The first known examples of the use of alchemical imagery in relation to meditation practices refer to Laozi as a deity to be visualized within one's inner body. The Inscription for Laozi (Laozi ming) of 165 CE states that he "goes in and out of the Cinnabar Hut (danlu), and rises from and descends into the Yellow Court (huangting).(La divinisation de Lao tseu dans le Taoisme des Han; Ecole Francaise d'Extreme-Orient, 1992,47-48 and 128.)

From the late second century also comes the first mention of the "inner embryo," one of the most distinctive notions of neidan. It is found in the Xiang'er commentary to the Laozi, written around 200 CE and associated with the Way of the Celestial Masters, and the meditations described below are still practiced today.(1)

Taken together, the above inscriptions show that alchemical imagery was used in relation to meditation practices by the turn of the third century CE, and that the notion of an "inner embryo" already existed by that time. The step is not a major one from the notion of an "embryo" dwelling within one's inner body to the idea of generating an "inner infant," who is equated with the inner elixir and represents one's own real self. In fact, as early as the fifth century a scripture belonging to the Lingbao (Numinous Treasure) corpus states that "the Golden Elixir is within your body" (jindan zai zi xing).

Both the meditation practices and the relevant terminology continued to be transmitted in the subsequent centuries, first within traditions related to meditation, and later within traditions related to neidan. The two main sources that document the relation of these traditions to both waidan and neidan are the Central Scripture of Laozi (Laozi zhongjing) and the Scripture of the Yellow Court (Huangting jing), both of which circulated in Jiangnan during the third century. Both the Central Scripture and the Yellow Court enjoin adepts to visualize the deities who reside within themselves. These deities perform multiple related roles: they serve as administrators of the body, allow the human being to communicate with the major (and in several cases corresponding) gods of the outer pantheon, and personify the formless Dao or impersonal notions such as Yin and Yang and the Five Agents. In both the Central Scripture and the Yellow Court, moreover, meditation on the inner gods is combined with the visualization of essences and pneumas that adepts drive through the body and deliver to the gods in the five viscera, the three Cinnabar Fields, and other loci in order to provide them with nourishment. Both Shangqing and neidan would incorporate not only these practices, but also much of the attached imagery.

In particular, the Central Scripture often instructs adepts to visualize a "yellow essence" (huangjing) and a "red pneuma" (chiqi) that respectively represent the Moon and the Sun. Adepts should merge them with each other and circulate them within their body:

Constantly think that below the nipples are the Sun and the Moon. Within the Sun and the Moon are a yellow essence and a red pneuma that enter the Crimson Palace (jianggong); then again they enter the Yellow Court (huangting) and the Purple Chamber (zifang). The yellow essence and the red pneuma thoroughly fill the Great Granary (taicang). (Laozi zhongjing, sec. 11)

In this practice, the yellow essence and the red pneuma are moved through the Crimson Palace (heart), the Yellow Court (spleen), and the Purple Chamber (gallbladder), and finally reach the Great Granary (stomach). The purpose is to nourish the Red Child (chizi), an infant who resides in the Great Granary and is said to represent the "real self" (zhenwu) of the human being. In another instance, the yellow essence and the red pneuma are joined and then ingested:

The saintly man dissolves the pearls; the worthy man liquefies the jade. For dissolving the pearls and liquefying the jade, the method is the same. Dissolving the pearls means ingesting the essence of the Sun: the left eye is the Sun. Liquefying the jade means feeding on the essence of the Moon: the right eye is the Moon. (Laozi zhongjing, sec. 39) The related practice consists in lying down and repeatedly visualizing the yellow essence and the red pneuma that descend from one's eyes and enter one's mouth, so that they may be swallowed.

The Yellow Court mentions the same essences and pneumas, saying for instance:

Circulate the purple (huizi) and embrace the yellow (baohuang) so that they enter the Cinnabar Field; an inner light in the Abyssal Chamber (youshi) illuminates the Yang Gate (yangmen). (Huangting neijing jing, sec. 2)

Here the two pneumas are circulated and guided to the upper Cinnabar Field, while the Gate of Life (or Yang Gate) in the lower Cinnabar Field is visualized as irradiated by a light issuing forth from the kidneys (the Abyssal Chamber).

