Great Treatise on the Manifestations of Yin and Yang

The Yellow Emperor said: Yin and yang are the universal principle of heaven and earth, the guiding framework of all transformation, the root of growth and destruction, and the storehouse of spiritual activity. In treating disease, one must seek the root from yin and yang. Therefore, clear yang accumulates and rises to become heaven, while turbid yin coagulates and descends to become earth. Yin governs stillness, yang governs activity; yang governs germination, yin governs growth; yang governs killing, yin governs storage. Yang transforms the formless qi, yin constitutes the formed substance. Extreme cold generates heat, extreme heat generates cold. Cold can produce turbid yin, heat can produce clear yang. If clear yang dwells below and does not rise, undigested food diarrhea occurs; if turbid yin dwells above and does not descend, abdominal distension and fullness occur. This is why when the normal movement of yin and yang is reversed, disease follows with varying patterns of rebellion and compliance.

Thus, clear yang ascends as heaven, turbid yin descends as earth. Earth qi rises to become clouds, heaven qi descends to become rain. Rain originates from earth qi after it rises and condenses; clouds originate from heaven qi after it descends and evaporates. Therefore, clear yang issues from the upper orifices, turbid yin issues from the lower orifices; clear yang disperses from the interstices, turbid yin moves inward through the five viscera; clear yang fills the four limbs, turbid yin flows to the six bowels. Water pertains to yin, fire pertains to yang. Yang is formless qi, yin is formed flavor. The five flavors nourish the physical body; the physical body in turn depends on the nourishment of primordial qi; primordial qi transforms to produce essence; essence in turn transforms into life activity. Essence relies on qi for nourishment; the physical body relies on the five flavors for support; life activity can produce essence; qi can generate the physical body. But excessive flavors damage the physical body; excessive qi damages essence. Essence can transform into qi; qi can also be harmed by the five flavors. The five flavors pertaining to yin are discharged from the lower orifices; yang qi pertaining to yang issues from the upper orifices. Thick flavor belongs to pure yin; thin flavor belongs to yin within yang. Thick qi belongs to pure yang; thin qi belongs to yang within yin. Thick flavor has a purging effect; thin flavor has a draining effect. Thin qi has a dispersing effect; thick qi can assist heat and generate fire. Rampant fire consumes righteous qi; gentle fire nourishes righteous qi. Rampant fire dissipates qi; righteous qi can nourish gentle fire. Rampant fire weakens qi; gentle fire strengthens qi. Among the flavors, those with acrid and sweet tastes that have a dispersing effect pertain to yang; those with sour and bitter tastes that have an emetic or purging effect pertain to yin. When yin qi predominates, yang qi becomes diseased; when yang qi predominates, yin qi becomes diseased. Yang qi predominance manifests as heat; yin qi predominance manifests as cold. Extreme cold produces heat signs; extreme heat produces cold signs. Cold pathogen damages the physical form; heat pathogen damages qi. When qi is injured, there is pain; when the form is injured, there is swelling. Therefore, if pain precedes swelling, qi is injured first and then affects the form; if swelling precedes pain, the form is injured first and then affects qi. When wind pathogen predominates, the body trembles and shakes; when heat pathogen predominates, redness and swelling occur; when dryness pathogen predominates, withering occurs; when cold pathogen predominates, edema occurs; when dampness pathogen predominates, watery diarrhea occurs.

Nature has the four seasons of spring, summer, autumn, and winter, and the five phases of wood, fire, earth, metal, and water, to manifest the laws of growth, development, harvest, and storage, and to generate the five climates of cold, heat, dryness, dampness, and wind. The human body has five viscera, which transform the five qi and produce the five emotions of joy, anger, grief, worry, and fear. Therefore, emotional changes like joy and anger injure qi; external pathogens like cold and summer heat injure the physical form. Sudden great anger damages yin; sudden great joy damages yang. If rebellious qi ascends and fills the channels and vessels, it causes the spirit to leave the body. If joy and anger are not moderated, and cold and summer heat excessively attack, life cannot remain stable. Thus, when yin reaches its extreme, it necessarily transforms into yang; when yang reaches its extreme, it necessarily transforms into yin. Therefore, it is said: If cold pathogen is contracted in winter without immediate onset, warm disease will inevitably occur in spring; if wind pathogen is contracted in spring, summer diarrhea with undigested food will occur; if summer heat pathogen is contracted in summer, malaria will occur in autumn; if dampness pathogen is contracted in autumn, coughing will occur in winter.

