is precisely this elevation of spirit and breath—from the Yin Heel Channel (Yinqiao mai 陰蹻脈) to the Mysterious Pass within the Void (xuwu qiao 虛無竅)—that constitutes the opportune moment for applying the key to penetrating: a focused yet non-coercive inward piercing that enables entry into the realm of chaotic obscurity.

4.1. Concentrating the Spirit and Entering the Cavity of Pneuma: The Preliminary Step to Concentrating the Spirit Within the Void

Li Xiyue asserted that concentrating the spirit and regulating the breath are the foundational practices required for cultivators newly entering the Postnatal Stage. On the one hand, this assertion builds upon and refines the earlier tradition of concentrating the spirit and entering the cavity of pneuma. For instance, Lu Xixing 陸西星, in his Xuanfu Lun 玄膚論 (Treatise on the Mysterious Body), explained these concepts: “Concentrating the spirit, it does not mean becoming absolutely immobile, but rather refers to the spirit entering the cavity of pneuma and dwelling there inseparably with it.” 所謂凝者, 非決然不動之謂也, 乃以神入於氣穴之中, 與之相守而不離也 (Lu 1992, p. 361). “Regulating the breath, means conforming to its natural rhythm.” 調息者, 依息之謂也 (Lu 1992, p. 365). Wu Shouyang 伍守陽 held that concentrating the spirit and entering the cavity of pneuma involved the spirit and qi coupling within the cavity of pneuma after discursive thought had ceased (Ding 2007, p. 186). Similarly, Li Xiyue viewed concentrating the spirit as focusing the already purified and tranquil mind within the cavity of pneuma. As he said: “When the mind is not yet clear, do not close the eyes inward. First, one must actively and diligently gather it back, achieving a state of coolness, calm, and tranquility. Only then should one gather it into the cavity of pneuma. This is what is called cocentrating the spirit.” 心未清時, 眼勿內閉. 先要自動自勉, 收他回來, 清涼恬淡, 始行收入氣穴, 乃曰凝神 (X. Li 1994d, p. 631). In other words, when the ordinary human mind is not yet tranquil, one performs the previously discussed work of dispersing desires, relinquishing affairs, and withdrawing thoughts. Once the mind is tranquil and the spirit clear, gathering and settling the spirit and qi within the cavity of pneuma constitutes concentrating the spirit. Moreover, Li Xiyue considered the regulation of breath not to be exceptionally difficult. He believed that when practitioners maintain internal mental collectedness, preventing their spirit from scattering outwardly, and instead allow the breath to follow its spontaneous course, they conform to the breath’s natural rhythm while applying a degree of mindful awareness. Gradually, the pneuma of the kidneys and the breath complex converge within the cavity of pneuma. Over time, the breath naturally becomes deep, long, subtle, even, and peaceful. This is what he expressed as: “directing the breath from the Yin Heel Channel to meet with the breath of our mind within the cavity of pneuma.” 調度陰蹻之息, 與吾心之息相會於氣穴中也 (X. Li 1994d, p. 631).

Where exactly is the “cavity of pneuma” located within Li Xiyue’s internal alchemy system? He provides two descriptions. First: “Once the nasal breath is calm and harmonious, close the eyes and observe internally, concentrate the spirit on the Yin Heel Channel beneath the root of the kidneys—in front of the anus, behind the scrotum.” 鼻息平和, 然後閉目內觀, 神注腎根之下陰蹻一脈(穀道前, 陰囊後) (X. Li 1994d, p. 631). Second: “When the heart-mind rests below the navel (qixia 臍下), it is called concentrating the spirit. When qi returns below the navel, it is called regulating the breath.”心止於臍下, 曰凝神; 氣歸於臍下, 曰調息 (X. Li 1994d, p. 631). As Li Xiyue specifies, the Yin Heel Channel refers to the perineum region (between the anus and scrotum). Below the navel generally refers to the lower Cinnabar Field (xia dantian 下丹田). Therefore, Li Xiyue’s concept of “concentrating the spirit and entering the cavity of pneuma” remains within the traditional internal alchemical practice of focusing intent on the lower Cinnabar Field.

4.2. Concentrating the Spirit Within the Void: The Essence of Penetrating Chaotic Obscurity

On the other hand, building upon the foundation laid by earlier masters, Li Xiyue further proposed “concentrating the spirit within the void”, providing practitioners with a tangible path to enter the state of chaotic obscurity. Li Xiyue’s method of concentrating the spirit and regulating the breath was not confined to the level of “concentrating the spirit and entering the cavity of pneuma”; rather, it advanced progressively from this point. In his view, after the practitioner’s spirit is focused on the Yin Heel Channel: “After a short time, lift the mind and breath into the Mysterious Pass within the Void—behind the navel, in front of the waist, above the kidneys and below the heart—the central area, not to be rigidly confined. Settle the spirit and pacify the breath, prioritizing naturalness.” 如此片時, 將心息提上虛無竅內 (臍後腰前, 心下腎上, 中間一帶, 不可拘執), 停神安息, 以自然為主 (X. Li 1994d, p. 631). Li Xiyue provided an external reference point for the Mysterious Pass within the Void by delineating it as the central zone encompassing the area behind the navel, in front of the waist, above the kidneys, and below the heart, while simultaneously emphasizing that one should not rigidly confine it to this tangible location. This reference point corresponds approximately to the Gate of Life (mingmen), where the dynamic qi between the kidneys—the primordial qi—stirs. It is precisely this qi that Li Xiyue’s writings identify as the primordial qi within the postcelestial. Consequently, the Mysterious Pass within the Void, as articulated by Li Xiyue, points to the generative locus of primordial qi associated with the Gate of Life, rather than to the middle Cinnabar Field as proposed by Huo Kegong (Huo 2007, p. 73). Li Xiyue placed particular emphasis on the principle of “not rigidly confining it” precisely to prevent later scholars from misunderstanding the Mysterious Pass within the Void as a specific acupuncture point.

Yet, he simultaneously emphasizes that practitioners should not rigidly confine it to these tangible locations. When a practitioner concentrates spirit within the Mysterious Pass within the Void to refine the activated primordial qi with the fire of the heart, the following principle must be observed: mental attention to the breath should be applied neither too intensely nor too loosely, but must instead conform to and preserve its natural rhythm. Subsequently, the inner breathing (neixi 內息)6 becomes harmonious and even, manifesting a state where “the breath is lively and the mind is at ease.” 息活潑而心自在 (X. Li 1994d, p. 631). Seizing this moment, the practitioner applies the “penetrating” method to enter the internal process of concentrating the spirit within the void. This aligns with Xiao Jinming’s assertion that “Li Xiyue’s foundational practice consists primarily of concentrating on the Mysterious Pass within the Void, which is precisely the practice he termed penetrating the chaotic obscurity” (Xiao 2012, p. 310). In other words, the essence of penetrating the chaotic obscurity is precisely concentrating the spirit within the void.