There are clear associations between the essences and pneumas of the Sun and the Moon, delivered by the adept of the Central Scripture to his inner gods, and the Yin and Yang essences and pneumas that a neidan adept circulates in his body to compound the elixir or nourish the "inner embryo." These associations become explicit when the Central Scripture refers to visualizing the pneuma of the Sun descending from the heart and the pneuma of the Moon arising from the kidneys; the adept should "join them making them one, and distribute them to the four limbs." An analogous practice is performed by the neidan adept when he joins the Fire of the heart and the Water of the kidneys to generate the first stage of the inner elixir. (Catherine Despeux, Taoisme et corps humain: Le Xiuzhen tu, 152- 58. )

Analogies with the alchemical process are also apparent in relation to another source of nourishment for the inner gods and their residences, namely the adept's own salivary juices. The main function of these juices is to aid the ingestion of essences and pneumas, but they are also used to "irrigate" (guan) the inner organs and, as we shall see presently, to feed the inner gods. (I.Robinet, Taoist Meditation,1999, 90.)

The Central Scripture and the Yellow Court refer to these juices using terms derived from waidan or having alchemical connotations, such as Mysterious Pearl (xuanzhu), Jade Sap (yujiang), Jade Blossom (yuying), Jade Pond (yuchi), Jade Liquor (yuye), Golden Nectar (jinli), and even Golden Liquor (jinye). Other sources refer to them as Divine Water (shenshui), White Snow (baixue), and Golden Essence (jinjing), all of which are also known as synonyms of ingredients of waidan elixirs. These terms suggest that in providing superior nourishment to the adept and his inner gods, the salivary juices perform a function analogous to the one that the elixirs, or their ingredients, do in waidan. The analogies of essences, pneumas, and salivary juices with waidan end where those with neidan begin: the adept nourishes himself and his gods not through the ingestion of external substances, but through components of his own inner body; he finds the vital ingredients within himself, and their ingestion takes place internally.

Similar dual associations with both waidan and neidan are evident in another feature of the methods of the Central Scripture. Although offering nourishment to the inner gods is the rule, in some cases it is the adept who asks the gods to deliver nourishment to him. To do so, he addresses invocations to the gods that recall the one pronounced by the Taiqing alchemist before he kindles the fire under the crucible. Now, however, he does not ask the gods to favor the compounding of the elixir; he asks, instead, that they dispense an elixir to him:

The highest god is styled Lord Great One of Original Radiance (Yuanguang Taiyi jun) Below he resides within the heart of human beings. At dawn and at midday, on the jiawu and the bingwu days, always call him and say:"Old Man of the Southern Ultimate, Lord Great One of Original Radiance! I want to obtain the Dao of long life of the Divine Elixir of the Great One!" (Laozi zhongjing, sec. 25)

In an invocation addressed to Master Yellow Gown (Huangchang zi), the father of the Red Child, the adept asks him to obtain "medicinal liquor" (yaojiu) and other nurture:

Master Yellow Gown! Master Yellow Gown! Real Man of the Yellow Court, reside in myself! Summon for me medicinal liquor, dried pine-seeds, rice, and broth of millet, so that I can eat and drink of them! Let them come right now! (Laozi zhongjing, sec. I I)

Double Indigo, the god of the liver, who is none other than Lord Lao himself, is invoked for the same purpose:

Flesh Child (Rouzi), Double Indigo (Lanlan)! Be my friend, stay here and be my envoy! I want to obtain the Divine Elixir of the Great One and ingest it! Let me live a long life! Do not leave my body! Constantly reside within the Palace of the Purple Chamber, joined with the Dao! (Laozi zhongjing, sec. 28)

If the term "inner elixir" was not already charged with other meanings and associations, it could be an appropriate definition for the nourishment that the inner gods are invited to provide. In fact, whether its elixir is "outer" or "inner," the Central Scripture regards alchemy and meditation as equivalent when it says: "If you cannot ingest the Divine Elixir and the Golden Liquor, and do not labor to become skilled in meditation, you merely bring suffering upon yourself."(Laozi zhongjing, sec. 21. The same sentence, without the reference to meditation, is found in the opening passages of the Scripture of the Nine Elixirs.)

