The theory of Five Elements rests on the notion that all phenomena in the universe are the products of the movement and mutation of five qualities: wood, fire, earth, metal, and water. These are known as Five Elements.
In Chinese medicine, like Yin-yang theory, Five Elements theory has had considerable influence in physiology, pathology, diagnosis, treatment, and pharmacology.
Characteristics and categorization
The ancient Chinese gained knowledge of the nature of Five Elements through long observation of nature and ascribed certain values to each. Thus:
“Wood is the bending and the straightening,” having the characteristics of growth, upbearing, and effusion.
“Fire is the flaming upward,” having the quality of heat and upward motion.
“Earth is the sowing and reaping,” representing the planting and harvesting of crops and the bringing forth of phenomena.
“Metal is the working of change,” having the qualities of purification, elimination, and reform.
“Water is the moistening and descending to low places,” having the qualities of moistening, downward movement, and coldness.
Five Elements theory is based on the understanding of the nature of these qualities, attributed to all phenomena in the universe. The interaction of Five Elements explains the nature of all phenomena. In medicine, the internal organs, body tissues, sense and other organs, emotions, and even properties of medicinal are all categorized according to these elements.
The four cycles
Interaction among the elements is viewed in terms of four cycles. Inter-promoting denotes the principle whereby each of the elements nurtures, produces, and benefits another specific element. Inter-acting refers to the principle by which each of the elements constrains another element.
Arranged in cyclic form, the inter-promoting relationships are as follows (starting with wood promoting fire):
wood fire earth metal water wood
The interacting cycle (starting with wood acts on earth) is as follows:
wood earth water fire metal wood
In their correspondences to the viscera, the inter-promoting and inter-acting cycles appear as follows:
inter-promoting: liver heart spleen lung kidney liver
inter-acting: liver spleen kidney heart lung liver
The notions of inter-promoting and inter-acting posit a conception of the natural world as a united whole made up of interrelated parts. In inter-promoting, there is inter-acting, and in inter-acting, there is inter-promoting. This belief that all movement and mutation in the phenomenal world derives from the mutually promoting and mutually acting relationships of all phenomena has had a profound influence on the visceral manifestation theory of Chinese medicine.
The principles of over-acting and counter-acting are disturbances of the normal cycles. In medicine, they explain pathologic manifestations. The principle of over-acting refers to the situation where one of Five Elements is weakened, causing the element that under normal circumstances would overcome it to invade and weaken it further. For example, wood normally acts on earth, but if earth is weak, then wood over-acts on it, rendering earth even weaker. In terms of the viscera, this means that the spleen, normally only acted on by the liver, will, if weak, be completely over-acted, becoming even weaker. According to the original theory of Five Elements, inter-acting and over-acting differ in that the former denotes the normal action of a given element in keeping another in check, while the latter refers to a disproportionately powerful influence when the normal balance has been upset.
The principle of counter-acting denotes the situation where one of Five Elements is disproportionately strong and rebels against the element that should normally acts on it. For example, wood is normally kept in check by metal, but if wood becomes too strong, it will rebel against metal. Powerless to withstand the attack, metal will succumb. In terms of the organs, this means that when the liver, normally kept in check by the lung, becomes too strong, it will rebel against the lung and overcome it.
Five Elements analysis of organ characteristics
The nature and function of the organs are seen to have correspondences to phenomena in nature and are classified with those phenomena according to Five Elements.
Liver-wood: The liver’s physiologic characteristic is that it thrives by orderly reaching. It governs upbearing and stirring and is like the “sprouting of trees and plants in spring.” Spring corresponds to wood in Five Elements, so that the liver is ascribed the attribute of wood.
Heart-fire: The physiologic characteristic of the heart is that it governs the blood vessels. It has the function of propelling Qi and blood to warm and nourish the whole body. It is likened to the heat of summer, when the whole of creation thrives. Summer corresponds to fire, and so the heart is ascribed the quality of fire.
Spleen-earth: The spleen’s physiologic characteristic is that it governs movement and transformation of the essence of grain and water and is the basis of the formation of Qi and blood. It is associated with late summer and humid weather, when the whole of nature is at its peak. Late summer corresponds to earth, so that the spleen is ascribed the attribute of earth.
Lung-metal: The physiologic characteristic of the lung is that it thrives by purity and governs downbearing. It is likened to the clear fresh air and purifying first frosts of autumn, when nature is withdrawing into itself. For this reason, it is ascribed the attribute of metal.
Kidney-water: The kidney has the physiologic function of storing essence and of governing fluids. It is associated with the bitter cold of winter, when nature is dormant.
