Basic Contents of the Yin-Yang Theory
1.Oppostion and Restriction between Yin and Yang
The theory of yin-yang holds that the two mutual opposite aspects of yin and yang exist in all things and phenomena in the natural world, and that the movement change of any thing is situated in the unity of opposites between yin and yang. As it is said in Chapter 5 of Plain Questions, "The water pertains to yin while the fire to yang, and yang transforms itself into qi while yin transforms itself into flavor. " It also is said in Chapter 6, "The heaven pertains to yang and the earth to yin. The sun pertains to yang and the moon to yin. " Other things, such as the upper and lower, the right and left, the motion and quiescence, the exiting and entering, the bright and dim, the cold and hot, etc. , also are the same.
Not only do non-living matters have the two opposite aspects of yin and yang, but living things also share this characteristic. Plain Questions states in Chapter 3 that, "The origination of life is rooted in yin and yang. " This means that all existences of life phenomena originate from the unity of opposites of yin and yang. Thus, Chapter 25 states,"The human body's configuration can not be considered apart from yin and yang. " It shows that the body is an organic whole of unity of opposites in the contradiction of yin and yang.
Yin and yang are opposite as well as united. The opposition is the aspect of mutual contrariness between both of them , while the unity is the aspect of mutual promotion between them. The lack of opposition results in the absence of unity, and the lack of mutual contrariness removes the possibility of mutual promotion.
The opposition between yin and yang is manifested mainly in the mutual restriction and mutual struggle between them. Through the mutual restriction and struggle, yin and yang are unified, and achieve a dynamic equilibrium. Because of this constant mutual rejection, struggle, and restriction between yin and yang, it is possible to promote things'development and change, and to maintain the dynamic equilibrium of things' development.
For example, the four seasons of spring, summer, autumn, and winter vary in their
degrees of warm, hot, cool, and cold weather. Originally, yang-heat is exuberant in summer. But after the Summer Solstice, yin-qi gradually grows in order to restrict the hot yang-qi. After the Winter Solstice, on the other hand, yang-qi gradually renews in order to restrict the cold yin-qi. The reason that it is warm and hot from spring to summer is that yang-qi is ascending and exuberant from spring to summer, thus restricting the cool and cold factors in autumn and winter. The reason that it is cool and cold from autumn to winter is that yin-qi is ascending and exuberant from autumn to winter, thus restricting the warm and hot factors of spring and summer. All of this is the result of the mutual restriction and struggle between yin and yang in the natural world.
The reason that human beings, as organic bodies, can carry out normal life activities also is the result of dynamic equilibrium resulting from the mutual restriction and struggle between yin and yang. The contradiction between yin and yang is the chief motivating force for maintaining and developing life activities. Life material is represented by yin(essence), while life functions are represented by yang (qi). Their contradictory movement process allows yang to transform into qi, and yin to constitute the form, i.e. , the process of "transformative function of qi" in the body. So the essential component of the "transformative function of qi" is the contradictory movement between yin-essence and yang-qi, between "transforming into qi" and "constituting the form. "
The mutual restriction between yin and yang can cause things to maintain temporary coordination and balance. In TCM, this state is known as "the even of yin and yang. " (Chapter 62 of Plain Questions. ) Chapter 3 calls this state "yin steady and yang consolidation resulting in harmonious life activities. " This demonstrates that only when yin and yang are coordinated can the body conduct its normal life activities. But the so-called "even of yin and yang" or "yin steady and yang consolidation" does not refer to an absolute balance in pure quantity. Instead, it merely refers to the relative dynamic equilibrium. If the opposite struggle between yin and yang is intensified and the restriction fails to be controlled, the dynamic equilibrium will be broken, and the alternate predominance of yin or yang will lead to disharmony, and inevitably, disease.
