素问·阴阳应象大论 Great Treatise on the Correspondences of Yin and Yang to Phenomena

Huangdi said: Yin and yang are the way of heaven and earth, the fundamental principle of the myriad things, the parents of change and transformation, the root and origin of life and death, the abode of spirit and brightness. In treating disease, one must always seek the root. Thus accumulated yang forms heaven, and accumulated yin forms earth. Yin is tranquil and yang is restless; yang generates, and yin matures; yang kills, and yin stores away. Yang transforms into qi, and yin forms into physical shape. When cold reaches its extreme, it generates heat; when heat reaches its extreme, it generates cold. Cold qi generates turbidity; heat qi generates clarity. When clear qi lies below, it causes undigested diarrhea; when turbid qi lies above, it causes distension and bloating. This is what happens when yin and yang act contrary to their proper places — the reversal and compliance that underlie disease.

Thus clear yang forms heaven, and turbid yin forms earth; the qi of earth rises to become clouds, and the qi of heaven descends to become rain. Rain issues from the qi of earth, and clouds issue from the qi of heaven.

Thus clear yang emerges from the upper orifices, and turbid yin emerges from the lower orifices; clear yang issues forth at the interstitial spaces of the skin, and turbid yin moves through the five viscera; clear yang fills and strengthens the four limbs, and turbid yin returns to the six bowels.

Water is yin, and fire is yang. Yang is qi, and yin is flavor. Flavor nourishes physical form, physical form is sustained by qi, qi is generated from essence, and essence arises through transformation. Essence is nourished by qi, and physical form is nourished by flavor; transformation generates essence, and qi generates physical form. Flavor, if excessive, injures physical form; qi, if excessive, injures essence. Essence transforms into qi, and qi may in turn be injured by flavor. Yin flavors exit through the lower orifices, and yang qi exits through the upper orifices. Flavors that are strong belong to yin; those that are mild belong to the yang aspect of yin. Qi that is strong belongs to yang; that which is mild belongs to the yin aspect of yang. Strong flavor causes purging; mild flavor allows free passage. Mild qi causes venting and dispersal; strong qi generates heat. The qi of vigorous fire weakens, while the qi of mild fire flourishes. Vigorous fire consumes qi, and qi is nourished by mild fire. Vigorous fire disperses qi, while mild fire generates qi. As for qi and flavor: the acrid and the sweet, which disperse outward, belong to yang; the sour and the bitter, which induce vomiting and purging, belong to yin.

When yin prevails, yang becomes diseased; when yang prevails, yin becomes diseased. When yang prevails, there is heat; when yin prevails, there is cold. Extreme cold generates heat; extreme heat generates cold. Cold injures physical form; heat injures qi. Injury to qi causes pain; injury to physical form causes swelling. Thus, when pain precedes swelling, it means qi has injured the physical form; when swelling precedes pain, it means the physical form has injured qi. When wind prevails, there is movement and tremor; when heat prevails, there is swelling; when dryness prevails, there is desiccation; when cold prevails, there is puffiness and edema; when dampness prevails, there is diarrhea with loose, watery stool.

Heaven has the four seasons and the five phases, by which it generates, grows, gathers in, and stores away, and by which it produces cold, summer heat, dryness, dampness, and wind. Man has the five viscera, which transform into five qi, giving rise to joy, anger, sorrow, worry, and fear. Thus joy and anger injure qi, while cold and summer heat injure the physical form. Sudden rage injures yin; sudden joy injures yang. When rebellious qi surges upward, it fills the vessels and departs from the physical form. If joy and anger are not moderated, and cold and heat exceed their proper bounds, then life cannot be secured. Thus extreme yin will inevitably turn into yang, and extreme yang will inevitably turn into yin. Hence it is said: if one is injured by cold in winter, one will certainly suffer a warm disease in spring; if injured by wind in spring, one will develop undigested diarrhea in summer; if injured by summer heat in summer, one will certainly suffer intermittent fevers in autumn; if injured by dampness in autumn, one will in time develop cough.

