《易》曰∶两仪生四象，乃天地气交，八卦是也。在人则清浊之气皆从脾胃出，荣气荣
养周身，乃水谷之气味化之也。
清阳为天（积阳成天。地气上为云，天气下为雨。水谷之精气也，气海也，七神也，元
气也，父也），清中清者，清肺以助天真。清阳出上窍（耳、目、鼻、口之七窍是也），清中
浊者，荣华腠理。清阳发腠理（毛窍也），清阳实四肢（真气充实四肢）。浊阴为地（积阴成地
。云出天气，雨出地气。五谷五味之精，是五味之化也。血荣也，维持神明也，血之将会
也，母也），浊中清者，荣养于神（降至中脘而为血，故曰心主血，心藏神）。浊阴出下窍（前
阴膀胱之窍也），浊中浊者，坚强骨髓。浊阴走五脏（散于五脏之血也，养血脉，润皮肤、
肌肉、筋者是也，血生肉者此也），浊阴归六腑（谓毛脉合精，经气归于腑者是也）。
天气清静光明者也，藏德不止，故不下也。天明则日月不明，邪害空窍，阳气者闭塞，
地气者冒明。云雾不精，则上应白露不下；交通不表，万物命故不施，不施则名木多死。恶
气不发，风雨不节，白露不下，则菀 不荣；贼风数至，豪雨数起，天地四时不相保，与道
相失，则未央绝灭。唯圣人从之，故身无苛病，万物不失，生气不竭。
此说人之不避大寒伤形，大热伤气，四时节候更改之异气，及饮食失节，妄作劳役，心
生好恶，皆令元气不行，气化为火，乃失生夭折之由耳。
The *I Ching* (Book of Changes) states: "Two Modes generate Four Images," referring to the interaction of Qi between Heaven and Earth, which corresponds to the Eight Trigrams. In the human body, both Clear and Turbid Qi originate from the Spleen and Stomach; Ying Qi (Nutritive Qi) nourishes the whole body, a transformation derived from the aroma and flavor of food and drink.
Clear Yang constitutes Heaven (accumulated Yang forms Heaven. Earthly Qi rises to become clouds, Heavenly Qi descends to become rain. This refers to the essence-Qi of water and grain, also known as the Sea of Qi, the Seven Spirits, Yuan Qi (Original Qi), and the Father). Among Clear Yang, the purest part clears the Lungs to assist Tianzhen (Innate True Qi). Clear Yang exits through the Upper Orifices (the seven orifices of the ears, eyes, nose, and mouth); among Clear Yang, the part that is clear yet contains turbidity provides luster to the Couli (interstitial spaces). Clear Yang disperses into the Couli (pores); Clear Yang fills the four limbs (True Qi enriches the four limbs).
Turbin Yin constitutes Earth (accumulated Yin forms Earth. Clouds emerge from Heavenly Qi, rain emerges from Earthly Qi. This refers to the essence of the five grains and five flavors, the transformation of the five flavors. Blood has a nourishing function, maintaining Shen (Spirit), and is the gathering place of blood, analogous to the Mother). Among Turbid Yin, the part that is turbid yet contains clarity nourishes the Shen (descending to the Zhongwan point to transform into blood; thus, it is said that the Heart governs Blood and houses the Shen). Turbid Yin exits through the Lower Orifices (the orifices of the anterior yin and the Bladder); among Turbid Yin, the purely turbid part strengthens the Marrow. Turbid Yin travels to the Five Zang Organs (blood dispersed in the Five Zang Organs, nourishing the vessels, moistening the skin, muscles, and sinews—this is how Blood generates Flesh); Turbid Yin returns to the Six Fu Organs (referring to the convergence of hair and vessel essence, where Jing Qi returns to the Fu Organs).
Heavenly Qi is clear, tranquil, and luminous; it harbors virtue without ceasing, hence it does not descend. If Heavenly Qi is excessively bright, the Sun and Moon will appear dim, pathogenic factors will harm the orifices, Yang Qi will be blocked, and Earthly Qi will obscure clarity. If clouds and mist are not pure, corresponding White Dew will not descend from above; if communication is not manifest, the life force of all things cannot be expressed; if not expressed, tall trees will perish. If foul Qi does not disperse, wind and rain will be irregular, and White Dew will not descend, causing stagnated matter to fail to nourish; if treacherous winds arrive frequently and torrential rains rise often, the Heaven, Earth, and Four Seasons lose their stability, deviating from the Dao, resulting in premature extinction of life. Only the Sage follows this principle; thus, his body suffers no severe diseases, all things retain their nature, and Sheng Qi (Vital Qi) never exhausts.
This discourse explains that failing to avoid extreme Cold damaging the form, extreme Heat damaging Qi, and the abnormal Qi of seasonal changes, combined with unregulated diet, reckless labor, and excessive emotional preferences, causes Yuan Qi to cease flowing. Qi transforms into Fire, which is the cause of losing vitality and premature death.