阴阳应象大论篇 帝曰∶阴阳者，天地之道也，万物之纪纲，变化之父母，生杀之本
始，神明之府也。治病必求其本。（指阴阳言。）故积阳为天，积阴为地。阴静阳躁，阳生阴长，
阳杀阴藏。阳化气，阴成形。故曰∶天地者，万物之上下也；阴阳者，血气之男女也；左右者，
阴阳之道路也；水火者，阴阳之征兆也；阴阳者，万物之能始也。故曰∶阴在内，阳之守也，阳
在外，阴之使也。
（此言阴阳为天地万物生杀之本，而人物之生，莫不具此天地阴阳。）
清阳为天，浊阴为地。地气上为云，天气下为雨。雨出地气，云出天气。故清阳出上窍，浊
阴出下窍；清阳发腠理，浊阴走五脏；清阳实四肢，浊阴归六腑。水为阴，火为阳。阳为气，阴
为味。味归形，形归气，气归精，精归化；精食气，形食味，化生精，气生形。味伤形，气伤精。
（气耗则伤精也。）精化为气，气伤于味。阴味出下窍，阳气出上窍。味浓者为阴，薄为阴之阳；
气浓者为阳，薄为阳之阴。味浓则泻，薄则通；气薄则发
泄，浓则发热。壮火之气衰，少火之气壮；壮火食气，气食少火；壮火散气，少火生气。气味辛
甘发散为阳，酸苦涌泄为阴。
（气得少火则生，故曰少火生气。气得壮火则耗，故曰壮火食气。）
天气通于肺，地气通于嗌，风气通于肝，雷气通于心，谷气通于脾，雨气通于肾。六经为川，肠
胃为海，九窍为水注之气。以天地为之阴阳，阳之汗，以天地之雨名之。阳之气，以天地之疾风
名之。暴风象雷，逆气象阳。
天不足西北，故西北方阴也。而人右耳目不如左明也。地不满东南，故东南方阳也，而人左
手足不如右强也。曰∶何以然？曰∶东方阳也，阳者其精并于上，并于上，则上明而下虚，故使
耳目聪明，而手足不便也。西方阴也，阴者其精并于下，并于下，则下盛而上虚，故其耳目不聪
明，而手足便也。故俱感于邪，其在上则右甚，在下则左甚，此天地阴阳所不能全也，故邪居之。
（夫阴阳之应天地，犹水之在器也，器圆则水圆，器曲则水曲。人之气血亦如是，故随不足
则邪气留居之，阴阳应象也。）
寒极生热，热极生寒。寒气生浊，热气生清。清阳在下，则生飧泄，浊气在上，则生 胀。
此阴阳反作，病之逆从也。
生气通天论曰∶阳气者，则天与日，失其所，则折寿而不彰。故天运当以日光明。是
故阳因而上，卫外者也。故阳气者，一日而主外，平旦人气生，日中而阳气隆，日西而阳气已虚，
气门乃闭。是故暮而收拒，无扰筋骨，无见雾露，犯此三时，形乃困薄。
（皆所以顺阳气也，阳出则出，阳藏则藏。暮阳气衰，内行阴分，故宜收敛，以拒虚邪。顺
此三时，天真久远。）
阴者藏精而起亟也，阳者卫外而为固也。阴不胜其阳，则脉流薄疾，并乃狂。阳不胜其阴，
则五脏气争，九窍不通。凡阴阳之要，阳密乃固。两者不和，若春无秋，若冬无夏，因而和之，
是谓圣度。故阳强不能密，
阴气乃绝。阴平阳闭，精神乃治；阴阳离决，精气乃绝。
（阴应于内，阳卫于外。起者，起而应也。亟者，数也。外有所召，则内数起以应之。如外以
顺召，则心以喜起而应；外以逆召，则肝以怒起而应，故曰起亟。阴阳之要在于阳密，阳密则固
而中和且平。若阴阳不和，则是偏阴偏阳，而绝阴阳之道。圣人惟贵密守，因而和之，有以节度，
则自然阴平阳闭，精神治。否则阳离阴厥，精神绝矣。）
金匮真言论曰∶阴中有阴，阳中有阳。平旦至日中，天之阳，阳中之阳也；日中至黄
昏，天之阳，阳中之阴也；合夜至鸡鸣，天之阴，阴中之阴也；鸡鸣至平旦，天之阴，阴中之阳
也。故人亦应之。夫言人之阴阳，则外为阳，内为阴；言人身之阴阳，则背为阳，腹为阴；言人
身脏腑中之阴阳，则脏者为阴，腑者为阳，肝心脾肺肾五脏皆为阴，胆胃大肠小肠膀胱三焦六腑
皆为阳。所以欲知阴中之阴，阳中之阳者何也？为冬病在阴，夏病在阳，春病在阴，秋病在阳，
皆视其所在，为施针石也。故背为阳，阳中之阳心也；背为阳，阳中之阴肺也；腹为阴，阴中之
阴肾也；腹为阴，阴中之阳肝也；腹为阴，阴中之至阴脾也。此皆阴阳表里内外雌雄相输应也，
故以应天之阴阳也。
（此言阴阳之中，而又有阴阳者焉，可见天人一理相为应孚，昼夜脏腑则同矣。）
Huangdi asked: Yin and Yang are the laws of Heaven and Earth, the guidelines of all things, the parents of change, the origin of life and death, and the residence of spiritual activities. In treating diseases, one must seek their root (referring to Yin and Yang). Therefore, accumulated Yang Qi forms Heaven, and accumulated Yin forms Earth. Yin is quiet, Yang is active; Yang generates, Yin grows; Yang kills (subdues), Yin stores. Yang transforms into Qi (vital energy), and Yin forms into shape (physical substance). Thus it is said: Heaven and Earth are the upper and lower positions of all things; Yin and Yang correspond to the male and female attributes of Qi and Blood (Qi is Yang like male, Blood is Yin like female); Left and Right are the pathways of Yin and Yang; Water and Fire are the omens of Yin and Yang; Yin and Yang are the starting point of all things. Thus it is said: Yin resides inside, guarding Yang; Yang resides outside, serving Yin.