The Yellow Emperor asked: I have heard that the sages of high antiquity discussed the forms of the human body, distinguished the categories of the viscera and bowels, examined the origins and connections of the channels and collaterals, harmonized the six conjunctions, and made them follow their respective channel courses; the points where qi and blood emerge each have their names; the depressions and crevices of muscles and the connections of bones each have their beginnings; the compliance and rebellion of the skin divisions each have their order; the changes of yin and yang in the four seasons each have their regular patterns; the correspondences between the external and internal environments of the body each have their surface and interior relationships. Are these statements indeed true?

Qi Bo replied: The east corresponds to spring. Yang is generated and wind stirs. Wind can nourish wood qi; wood qi can produce sour flavor; sour flavor can nourish the liver; the liver can nourish the sinews; the sinews can nourish the heart; the liver also governs the eyes. Its function, in heaven, is the mysterious and subtle qi; in the human realm, it is the Dao; on earth, it is transformation and generation. Earth can transform and generate the five flavors; the Dao produces wisdom; the mysterious produces spirit. Spirit in heaven is wind; on earth, it is wood; in the human body, it is the sinews; in the five viscera, it is the liver; in the five colors, it is green; in the five notes, it is jue; in vocal expression, it is shouting; in pathological manifestations, it is grasping; among the seven orifices, it is the eyes; among the five flavors, it is sour; among the emotions, it is anger. Anger can harm the liver, but grief can restrain anger; wind can harm the sinews, but dryness can restrain wind; sour flavor can harm the sinews, but acrid flavor can restrain sour flavor.

The south corresponds to summer. Yang qi flourishes and generates heat. Heat can generate fire; fire can produce bitter flavor; bitter flavor can nourish the heart; the heart can generate blood and vessels; blood and vessels can nourish the spleen; the heart also governs the tongue. Its function, in heaven, is heat; on earth, it is fire; in the human body, it is blood and vessels; in the five viscera, it is the heart; in the five colors, it is red; in the five notes, it is zhi; in vocal expression, it is laughter; in pathological manifestations, it is worry; among the seven orifices, it is the tongue; among the five flavors, it is bitter; among the emotions, it is joy. Joy can harm the heart, but fear can restrain joy; heat can harm qi, but cold can restrain heat; bitter flavor can harm qi, but salty flavor can restrain bitter flavor.

The center corresponds to long summer. Dampness flourishes. Dampness can generate earth; earth can produce sweet flavor; sweet flavor can nourish the spleen; the spleen can generate muscles; muscles can nourish the lung; the spleen also governs the mouth. Its function, in heaven, is dampness; on earth, it is earth; in the human body, it is muscles; in the five viscera, it is the spleen; in the five colors, it is yellow; in the five notes, it is gong; in vocal expression, it is singing; in pathological manifestations, it is retching; among the seven orifices, it is the mouth; among the five flavors, it is sweet; among the emotions, it is pensiveness. Pensiveness can harm the spleen, but anger can restrain pensiveness; dampness can harm muscles, but wind can restrain dampness; sweet flavor can harm muscles, but sour flavor can restrain sweet flavor.

The west corresponds to autumn. Yin qi flourishes and generates dryness. Dryness can generate metal; metal can produce acrid flavor; acrid flavor can nourish the lung; the lung can generate skin and body hair; skin and body hair can nourish the kidney; the lung also governs the nose. Its function, in heaven, is dryness; on earth, it is metal; in the human body, it is skin and body hair; in the five viscera, it is the lung; in the five colors, it is white; in the five notes, it is shang; in vocal expression, it is weeping; in pathological manifestations, it is coughing; among the seven orifices, it is the nose; among the five flavors, it is acrid; among the emotions, it is grief. Grief can harm the lung, but joy can restrain grief; heat can harm skin and body hair, but cold can restrain heat; acrid flavor can harm skin and body hair, but bitter flavor can restrain acrid flavor.