What is meant by “concentrating the spirit within the void”? Li Xiyue explains: “Abiding within emptiness, without deviation or bias, is precisely concentrating the spirit within the void.” 坐虛無中, 不偏不倚, 即是凝神於虛 (X. Li 1994d, p. 631). This further manifests as the practitioner “taking the void and emptiness as the repository for the mind, and using the dark silence as the dwelling place for resting the spirit”. 以虛空為藏心之所, 以昏默為息神之鄉 (X. Li 1994d, p. 631). The “void” to which Li Xiyue refers represents the primordial state of unity with the Dao, revealed when body and mind are utterly still and the internal and external are transparently unified. It is not a physical space that can be defined by spatial orientation. When the work of collecting the mind, regulating the breath, closing the eyes, and preserving the spirit reaches maturity, the practitioner achieves a state of complete relinquishment and total forgetfulness. Within this void, spirit and qi fuse completely, thereby entering the undifferentiated realm of chaotic obscurity.

4.3. From Action to Non-Action: The Key to Concentrating the Spirit Within the Void

By concentrating the spirit within the void, practitioners of Daoism can penetrate the realm of chaotic obscurity. The realization of this crucial task hinges not only on lifting the mind and breath into the Mysterious Pass within the Void, but also on the transition from action (youwei 有為) to non-action (wuwei 无為). Regarding this latter point, Li Xiyue explains: “After repeated cycles of refinement, suddenly mind and breath forget each other, and spirit and qi merge as one.” 三番兩次, 澄之又澄, 忽然心息相忘, 神氣融合 (X. Li 1994d, p. 631). From the perspective of internal alchemy, the mutual forgetting of mind and breath is the inevitable result of deepening the practice of the interdependence of mind and breath. Li Xiyue here reveals an important cultivation sequence: practitioners do not achieve forgetting at the outset; rather, they must undergo a repeated process of refinement. As mental awareness and breath grow increasingly purified, spirit and qi enter a state of mutual dependence and inseparability. This state is no longer sustained by postcelestial consciousness through forced effort, but represents a spontaneous coupling at the primordial level. The mutual forgetting of mind and breath represents a deeper stage than the interdependence of mind and breath. In the latter stage, there remains a dualistic distinction—a mind that depends on breath, and a breath that is available for the mind to depend upon. In the stage of mutual forgetting, however, the perceiving subject and the perceived object both dissolve, and the distinction between mind and breath melts away. At this point, the fusion of spirit and qi occurs spontaneously. Li Xiyue further elaborates: “Spirit and breath reach equilibrium—seemingly present yet seemingly absent, one no longer knows whether spirit is breath or breath is spirit.” 神息兩平, 若存若亡, 不知神之為息, 息之為神也 (X. Li 1994a, p. 623). Once spirit and breath achieve a state of dynamic equilibrium and undifferentiated unity, they transcend even the subtle awareness of conscious distinction. This state resonates with the description in the Qingwei Danjue 清微丹訣 (Qingwei Branch Instructions on Inner Alchemy): “Dim and silent, dark and obscure, consciousness roams the vast emptiness… form and spirit intermingle” 昏昏默默, 杳杳冥冥, 意游长空……形神相杂 (Qingwei Danjue 清微丹訣 [Qingwei Branch Instructions on Inner Alchemy] 1988, p. 962)—it is the prelude to entering the realm of chaotic obscurity.

Furthermore, Li Xiyue pointed out the efficacy experienced by the practitioner after penetrating chaotic obscurity, namely that Yang Pneuma (Yangqi 陽氣) production occurs spontaneously in a state of unawareness. He described this phenomenon as: “In the interval free of knowledge and discrimination, One Yang returns for the first time, precisely like spring emerging from winter, or dawn approaching from night.” 無知無識之際, 才有一陽來複, 恰如冬之生春, 夜之向曙 (X. Li 1994c, p. 628). In summary, when the practitioner achieves the concentration of spirit within the void at the culmination of the foundational practice, leading to the unification of spirit and breath, and progressively develops from the interdependence of mind and breath to their mutual forgetting, they not only penetrate deeply into the realm of chaotic obscurity but also as stated in the Xuanguan Xianmi Lun 玄關顯秘論 (Treatise on the Manifestation of the Mysterious Cavity): “For a practitioner of the Dao, by concentrating the mind and coalescing the spirit to attain utmost emptiness and preserve stillness, brightness is thus born in the empty chamber.” 若學道之士, 冥心凝神, 致虛守靜, 則虛室生白 (Bai 1988, p. 142). Thereby triggering the activation of the Primordial qi within the Postnatal Stage and the emergence of what Internal Alchemists term the Mysterious Pass (xuanguan 玄關).

4.4. The Subsequent Evolution of Concentrating the Spirit Within the Void

It must be noted that Li Xiyue’s concept of “concentrating the spirit within the void” differs slightly from the practice of “concentrating the spirit in the void outside the body” advocated by the collateral transmission branch of the Western School. For Li Xiyue, the “void” denotes a primordial state that transcends spatial location. His method of concentrating the spirit within the void builds upon the foundation of spirit and qi having returned to the lower Cinnabar Field; it employs the penetrating method to nurture the true breath from within the void, thereby activating the Primordial qi within the Postnatal Stage. In contrast, the collateral transmission branch of the Western School, represented by Wang Dongting 汪东亭 and Xu Haiyin7 徐海印, explicitly emphasizes the addition of the phrase “outside the body” before “void”. Xu identifies “the square inch of space beyond the nostrils” (bikong wai fangcun zhi di 鼻孔外方寸之地) as the concrete reference point for this void outside the body. This represents a concretized interpretation of Li Xiyue’s thought, reflecting the creative transformation of Western Branch alchemy in the process of transmission. However, the collateral transmission branch did not, on this basis, propose a corresponding concept of a void within the body. Huo Kegong’s classification of the Mysterious Pass within the Void as a void within the body juxtaposed against the “boundless cosmos outside the body” (Huo 2007, p. 73) constitutes a binary distinction that aligns neither with Li Xiyue’s own discourse nor with the textual evidence of the collateral transmission branch. Furthermore, some studies have directly equated Li Xiyue’s “concentrating the spirit within the void” with “concentrating the spirit and regulating the breath in the void outside the body” (Qing and Zhan 2019, p. 418; X. Zhang 1999, p. 116). Such an equation fails to accurately represent the original meaning of Li Xiyue’s thought while also neglecting the creative transformation that Western Branch alchemy underwent in the process of transmission.