2. Mutual Dependen.ce and Interaction between Yin and Yang
Mutual dependence and interaction refer to the relationships of mutual dependence and promotion between the two mutual opposite aspects of yin and yang of things or phenomena. In other words, any aspect of yin or yang cannot exist singly without the other aspect, and each must take the other as the condition of prerequisite for its existence.Without yin there would be no yang, and without yang there would be no yin. Wang Bing, .in his annotation on Chapter 2 of Plain Questions, says: "Yang-qi is dependent on yin and yin-qi is dependent on yang. " It also is said in Classified Canon that "Yang rises inyin and yin rises in yang," and "The solitary yin cannot grow and the solitary yang cannot develop. " For instance, the upper is yang and the lower is yin. Without the upper, there would be no lower; without the lower, there would be no upper. For another example, hot is yang and cold is yin. Without hot, there would be no cold, and without cold, .there would also be no hot. Yang is dependent on yin and yin is dependent on yang,and the two cannot be separated. In TCM, this dependent relationship between yin and yang is called "mutual dependence and interaction. "
Chapter 5 in Plain Questions says: "Yin grows while yang is generated, and yin
conceals while yang is restrained. " It is pointed out more definitively in Medical Origin,Discussion on Mutual Dependence Between Yin and Yang that "Yang cannot be established by itself, it will be established after gaining yin. So yang takes yin as its base, and yin acts as the mother of yang. Yin cannot be manifested by itself, but will be manifested after gaining yang. So yin takes yang as its commander, and yang acts as the father of yin. Depending on yin or yang, it is a common principle both in the body and in the universe. Just as yang is upper and yin is lower, the human body also corresponds to this.Yin is ascending and yang is descending, and the effect of their movement is great... Yin and yang depend upon each other and they are originally the same one of qi. They are divided into two just because of their ascending and descending motion. "
The perspective of mutual dependence and interaction between yin and yang is applied extensively to various fields in TCM, such as physiology, pathology, therapeutics,and so on. For instance, the theory of "body pertaining to yin and function to yang," which is used to discuss the physiological functional activities of viscera, is a concrete incarnation of this relationship of mutual dependence and interaction between yin and yang.The "body pertaining to yin" refers to the substances of internal viscera, and materials such as essence, blood, body fluid, and so on. The "function pertaining to yang" refers to the movement and change of these materials, and their functional effects. Body pertaining to yin and function to yang means that there is the relationship of mutual dependence and interaction between these material bases and their physiological activities (or functional effects). Their physiological activities are the processes of transforming materials into functions. The results of these transforming activities conversely are constantly producing and replenishing essence, blood, and body fluid i. e. , the process of transforming functions into materials.
The visceral functional activities also embody the relationship of mutual dependence and interaction between yin and yang. The five zang-viscera can store yin-essence and vitality while the six fu-viscera can transport materials and promote transformation of yinessence. This also demonstrates the relationship of mutual dependence and interaction between the "store" and "transformation. " Just as it is said in The Abstruse Sense of the Internal Classic, "The five zang-viscera pertain to yin in which yang-vitality is stored.Without the storing function of the five zang-viscera, the yang-vitality will flee. The six fu-viscera pertain to yang in which yin-essence is transformed. Without the transforming function of the six fu-viscera, yin-essence will be exhausted. This is the mutual dependence between yin and yang. The vitality does not escape upwards because yin is to embrace yang, and the essence does not flow downwards because yang is to warm yin. "
Similarly, the relationship between qi and blood in the body is expounded by the relationship of mutual dependence and interaction between yin and yang. Qi pertains to yang while essence and blood pertain to yin. However, qi can promote the production of blood and is contained in blood. Qi can promote the production of essence, and essence can be transformed into qi. In addition, essence and blood can be transformed mutually.
The perspective of mutual dependence and interaction between yin and yang is embodied in the understanding of the development process of disease, as well. For example,in the syndrome of yang-deficiency, when it has developed to a certain degree, it can consume the body's yin fluid further and lead to yin-deficiency, also called "impairment of yang affecting yin. " This is because "there would be no production of yin without yang. "For the syndrome of yin-deficiency, when it has developed to a certain degree, it also may damage yang-qi further, and lead to yang-deficiency, also called "impairment of yin affecting yang. " This is because "there would be no transformation of yang without yin. " Both of these conditions eventually lead to the deficiency syndrome of both yin and yang.
