QI is one of the most complex and multifaceted terms in all of Chinese philosophy, religion, and science. No single word can translate it adequately. Its root meaning is "moist emanation." Steam, clouds, and mist are qi, and the word appears frequently in compounds that refer to meteorological phenomena. Another basic meaning is "breath." Later, these meanings were sometimes amalgamated; the Daoist philosopher Zhuangzi (fourth century bce) wrote, "When the Great Clod [the Earth] exhales breath, it is called wind."
During the Warring States period (481–221 bce), the classical age of Chinese philosophy, the word qi began to be employed in an expanded variety of meanings. The concept of breath gave rise to the meaning "vital spirit," that is, the life force of all creatures. "Nourishing the vital spirit" (yang qi ) by means of diet, yogic exercises, breath control, or sexual yoga became an important part of the Daoist quest for immortality from the late Warring States period onward. A true adept could dispense with food and even with the physical body itself; immortal spirits nourished themselves on qi. Qi could also be thought of as a flow of energy within the body. To control this flow of qi, traditional Chinese medicine employed acupuncture, therapeutic massage, and other techniques. The East Asian martial arts, which have a strong spiritual component, emphasize the need to regulate one's qi in order to achieve absolute physical mastery of the body.
Drawing on such earlier concepts as yinyang and the Five Phases (wuxing, sometimes misleadingly called "five elements"), Zou Yan (fourth century bce) and his followers employed the idea of qi as the key to a systematic organic natural philosophy. For them, qi had two sets of meanings. First, it was an extension of the idea of "vital spirit," whereby all things, animate or not, are what they are. Things with similar qi, as determined by such classificatory criteria as yinyang and the Five Phases, were similar in nature and could interact organically without a demonstrable mechanical cause-and-effect relationship. A typical summation is that found in the second-century bce Huainanzi : "All things are the same as their qi ; all things respond within their own class." Second, qi was a sort of ethereal resonating medium through which such interactions took place. Both concepts entered the mainstream of Chinese philosophy during the early Han period (206 bce–7 ce), especially in the work of the Confucian syncretist Dong Zhongshu (179?–104? bce). During this period qi also came to mean something like "power"; thus, character traits and psychological states such as vigor, rage, or fortitude could be described with reference to a person's qi. This sense survives in the modern vernacular Chinese term meaning "to become angry": shengqi, literally, "to engender qi."
In the Neo-Confucian revival of the Northern Song period (960–1127) the term qi acquired a radically new meaning. Cheng Yi (1033–1108) and especially Zhu Xi (1130–1200) developed a Neo-Confucian metaphysics according to which all phenomena are manifestations of preexisting ideal principles. Qi was what gave physical substance to metaphysical ideals (li). From the time of Zhu Xi, this sense of qi tended to be dominant in Chinese philosophy and religion, although the earlier senses persisted as well.
Neo-Confucian metaphysics provided indigenous (non-Buddhist) Chinese philosophy and religion with a comprehensive explanation of the phenomenon of evil. Confucianism had always held that the world and everything in it is by nature good; yet evil undeniably exists. For the Neo-Confucians, the resolution of this enigma involved the concept of qi. All metaphysical principles (li) are inherently good, but their physical manifestations may be good or not, according to the quality of qi. The qi that gives physical substance to li may be pure, clear, and good, or it may be turbid and flawed. A person whose qi is "muddy" will exhibit a flawed moral nature and will be capable of acting in evil ways, despite the fundamental goodness of man.
Fortunately, such flaws could be overcome; and the quest to do so was what gave Neo-Confucianism some of the qualities of a personal religion as well as a moral and ethical social philosophy. Sagehood—human perfection—was to be sought through the "investigation of things"; one should, through study and self-cultivation, inquire exhaustively into the perfect and enduring principles of things, and, by imitating them, purge oneself of all that is impure and inhar-monious.
However, for later generations of Neo-Confucians, the "investigation of things" too often became the investigation of books. Received authority rather than active inquiry guided attempts at self-cultivation. Partly in response to this tendency, the Ming dynasty philosopher Wang Yangming (1472–1529) emphasized instead introspection and meditation. Yet in both cases the goal was the same: the purification of qi, leading to enlightenment and the perfect unity of consciousness and action.
Used continuously and pervasively in a variety of technical and vernacular senses, the term qi over the centuries has repeatedly acquired new meanings and connotations while retaining older ones. Any occurrence of the term, therefore, will be correctly understood only through careful attention to its context.
A good explanation of the concept of qi and its role in Chinese natural philosophy can be found in Joseph Needham's Science and Civilisation in China, vol. 2, History of Scientific Thought (Cambridge, 1956). Fung Yu-lan's standard A History of Chinese Philosophy, 2d ed., 2 vols., translated by Derk Bodde (Princeton, 1952–1953), deals extensively with the term in its various religious and philosophical contexts.
John S. Major (1987)