The practice of taking the “void outside the body” as the point of departure in the collateral transmission branch of the Western School likely originated with Wu Tianzhi 吴天秩. Clues supporting this can be found in the writings of Wang Dongting, who states: “Following Master Wu’s method, place the spirit outside and let it depend on the breath.” 依吴师法, 以砷放在外邊, 舆氯息相依 (D. Wang 2010, p. 205). Xu Haiyin not only inherited this teaching but also actively constructed a lineage connecting Li Xiyue and Wu Tianzhi (Xu 2010, p. 696). Furthermore, Xu Haiyin maintained that the classical Daoist records of “concentrating the spirit and entering the cavity of pneuma” actually refer to this square-inch space beyond the nostrils. Based on this, Xu distinguished between an indirect and a direct method for mind-breath interdependence: the former focuses on “the breath moving in and out, coming and going within the void outside.” 呼吸出入往來於外面虛空之中 (Xu 2010, p. 677), while the latter emphasizes “directly placing the spirit within the void outside.” 徑以神放在外面虛空之中 (Xu 2010, p. 677). Regarding Xiao Jinming’s assertion that “the method of concentrating on the void outside the body, transmitted by Wu Tianzhi to Wang Dongting, did not originate from Li Xiyue” (Xiao 2015, p. 215), this article, due to space limitations, does not undertake a detailed examination of the lineage’s authenticity. While not excluding the possibility that the concept of the “void outside the body” may have drawn from other intellectual sources, this article is more inclined to interpret it as a theoretical transformation shaped by the collateral transmission branch of the Western School within a specific historical context—namely, a creative adaptation that, while grounded in the foundational logic of Li Xiyue’s alchemical system, integrated multiple influencing factors. Accordingly, this article acknowledges the differences between the collateral branch and Li Xiyue’s original thought while seeking to elucidate the underlying continuity between them, thereby rejecting any interpretation that posits a fundamental rupture or disjunction.

The collateral transmission branch of the Western School takes the interdependence of mind and breath as its essential secret, which shares a continuous lineage with Li Xiyue’s thought. Wang Dongting once stated: “The secret I received from Master Wu was simply the transmission of the four characters mind and breath interdependence.” 我得吴老師傅訣, 就是傅心息相依四字 (D. Wang 2010, p. 236). Even more notably, regarding the elucidation of the interdependence of mind and breath and their mutual forgetting—the prerequisites for concentrating the spirit within the void—Xu Haiyin’s exposition is largely consistent with that of Li Xiyue. Xu Haiyin stated:

The interdependence of mind and breath is the unique method of the Mysterious Tradition (Xuanzong 玄宗). Through it, one attains the state where body and mind become one, and waking and sleeping become one. Placing the spirit externally, allowing it to follow the breath freely, while simply employing contemplation—gently illuminating—this is the Mysterious Tradition’s Avalokiteśvara (Guanzizai 觀自在). Placing the spirit externally, allowing it to follow the breath’s inhalation and exhalation, its coming and going, until the two naturally unite—this is the Mysterious Tradition’s Tathāgatagarbha (Rulaizang 如來藏). After prolonged interdependence, mind and breath are both forgotten, and one abruptly enters stillness; after prolonged stillness, one becomes profoundly serene—this is the Mysterious Tradition’s Ocean of Nirvāṇa (Jiemie Hai 寂滅海). 心息相依, 乃玄宗不二法門, 由此以達到身心一如, 寤寐一如之境焉. 以神放在外面, 隨息自在, 我只用觀照, 微微照著, 即是玄宗之觀自在. 以神放在外面, 隨息出入, 一往一來, 自然合體, 即是玄宗之如來藏. 依久, 心息二忘, 脩然入定, 定久湛寂, 即是玄宗之寂滅海.

(Xu 2010, p. 679)

The foregoing analysis represents a synthesis and creative transformation of Buddhist thought. Xu Haiyin employs three distinct Buddhist concepts—Avalokiteśvara, Tathāgatagarbha, and the Ocean of Nirvāṇa—to artfully delineate the three progressive stages of the Daoist practice known as the interdependence of mind and breath. First, drawing on the Buddhist notion of vipaśyanā (guanzhao 观照), Xu uses Avalokiteśvara to analogize the initial phase of Daoist cultivation, in which the practitioner maintains a subtle awareness without deliberately controlling the breath. This stage emphasizes the natural ease of following the breath spontaneously. Here, mind and breath begin to conjoin, yet a subtle duality persists between the observing mind and the observed breath; it thus belongs to the realm of action. Second, Xu invokes the concept of Tathāgatagarbha—the womb of the Thus-Come One—to symbolize the nascent stirring of primordial qi within the Daoist framework. At this stage, spirit and qi are united but not yet fully integrated, much like a fetus gestating in the womb, pregnant with latent vitality. The practice here deepens from mere interdependence toward genuine union, wherein the distinction between subject and object gradually dissolves. This corresponds to a transitional phase from action gradually entering non-action. Finally, Xu employs the Ocean of Nirvāṇa to represent the pinnacle of Daoist cultivation—a state of profound stillness in which body and mind are utterly forgotten and one abides in deep meditative absorption. Within this vast, tranquil expanse, primordial qi emerges from the undifferentiated realm of chaotic obscurity, just as Nirvāṇa is characterized by perfect stillness and boundlessness. This is the stage of non-action, where yin and yang have not yet differentiated and the very source of the ingredients (yaowu 藥物) is generated.

Although Xu Haiyin and others concretely identified the “void” as a location outside the body, they nonetheless upheld the interdependence of mind and breath as the sole essential method for alchemical cultivation. They likewise maintained that “concentrating the spirit within the void to attain stability is what is meant by ‘practicing meditation within the chamber of spirit’—the profound essence of Daoist sitting meditation.” 凝神於虛而獲定, 是謂打坐神室之內, 玄宗坐禪之妙旨 (Xu 2010, p. 679). This reflects both a development of Li Xiyue’s thought on the interdependence and mutual forgetting of mind and breath, as well as the concretized transformation of the concept of “concentrating the spirit within the void” in the process of transmission.

Therefore, this article respectfully disagrees with Ding Changchun’s assertion that “Xu Haiyin’s advocacy of concentrating the spirit and regulating the breath in the void outside the body has no basis in Li Xiyue’s thought” (Ding 2021, p. 84). As demonstrated in the preceding analysis, Xu Haiyin’s exposition of the cultivation process of the interdependence of mind and breath as it progresses from deliberate effort to non-action follows the same lineage as Li Xiyue’s thought on the progression from the interdependence of mind and breath to the mutual forgetting of mind and breath. Although Xu incorporated more Buddhist terminology and offered a more concretized interpretation contextualized by the late Qing and Republican era, the fundamental logic of alchemical practice and the essential sequence of cultivation remain traceable to clear origins in Li Xiyue’s theoretical system. Ding Changchun’s assertion thus appears to conflate “differences in doctrinal formulation” with a “rupture in intellectual lineage”, thereby failing to fully apprehend the inherent continuity of the Western Branch’s alchemical transmission. This article maintains that the collateral transmission branch’s inheritance of Li Xiyue’s thought is embodied primarily in the fundamental logic of alchemical practice, rather than in a complete equivalence of doctrinal formulations. Scholars should distinguish between Li Xiyue’s own thought and its subsequent development by later adherents, avoiding the retrospective definition of the master’s teachings through the lens of his followers.