In treating the syndrome of blood deficiency, the method of reinforcing both qi and blood often is used, because qi can promote the production of blood. In the condition of heavy bleeding, qi collapses, and a therapy of "in blood collapse, first to reinforce qi," must be adhered, so the method of reinforcing qi to stop bleeding should be selected first. As another example, the treatment of the syndrome of insufficiency of kidney-qi usually combines herbs for tonifying kidney-essence in addition to applying herbs for reinforcing kidney-qi This is effective because essence can be transformed into qi and enough essence results in plenty of qi. These are the concrete applications of the theory of mutual dependence and interaction between yin and yang in clinical treatment.
It should be pointed out that the reason that yin and yang can be transformed mutually under certain conditions is that they take the relationship of mutual dependence and interaction between them as their basis. Without this relationship, the two opposite aspects of yin and yang will be unable to mutually transform themselves.
However, if this relationship is broken, these two aspects lose the condition of coexistence, and because "yin does not grow without yang and yang does not develop without yin" (Classified Canon), the "solitary yin" and "solitary yang" cannot exist in isolation.For example, if the body's mutual dependence relationship between yin and yang, such as yang-qi and yin-fluid, material and function, etc. , suffers from severe damage to only one half of the relationship, it will lead to the other aspect losing its prerequisite to existence. Such a divorce of yin and yang results in the disappearance of contradiction between yin and yang, thus leading to "divorce of yin and yang resulting in exhaustion of essential-qi" (Chapter 3 in Plain Questions). The life activity also will end given this condition.
3. Wane-Wax and Equilibrium Between Yin and Yang
The wane-wax between yin and yang refers to the fact that the mutual opposite two aspects of yin and yang of things or phenomena are not in the static state, but rather are in the process of movement changes. The wane-wax between yin and yang (referred to as yang waning while yin waxing" and "yin waning while yang waxing") is one of the basic movement patterns of yin and yang.
Under normal conditions, because there is a mutual restriction relationship between yin and yang, the wane-wax movement always maintains a certain limitation and dynamic equilibrium, i.e. , one waning with the other waxing, one progressing with the other declining. Due to this movement, yang is unlikely to become excessively exorbitant because it gets help from yin. Likewise, yin does not decline excessively, as it receives aid from yang. Thus, yin and yang both are able to maintain normal development and change. Under abnormal conditions, however, this harmonious relationship of mutual restriction is lost, and certain aspects may exhibit over-exorbitance or excessive declination.TCM applies the theoretical perspective of wane-wax, dynamic equilibrium, and relative exorbitance or declination between yin and yang to explain the climatic changes in the natural world, and the physiology or pathology of human body.
Take, for example, the climatic changes of the four seasons in the natural world.From spring to summer, the cold-agent gradually decreases and the hot-agent increases daily, namely, "yin waning while yang waxing. " From autumn to winter, the hot-agent gradually decreases and the cold-agent increases daily, namely, "yang waning while yin waxing. " Just because of the regular wane-wax between yin and yang in the four seasons of a year, the climatic changes of hot, cold, warm, and cool come into being.
In Chapter 17 of Plain Questions, it is said "During fourth-five days after the Winter Solstice, yang-qi is ascending slightly and yin-qi is descending slightly~ during fourthfive days after the Summer Solstice, yin-qi is ascending slightly and yang-qi is descending slightly. " The "fourth-five" days refer to the time from the Winter Solstice to the Beginning of Spring, or from the Summer Solstice to the Beginning of Autumn. On the Winter Solstice the first-yang begins to germinate, and after the Beginning of Spring yang-qi ascends with the declination of yin-qi. When summer comes, yang-heat is in its extremity with the interior latency of yin-qi, and at the time of Summer Solstice, the first-yin begins to grow. After the Beginning of Autumn, yin-qi ascends with the declination of yang-qi, and in winter, yin-cold is in its extremity with the interior latency of yang-qi.In this way, the wane-wax between yin and yang circulates unceasingly year after year.
The human body's physiological activity provides another example. The production of various functional activities (yang) inevitably needs to consume certain nutrient materials (yin), which is the process of "yang waxing while yin waning. " On the other hand,the metabolism of various nutrient materials (yin) also inevitably needs to consume certain energy (yang), which is the process of"yin waxing while yang waning. " Under the normal physiological state, the wane-wax between yin and yang is in the state of relative dynamic equilibrium, namely, the so-called "yin steady and yang consolidation resulting in harmonious life activities. " So the physiological dynamic equilibrium of wane-wax between yin and yang is the process of normal generation and transformation for human body, which does not have the manifestations of external cold or hot.