In another passage, the Central Scripture states:

"If you constantly ingest breath, you will obtain a long life and be a divine immortal. If you visualize the gods and ingest the elixir, you will become a Real Man." (Laozi zhongjing, sec. 38. )

As we have seen, leading the yellow essence and the red pneuma to the stomach provides nourishment to the Red Child, the innermost deity residing within the human being. The Central Scripture describes him as follows. However the initial part of the passage quoted below defies a proper translation, for Laozi (the speaker of the Central Scripture) refers to himself in both the first and the third persons. He introduces himself as "I" (wu) and says that he resides in every human being ("human beings also have me," i.e., "him"); he is, therefore, one's own "self" (wu), represented by the Red Child. For similar statements see sec. 23 ("Child-Cinnabar, Original Yang, is the self"), 37 ("the stomach is the Great Granary, the residence of the Prince, the hut of the self"), 37 ("Child-Cinnabar is the self"), and 39 ("the Dao is the self"):

The self is the son of the Dao; this is what he is. Human beings also have him, not only me. He resides precisely in the ducts of the stomach, the Great Granary. He sits facing due south on a couch of jade and pearls, and a flowery canopy of yellow clouds covers him. He wears clothes with pearls of five hues. His mother resides above on his right, embracing and nourishing him; his father resides above on his left, instructing and defending him. (Laozi zhongjing, sec. 12)

The Child's mother is the Jade Woman of Mysterious Radiance (Xuanguang Yunii). Through the nourishment that she provides, the Child "feeds on yellow gold and jade dumplings, and ingests the Divine Elixir and the zhi plant." But the Child should also be nourished by the adept: "He feeds on the yellow essence and the red pneuma, drinking and ingesting the Fountain of Nectar (liquan)," another name of the salivary juices produced during the meditation practices. The Child's father, whose task is "instructing and defending" his son, is the Yellow Old Man of the Central Ultimate (Zhongji Huanglao), god of the Yellow Court. The Central Scripture often calls him Master Yellow Gown (Huangchang zi). The Red Child's father is also called Lingyang ziming, a name that in waidan is a synonym of mercury. Both the Red Child, under the name of Child-Cinnabar (Zidan), and Yellow Gown are also mentioned in the "Inner" version of the Yellow Court, whereas the "Outer" version grants Child-Cinnabar the honor of being the only deity mentioned by name in the entire text.

The alchemical imagery associated with the nourishment of the Red Child-gold, jade, the Divine Elixir itself-does not need to be emphasized again. Another point, instead, requires attention, namely the relation of the Red Child to the inner embryo of neidan. This relation is complex, for the image of the embryo changes according to the understanding of neidan itself: although some neidan texts emphasize the notion of "generating" and "raising" the inner embryo through practices performed for this purpose, others refer to the embryo, and to the elixir itself, as an image of one's own authentic self, and of one's own awakened state, which is inherent and does not need to be "generated." Both ways of seeing have affinities with the image of the "inner infant" as it appears in the Central Scripture. On the one hand, nourishing the Red Child in meditation and generating and raising the embryo in neidan are achieved through similar practices, namely by joining essences and pneumas related to the Sun and the Moon, or to Yin and Yang. On the other hand, the "inner infant" and the inner embryo are both representations of the "real self," which, just like the Red Child in the Central Scripture, is innate and is raised by the same forces that sustain life-represented by the Child's parents in the Central Scripture- but also requires one's continuous sustenance and nourishment.

The Central Scripture of Laozi and the Scripture of the Yellow Court merge and develop several trends apparent in earlier or contemporary sources: the visualization of inner gods, the practices for channeling the inner essences and pneumas, and especially the use of alchemical images and terms to define loci of the inner body. Other stages of development, however, were necessary before neidan could emerge as it is known from the Tang period onward. Shangqing Daoism is associated with the first of these stages.