5. Effectuating the Method of Penetrating the Chaotic Obscurity: Manifesting the Living Mysterious Pass

In Daoist scholarship, the experiential signs that emerge during internal alchemy practice are regarded as tangible proof of the practitioner’s spiritual progress (Eskildsen 2001, p. 139). Li Xiyue believed that when practitioners concentrate their spirit within the void, they have already deeply entered the realm of chaotic obscurity. In this state, the Mysterious Pass manifests spontaneously. As he stated: “If one can proceed directly to chaotic obscurity, the Mysterious Pass will spontaneously manifest.” 若能直造杳冥, 自當透出玄竅 (X. Li 2009, p. 55). In other words, when practitioners attain a state of utmost tranquility and quiescence, with spirit concentrated and breath harmonized, they spontaneously enter the realm of chaotic obscurity. From this state, a sublime condition—vast beyond all measure and subtle beyond description—spontaneously manifests. This is what is termed the Manifestation of the Mysterious Pass (xuanguan xianxiang 玄關現象).

5.1. The Dead and Living Mysterious Pass: Li Xiyue’s Inheritance from and Breakthrough in Previous Theories of the Mysterious Pass

The Mysterious Pass elucidated by Li Xiyue shares similarities with yet possesses crucial differences from the understandings of previous internal alchemists. What, then, is the Mysterious Pass? Li Xiyue stated:

The Mysterious Pass, emerges from within the void. It does not reside within the five viscera and six bowels (wuzang liufu 五臟六腑), let alone among the limbs. To speak from the perspective of its name: This Pass is a mechanism of sublime wonder, hence it is called the Mysterious Pass. This Cavity is the place where the ten thousand methods return to unity, unique and without counterpart, hence it is called the Single Cavity (yiqiao 一竅). To summarize in a word: Center (zhong 中). This center lies in the middle of above and below, yet is not confined to the middle of above and below, for there is a distinction between a dead center and a living one. 玄關一竅, 自虛無中生. 不居於五臟六腑, 肢體間無論也. 今以其名而言：此關為玄妙機關, 故曰玄關. 此竅為萬法歸一之地, 有獨無對, 故曰一竅. 一言以備之曰：中是也. 中在上下之中, 亦不在上下之中, 有死, 有活故也.

(X. Li 1994a, p. 618)

This passage delineates three key implications of the Mysterious Pass.

First, the Mysterious Pass emerges from the void. As Li Daochun 李道純 stated: “The Mysterious Pass is the mechanism of utmost mystery and subtlety. Most learners today search for it based on the physical form, but no organ within the physical body corresponds to it, yet one cannot completely abandon this body to seek it externally.” 夫玄關一竅者, 至玄至妙之機關也. 今之學者多泯於形體, 但著在形體上都不是, 亦不可離此一身向外尋求 (D. Li 1988, p. 498). Li Xiyue similarly held that the Mysterious Pass is not an acupoint located at a specific place within the body; if practitioners wish to recognize it, they must not seek it solely within the body. However, the manifestation of the Mysterious Pass is the result of penetrating the state of chaotic obscurity; therefore, one cannot seek it purely externally, completely detached from the human body. It is called the Mysterious Pass precisely because it possesses the qualities of subtlety, profundity, and mysterious penetration—being unique and without counterpart.

Second, the Mysterious Pass is the “Center”. Influenced by Li Daochun, Li Xiyue proposed: “What is the ‘Center’? It is the Mysterious Pass.” 中者何？玄關是也 (X. Li 1994a, p. 619). In Zhonghe Ji 中和集 (The Book of Balance and Harmony), Li Daochun pointed out: “In which palace is the Mysterious Pass located? Seek it in the Center.” 問玄關一竅在何宮？中間覓 (D. Li 1988, p. 518), and “This word ‘Center’ clarifies the Mysterious Pass.” 此中字, 玄關明矣 (D. Li 1988, p. 498). Li Daochun believed that earlier Daoist texts did not explicitly indicate the specific location of the Mysterious Pass within the body because it is difficult to describe in words. The ancient sages used the word “Center” to hint at its nature; in fact, this “Center” itself reveals the “Mysterious Pass”. However, the “Center” referred to here is not a spatial midpoint, nor the center among the four directions of above, below, left and right, nor a “center” fixed in a specific location. Rather, it is a sublime realm, transcending space, form, and characteristics, which practitioners experience during the process of cultivation. Building upon the foundation laid by earlier masters, Li Xiyue asserted that “Above and below, left and right, front and back combine to secretly conceal a single Center. This Center is the Mysterious Pass within the Void8 (xuwu qiao虛無竅). The external sun and moon move back and forth; the internal sun and moon (spirit and qi) turn upside down; the continuous, subtle respiration is uniformly within this Mysterious Pass within the Void.” 合上下左右前後, 暗藏一個‘中’字, 此‘中’乃虛無竅也. 外日月一往一來, 內日月一顛一倒. 綿綿呼吸, 均在此虛無竅中 (X. Li 2009, p. 173). “Center” is another name for the Mysterious Pass, serving as the pivotal axis for returning from the postcelestial to the precelestial realm—transcending all form and abiding in neither extreme. The Mysterious Pass within the Void (xuwu qiao 虛無竅) is not a specific acupoint located within the physical body; rather, it is a precelestial state attained through the fusion of spirit and qi and the interdependence of mind and breath. Here, Li Xiyue directly equates “Center” with the Mysterious Pass within the Void, maintaining that the reversal of Kan 坎 and Li 離, the intercourse of spirit and qi, and the generation of embryonic breathing all occur within this cavity. This reveals the twofold yet unitary relationship between the Mysterious Pass and the Mysterious Pass within the Void. Because both above and below, and Being and Non-Being are encompassed within this Mysterious Pass, Li Xiyue regarded the Mysterious Pass as the source of all generation and transformation. He indicated that “the Mysterious Pass is the gate of the Great Dao. Creating lead and obtaining the elixir are not external to this.” 一孔玄關, 大道之門. 造鉛得丹, 不外乎此也 (X. Li 2009, p. 90). Drawing on the idea, frequently found in neidan texts, that “the One Opening of the Mysterious Pass is a synonym of the Mysterious Female, the Door of Life and Death” (Pregadio 2008, p. 1131), he sought to elucidate that the Mysterious Pass serves as the gateway to entering the Dao and returning to the primordial source, permeating the entire process of internal alchemy cultivation. If a practitioner can recognize this Mysterious Pass and enter through this gate, they grasp the key to ascending the path and advancing in attainment. If they fail to find this gate, even a lifetime of cultivation will yield no genuine achievement.