The north corresponds to winter. Cold qi flourishes. Cold can generate water; water can produce salty flavor; salty flavor can nourish the kidney; the kidney can generate bone marrow; bone marrow can nourish the liver; the kidney also governs the ears. Its function, in heaven, is cold; on earth, it is water; in the human body, it is bones; in the five viscera, it is the kidney; in the five colors, it is black; in the five notes, it is yu; in vocal expression, it is groaning; in pathological manifestations, it is shivering; among the seven orifices, it is the ears; among the five flavors, it is salty; among the emotions, it is fear. Fear can harm the kidney, but pensiveness can restrain fear; cold can harm blood, but dryness can restrain cold; salty flavor can harm blood, but sweet flavor can restrain salty flavor.

Therefore it is said: Heaven and Earth are that which covers and supports the myriad things; yin and yang are the male and female of qi and blood (representing the opposing pair); left and right are the pathways along which yin and yang circulate; water and fire are the signs and manifestations of yin and yang; yin and yang are the root of the generation of all things. Hence it is said: Yin, being within, is the guardian of yang; yang, being without, is the servant of yin (yin provides the material basis for yang, and yang performs the functional activities for yin).

Huangdi asked: How can one take the patterns of yin and yang as a model?

Qibo said: When yang qi predominates, the body will experience fever, the interstices will be blocked, breathing will be rapid and the body will lean forward and backward, there will be no sweating, fever, dry teeth, mental vexation, and abdominal distension—this is a fatal sign. This disease can be tolerated in winter, but cannot be endured in summer. When yin qi predominates, the body will feel cold, there will be sweating, the body will often feel chilly, with frequent shivering and chills; when the cold is severe, the hands and feet become cold; when coldness reaches this point, the abdomen becomes distended—this is a fatal sign. This disease can be tolerated in summer, but cannot be endured in winter. These are the pathological manifestations and disease patterns of the changes in yin and yang predominance.

Huangdi asked: How can one regulate these two kinds of predominance in yin and yang?

Qibo said: If one can understand the principle of the seven injuries and eight benefits (ancient laws of sexual cultivation or yin-yang harmonization), then yin and yang can be harmonized; if one does not know how to apply this principle, premature aging will occur. When a person reaches forty years of age, yin qi has naturally declined by half, and movements and activities also show decline. At fifty, the body becomes heavy, and the ears and eyes are no longer sharp. At sixty, impotence (decline of sexual function) occurs, the vital qi greatly weakens, the nine orifices become dysfunctional, the lower part is deficient while the upper part is excessive (such as flaring of deficient fire), and tears and nasal discharge easily flow. Therefore it is said: Those who understand the way of nurturing life have strong bodies; those who do not understand age prematurely; thus, though people are the same, the outcomes differ. The wise, while still healthy, can perceive the common principles of nurturing life; the foolish only see the different manifestations of decline. The foolish often feel insufficiency, while the wise often feel abundance. With abundance, the ears and eyes are sharp, the body is light and strong, the aged can regain vigor, and the strong become even healthier. Therefore the sage does things that accord with nature without contrivance, delights in the cultivation of tranquility and emptiness, seeks joy of the mind, and abides in the realm of emptiness. Thus his lifespan is limitless, and he can share the end of heaven and earth. This is the method of nurturing life practiced by the sage.

The qi of heaven is insufficient in the northwest, so the northwest belongs to yin, and the right ear and eye of humans are not as sharp as the left. The qi of earth is deficient in the southeast, so the southeast belongs to yang, and the left hand and foot are not as strong as the right.

Huangdi asked: Why is this so?