Huangdi said: I have heard that the sages of high antiquity, in discussing and ordering the human body, distinguished and classified the viscera and bowels, traced and connected the channels and vessels, joined and linked the six confluences, each following its own channel; the qi-points that arise each have their own location and name; the valleys and ravines belonging to the bones each have their own point of origin; the divisions and regions, whether contrary or compliant, each have their own order and pattern; the yin and yang of the four seasons all have their governing sequence; and the correspondences between outer and inner all have their exterior and interior aspects. Is this truly so? Qibo replied: The east generates wind; wind generates wood; wood generates the sour flavor; the sour flavor generates the liver; the liver generates the sinews; the sinews generate the heart; the liver governs the eyes. In heaven this is the mysterious and profound; in man it is the Way; on earth it is transformation. Transformation generates the five flavors; the Way generates wisdom; the mysterious and profound generates spirit. Spirit in heaven is wind, on earth is wood, in the body is the sinews, in the viscera is the liver, in color is verdant green, in musical note is jue, in the vocal sound is shouting, in movement is grasping, in the orifice is the eyes, in flavor is sour, in emotion is anger. Anger injures the liver; sorrow overcomes anger. Wind injures the sinews; dryness overcomes wind. Sour flavor injures the sinews; the acrid flavor overcomes the sour. The south generates heat; heat generates fire; fire generates the bitter flavor; the bitter flavor generates the heart; the heart generates blood; blood generates the spleen; the heart governs the tongue. In heaven this is heat, on earth is fire, in the body is the vessels, in the viscera is the heart, in color is red, in musical note is zhi, in the vocal sound is laughter, in movement is anxious agitation, in the orifice is the tongue, in flavor is bitter, in emotion is joy. Joy injures the heart; fear overcomes joy. Heat injures qi; cold overcomes heat. Bitter flavor injures qi; the salty flavor overcomes the bitter. The center generates dampness; dampness generates earth; earth generates the sweet flavor; the sweet flavor generates the spleen; the spleen generates flesh; flesh generates the lung; the spleen governs the mouth. In heaven this is dampness, on earth is earth, in the body is the flesh, in the viscera is the spleen, in color is yellow, in musical note is gong, in the vocal sound is singing, in movement is retching, in the orifice is the mouth, in flavor is sweet, in emotion is pensiveness. Pensiveness injures the spleen; anger overcomes pensiveness. Dampness injures the flesh; wind overcomes dampness. Sweet flavor injures the flesh; the sour flavor overcomes the sweet. The west generates dryness; dryness generates metal; metal generates the acrid flavor; the acrid flavor generates the lung; the lung generates the skin and body hair; the skin and body hair generate the kidney; the lung governs the nose. In heaven this is dryness, on earth is metal, in the body is the skin and body hair, in the viscera is the lung, in color is white, in musical note is shang, in the vocal sound is weeping, in movement is coughing, in the orifice is the nose, in flavor is acrid, in emotion is worry. Worry injures the lung; joy overcomes worry. Heat injures the skin and body hair; cold overcomes heat. Acrid flavor injures the skin and body hair; the bitter flavor overcomes the acrid. The north generates cold; cold generates water; water generates the salty flavor; the salty flavor generates the kidney; the kidney generates the bone marrow; the marrow generates the liver; the kidney governs the ears. In heaven this is cold, on earth is water, in the body is the bones, in the viscera is the kidney, in color is black, in musical note is yu, in the vocal sound is groaning, in movement is shivering, in the orifice is the ears, in flavor is salty, in emotion is fear. Fear injures the kidney; pensiveness overcomes fear. Cold injures the blood; dryness overcomes cold. Salty flavor injures the blood; the sweet flavor overcomes the salty. Hence it is said: heaven and earth are the above and below of the myriad things; yin and yang are the male and female of blood and qi; left and right are the pathways of yin and yang; water and fire are the manifest signs of yin and yang; yin and yang are the capacity and origin of the myriad things. Hence it is said: yin, dwelling within, is that which yang guards and preserves; yang, dwelling without, is that which yin puts to use and directs.

Huangdi said: How does one take yin and yang as the model? Qibo said: When yang prevails, the body is hot, the interstitial spaces of the skin are closed, breathing is coarse and labored, causing one to bend forward and back; sweat does not come out, and heat persists; the teeth become dry, and there is vexation, oppression, and abdominal fullness — this is fatal. Such a person can endure winter but not summer. When yin prevails, the body is cold and sweats, the body is habitually cool, one shivers repeatedly and feels cold; when cold reaches an extreme it becomes reversal, and reversal causes abdominal fullness — this is fatal. Such a person can endure summer but not winter. These are the transformations that occur when yin and yang alternately prevail — the manifest forms and states of disease.

Huangdi said: How does one harmonize these two? Qibo said: If one is able to understand the seven depletions and eight benefits, then the two can be harmonized; if one does not know how to apply this, then the season of early decline sets in. At forty years of age, one's yin qi is already reduced by half, and daily activity begins to decline. At fifty, the body feels heavy, and the ears and eyes are no longer sharp and clear. At sixty, yin withers, qi greatly declines, the nine orifices no longer function smoothly, there is deficiency below and excess above, and tears and mucus flow together. Hence it is said: those who understand this remain strong, and those who do not grow old — though they issue from the same source, they come to differ in name. The wise observe what is common; the foolish observe what is different. The foolish are insufficient; the wise have surplus. When there is surplus, the ears and eyes are sharp and clear, the body is light and strong, the old are restored to vigor, and the vigorous become even more sound. This is why the sage attends to the affairs of non-action, delights in the capacity for calm and contentment, follows his desires and pleases his intent within the guarding of emptiness and nothingness — and thus his years and life are without limit, ending only together with heaven and earth. This is how the sage cultivates the body.