Third, the Mysterious Pass has both a dead and a living aspect. Li Xiyue held that the manifestations of the Mysterious Pass are varied and changeable. Successive generations of alchemists, based on the different inner landscapes witnessed through their own cultivation and verification, have given it various distinct names. Although the Mysterious Pass is extremely important in internal alchemy practice, accomplished practitioners of the past often kept the core secrets of cultivation closely guarded, transmitting them to disciples only after strict ceremonies, such as the ceremony combining head-touching (moding 摩頂) for empowerment with formal pledge to precepts (shoujie 受戒). Even when they occasionally divulged information, they might only briefly state that the Mysterious Pass was neither in the heart nor the kidneys, without specifying its location or essence. Li Xiyue’s departure from his predecessors lies in his explicit revelation in writing of both the Living and Dead Mysterious Pass. So, what is meant by “dead”? And what is meant by “living”? His explanation is as follows:

Physical locations—such as the Yellow Court (Huangting 黃庭), the Cavity of Pneuma (Qixue 氣穴), and the Cinnabar Field (Dantian 丹田) —constitute the Dead Mysterious Pass (si xuanguan 死玄關). It is the Mysterious Pass that manifests after concentrating spirit and gathering qi that is the Living one (huo xuanguan 活玄關). 以黃庭、炁穴、丹田為此中, 就是死的. 以凝神聚炁, 現出此中, 就是活的.

(X. Li 1994a, p. 619)

The Yellow Court, the Cavity of Pneuma, and the Cinnabar Field are all specific bodily locations commonly referenced in classical Daoist alchemical texts. If practitioners regard these fixed physical sites as the Mysterious Pass itself, then this Mysterious Pass is “dead”. Li Xiyue does not deny the function of the Yellow Court, the Cavity of Pneuma, or the Cinnabar Field. On the contrary, in his cultivation sequence, concentrating the spirit and entering the Cavity of Pneuma constitutes the foundational practice. However, if one becomes attached to these fixed locations as the Mysterious Pass itself, one remains confined to the realm of form and substance, failing to enter the precelestial state. He therefore designates these as “dead” to caution practitioners against clinging to physical traces. When practitioners, through the interdependence of mind and breath and concentrating the spirit within the void, penetrate the realm of chaotic obscurity, a “Center” naturally “manifests” of its own accord. This ‘Center” is neither premeditated nor forcibly attained; rather, it is a sublime realm that emerges spontaneously—this is the Living Mysterious Pass. Li Xiyue further describes it as the “luminous glow of the union between spirit and qi.” 神氣交媾之靈光 (X. Li 1994a, p. 618). In Li Xiyue’s alchemical theory, the manifestation of the Mysterious Pass refers specifically to this Living Mysterious Pass—that is, as he stated, “I say it is certainly not the Yellow Court, the Cavity of Pneuma, or the Cinnabar Field.” 吾謂其並非黃庭、炁穴、丹田也 (X. Li 1994a, p. 618). The Living Mysterious Pass is precisely the aforementioned Mysterious Pass within the Void, as he indicated: “Using the Mysterious Female of the Void to nourish the Valley Spirit of the Void.” 假虚無之玄牝, 養虚無之穀神 (X. Li 1994a, p. 618). By distinguishing between the “dead” and “living” Mysterious Pass, Li Xiyue guides practitioners to begin their cultivation from the tangible, “dead” locations and gradually enter the intangible, “living” realm—neither clinging to fixed loci nor falling into vacuity, but taking the concentration of spirit and gathering of qi as the essential practice, awaiting the spontaneous manifestation of the Mysterious Pass as the verification. This is precisely the hidden principle by which the practice of penetrating chaotic obscurity enables one to break through the Mysterious Pass.

He believed that for practitioners to recognize the Living Mysterious Pass, they must progress through three sequential stages: Firstly, when the Living Mysterious Pass is initially perceived, its manifestation is unstable, alternately appearing clear and vague. Secondly, when first entering the state of the Living Mysterious Pass, because spirit and qi have just begun to merge and have not yet stabilized, one consequently experiences it as elusive and difficult to grasp. Finally, only when the interaction between spirit and qi matures, and the mind is fully settled and free from scattering, can one truly realize the realm where the Living Mysterious Pass is the “Center”. When practitioners reach the third stage, the distinction between self and others dissolves; even ghosts and spirits cannot perceive it. Everything exists in a state of undifferentiated unity and pristine spontaneity, wherein body and mind experience profound tranquility and vitality. In brief, the practitioner’s apprehension of the Living Mysterious Pass evolves from initial instability and elusiveness to gradual stabilization, ultimately culminating in a self-forgetful, pure state of unity with heaven and earth. The Living Mysterious Pass emerges from the union of spirit and qi. As Li Xiyue stated: “This union is the basis of the utmost yin and the root of the chaotic obscurity. One must be able to penetrate chaotic obscurity to achieve this union.” 交媾者, 至阴之本, 杳冥之根也. 人能钻入杳冥, 方能得成交媾 (X. Li 1994d, p. 632). Therefore, when spirit and qi initially merge but have not yet solidified, the Living Mysterious Pass appears flickering and elusive. Once the embrace of spirit and qi becomes proficient, leading to the forgetting of self and others and entry into the state of chaotic obscurity, the Living Mysterious Pass spontaneously reveals itself.

5.2. The Inner and Outer Mysterious Pass: The Subsequent Evolution of Li Xiyue’s Theory of the Mysterious Pass

Li Xiyue’s theory of the Mysterious Pass underwent a degree of evolution among the collateral transmission branch. For instance, Xu Haiyin 徐海印 proposed the concepts of the Outer Mysterious Pass (wai xuanguan 外玄關) and the Inner Mysterious Pass (nei xuanguan 內玄關). The specific content is as follows: “When the heart-mind and breath are interdependent within the void outside, merging into a single whole, this constitutes the Outer Mysterious Pass. When the interdependence of mind and breath outside reaches a state of stillness and stability, and after prolonged stability becomes profoundly serene, then within the physical body, not a single thought arises, not a single intention stirs—this is the Inner Mysterious Pass. … The moment the Outer Mysterious Pass manifests, the entire body naturally becomes soft, supple, wonderfully pleasant, entering a state of penetrating the chaotic obscurity. The Primordial qi arrives spontaneously, and the ingredients arises autonomously.” 心息相依在外面虛空之中, 打成一片, 是為外玄關. 外面心息依到靜定, 定久湛寂, 色身之內, 一念不起, 一意不動, 為內玄關. ……外玄關一現, 周身自然酥軟美快, 恍惚杳冥, 先天一炁自來, 藥物自生 (Xu 2010, p. 674). In other words, when the mind and breath intertwine and merge into one within the void outside the body, this constitutes the Outer Mysterious Pass. When this external interdependence of mind and breath reaches a state of stillness and stability, and after prolonged stillness becomes profoundly serene, then within the body, not a single thought arises, not a single intention stirs—this is the Inner Mysterious Pass. Once the Outer Mysterious Pass manifests, the entire body naturally experiences a sensation of softness, comfort, and exquisite pleasure, and consciousness enters a state of indistinctness and profound obscurity. At this moment, the Primordial qi arrives spontaneously, and the essential ingredients required for alchemical refinement naturally emerge.