Qibo said: The east belongs to yang, and the essence qi of yang gathers in the upper part; gathering in the upper part makes the upper part abundant and the lower part deficient, so the ears and eyes are sharp, but the hands and feet are not agile. The west belongs to yin, and the essence qi of yin gathers in the lower part; gathering in the lower part makes the lower part abundant and the upper part deficient, so the ears and eyes are not sharp, but the hands and feet are agile. Therefore, when the same pathogenic factor attacks, in the upper part it is more severe on the right side, and in the lower part it is more severe on the left side; this is because the distribution of yin and yang of heaven and earth is not completely balanced, so the pathogenic qi lodges in the relatively weaker side. Thus heaven has essence qi, and earth has form; heaven has the patterns of the eight nodal periods (eight important seasonal nodes), and earth has the principles of the five regions; therefore heaven and earth can be the parents of the myriad things. Clear yang qi ascends and returns to heaven, turbid yin qi descends and returns to earth; thus the movement and stillness of heaven and earth are governed by the changes of spirit illumination, enabling growth, harvest, storage, and the cycle of beginning and end. Only the worthy person, above, accords with heaven qi to nurture the head; below, imitates earth qi to nurture the feet; and in the middle, refers to human affairs to nurture the five viscera. Heaven qi (the qi of respiration) communicates with the lung; earth qi (the qi of food and drink) communicates with the throat; wind qi communicates with the liver; thunder qi (fire qi) communicates with the heart; valley qi (earth qi) communicates with the spleen; rain qi (water qi) communicates with the kidney. The six channels (the three yin and three yang channels of the hands and feet) are like rivers; the intestines and stomach are like the sea; the nine orifices are like channels through which water qi pours. Using heaven and earth to analogize the yin and yang of the human body, the yang qi (sweat) of the human body can be named after the rain of heaven and earth; the yang qi (movement) of the human body can be named after the swift wind of heaven and earth. The qi of violent anger in humans is like thunder and lightning; the qi of rebellious ascent is like yang heat (or like the upward rebellion of yang qi in heaven and earth). Therefore, if treatment does not take the patterns of heaven as a model and does not use the principles of earth, then calamities will arrive.

Thus the arrival of pathogenic wind is as swift as wind and rain; therefore the skilled physician treats it when the pathogenic factor first invades the skin and body hair; next, he treats it when the pathogenic factor is in the skin and muscles; next, he treats it when the pathogenic factor is in the sinews and vessels; next, he treats it when the pathogenic factor is in the six bowels; next, he treats it when the pathogenic factor is in the five viscera. When the pathogenic factor has already reached the five viscera, the outcome is half dead and half alive. Therefore, when the pathogenic qi of heaven is contracted, it harms the five viscera of humans; when the cold or heat of water, grain, food, and drink is inappropriate, it harms the six bowels; when the damp qi of earth is contracted, it harms the skin, flesh, sinews, and vessels. Hence the skilled practitioner of acupuncture guides yang from the yin aspect, guides yin from the yang aspect, treats diseases on the left by using points on the right, treats diseases on the right by using points on the left, uses the normal state of himself to understand the abnormality of the patient, infers the internal condition from the external symptoms, thereby observing the patterns of excess and deficiency in disease, and seeing the subtle signs, he can know the error of the disease; applying this method, there will be no danger.

The skilled diagnostician observes the patient's complexion and palpates the pulse; first, he distinguishes yin and yang; he examines the clarity or turbidity of the complexion, thereby knowing the location of the disease; he observes the patient's panting and listens to the patient's voice, thereby knowing the patient's suffering; he examines whether the pulse in the four seasons is normal or abnormal, thereby knowing the seat of the pathogenic factor. By palpating the cun-kou pulse at the wrist, and observing whether the pulse is floating, sinking, slippery, or rough, he knows the cause of the disease; thus treatment will have no error, and diagnosis will have no mistake.

Therefore it is said: When disease first begins, it can be cured with acupuncture; when the disease is at its peak, one can wait until it has slightly subsided before treating. Thus, according to the lightness of the pathogenic factor, use dispersing methods; according to the depth of the pathogenic factor, use purging methods; according to the weakness of the correct qi, use supplementing methods. When the body is insufficient, supplement it by warming the qi; when essence qi is insufficient, fill it with rich-flavored substances. When the pathogenic factor is in the upper part, use emetic methods to drive it upward; when the pathogenic factor is in the lower part, use draining methods to expel it downward completely; when the middle is distended, treat it from within with purging methods; when external pathogens are present, soak the body in medicated decoctions to induce sweating; when the pathogenic factor is on the skin surface, use sweating methods to disperse it; when the disease is violent and acute, use restraining and gathering methods to control it; when the pathogenic factor is substantial, use dispersing and purging methods to treat it. Carefully examine the yin or yang nature of the disease to distinguish its softness or hardness; yang diseases can be treated by addressing the yin aspect, yin diseases can be treated by addressing the yang aspect; stabilize the blood and qi of the patient to restore their respective functions to normal; when blood is substantial, use bloodletting; when qi is deficient, use guiding methods.