(This passage states that Yin and Yang are the root of growth and decline for all things in Heaven and Earth, and that humans and creatures possess this Heavenly and Earthly Yin and Yang.)
Clear Yang rises to form Heaven, and turbid Yin sinks to form Earth. Earth Qi rises to become clouds, and Heaven Qi descends to become rain. Rain originates from Earth Qi, and clouds originate from Heaven Qi. Therefore, Clear Yang exits through the upper orifices (eyes, ears, mouth, nose), and turbid Yin exits through the lower orifices (urethra, anus); Clear Yang disperses into the Couli (skin pores), and turbid Yin travels to the Zang organs; Clear Yang fills the four limbs, and turbid Yin returns to the Fu organs. Water belongs to Yin, Fire belongs to Yang. Qi belongs to Yang, Flavor belongs to Yin. Flavor nourishes Shape (physical body), Shape relies on Qi, Qi transforms into Essence (Jing), and Essence transforms into Metabolism (Hua); Essence consumes Qi for nourishment, Shape consumes Flavor for nourishment, Metabolism generates Essence, and Qi generates Shape. Excessive Flavor damages Shape, and excessive Qi damages Essence. (When Qi dissipates, it damages Essence). Essence can transform into Qi, but Qi can be damaged by Flavor. Yin flavors exit through the lower orifices, and Yang Qi exits through the upper orifices. Strong flavors belong to pure Yin, weak flavors belong to Yin within Yang; strong aromas belong to pure Yang, weak aromas belong to Yang within Yin. Strong flavors have a purgative effect, weak flavors have a unblocking effect; weak aromas have a dispersing and venting effect, strong aromas have a heating effect. Vigorous Fire (hyperactive Yang/pathological fire) causes Qi to decline, while Mild Fire (normal mild Yang/physiological fire) causes Qi to strengthen; Vigorous Fire consumes Qi, while Qi nourishes Mild Fire; Vigorous Fire scatters Qi, while Mild Fire generates Qi. Pungent and sweet flavors with dispersing properties belong to Yang, sour and bitter flavors with vomiting and draining properties belong to Yin.
(Qi generates when it receives Mild Fire, hence "Mild Fire generates Qi." Qi is consumed when it encounters Vigorous Fire, hence "Vigorous Fire consumes Qi.")
Heavenly Qi connects with the Lung, Earthly Qi connects with the throat, Wind Qi connects with the Liver, Thunder Qi connects with the Heart, Grain Qi connects with the Spleen, and Rain Qi connects with the Kidney. The Six Meridians are like rivers, the Intestines and Stomach are like seas, and the Nine Orifices are the channels where water Qi flows. Using Heaven and Earth as metaphors for Yin and Yang, human sweat is named after Heaven's rain; human Qi activity is named after Heaven's fierce wind. Violent storms resemble Thunder, and rebellious Qi resembles Yang.
Heaven's clarity is insufficient in the Northwest, so the Northwest direction belongs to Yin. Therefore, a person's right ear and eye are not as sharp as the left. Earth's turbidity is incomplete in the Southeast, so the Southeast direction belongs to Yang. Therefore, a person's left hand and foot are not as strong as the right. Question: Why is this? Answer: The East belongs to Yang. The essence of Yang gathers in the upper part. When gathered in the upper part, the upper becomes clear and the lower becomes deficient, thus making the ears and eyes sharp but the hands and feet inconvenient. The West belongs to Yin. The essence of Yin gathers in the lower part. When gathered in the lower part, the lower becomes abundant and the upper becomes deficient, thus making the ears and eyes less sharp but the hands and feet convenient. Therefore, if both are affected by pathogenic factors, those affecting the upper part are more severe on the right, and those affecting the lower part are more severe on the left. This is because the Yin and Yang of Heaven and Earth cannot be complete, so pathogens reside there.