Building upon the foregoing discussion of Li Xiyue’s concept of concentrating the spirit within the void, it becomes evident that in his system, practitioners, after penetrating the chaotic obscurity, generate yang qi, whereupon the Mysterious Pass manifests. This Mysterious Pass is precisely the Living Mysterious Pass. Xu Haiyin, however, grounding his approach in the interdependence of mind and breath within the void outside the body, describes a comparable experiential outcome as the manifestation of the Outer Mysterious Pass.

5.3. Advanced Cultivation After the Manifestation of the Living Mysterious Pass: Unfolding of Cavities and Opening of Passes

It should be noted that in Li Xiyue’s internal alchemy theory, once the Living Mysterious Pass manifests, the Primordial qi within the Postnatal Stage emerges. At this moment, by seizing this qi, practitioners can naturally unfold the cavities and open the passes. This unfolding and opening are a gradual and spontaneous accomplishment, but practicing this method of the elixir requires two prerequisite conditions.

The first prerequisite is establishing the furnace and tripod (dingqi 鼎器). Li Xiyue’s view is articulated in the principle that: “Once the furnace and tripod are established, spirit and qi interact. Once spirit and qi interact, the accumulation becomes substantial. Once the accumulation becomes substantial, the impulse becomes vigorous. Once the impulse becomes vigorous, the cavities unfold and the passes open.” 鼎器立, 則神氣交. 神氣交, 則積累厚. 積累厚, 則衝突健. 衝突健, 則關竅展 (X. Li 1994a, p. 610). This concept is an extension of the lineage of Sun Jiaoluan 孫教鸞 and Tao Susi 陶素耜, who held that “Those who cultivate the Dao must first use the furnace and tripod to open the passes and cavities.” 修身之人, 必先用鼎器以開關竅 (X. Li 1994a, p. 610). Since Li Xiyue divided alchemical cultivation into Postnatal and Prenatal stages, his theory of the furnace and tripod likewise distinguishes between the Postnatal Furnace and Tripod (Houtian ding 後天鼎) and the Prenatal Furnace and Tripod (xiantian ding 先天鼎). While detailed discussions appear scattered throughout his works—including Discourses on the Daoqiao Tan 道竅談 (Discourses on the Subtleties of the Dao), Wugenshu Ci Zhujie 無根樹詞注解 (Annotation on the Lyric of the Rootless Tree), and Houtian Chuanshu Wenzhong Jing 後天串述文終經 (The Final Classic on the Sequential Elucidation of the Postnatal)—the present scope permits only an exposition of his postnatal furnace and tripod concept. Li Xiyue elaborated on the postnatal furnace and tripod as follows: “The Postnatal Furnace and Tripod is precisely the locus where the Original Spirit and Original Qi mutually interact and blend.” 後天鼎者, 即元神, 元炁交合之所也 (X. Li 2009, p. 51). Thus, in Li Xiyue’s system, the Postnatal Furnace and Tripod is the locus, where within the state of chaotic obscurity, the practitioner’s spirit and qi couple and fuse—namely, the previously discussed Mysterious Pass within the Void and the Living Mysterious Pass.

The second prerequisite is seizing the moment when Yangqi arises. In Li Xiyue’s view, “When the vital base is generated and the Yangqi spontaneously grows, one can then open the passes and circulate the qi.” 命蒂生而陽氣自長, 乃可以開關運氣矣 (X. Li 1994d, p. 631). When spirit and qi fully merge—analogous to the coupling of male and female essences—the True Seed (zhenzhong 真種) is transformed and born. This True Seed refers precisely to the genuine qi (zhenqi 真氣) produced within the Postnatal Furnace and Tripod, namely the Yangqi mentioned here. This qi is the energetic mechanism that arises when practitioners focus their spirit on the Yin Heel Channel, then elevate the mind and breath to the Mysterious Pass within the Void, abiding within the state of chaotic obscurity. It is also termed the Primordial qi within the Postnatal Stage. Within Li Xiyue’s alchemical system, this qi serves as the ingredients required for the stage of the Coagulation of the Jade Liquor to the Cinnabar Field9 during the Postnatal Stage.

What Li Xiyue termed Unfolding the Cavity and Opening the Passes (zhanqiao kaiguan 展竅開關) is, in essence, the natural outcome achieved after a practitioner’s skill in penetrating the chaotic obscurity has matured; it is the spontaneous result of abundant Yangqi, where the cavity and pass open effortlessly once conditions are ripe. Moreover, he refuted the common view that Lu Xixing disparaged the method of opening the passes and unfolding the cavities. He pointed out that Lu Xixing did not reject this practice altogether; rather, he lamented that those whose primordial condition had already been compromised had no choice but to resort to this method as a means of bodily restoration and cultivation (see X. Li 1994a, p. 609). In his view, children whose innate constitution remains unbroken can naturally open their passes and cavities through quiescent cultivation that replenishes qi and stabilizes spirit, thus having no need for the acquired method of Unfolding the Cavity and Opening the Passes. However, for middle-aged learners whose primordial qi has already been depleted, this method alone cannot rapidly replenish the deficit. They must instead practice the skill of concentrating the spirit and regulating the breath. When the Living Mysterious Pass first manifests, they must not attach to any phenomenon. Once the Yangqi has become abundant, they can then perform the work of Unfolding the Cavity and Opening the Passes to achieve a return to the origin and recovery of the fundamental state. In his Houtian Chuanshu Wenzhong Jing 後天串述文終經 (The Final Classic on the Sequential Elucidation of the Postnatal), Li Xiyue provided clear explanations for the meanings of Unfolding the Cavity and Opening the Passes. He stated: “Abruptly, within the Mysterious Pass within the Void that serves as the Inner Tripod, an intensely vibrant qi surges forth. It leaps and surges, brimming and spouting, ascending directly along the Thoroughfare Vessel (chong mai 冲脉) to the region of the heart. This is Unfolding the Cavity. Once this conflicting force has accumulated sufficient power, the practitioner transforms spirit into awareness, guiding this qi to surge from the Caudal Funnel (weilü 尾閭). It successively bursts through the three passes—the Caudal Funnel, the Spinal Handle (jiaji 夾脊), and the Jade Pillow (yuzhen 玉枕)—and finally soars up to the Muddy Pellet (niwan gong 泥丸宮) at the crown of the head. This entire process constitutes Opening the Passes.” 忽然而內鼎之間, 沖出一物, 跳跳躍躍, 噓噓噴噴, 直由沖脈上至心府, 即展竅時也. 俟其衝突有力時, 乃變神為意, 引出尾閭, 一撞三關, 飛上泥丸, 即開關也 (X. Li 2009, p. 52). The Inner Tripod is identical to the aforementioned Postnatal Tripod, which stands in contrast to the Prenatal Furnace and Tripod, also termed the Outer Tripod. In his view, once the Postnatal Tripod is established, the Primordial qi within the Postnatal Stage is generated therefrom. This qi first spirals upward from the lower Cinnabar Field until it reaches the Crimson Palace; this is Unfolding the Cavity. As this qi accumulates daily, growing substantial and powerful, the practitioner gently applies intention to guide it to the Caudal Funnel. It then moves inversely upward through the Spinal Handle and the Jade Pillow until it ascends to the Muddy Pellet; this constitutes Opening the Passes. In Li Xiyue’s internal alchemy theory, Unfolding the Cavities occurs prior to Opening the Passes.