Methods of visualization of the deities of the inner pantheon, and chants addressed to them, form the subject matter of the Authentic Scripture of the Great Cavern (Dadong zhenjing), the main Shangqing text. Although this "" pantheon differs from the ones of the Central Scripture and the Yellow Court,the "inner infant" plays within it the same central role. The Scripture of the Great Cavern ends by describing how an adept generates an inner "divine being" by coagulating and ingesting pneumas that descend from the Muddy Pellet (niwan), the upper Cinnabar Field in the region of the brain:

Visualize a five-colored purple cloud entering within yourself from your Muddy Pellet. Then ingest that divine cloud with your saliva. It will coalesce into a divine being (shenshen), surrounded by a five-colored, purple, white, and roseate round luminous wheel. The god is inside the wheel. Below he spreads himself within your entire body, distributing his pneuma to your nine openings and coagulating it over the tip of your tongue. (Shangqing dadong zhenjing, 6.13 b-14a)

In other contexts, the image of the "inner infant" or the inner embryo reveals alchemical connotations even stronger than those seen in the preShangqing texts. One of the Shangqing revealed scriptures applies the term Nine Elixirs (jiudan) to the pneumas of the Nine Heavens (jiutian zhi qi) received by human beings during their embryonic development:

In the first month, one receives the pneuma; in the second, the numina (ling); in the third, they are transformed together; in the fourth, one coagulates the essence; in the fifth, the trunk and the head are established; in the sixth, one alters oneself and takes form; in the seventh, the [inner] deities take their positions; in the eighth, the nine orifices are luminous; and in the ninth, the pneumas of the Nine Heavens are distributed and one obtains the voice. In the tenth month, the Director of Destinies (Siming) inscribes the Registers: one receives one's destiny and is born. Therefore everyone is endowed with the pneumas of the Nine Heavens and the essences of Yin and Yang.

These are called the Nine Elixirs, and together they form the human being. (Shangqing jiudan shanghua taijing zhangji jing, 3a)

In the view of this and other Shangqing texts, however, the gestation process also accounts for the creation of "knots and nodes" (jiejie); their function is "holding together the five viscera," but eventually they are responsible for one's death:

When one is generated, there are in the womb twelve knots and nodes that hold the five viscera together. The five viscera are obstructed and squeezed, the knots cannot be untied, and the nodes cannot be removed. Therefore the illnesses of human beings depend on the obstructions caused by these nodes, and the extinction of one's allotted destiny (i.e., one's death) depends on the strengthening of these knots. (Shangqing jiudan shanghua taijing zhangji jing, 3a-b)

To untie the "knots of death," the adept is instructed to re-experience his embryonic development in meditation, receiving again the Nine Elixirs, which here denote the pneumas of the Nine Heavens. Then he visualizes the Original Father (yuanfu) in his upper Cinnabar Field and the Original Mother (yuanmu) in his lower Cinnabar Field, who issue pneumas that the adept joins in his middle Cinnabar Field to generate, this time, an inner immortal body. The Original Father and the Original Mother play, in this practice, a role analogous to the one of the father and the mother of the Red Child in the Central Scripture. This view of the gestation process and its re-enactment in meditation is the topic of the entire Shangqing jiudan shanghua taijing zhongji jing (Highest Clarity Scripture of the Central Record of the Higher Transformation of the Nine Elixirs into the Essence of the Embryo; Kristofer Schipper, Concordance du Tao-tsang: Titres des ouvrages, Ecole Franaise d'Extreme-Orient, 1975, 1382).

Another set of Shangqing methods based on the image of the embryo consists of the practices performed to ensure that the souls of one's ancestors obtain release from the underworld. Through the meditation practices performed by their descendants, ancestors may "return to the embryo" (fantai) and become "immortals in the embryonic state" (taixian), obtaining, this time, rebirth in heaven. The notion of purification underlying these practices is also associated with alchemical imagery and terminology: the ancestors rise to the Golden Gate (jinmen, a station in the heavenly circuit of the Sun) where they "refine their matter" (lianzhi) by bathing themselves in the Water of Smelting Refinement (yelian zhi shui).

