A confluence of humors: Ayurvedic conceptions of digestion and the history of Chinese "phlegm" (tan).

• Author: Kohle, Natalie
• Position: Report

When one peruses medical case histories from the Qing dynasty, one sees constant references to phlegm, tan, as both cause and consequence of disease. That is to say phlegm figures as a central, indispensable concept in the late imperial Chinese imagination of the body and its pathologies. Curiously, however, when one goes back to the Huangdi neijing the earliest and foundational classic of Chinese medicine (ca. 1st c. B.C.E.), the term tan does not appear at all. Despite the central importance of phlegm in late imperial (and contemporary) Chinese medicine, only a few scholars have noticed this puzzle, and even fewer have engaged with it. Some have argued that the concept developed from the fluid yin. Others speculate that its development is owed to Ayurvedic conceptions received through Chinese translations of Indie Buddhist texts. Yet to date no one has put forward a sustained historical study of the origin and the development of the concept of phlegm in China.

This article is a first step in that direction. The first to consider both Chinese- and Sanskrit-language material, it investigates the earliest, formative period of the concept of phlegm in China. It argues that the initial emergence of the substance tan that later became "phlegm" was an indigenous development, while the formation of the concept of phlegm in Chinese medicine was influenced by Ayurveda. The influence hinges on the coincidence of Indie and Chinese intuitions about digestion.

The discussion proceeds along the following lines: (1) i first give a brief outline of indigenous Chinese theories of yin fluids and suggest how "phlegm" may have derived from them. (2) I then outline Indie physiological concepts relevant for discussions of phlegm in Buddhist texts. (3) Subsequently I consider the reception of Indie physiological concepts in Chinese Buddhism. (4) This leads to a short excursion into perceptions of phlegm (and bile) in contemporary Ayurvedic texts, and (5) a close reading of one sample passage in one of the Ayurvedic classics. (6) I argue that the divergent terminology for phlegm and bile in Chinese translations reflects a temporal shift in the perception of humors in India itself. (7) I then conclude by considering the influence of Ayurvedic conceptions of phlegm on Chinese medical traditions and suggest how the transfer of these conceptions from the corpus of Chinese Buddhist translations to the Chinese medical tradition could have taken place.

1. THE EMERGENCE OF TAN IN THE CONTEXT OF YIN

   It is often stated that the character tan--later "phlegm"--first occurred in Zhang Zhongjing's (142-220? c.E.) Jingui yaolUe (ca. 200 C.E.). Evidence from treatises with older extant editions than the Jingui yaoliie suggests, however, that tan was originally written dan in the oldest versions of the treatise. (1) Dan moreover, first occurs in conjunction with yin, in the compound danyin which is part of a series of four yin diseases: "overflowing yin," yiyin; "hanging yin," xuanyin "blocked yin," zhiyin and danyin. (2) In other words, at first dan was a type of yin.

   The primary meaning of yin is "drink." It is used both as a verb and a noun, meaning "drinking" and also "that which is drunk," "a drink." Instances of this meaning of yin go back as far as the Rites of Zhou (Zhou li). (3) A more specialized meaning of yin, however, evolved in medical usage; it began to refer to ingested fluids, specifically to harmful ingested fluids: when something went wrong with what one had drunk. The first occurrence of this kind of pathological yin fluid goes back to the Huangdi neijing. Excluding the doubtful Suwen Yunqi qipian chapters, (4) the treatise has three instances of "overflowing yin." "Overflowing yin" there refers to ingested surplus fluid, which the body is unable to process, so that it "overflows" (see the quote at the end of section 1 below). While "hanging" and "blocked" are also quite straightforward description of respective states of yin fluid, the meaning of dan is not so clear. Historical discussions of Chinese and Japanese scholars--principally Taki Motoyasu (1755-1810), Taki Motokata (1795-1857), Mo Meishi (1837-1907) and Zhang Shanlei (1873-1934)--revolve around the question how dan should be understood and how tan developed from dan.

   As Mo and Zhang observe, dan means "clear." Hence, one would assume that danyin means "clear yin fluid" in the same manner in which yi, xuan, and zhi denote different states of yin fluids. However, in the Jingui yaoliie, danyin is also described as "sloshing around in the bowels." Thus Mo and Zhang ask: how could the author, Zhang Zhongjing, possibly have known or stated that yin fluid inside the bowels is "clear"? They suggest that dan is a scribal error for liu, "flowing." The shape of the character liu is close enough to dan to allow for this mistake, and it would make more sense to call a fluid sloshing around in the bowels "flowing" rather than "clear." Indeed, Chao Yuanfang (ca. 550-630) and Sun Simiao (581-682) list an independent category of "flowing yin" (liuyin) disease, whose definition is almost identical to the Jingui yaoliie's definition of danyin. This corroborates Mo and Zhang's argument. (5)