Li Xiyue, influenced not only by Tao Susi’s doctrine that “attempting to lay the foundation and refine the self without opening the passes is like scratching an itch through one’s boot—utterly futile.” 若不開關, 而築基煉己, 乃是隔靴搔癢, 無益於事 (Tao 1992, p. 96), but also by his own formulations that “unfolding the cavities and opening the passes serve to unlock the Mysterious Gate and clear the path” 展竅開關, 所以啟玄門而辟徑路 (X. Li 1994a, p. 609) and “using the opening of the passes to pave the way for laying the foundation”. 以開關辟築基之路 (X. Li 1994a, p. 610). He further asserted that one must “draw the primordial yang into the inner crucible, allowing embryonic breathing to continue unbroken, and only then generate the postcelestial medicament to carry out the work of Jade Coagulation.” 攝元陽而入內鼎, 胎息綿綿, 然後生後天之藥, 而行玉煉之功 (X. Li 1994a, p. 610). The implication is that for practitioners in the Postnatal Stage of cultivation, after undergoing the processes of collecting the mind, regulating the breath, concentrating the spirit and gathering qi, and penetrating the realm of chaotic obscurity, they generate the medicament necessary for Jade Coagulation and Elixir formation—namely, the Primordial qi within the Postnatal Stage. They subsequently unfold the cavities and open the passes, thereby formally initiating the foundational practice of refining the self and the process of Jade Coagulation within great foundation-building. Therefore, it can be said that penetrating the chaotic obscurity is an essential prerequisite for Jade Coagulation and Elixir formation.

Significantly, Huang Yuanji 黃元吉, a native of Fushun, Sichuan, active during the Xianfeng and Guangxu reigns, articulated ideas concerning the manifestation of the Mysterious Pass and the unfolding of the cavities and opening of the passes that bear notable resemblance to those of Li Xiyue. For instance, Huang states in his Luyutang Yulu 乐育堂语录 (Recorded Sayings of the Joyful Hall): “When spirit and qi merge and mind and breath become interdependent, the body, both internally and externally, feels harmonious and integrated, with a sensation of softness and pliancy as if floating on cotton—this is the sign of the generation of qi. At the moment this qi is generated, the Mysterious Pass opens.” 神氣混合, 心息相依, 其身體內外泰然融然, 有蘇軟如綿之意, 此即氣生之兆也. 但此氣生時, 即玄關竅開時 (Ge 2013, p. 271). He further observes: “Once the ordinary breath ceases, embryonic breathing gradually appears. Nurtured slowly in this manner, the true qi naturally surges upward, reaching the region of the heart—this is the unfolding of the cavity.” 凡息一停, 胎息自見, 如此慢慢涵養, 自然真氣衝衝, 上達心府, 此展竅也 (Ge 2013, p. 412). Thus, although Li and Huang differ in their terminological expressions, they share a consistent description of the cultivation process: practitioners adhere to the principle of “neither forgetting nor assisting”, following the interdependence of mind and breath, true qi is generated, the Mysterious Pass manifests, and after nurturing this qi, the cavities naturally unfold and the passes open. While no direct historical evidence currently attests to personal contact between them, several contextual clues suggest the possibility of local continuity and implicit exchange of Western Branch alchemical teachings within Sichuan. These include geographical proximity, chronological succession and the hagiographic account in the Li Hanxu Zhenren Xiaozhuan 李涵虛真人小傳 (the Brief Biography of Li Hanxu), recording that after Li’s death, his immortal countenance appeared at Ziliujing—a location historically part of Fushun County, Huang Yuanji’s native place.10 Such resonances in thought suggest that the Daoist alchemical circles in late Qing Sichuan were not characterized by isolated sectarian transmissions but rather by theoretical interweaving and mutual resonance.

Existing studies on the relationship between Li Xiyue’s “penetrating the chaotic obscurity” and “unfolding the cavities and opening the passes” primarily present two viewpoints. One view, represented by Zhongguo Daojiao Tongshi 中国道教通史 (A Comprehensive History of Chinese Daoism), holds that what Ming and Qing dynasty alchemical texts refer to as “opening the passes and unfolding the cavities” is precisely the preliminary practice undertaken before foundation-laying, which Li Xiyue termed “penetrating the chaotic obscurity” (Qing and Zhan 2019, p. 416). The other view, represented by Ding Changchun, argues that “penetrating the chaotic obscurity” enables yang qi to grow naturally, thereby allowing one to open the passes and circulate qi. It belongs to the initial practices but not to the preliminary work of opening the cavities and passes undertaken before foundation-laying (Ding 2021, p. 81). Based on the foregoing analysis, this article affirms Ding Changchun’s view that penetrating the chaotic obscurity can open the passes and circulate qi. It points out that in Li Xiyue’s alchemical theory, once the practice of penetrating the chaotic obscurity achieves a certain level of efficacy, the Postnatal Crucible is established, naturally giving rise to the Primordial qi within the Postnatal Stage, which then opens the Conception and Governing Vessels (rendu ermai 任督二脈) and the Three Passes (sanguan 三關), thereby accomplishing the unfolding of cavities and opening of passes. Thus, a causal relationship exists between penetrating the chaotic obscurity and unfolding the cavities and opening the passes; they are not identical practices, as suggested by Zhongguo Daojiao Tongshi and similar studies. On the other hand, in light of Li Xiyue’s statement that “once the cavities and passes are opened, one then performs the work of nurturing oneself and discusses the way of foundation-laying.” 關竅既開, 乃行養己之功, 而談築基之道 (X. Li 2009, p. 52). This article affirms the macro-level judgment of Zhongguo Daojiao Tongshi that positions “penetrating the chaotic obscurity” as a practice undertaken “before foundation-laying”. It maintains that after practitioners penetrate the chaotic obscurity and unfold the cavities and open the passes, they thereby pave the way for foundation-laying. Given that the efficacy of penetrating the chaotic obscurity includes not only the manifestation of the Living Mysterious Pass but also a further stage of cultivation—namely, unfolding the cavities and opening the passes—this article suggests that Ding Changchun’s strict limitation of “penetrating the chaotic obscurity” to “the foundational practice of refining essence into qi” while excluding its role as “preparatory work for opening the cavities and passes before foundation-laying” may not fully capture the complete significance of this practice within Li Xiyue’s alchemical system.