The role of the Sun as a purifying agent-analogous to the role of fire as a refining agent in waidan-recurs in the Shangqing practices based on the images of the Sun and the Moon. Here Shangqing clearly develops the legacy of the earlier traditions represented by the Central Scripture of Laozi, where, as we have seen, pneumas and essences associated with these two celestial bodies perform a major role. In the Shangqing practices, however, the essences and pneumas are not those found within the adept's own body, but those of the Sun and the Moon themselves. In one method, whose analogies with waidan are transparent, the adept collects the essences of the Sun and the Moon in a vessel containing water and a talisman, then ingests some of that water and uses the other part to wash himself. In another method, he meditates on the circuits of the Sun and the Moon, then visualizes their essences and joins and ingests them. These and similar methods end with the adept visualizing himself as being ignited by the Sun and transformed into pure light.

The notions underlying these practices have an even deeper relation to alchemy than those seen before. As Isabelle Robinet has noted, the Shangqing texts sometimes exchange the Yin and Yang qualities of the Sun and the Moon, so that each of them is said to contain an essence of the opposite sign (Yin for the Sun, Yang for the Moon). This anticipates an essential pattern of neidan, where the alchemical work is based on gathering Yin within Yang (i.e., Real Yin, zhenyin) and Yang within Yin (i.e., Real Yang, zhenyang) in order to join them and compound the elixir.

After those reflected in the earliest sources and in the Shangqing texts, the third historical stage of the encounter between meditation and alchemy was the one that harbored the most durable consequences for the history of both waidan and neidan. Whereas the Scripture of the Nine Elixirs and the other Taiqing texts emphasize the performance of rites and techniques and devote virtually no space to doctrinal statements, the doctrinal aspects of alchemy are the main focus of many waidan sources dating from the Tang period onward. These sources are not concerned with the ritual aspects of the alchemical practice; they explain the alchemical process by borrowing the language and emblems of the Book of Changes (Yijing) and of the system of correlative cosmology, and describe the compounding of an elixir made of lead and mercury, which ingredients replace the much larger variety of ingredients typical of the earlier methods.

From the beginning of the seventh century, no other scripture has had an influence on the history of Chinese alchemy comparable to that of the Token for the Agreement of the Three. Through this text, the whole array of emblems and patterns of correlative cosmology entered the language and imagery of alchemy. These emblems make it possible to describe and relate to each other different cosmological configurations represented by Yin and Yang, the Five Agents, the trigrams and hexagrams of the Book of Changes, the Celestial Stems and the Earthly Branches, the twenty-eight lunar mansions, and so forth, in ways unknown to the earlier tradition represented by the Taiqing and other waidan texts.

The waidan or neidan practices apply those principles to different domains (sometimes with remarkable variations among subtraditions or lineages, especially in the case of neidan). The Token-which is neither a waidan nor a neidan text, although it contains allusions to both-provides an illustration of those principles; the task of connecting them to waidan and neidan is left to a large number of commentaries and related texts that explicate them and apply them to the alchemical practice. Thus the meditation methods surveyed above were relevant to these developments in the history of alchemy in two ways.

First, the Scripture of the Yellow Court provided the Token for the Agreement of the Three with imagery and technical vocabulary. One of the most noticeable examples is the description of the elixir in the Token, where it is said to be "square and round and with a diameter of one inch" (fangyuan jingcun).

