The relationship between Taoism and Traditional Chinese Medicine (TCM) is very close, and the influence of Taoist internal alchemy on the study of pulse diagnosis in TCM is particularly worthy of research. Internal alchemy practices use the human body as a furnace, and the meridian system within the body is the pathway for the circulation of essence and qi. “The meridians are the means to determine life and death, address various diseases, and regulate deficiency and excess; they must be unobstructed.” Pulse diagnosis is the theoretical foundation of acupuncture and internal alchemy, so many Taoist internal alchemists emphasize the study of pulse theory, leading to many insights and innovations in the theory of meridians during their internal cultivation practices.
Among them, the pulse study monograph “The Eight Extraordinary Meridians” by Zhang Boduan, the founder of the Southern School of the Golden Elixir during the Northern Song Dynasty, has had a significant impact. This book presents new insights into the distribution and pathways of the Eight Extraordinary Meridians, which were highly praised by the Ming Dynasty pharmacologist Li Shizhen in his work “On the Eight Extraordinary Meridians.” In Taoist internal alchemy, the Eight Extraordinary Meridians contain the secrets of transforming the body’s constitution from weak to strong and prolonging life, playing a crucial role in internal alchemy practices. The Ren (Conception) and Du (Governing) meridians, as the pathways for the reversal and ascent of true qi, receive special attention.
For a long period, the unique understanding of the Eight Extraordinary Meridians by internal alchemists was limited to a few individuals who passed it down orally. After the Tang Dynasty, discussions on the application of the Eight Extraordinary Meridians gradually appeared in alchemical texts, and it was not until the Ming and Qing Dynasties that more comprehensive theoretical explanations emerged. The reason for this is that the Qing Dynasty internal alchemist Zhang Ruoxu pointed out in his “Guide to Alchemical Classics” that the hidden points of the Yin Qiao (Yin Heel) contain the secret to transforming the kidney yang from weak to strong. Throughout history, internal alchemists have guarded this secret as a treasure, believing that if it were easily leaked, it would invite divine retribution. The path of internal alchemy is meant to help people prolong life, and if passed on improperly, it could lead to mischief and harm to society.
Therefore, throughout history, the transmission of this knowledge has required careful selection of successors. Since the Ming and Qing Dynasties, physicians have absorbed the theoretical viewpoints regarding the Eight Extraordinary Meridians from alchemical texts, placing great importance on their guiding role in clinical practice. For example, Ye Tianshi’s “Clinical Guidelines and Medical Cases” is a successful application of this. Modern TCM practitioners widely apply the Eight Extraordinary Meridians in clinical practice, viewing them as the theoretical foundation for diagnosing and treating internal and gynecological diseases. Similarly, in modern studies of Taoist health preservation and medicine, there has been a deeper understanding of the theory and practice of the Eight Extraordinary Meridians.
Specifically, in the past twenty years, many related studies and writings on Taoist practices have elaborated on the Eight Extraordinary Meridians and their applications. For instance, Dr. Li Shaobo’s “Method of Qi Circulation” focuses on the treatment of diseases and health preservation through the Ren and Du meridians; Mr. Wang Qingyu and Mr. Kuang Wen’an in “Secrets of Taoist Medicine” introduce the guiding role of the Ren and Du meridians in acupressure therapy; Mr. Wang Buxiong and Mr. Zhou Shirong discuss the development of meridian guiding techniques centered on the Ren and Du meridians in “A History of Qigong Academic Development”; and Mr. Mei Ziqiang introduces the specific applications of the Three Passes and Nine Orifices, as well as the Ren and Du meridians in internal cultivation in “The Art of Reversal,” among others.
However, overall, academic research on the Eight Extraordinary Meridians in internal alchemy has focused more on practical applications, and the discussions in internal alchemical literature regarding the Eight Extraordinary Meridians have not yet been systematically organized in detail. Therefore, this article aims to systematically sort and interpret the discussions and viewpoints regarding the Eight Extraordinary Meridians in internal alchemical literature, in order to gain a deeper understanding of the connotations, theoretical evolution, and medical functions of the traditional concept of the Eight Extraordinary Meridians.
Origin and Medical Connotation of the Eight Extraordinary Meridians
The Eight Extraordinary Meridians, as an important component of the human meridian system, can trace their theoretical origins back to the Warring States period, with the earliest literary record found in the “Zhuangzi.” In the chapter “On Nourishing Life,” it states: “By relying on the Du meridian, one can protect the body, preserve life, nourish parents, and extend years.” Here, the “Du” refers to the Du meridian of the Eight Extraordinary Meridians, which elucidates the important role of the Du meridian in nourishing life and prolonging longevity. Ancient alchemists, through their practices, reflected on the need for the internal qi to follow relatively constant pathways within the body, believing that only by following these pathways could it be effective.
However, the preliminary discussions on the system of the Eight Extraordinary Meridians did not appear until the Eastern Han Dynasty, in the classical TCM text “Huangdi Neijing.” The slightly later text “Nanjing” systematically reviewed the scattered discussions of the Eight Meridians found in various chapters of “Huangdi Neijing,” forming a complete system of the Eight Extraordinary Meridians. The twenty-sixth difficulty states: “There are Yang Wei, Yin Wei, Yang Qiao, Yin Qiao, Chong, Du, Ren, and Dai meridians. All these eight meridians are not confined to the regular meridians, hence they are called the Eight Extraordinary Meridians.” This summarizes the eight meridians discussed in “Huangdi Neijing” and explains why they are referred to as “extraordinary.”