It should be pointed out that, in TCM, the movement change is a general under-
standing of the natural world and the body's life activities. It is the incarnation of the perspective of the universe's constant movement. This movement change includes the processes of quantitative change and qualitative change. The normal physiological state of human body is generalized as "yin steady and yang consolidation'and the even of yin and yang. " Quantitatively, the changes in the two aspects of yin and yang do not exceed certain physiological limitations, through the demarcation line of coordination between yin and yang. The unity of the two opposite aspects of the contradiction between yin and yang allows them to remain in equilibrium. The natural world and the body is able to maintain its normal movement and development. As concerns the body, equilibrium is the means of maintaining life, reaching the normal threshold is the feature of health. The wane and wax of yin and yang on a certain physiological scale embody the life activity processes of the body's dynamic equilibrium.
But if the wane-wax between yin and yang exceeds certain physiological limitation,and cannot maintain a relative dynamic equilibrium, the range of wane-wax between yin and yang will be more obvious, leading to partial exuberance or decline. The organic body will be transformed into the pathological state from the physiological one. Generally, the pathological wane and wax or exuberance and decline of yin and yang present themselves in four conditions: partial exuberance of yin impairing yang, partial exuberance of yang impairing yin, insufficient yin resulting in hyperactivity of yang, and insufficient yang leading to exuberance of yin. The yang exuberance is usually manifested in heat syndrome (excess-heat or deficiency-heat), while yin exuberance is usually manifested in cold syndrome (excess-cold or deficiency-cold).
Similarly, in the clinical practice, according to the law of dynamic equilibrium of mutual wane and wax between yin and yang, treatment of disease is provided by adopting certain conditions and measures to rectify or adjust the partial exuberance or decline of yin and yang, thus recovering their wane-wax to a normal physiological level and achieving the goal of curing disease.
4. Mutual Transformation Between Yin and Yang
Mutual transformation between yin and yang refers to the fact that the property of yin or yang can be transformed into the opposite aspect under certain conditions. The mutual transformation between yin and yang also is another form of the movement of yin and yang. That is to say that when the wane-wax movement of yin and yang develops to a certain stage, yin can be transformed into yang and yang into yin. This generally occurs at the "extremity" stage during the development change of things. As it was once said, "Once a certain extremity is reached, a change in the opposite direction is inevitable. " So, in the process of development change, if the wane-wax between yin and yang is regarded as a process of quantitative change, the mutual transformation can be seen as a process of qualitative change.
The reason that the two opposite aspects of things or phenomena can transform
themselves into each other is that both of them have the latent factors of the other. As it is said in Chapter 68 of Plain Questions, "The generation of things is due to transformation, and the extremity of things leads to changes. The interaction of transformation and change determines the success or failure of things and success or failure is latently determined by movement. The unceasing movement results in changes. " In saying that"success or failure is latently determined by movement," (Plain Questions) refers to the fact that the decaying factor is incubated when a new thing is formed, and that the factor
of a new thing in formation is impregnated when an old thing is declined. The most fundamental cause of this process is unceasing movement.
It should be pointed out that there are certain conditions in the transformation of yin and yang. For example, it is said in Chapter 74 of the Spirit Pivot, "For the changes of the four seasons and the predominance of cold or hot, the extreme yin will turn into yang and the extreme yang will turn into yin. So yin dominates cold and yang dominates hot.The cold abundance results in hot and the hot abundance results in cold. Thus, it is said that cold leading to hot, and hot leading to cold, are due to the transformation between yin and yang. " Chapter 5 of Plain Questions also says, "The extreme cold gives rise to hot, while the extreme hot gives rise to cold. " Here, the "extreme" and "abundance" refer to the stages or conditions of transformation. It means that yin and yang will transform themselves into each other if they reach the stage of "abundance"; cold and hot would be mutually transformed if they achieve the condition of "extremity. "
What this condition or stage actually is depends upon the specific circumstance. Consider the climatic changes in the four seasons as examples. From the spring-warm developing into the summer-hot, it then is possible to turn into cool and cold gradually; and from the autumn-cool developing into the winter-cold it is possible to turn into warm and hot. Other processes, such as the alternation of day and night, and the change from clouds to rain, also work in the same way.