Besides this, the Yellow Court also influenced the changes that occurred in the alchemical tradition in an indirect way. Not all the shared terms and expressions are used with the same or a similar purport in the Yellow Court and the Token. The Token actually uses some terms and phrases derived  from the Yellow Court in order to criticize the practices at the basis of the latter text. For instance, the adept of the Yellow Court should "perform ablutions (muyu) to attain complete purity, and discard fat and fragrant foods." For the Token, "performing ablutions, fasting, or keeping the precepts [ ... ] is like using glue to repair a pot." According to the Yellow Court, "if you observe internally (neishi) and gaze intimately, you see the Perfected everywhere." The Token counters that "if you observe internally, your thoughts will absorb your mind." In the Yellow Court, "you open up the hundred channels (baimai) and unblock the blood and the fluids." This, for the Token, means only that "your hundred channels stir like a cauldron." In the practices of the Yellow Court, one Jiould "tightly close the Golden Pass (jinguan) and conceal the Pivotal Mechanism (shuji)." The Token says that those practices result in "your actions turning against you, for you have contravened and lost the Pivotal Mechanism." 33 Finally, the Yellow Court recommends the steadfast practice of its methods, saying that "by being sleepless day and night, you will achieve perfection." The Token replies that "by being sleepless day and night, and never taking a pause month after month, daily your body becomes tired and exhausted."

The Token that distinguishes alchemy from several other practices:

This is not the method of passing through the viscera, contemplating within and concentrating on something; of treading the Dipper and pacing the asterisms, using the six jia as chronograms (richen); of sating yourself with the nine-and-one in the Way of Yin, fouling and tampering with the original womb (yuanbao); of ingesting breath till it chirps in your stomach, exhaling the upright and inhaling the external and evil. By being sleepless day and night, and never taking a pause month after month, daily your body becomes tired and exhausted: you are "vague and indistinct," but look like a fool. Your hundred channels stir like a cauldron, unable to clear and to settle; by piling soil you set up space for an altar, and from morning to sunset reverently worship. (Zhouyi cantong qi fenzhang zhu, sec. 8) All this, concludes the Token, will be pointless when "you leave your bodily form to rot."

Two different meditation practices are mentioned in the passage quoted above, namely "passing through the viscera" (lizang) and "treading the Dipper and pacing the asterisms" (liixing bu douxiu). The first term appears frequently in meditation texts, including the Central Scripture of Laozi. The second _expression alludes to the Shangqing meditation methods of "pacing the celestial net" (bugang). Other terms in this passage allude to other practices. "Six jia" (liujia) refers to calendrical deities, in particular those of the divination method of the "orphan-empty" (guxu), which in one of its applications allows adepts ritually to exit the cycle of time and the directions of space. "Way of Yin" (yindao) denotes the sexual techniques, and "nineand-one" (jiuyi) refers to "nine shallow and one deep" penetrations in intercourse. "Reverently worship" obviously alludes to rites performed in honor of minor deities and spirits. The last sentence in the first paragraph, as well as the first two lines in the second quatrain, refers to breathing techniques.

This section of the Token, in other words, mentions a sample of methods that were current during the Six Dynasties and denounces them as inadequate. The Token is not content with criticizing these methods, but refers to them with irony. "Exhaling the old and inhaling the new" (tugu naxin), a common _expression that denotes ingesting and circulating breath, is overturned into "exhaling the upright and inhaling the external and evil" (tuzheng xi waixie). Breath is ingested "till it chirps in your bowels." The adept who devotes himself to these practices is "vague and indistinct" (huanghu), an expression employed in the Laozi and many other texts to refer to the Dao itself, but deliberately used in the Token to describe a practitioner who "looks like a fool."

For the authors of the alchemical version of the Token, borrowing terms from Scripture of the Yellow Court was an effective way to assert the superiority of alchemy over the earlier meditation practices. Similar borrowings, although less frequent, also occur from the Central Scripture of Laozi. One example may be enough as regards this text. On three occasions, the Central Scripture instructs its adepts to visualize their inner essences and pneumas, saying that they should "moisten and impregnate" (runze) several organs of the body. The Cantong qi uses the same expression, but with a different intent: it is not the viscera of the adept in meditation to be "moistened and impregnated," but the cosmos itself when the Sun and the Moon join with each other at the end of a time cycle, and release their "nurturing fluids" (ziye, a compound formed by two terms that in the Central Scripture and other texts define the salivary juices). This event is related to one of the cardinal notions in the Token, namely the periodic joining of the Sun and the Moon:

Between the last day of a month and the first day of the next, they join their tallies and move to the Center.In chaos, vaporous and opaque, female and male follow each other: their nurturing fluids moisten and impregnate, emanating and transmuting, they flow and pervade. (Zhouyi cantong qi fenzhang zhu, sec. 18)

This passage refers to the Sun and the Moon as respectively harboring Real Yin and Real Yang. Their conjunction, which occurs at the end of each month, when the Sun and the Moon "join their tallies and move to the Center," causes Real Yin and Real Yang, the dual aspects of the timeless Dao, to join and generate the next time cycle. These continuous temporal sequences are responsible for the occurrence of change, but in the view of the Token they are also the means through which Real Yin and Real Yang "flow and pervade" the cosmos, rising and descending through all its time cycles.

In this renewed context, the inner gods of the Daoist meditation practices, and the ritual framework of the Taiqing alchemical practices serve no more. It is enough to look at some clusters of terms that recur in the Token to realize how its adept is not asked to meditate on the deities that reside within himself, or to address those who dwell in heaven. Instead, he surveys (can), examines (cha), investigates (kao), explores (tan), inquires (ji), and inspects into the Shangqing corpus, give priority to methods based on a large variety of ingredients. By the middle of the Tang period, however, the methods based on refining mercury from cinnabar had grown in importance. The best illustration of the enhanced role of cinnabar is found in the writings of Chen Shaowei, who was active during the second decade of the eighth century. His two works (originally part of a single treatise) describe the preparation of an elixir obtained by refining cinnabar. In the first part of the process, each cycle yields a "gold" that can be ingested or used as an ingredient in the next cycle. In the second part of the process, the final product of the first part is used as an ingredient of a Reverted Elixir (huandan). Without any explicit mention of the Token for the Agreement of the Three, or any apparent reference to its system, Chen Shaowei describes his method using cosmological emblems, especially in the portions devoted to the stages of heating.

Some Tang sources related to the Token for the Agreement of the Three explicitly criticize such methods as the one described by Chen Shaowei through their rejection of cinnabar and their advocacy of lead and mercury. Invariably, these sources present as their rationale the fact that a Yin or Yang ingredient alone cannot produce the elixir. The waidan commentary to the Token dating from about 700 CE, to which we referred above, says in this regard:

Without male and female, how could there be fixation, transmutation, and accomplishment of the elixir? The male is mercury, the female is the essence of lead. Jiuyuan jun said: "Ingesting only the reddened mercury (i.e., refined mercury) is called 'orphan Yang' (guyang), and ingesting only the flower of lead (i.e., refined lead) is called 'orphan Yin' (guyin). Therefore lead and mercury need each other to accomplish the elixir. If the elixir is accomplished without obtaining both Yin and Yang, it would not obtain its principle. When the two ingredients accomplish the elixir and are ingested to· gather, this is the Way of the correct conjunction of Yin and Yang. (Zhouyi cantong qi zhu, I.2Ib-22a)

Another passage of the commentary addresses its criticism to the Scripture of the Nine Elixirs itself, showing that the denunciation was not limited to methods based on cinnabar and mercury, but was extended to any method that was seen as not accomplishing a proper conjunction of Yin and Yang:

According to the Scripture of the Nine Elixirs (fiudan jing), one should smear the crucible with the Flower of Metal (jinhua, i.e., refined lead) in order to nourish mercury. But could one ever use the words "Yin and Yang" or "Dragon and Tiger" if [the elixir] is accomplished by placing only mercury in an empty tripod? It is necessary to add to and subtract from what is different (hie). If mercury is used alone, this would amount to using the word "sublime" (miao) to define the "orphan Yang." Jiuyuan jun said: "An elixir made of 'orphan Yang' cannot be ingested as it is: one should accomplish the elixir by also availing oneself of Yin. If one stops when lead is accomplished, could one use it alone without a Yin ingredient?" (Zhouyi cantong qi zhu, 2.45a-b)