   Like Mo and Zhang, Taki Motokata had also argued that yi, xuan, and zhi are descriptive of a state of yin fluid. But for him, dan is neither a miscopied liu nor does it mean "clear." Rather, it means "sloshing" (yaodong), an attested if obscure meaning of dan. In his definition, dan functions as a homonym and homophone of dan "sloshing fluid," and was used as a vulgar variant for the more complicated character. (6) In support of this claim, Taki Motokata cites evidence from a variety of sources: the Shuowen jiezi (121 c.e.), which defines dan as "water that is being moved around" (7) a passage from the Lingshu, "water that agitates beneath the heart in conjunction with fear that one will be apprehended by someone" (8) as well as a number of commentaries on poems that attest to the meaning of "agitated water" and to the interchangeability of dan with dan There is also evidence that tan and dan had the same meaning in the Xiaopinfang (ca. 445-73) and in Tao Hongjing's (456-536) Xiaoyan fang two lost works partially transmitted in the Japanese classic Ishimpo

   [TEXT NOT REPRODUCIBLE IN ASCII]: Dan in the chest, violent dry retching, and a bothered feeling. (9) [TEXT NOT REPRODUCIBLE IN ASCII]: Dan water in the chest. (10) These two phrases, which use tan in place of dan, are extremely common in later phlegm-related literature. (11) Mo, Zhang, and the two Takis agree in arguing that tan developed from dan through a change from the water radical to the illness radical.

   Following Taki Motoyasu, Taki Motokata observes that tan is not listed in either the Shuowen or Yupian (543) dictionaries, and medieval Buddhist dictionaries define dan and tan in almost identical terms as "ye body fluid in the chest" (12) and "water sickness above the chest". (13) The Song writer Huang Bosi (1079-1118), moreover, complains that his contemporaries frequently miscopy: "nowadays people write tan for dan; this is incorrect" [TEXT NOT REPRODUCIBLE IN ASCII]. (14) These instances show that dan and tan functioned as homonyms. (15)

   Taki Motoyasu was also the first scholar to argue for Indie influences in the formation of the Chinese concept of phlegm. He noted that the initial location of dan in the Jingui yaoliie was the abdomen, whereas later texts primarily locate dan and tan in the chest. Taki therefore concluded that dan (and tan) of the later texts are not quite the same as the early instances of dan in the Jingui yaoliie, which essentially referred to an abdominal fluid. In his opinion, the later description of the location of tan in the chest is the sign of Indie influence. (16)

   What is most interesting and pertinent for discussing the early understanding of dan tan in Chinese medicine is that Mo, Zhang, and the Takis all agree in understanding danyin as a subtype of yin, rather than ascribing any independent meaning to dan /tan as a substance in itself. Indeed, it is possible to construe a meaningful relationship between the definition of yiyin in the Huangdi neijing and the definition of danyin in the Jingui yaolue:

   Soft and dispersed liver pulse with lustrous complexion indicates overflowing yin. Overflowing yin is when, being thirsty, one drinks copiously and suddenly, so that [the ingested liquid] {overflows and) (17) enters the muscles and the skin outside the stomach and the intestines. [TEXT NOT REPRODUCIBLE IN ASCII] (Suwen 17, "Maiyao jingwei lun") If a person who was once thriving is now thin, and water goes around in his intestines, making a sloshing sound, it is danyin. [TEXT NOT REPRODUCIBLE IN ASCII] (Jingui yaolue, "Tanyin kesou bing maizheng bing zhi") Yiyin and danyin are both harmful body fluids; they are both found in and around the stomach and intestines and seem both to be related to an intake of external fluids (this is spelled out clearly in the case of yiyin, and implied by the abdominal location in the case of danyin). The emergence of dan /tan can therefore cogently be described as a system-internal evolution from yin: yin and dan first denoted a gastro-intestinal pathology, and--as perceptively noted by the Takis--there is no indication that the earliest dan /tan had any relationship with the new substance of "phlegm."

2. PHLEGM (AND BILE) IN BUDDHIST PHYSIOLOGIES

   There is a possible alternative way to explain the provenance of dan /tan in Chinese medicine: the simultaneity of the emergence of danyin in medical texts with the emergence of Buddhist translations in China could indicate that danyin shows an Indic influence in Chinese medicine. This explanation is plausible, because phlegm features prominently in Buddhist physiology and large-scale scriptural transmissions of Indic thought only commenced with the arrival of Buddhism to China. (18) Yet, unlike in Tibet, where this...