As regards the body's physiology, the metabolism process between material and
function merely is the transforming process between yin and yang. In this process,the
nutrient materials (yin) constantly transform into functional activities (yang) while the functional activities also transform into nutrient materials. In fact, in the process of life activities, the metabolism process between materials and functions is the unity of wanewax and the transformation between yin and yang ,the unity of quantitative and qualitative changes.
In the normal physiological condition, the transformation between yin and yang is not as sudden or obvious as it is under abnormal conditions. In the course of a disease's occurrence and development, it is easier to see the transformation take place. The hyperfunctional yang-heat syndrome may transform itself into the hypofunctional yin-cold syndrome. In the case of pneumonia, such symptoms as high fever, flushed complexion,vexation, powerful and rapid pulse, etc. , come from the manifestation of the reactive excitement of the organism, which pertains to yang syndrome, heat syndrome, and excessive syndrome, and which should be treated with cold and cool herbs. But if such a disease is not treated or the therapy fails, the patient's condition may develop into the critical stage, with symptoms of sweating, cold limbs, descending temperature and blood pressure, shallow and rapid breath, pale complexion, thin pulse or no pulse. This shows that the reactivity of the organism decreases with hypofunction, pertaining to yin syndrome, cold syndrome, and deficient syndrome. It is the reflection of"extreme yang turning into yin. "
Take ordinary bronchial asthma as another example. In ordinary cases, it is mani-
fested without fever, but with cough and asthma with white frothy sputum, and is aggravated when being attacked by cold, which pertains to yin syndrome, cold syndrome.But it also may instead present itself with such symptoms as fever, aggravated cough and asthma, stuffiness of the chest, husky breath with yellow and thick purulent sputum, thirst, red tongue, and rapid pulse. This usually happens because of suffering from the exogenous pathological cold, by which yang is closed and stagnated so as to be transformed into heat, which shows that it has been transformed into yang syndrome, heat syndrome. This is the reflection of "extreme yin turning into yang.
In addition, the common transformation of syndromes all are examples of transformation between yin and yang, such as the transformation from excess into deficiency (e. g., damp-heat in spleen and stomach or stagnation of liver-qi in acute hepatitis transforming itself into deficient spleen failing to transport in chronic hepatitis characterized by abdominal distension and loose stool) ; the transformation from deficiency to excess (e.g. , the deficient spleen failing to transport in chronic hepatitis develops to ascites due to the retention of watery-dampness in cirrhosis to form the syndrome of the genuine-deficiency and evil-excess). Transformations also take place from exterior to interior (e. g. ,
an exterior syndrome, such as fever with aversion to cold at the initial stage of encephalitis, if not treated promptly, develops into a condition where the exterior evil enters the interior and the pericardium, causing such symptoms as high fever, coma, convulsion,and so on) and from interior to exterior (e. g. , in child measles, if the rashes have been erupted thoroughly, the measles poison will be dispelled through the exterior).
It should be pointed out that these transformations of syndrome are determined mainly by the conditions of the strong or weak resistance of the organisms, the different natures of the evils, treatment methods, treatment time, etc. All of these factors can result in the transformation between cold and heat, deficiency and excess, exterior and interior, etc. Hence, this transformation requires certain prerequisite conditions without which there can be no transformation of yin and yang.
In summary, the laws of mutual restriction, mutual dependence and interaction,
wane-wax and equilibrium, and mutual transformation between yin and yang are all related to each other. The two opposite aspects of yin and yang must take the existence of their opposite aspect as the prerequisite of existence. The wane-wax movement between the opposite aspects is absolute, and the equilibrium between the opposite aspects is relative. Under certain conditions, the wane-wax movement between the opposite aspects may lead to quantitative leaps, so as to form the mutual transformation of yin and yang.These relationships and characteristics constitute the components of yin-yang theory in TCM.