(Yin and Yang responding to Heaven and Earth is like water in a vessel; if the vessel is round, the water is round; if the vessel is curved, the water is curved. Human Qi and Blood are the same; thus, where there is deficiency, pathogenic Qi remains. This is the correspondence of Yin and Yang.)
Extreme cold generates heat, and extreme heat generates cold. Cold Qi generates turbidity, and Heat Qi generates clarity. If Clear Yang is located below, it causes diarrhea with undigested food (Sun Xie); if turbid Qi is located above, it causes distension. This is the reversal of Yin and Yang functions, representing the adverse or normal progression of disease.
The *Suwen: Shengqi Tongtian Lun* states: Human Yang Qi is like Heaven and the Sun. If it loses its proper place, lifespan is shortened and brilliance is obscured. Therefore, the movement of Heaven depends on the brightness of the Sun. Thus, Yang Qi is located superiorly and guards the exterior. Human Yang Qi governs the exterior during the day: at dawn, human Qi begins to generate; at noon, Yang Qi is most vigorous; at sunset, Yang Qi is already deficient, and the Qi gates (pores) close. Therefore, in the evening, one should gather and repel [pathogens], not disturb sinews and bones, and not expose oneself to fog and dew. Violating these three times leads to physical exhaustion and weakness.
(All these measures are to follow Yang Qi. When Yang exits, one exits; when Yang hides, one hides. In the evening, Yang Qi declines and moves inward to the Yin aspect, so one should converge to repel empty evils. Following these three times ensures longevity of True Qi.)
Yin stores Essence and responds frequently (Qi Ji). Yang guards the exterior and maintains solidity. If Yin cannot overcome Yang, blood vessels flow rapidly and violently, leading to mania. If Yang cannot overcome Yin, the Qi of the Five Zang organs conflicts, and the nine orifices become blocked. The key to Yin and Yang is that Yang must be dense to ensure solidity. If the two are not in harmony, it is like having Spring without Autumn, or Winter without Summer. Therefore, harmonize them; this is called the standard of the Sage. If Yang is overly strong and cannot be dense, Yin Qi will be exhausted. When Yin is peaceful and Yang is solid, Spirit (Shen) is regulated; when Yin and Yang separate and决 (break off), Essence and Qi are exhausted.
(Yin corresponds to the interior, Yang guards the exterior. "Qi" means rising to respond; "Ji" means frequent. When summoned externally, the interior rises frequently to respond. For example, if summoned smoothly externally, the Heart responds with joy; if summoned inversely externally, the Liver responds with anger. Hence "Qi Ji". The key to Yin and Yang lies in the density of Yang. When Yang is dense, it is solid, neutral, and peaceful. If Yin and Yang are not harmonious, there is either excess Yin or excess Yang, cutting off the way of Yin and Yang. The Sage values strict preservation and harmonization with moderation, resulting naturally in peaceful Yin and solid Yang, with regulated Spirit. Otherwise, Yang separates and Yin collapses, and Spirit is lost.)
The *Suwen: Jin Gui Zhen Yan Lun* states: There is Yin within Yin, and Yang within Yang. From dawn to noon, it is Heaven's Yang, which is Yang within Yang; from noon to dusk, it is Heaven's Yang, which is Yang within Yin; from nightfall to rooster crow, it is Heaven's Yin, which is Yin within Yin; from rooster crow to dawn, it is Heaven's Yin, which is Yin within Yang. Humans also correspond to this. Speaking of human Yin and Yang generally, the exterior is Yang and the interior is Yin. Speaking of Yin and Yang in the human body, the back is Yang and the abdomen is Yin. Speaking of Yin and Yang within the Zang-Fu organs, the Zang organs are Yin and the Fu organs are Yang. The Liver, Heart, Spleen, Lung, and Kidney (Five Zang) are all Yin; the Gallbladder, Stomach, Large Intestine, Small Intestine, Bladder, and San Jiao (Six Fu) are all Yang. Why know what Yin within Yin and Yang within Yang are? Because winter diseases are in Yin, summer diseases are in Yang, spring diseases are in Yin, and autumn diseases are in Yang. One must look at their location to apply acupuncture and stone therapy. Therefore, the back is Yang; among Yang, the Heart is Yang within Yang. The back is Yang; among Yang, the Lung is Yin within Yang. The abdomen is Yin; among Yin, the Kidney is Yin within Yin. The abdomen is Yin; among Yin, the Liver is Yang within Yin. The abdomen is Yin; among Yin, the Spleen is Extreme Yin (Zhi Yin). These are all the mutual responses of Yin-Yang, interior-exterior, and male-female relationships, thus corresponding to the Yin and Yang of Heaven.
(This passage explains that within Yin and Yang, there is further Yin and Yang, showing that Heaven and Man share the same principle and respond to each other. The Yin and Yang of day/night and Zang-Fu are the same.)