History yields to mythology in accounts of the Three Celestial Emperors, who are revered as the founders of Chinese civilization. Fu Hsi, who is said to have reigned about 2000 B.C.E., is the legendary founder of China’s ﬁrst dynasty. His most important inventions included writing, painting, music, the original eight mystic trigrams, and the yin–yang concept. The I Ching or Canon of Changes, honored as the most ancient of Chinese books, is ascribed to Fu Hsi.
The invention of the fundamental techniques of agriculture and animal husbandry are attributed to Shen Nung, the second Celestial Emperor. When the Emperor, who was also known as the Divine Peasant, saw his people suffering from illness and poisoning, he taught them to sow the ﬁve kinds of grain and he personally investigated a thousand herbs so that the people would know which were therapeutic and which were toxic. In his experiments with poisons and antidotes, Shen Nung is said to have taken as many as seventy different poisons in one day. Having collected many remedies in the ﬁrst great treatise on herbal medicine while setting a magniﬁcent example of unselﬁsh devotion to medical research, Shen Nung died after an unsuccessful experiment.
During his hundred-year reign, Huang Ti, the last of the legendary Celestial Emperors, gave his people the wheel, the magnet, an astro- nomical observatory, the calendar, the art of pulse measurement, and the Huang-ti Nei Ching (The Inner Canon of the Yellow Emperor), a text that has inspired and guided Chinese medical thought for over 2,500 years. Like many ancient texts, the Nei Ching has been corrupted over the centuries by additions, excisions, and misprints. Scholars agree that the existing text is very ancient, perhaps dating back to the ﬁrst century B.C.E., but the time of its composition is controversial. Most historians believe that the text in existence today was compiled at the beginning of the T’ang Dynasty (618–907). Other medical texts have sometimes overshadowed it, but most of the classics of Chinese medi- cine may be considered interpretations, commentaries, and supplements to the Yellow Emperor’s Canon.
Although The Inner Canon is revered as one of the oldest and most inﬂuential of the classical Chinese medical texts, studies of medical manuscripts that were buried with their owner, probably during the second century B.C.E., and recovered in Mawangdui, Hunan, in the 1970s, have provided new insights into early Chinese medical thought. As newly recovered texts are analyzed, scholars are beginning to illumi- nate the philosophical foundations of Chinese medicine and the ways in which the learned physicians of the fourth to ﬁrst centuries B.C.E. were able to separate themselves from shamans and other popular healers. Physicians apparently were still exploring approaches to physiology, pathology, and therapy that differed from those found in the Inner Canon. Therapeutics in the older texts included medicinal drugs, exorcism, magical and religious techniques, and surgical operations, but acupuncture, the major therapeutic technique in the Inner Canon, was not discussed in the Mawangdui manuscripts.
As it exists today, the Nei Ching is a collection of sometimes contradictory ideas and interpretations forced into a supposedly inte- grated conceptual system. The Inner Canon is cast in the form of a dialogue between Huang Ti and Ch’i Po, his Minister of Health and Healing. Together, Emperor and Minister explore a medical philosophy based on the balance of yang and yin, the ﬁve phases (also called the ﬁve elements), and the correlations found among them and almost every conceivable entity impinging on human life, from family and food to climate and geography. The terms yin and yang are generally taken to represent all the pairs of opposites that express the dualism of the cosmos. Thus, whereas yin is characterized as female, dark, cold, soft, earth, night, and empty, yang represents male, light, warm, ﬁrm, heaven, day, full, and so forth. Yang and yin, however, should be understood as ‘‘relational concepts,’’ that is, not ﬁrm or soft per se, but only in comparison to other states or entities.
The original meanings of the characters for yin and yang are obscure, but light and shade appear to be fundamental aspects. The original characters might have represented the banks of a river, one in the shade and the other in the sun, or the shady side and the sunny side of a hill. Applying these concepts to the human body, the outside is relatively yang, the inside is relatively yin, and speciﬁc internal organs are associated with yang or yin.
Huang Ti taught that the principle of yin–yang is the basis of everything in creation, the cause of all transformations, and the origin
The ﬁve phases. As individual names or labels for the ﬁner ramiﬁcations of yin and yang, the ﬁve phases represent aspects in the cycle of changes. The ﬁve phases are linked by relationships of generation and destruction. Patterns of destruction may be summarized as follows: water puts out ﬁre; ﬁre melts metal; a metal ax cuts wood; a wooden plow turns up the earth; an earthen dam stops the ﬂow of water. The cycle of generation proceeds as water produces the wood of trees; wood produces ﬁre; ﬁre creates ash, or earth; earth is the source of metals; when metals are heated, they ﬂow like water.
of life and death. Yin and yang generate the ﬁve phases: wood, ﬁre, earth, metal, and water. Because the terms yang and yin are essentially untranslatable, they have been directly adopted into many languages. But the same lack of meaningful correspondence applies to the wu-hsing, a term that was usually translated as ‘‘ﬁve elements,’’ because of a false analogy with the four elements of the ancient Greeks. The Chinese term actually implies passage, transition, or phase, rather than stable, homo- geneous chemical constituents. In recent years, scholars have invented new terms such as ‘‘ﬁve conventional values’’ and ‘‘ﬁve evolutive phases’’ to convey a more precise meaning. For the sake of simplicity, we shall use the term ‘‘ﬁve phases.’’ Chinese philosophers and scientists created an elaborate system to rationalize the relationships of the ﬁve phases to almost everything else. Thus, the sequences of creation and destruction among the ﬁve phases pro- vided a foundation for classical concepts of human physiology.