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Philosophical roots

The earliest texts that speak of qi give some indications of how the concept developed. In the Analects of Confucius, qi could mean "breath". Combining it with the Chinese word for blood (making 血氣, xue –qi, blood and breath), the concept could be used to account for motivational characteristics:

The noble man guards himself against three things. When he is young, his xue –qi has not yet stabilized, so he guards himself against sexual passion. When he reaches his prime, his xue –qi is not easily subdued, so he guards himself against combativeness. When he reaches old age, his xue –qi is already depleted, so he guards himself against acquisitiveness.

The philosopher Mozi used the word qi to refer to noxious vapors that would eventually arise from a corpse were it not buried at a sufficient depth. He reported that early civilized humans learned how to live in houses to protect their qi from the moisture that troubled them when they lived in caves. He also associated maintaining one's qi with providing oneself with adequate nutrition. In regard to another kind of qi, he recorded how some people performed a kind of prognostication by observing qi (clouds) in the sky.

Mencius described a kind of qi that might be characterized as an individual's vital energies. This qi was necessary to activity and it could be controlled by a well-integrated willpower. When properly nurtured, this qi was said to be capable of extending beyond the human body to reach throughout the universe. It could also be augmented by means of careful exercise of one's moral capacities. On the other hand, the qi of an individual could be degraded by adverse external forces that succeed in operating on that individual.

Living things were not the only things believed to have qi. Zhuangzi indicated that wind is the qi of the Earth. Moreover, cosmic yin and yang "are the greatest of qi ". He described qi as "issuing forth" and creating profound effects. He also said "Human beings are born the accumulation of qi. When it accumulates there is life. When it dissipates there is death... There is one qi that connects and pervades everything in the world."

The Guanzi essay Neiye (Inward Training) is the oldest received writing on the subject of the cultivation of vapor and meditation techniques. The essay was probably composed at the Jixia Academy in Qi in the late fourth century B.C.

Xun Zi, another Confucian scholar of the Jixia Academy, followed in later years. At 9:69/127, Xun Zi says, "Fire and water have qi but do not have life. Grasses and trees have life but do not have perceptivity. Fowl and beasts have perceptivity but do not have yi (sense of right and wrong, duty, justice). Men have qi, life, perceptivity, and yi." Chinese people at such an early time had no concept of radiant energy, but they were aware that one can be heated by a campfire from a distance away from the fire. They accounted for this phenomenon by claiming "qi" radiated from fire. At 18:62/122, he also uses "qi" to refer to the vital forces of the body that decline with advanced age.

Among the animals, the gibbon and the crane were considered experts at inhaling the qi. The Confucian scholar Dong Zhongshu (ca. 150 BC) wrote in Luxuriant Dew of the Spring and Autumn Annals: "The gibbon resembles a macaque, but he is larger, and his color is black. His forearms being long, he lives eight hundred years, because he is expert in controlling his breathing." (" 猿似猴。大而黑。長前臂。所以壽八百。好引氣也。 ")

Later, the syncretic text assembled under the direction of Liu An, the Huai Nan Zi, or "Masters of Huainan", has a passage that presages most of what is given greater detail by the Neo-Confucians:

Heaven (seen here as the ultimate source of all being) falls (duo 墮, i.e., descends into proto-immanence) as the formless. Fleeting, fluttering, penetrating, amorphous it is, and so it is called the Supreme Luminary. The dao begins in the Void Brightening. The Void Brightening produces the universe (yu – zhou). The universe produces qi. Qi has bounds. The clear, yang was ethereal and so formed heaven. The heavy, turbid was congealed and impeded and so formed earth. The conjunction of the clear, yang was fluid and easy. The conjunction of the heavy, turbid was strained and difficult. So heaven was formed first and earth was made fast later. The pervading essence (xi – jing) of heaven and earth becomes yin and yang. The concentrated (zhuan) essences of yin and yang become the four seasons. The dispersed (san) essences of the four seasons become the myriad creatures. The hot qi of yang in accumulating produces fire. The essence (jing) of the fire-qi becomes the sun. The cold qi of yin in accumulating produces water. The essence of the water-qi becomes the moon. The essences produced by coitus (yin) of the sun and moon become the stars and celestial markpoints (chen, planets).

Qi is linked to East Asian thought on magic, and certain body parts were important to magic traditions such as some Taoist sects.