6. Conclusions

Li Xiyue’s designation of “penetrating the chaotic obscurity” as the foremost difficult task in internal alchemy practice underscores both the challenge faced by practitioners in entering the state of chaotic obscurity and the pivotal role of this method within his alchemical system. For Li, penetrating the chaotic obscurity is not merely a technique for achieving stillness but rather the essential gateway through which practitioners, grounded in spirit and qi, undertake the cultivation of the Postnatal Stage. It marks the critical transition from deliberate effort to the primordial state of non-action. Although certain aspects may appear intricate—at times even obscuring the overall structure—once the underlying thread is grasped and these apparent obstacles are navigated, the depth and precision of his theoretical analyses become fully apparent.

Within Li Xiyue’s alchemical framework, penetrating the chaotic obscurity represents the culmination of the foundational practices, attained through prolonged cultivation of the interdependence of mind and breath. By regulating the body, closing the eyes, and sitting in stillness, the practitioner undertakes the work of withdrawing thoughts, dispersing desires, and relinquishing affairs, thereby returning the mind from agitation to quiescence. On this basis, breath is harmonized and spirit is concentrated. As the mind grows increasingly still, respiration naturally becomes relaxed, subtle, even, and prolonged, while spirit gradually returns to its original state of clarity and stillness, ultimately becoming one with the mind. The concentration of spirit and regulation of breath are mutually dependent and inseparable. The practitioner must adhere to the principle of “neither forgetting nor assisting”: any deliberate attempt to pursue or suppress the breath leads to dissipation of spirit and disorder of qi, or to drowsiness and lethargy. Only by conforming to the natural rhythm of respiration can spirit and breath truly unite. When they merge completely, the practitioner enters a state of chaos, indistinctness, and profound stillness, wherein distinctions between inner and outer dissolve—this is the realization of penetrating the chaotic obscurity.

In Li Xiyue’s thought, “chaotic obscurity” is intimately connected with “void”; penetrating the former is, in practice, a manifestation of “concentrating the spirit within the void”. After the mind has been pacified, the practitioner first performs the work of concentrating the spirit and entering the cavity of pneuma, focusing awareness on the Yin Heel Channel. After a short time, the mind and breath are elevated to the Mysterious Pass within the Void, where spirit is concentrated without bias or attachment. Li Xiyue cautions against rigidly locating this cavity in any fixed physical site; it is not a specific acupoint but rather the locus of transformation naturally manifested through the fusion of spirit and qi within the void. His reference to the Gate of Life region as an external coordinate serves only to indicate that this cavity is the source from which the Primordial qi within the Postnatal Stage emerges, not to reify it as a material locus.

When the practitioner deeply enters the state of chaotic obscurity, the Mysterious Pass spontaneously manifests. As spirit and qi completely merge within the void, the interdependence of mind and breath evolves into the mutual forgetting of mind and breath. The postnatal mind and breath, as it were, vanish, and in their place the Primordial qi within the Postnatal Stage is summoned and activated from within the void, giving rise to the phenomenon known as the Manifestation of the Mysterious Pass. Li Xiyue not only inherits and develops the classical understanding that the Mysterious Pass emerges from the void and is identical with the “Center”, but also innovatively distinguishes between the “dead” and “living” Mysterious Pass. The Mysterious Pass that manifests after penetrating chaotic obscurity refers specifically to the Living Mysterious Pass—the luminous fruition of spirit and qi congealed within the void enclosure. When the Living Mysterious Pass appears, the Postnatal Furnace and Tripod is established; when the Primordial qi within the Postnatal Stage emerges, the ingredients for the Coagulation of the Jade Liquor to the Cinnabar Field are prepared. Seizing this pivotal moment of qi dynamism, the practitioner naturally accomplishes the unfolding of the cavities and opening of the passes. Therefore, penetrating the chaotic obscurity is the prerequisite for unfolding the cavities and opening the passes; the two are not equivalent practices.

Thus, within Li Xiyue’s alchemical theory, the practice of penetrating the chaotic obscurity occupies a definitive pivotal position. It is at once the consummation of the foundational practices—withdrawing the mind, regulating the breath, and establishing the interdependence of mind and breath—and the indispensable prerequisite for the deeper stages of cultivation, including the unfolding of the cavities and the coagulation of the jade liquor. As Monica Esposito noted, Li Xiyue’s alchemical thought fully reflects the trend of the era, which interpreted neidan techniques from a bodily perspective (Esposito 2019, p. 8). Through his detailed exposition of the sequential stages of Postnatal cultivation, Li Xiyue illuminates the subtle developments in internal alchemy theory during the mid-to-late Qing period, elevating alchemical practice from technical procedure to a philosophical realization of the primordial void.

It is worth further reflection that the essence of penetrating the chaotic obscurity lies in concentrating the spirit within the void. Thus, regarding this as the essential method of the Western Branch is fundamentally sound. However, Li Xiyue’s conception of the “void” as the realm of unity with the Dao was later concretized by Xu Haiyin and the collateral transmission branch into the square inch of space beyond the nostrils, giving rise to the distinct notions of the Outer Mysterious Pass and Inner Mysterious Pass. This theoretical evolution reflects both the creative transformation of Western Branch alchemy in the process of transmission and the dynamic responsiveness of Daoist internal alchemy to broader intellectual currents during the late Qing and Republican periods, including the incorporation of Buddhist conceptual frameworks. It reminds us that Daoist alchemical theory is not a static dogma but a living tradition continually reinterpreted and enriched within specific historical contexts. Understanding the unique significance of Li Xiyue’s penetrating the chaotic obscurity not only illuminates the core essence of Western Branch alchemy but also offers a valuable lens through which to explore how nineteenth-century Chinese religious practice negotiated self-cultivation, integrated diverse traditions, and responded to the challenges of its time.