Heaven is insufficient in the northwest, hence the northwest is yin, and in man the right ear and eye are not as sharp as the left. Earth is not full in the southeast, hence the southeast is yang, and in man the left hand and foot are not as strong as the right. Huangdi said: Why is this so? Qibo said: The east is yang; in yang, its essence gathers above — gathering above, the upper part is bright and clear while the lower part is deficient, and so the ears and eyes are sharp and clear, but the hands and feet are less agile. The west is yin; in yin, its essence gathers below — gathering below, the lower part is abundant while the upper part is deficient, and so the ears and eyes are not sharp and clear, but the hands and feet are agile. Thus when both are affected by pathogenic influence, if it is above the right side is more severely affected, if it is below the left side is more severely affected — this is because heaven and earth, and yin and yang, cannot themselves be entirely complete, and so pathogenic qi lodges in the incomplete places. Thus heaven possesses essence, and earth possesses physical form; heaven has its eight guiding sequences, and earth has its five patterns, and so they are able to serve as the parents of the myriad things. Clear yang ascends to heaven, and turbid yin returns to earth; thus the movement and stillness of heaven and earth are governed by spirit and brightness as their guiding principle, and so they are able to generate, grow, gather in, and store, ending only to begin again. Only the worthy person, above, aligns with heaven to nourish the head; below, models earth to nourish the feet; and in the middle, draws on human affairs to nourish the five viscera. The qi of heaven communicates with the lung; the qi of earth communicates with the throat; the qi of wind communicates with the liver; the qi of thunder communicates with the heart; the qi of grain communicates with the spleen; the qi of rain communicates with the kidney. The six channels are like rivers; the intestines and stomach are like the sea; the nine orifices are the qi through which water pours forth. Taking heaven and earth as yin and yang: the sweat of yang is named after the rain of heaven and earth; the qi of yang is named after the swift wind of heaven and earth. Sudden, violent qi resembles thunder; rebellious qi resembles yang. Thus, if in treatment one does not model the guiding sequences of heaven and does not apply the principles of earth, calamity and harm will arrive.

Thus when pathogenic wind arrives, it is as swift as wind and rain. Therefore the skilled physician treats the skin and body hair; the next best treats the muscles and flesh; the next treats the sinews and vessels; the next treats the six bowels; and the next treats the five viscera. One who must treat the five viscera has an even chance of life and death. Thus the pathogenic qi of heaven, if it invades, harms the person's five viscera; the cold and heat of food and drink, if they invade, harm the six bowels; the damp qi of earth, if it invades, harms the skin, flesh, sinews, and vessels. Therefore the physician skilled in the use of needles draws yang from yin and draws yin from yang, treats the left to address the right and treats the right to address the left, uses himself to understand the other, uses the exterior to know the interior, and observes the principle of excess and insufficiency; by perceiving the subtle he grasps the fault, and so his use of the needle is never dangerous. The physician skilled in diagnosis examines the complexion and palpates the pulse, first distinguishing yin and yang; he discerns clarity and turbidity, and thereby knows the region of disease; he observes the breathing and listens to the voice, and thereby knows the source of suffering; he observes the seasonal pulse standards, and thereby knows what governs the disease. He presses the cubit and inch pulse positions, observes whether the pulse is floating, sunken, slippery, or rough, and thereby knows where the disease arises; in treating, he makes no error, and in diagnosing, he loses nothing. Hence it is said: when a disease first arises, it can be resolved by needling alone; when it is at its height, one must wait for it to wane before it can be resolved. Thus, according to its lightness, disperse it upward and outward; according to its severity, diminish it; according to its decline, restore and make it manifest again. When the physical form is insufficient, warm it with qi; when essence is insufficient, supplement it with flavor. When the disease is high in the body, induce vomiting to expel it; when it is low, draw it out and drain it away; when there is fullness in the middle, purge it from within; when there is pathogenic qi present, soak the body to induce sweating; when it is in the skin, sweat it out and disperse it; when it is fierce and swift, press and restrain it; when it is excess, disperse and drain it. Examine the yin and yang to distinguish the soft from the hard: treat yang disease through yin, and yin disease through yang; fix the blood and qi so that each keeps to its own place. When blood is in excess, one should drain it off; when qi is deficient, one should guide and lead it.