One of the earliest waidan texts to emphasize the role of lead and mercury as ingredients of the elixir, Zhang Jiugai's Treatise of the Perfected Zhang on Metals, Stones, and Cinnabar (Zhang zhenren jinshi lingsha lun) dating from the mid-eighth century, provides a similar explanation of why one should not use only cinnabar:

The common people who search for immortality by ingesting only lustrous cinnabar (guangming sha) and purple cinnabar (zisha), without a process for the conjunction [of Yin and Yang], go afar from the Way .... One cannot transcend the generations [of mortals] by ingesting lustrous cinnabar or purple cinnabar. Why? Because the Reverted Elixir, taking the essences of Yin and Yang, is patterned on the creative and transformative action of Heaven and Earth. If the Yin of mercury within cinnabar alone forms the body [of the elixir] and does not couple with Yang to generate [the elixir], it cannot join the Four Emblems (sixiang) to each other and cannot put the Five Agents in motion (yun). Therefore an orphan Yin cannot nourish anything, and a lone Yang cannot generate anything. It is the coupling of Yin and Yang that accomplishes the Reverted Elixir. (Zhang zhenren jinshi lingsha lun, 4a-b)

Finally, two other Tang texts related to the Token for the Agreement of the Three assert the superiority of lead and mercury over all other minerals:

The arts of the Great Elixir derive from lead and mercury, and the principles of lead and mercury are the foundation of the Great Elixir. (Dadan qianhong lun, ra) Therefore one knows that the sublimity of the Great Elixir is owed only to the fact that lead and mercury are the perfect ingredients (zhiyao); it does not consist in using the four yellows and the eight minerals (sihuang bashi). If the pneuma of any mineral ingredient enters the two substances that make the Great Elixir, this will be extremely poisonous. (Danlun jue zhixin jian, ra)

With its mention of the "four yellows" (realgar, orpiment, arsenic, and sulphur) and the "eight minerals" (cinnabar, realgar, mica, malachite, sulphur, salt, saltpeter, and orpiment), the last passage quoted above echoes the admonishment of the Token for the Agreement of the Three: "Dispose of realgar, get rid of the eight minerals!"

These changes in the understanding of the alchemical process affected not only the history of waidan, but also the rise and development of neidan. From the beginning of the Tang period, some authors began to describe the alchemical process as happening entirely within the human being, with no dependence on minerals, metals, instruments, or fire, as other alchemists had used earlier, and employing the same terminology, imagery, and symbolism as those found in the Token for the Agreement of the Three. The earliest extant text that can be labeled as neidan in this sense is a short treatise written by Liu Zhigu in the first half of the eighth century, which emphatically criticizes the waidan interpretations of the Token and offers its first neidan reading. The development of neidan in the form it took from the Tang period onward would not have been possible without the earlier traditions of Daoist meditation, and occurred in parallel with two shifts, related to each other, in waidan-from a ritual framework to a cosmological framework, and from methods based on cinnabar or other ingredients to methods based on lead and mercury.

Due to these developments, the alchemy of the Great Clarity lost its reason to exist. Adepts began to look at alchemy as a way to express and to understand the principles that govern the cosmos, but no longer as a means of getting closer to the gods and warding off demons and spirits. The classic system of Daoist cosmography, as expressed in the scheme of the Three Caverns (sandong), had no place in these new traditions, for the compounding of the elixirs was no longer seen as a means of rising to a higher heaven. Complex cosmological notions and patterns of abstract emblems now played a role unknown in the earlier tradition.

1) Still existing in Taiwan today it is called Zhengyi Celestial Master Taoism, or Dragon-Tiger. Its founder, Zhang Daoling, lived in the second century C.E. Dragon-Tiger or Zhengyi Taoists meditate on the Lao-tzu Tao-te Ching as a sacred book, practice rites of healing and renewal, and receive a special Zhengyi Mengwei (Cheng-i Meng-wei) register in twenty-four segments when they are ordained Taoists. Their sacred mountain is Lunghu Shan (Dragon-TIger Mountain) in southeast Jiangxi Province. These Taoists marry and pass on their registers to at least one of their children in each generation.