The correspondences between five Elements and organ function clearly have adequate foundation. However, the accumulated knowledge concerning the organs over the long history of Chinese medicine goes far beyond the confines of Five Elements. For example, the liver not only governs upstirring and thrives by orderly reaching; liver Yin and liver blood have a nourishing function for which the correspondence to wood cannot account. Similarly, the heart represents not only the warming function and the strength of the heart’s Yang Qi, but also the nourishing, calming function of heart Yin, which does not accord with the notion of fire. The functions of the stomach and spleen include not only formation (of Qi and blood), but also upbearing effusion and free downflow, which are not entirely in keeping with the notion of earth. The lung has not only the function of depuration, but also that of diffusion, which cannot be accounted for by the notion of metal. Finally, the functions of the kidney include not only storing essence and governing water, but also warming and propulsion of fluids which are not associated with the notion of water.
For these reasons, it is felt that the theory of Five Elements is incomplete and fails to embrace all the physiologic functions of the five viscera. It is only through clinical practice and research that our understanding of the functions of the organs can be increased and new breakthroughs accomplished.
The four cycles in inter-organ relationships and prognosis
The inter-promoting and inter-acting cycles each have two aspects: promoting and being promoted; acting and being acted. These aspects explain the relationship of each of the elements to the remaining four. The liver, for example, is promoted by the kidney, and promotes the heart; it is acted on by the lung and acts on the spleen. The liver relies on kidney water for nourishment, a relationship known as water moistening wood. Failure of kidney water to fulfill this function is known as water failing to moisten wood. The lung’s governing of depurative downbearing counterbalances the liver’s governing of upstirring, which is known as metal constraining wood. When liver fire is effulgent and invades the lung, this is wood fire tormenting metal. Most liver disorders affect the spleen, an occurrence known as wood acting on earth. Finally, when kidney fire and heart fire give rise to each other, it is known as “water and fire sharing the same Qi”.
The theory of Five Elements is also used in disease prognosis. If a condition spreads in the order of the inter-promoting cycle, the prospects for a good recovery are favorable and the disease can be considered minor. If, on the contrary, the condition spreads in the order of the inter-acting cycle, the prospects are unfavorable and the disease is serious. For example, a liver disease affecting the heart is considered normal, because the liver (wood) promotes the heart (fire). Should it progress in the order of the inter-acting cycle to the spleen, the condition is serious.
Although the preceding explanation of the physio-pathologic relationships between the organs in terms of Five Elements does have some definite clinical justification, current thought is that the physiologic activity of any given organ forms part of the general physiologic activity of the entire body. Morbid changes in any given organ may, under specific conditions, affect any of the other organs. For example, kidney Yin vacuity may deprive the liver of its nourishing effect (“water failing to moisten wood”). Although this is accounted for by Five Elements theory, unexplained is the fact that the heart or lung may be similarly affected causing upflaming of heart fire or lung heat dry cough. Taking another example, liver fire may invade not only the lung, but also the stomach and may further affect the kidney. The inherent interrelationships among the organs cannot be explained in terms of the inter-promoting and inter-acting cycles alone. To stick rigidly to the theory of Five Elements in this particular area would be to go against objective reality.
As far as disease shifts and prognosis are concerned, the factors and conditions are even more complex and are dependent on the nature of the evil, the strength of right Qi, and the treatment prescribed. The inter-promoting and inter-acting relationships are of relatively little use in estimating a patient’s progress. The errors and insufficiencies of the theory of the four relationships of Five Elements in their application to medicine must be clearly identified and eliminated to be able to apply what is true and useful.
The inter-promoting and inter-acting cycles in determining treatment
The theory of the inter-promoting and inter-acting cycles can help to determine the right method of treating disorders through a series of rules. Boosting fire to promote earth, banking up earth to promote metal, mutual promoting of metal and water, enriching water to moisten wood, banking up earth to control water, are examples. These rules represent practical guidelines for clinical practice. However, a critical approach should be adopted to eliminate the unreasonable factors and verify what is rational. These “rules of thumb” may be considered individually:
Boosting fire to promote earth:
In practice, this means warming and supplementing kidney Yang to treat disorders such as clear-food diarrhea, enduring diarrhea, or fifth-watch diarrhea when caused by a spleen-kidney Yang vacuity. In Five Elements theory, the spleen corresponds to earth. Conditions such as spleen-vacuity diarrhea require that fire be supplemented to promote earth, restoring the spleen to normal functioning. Since “fire” here refers not to the heart fire (fire corresponding to the heart in Five Elements) but to kidney Yang (life gate fire), this rule of thumb is not strictly in keeping with Five Elements theory. Correct interpretation of the word relies on the understanding that in medicine, kidney Yang is the root of the Yang Qi of all the organs. Warming and supplementing kidney Yang indirectly strengthens spleen, heart, and lung Yang. Even assuming that fire represents kidney Yang, a strict interpretation of Five Elements theory would limit the effect of warming and supplementing kidney Yang to merely fortifying the spleen, which is not in keeping with organ theory.
Banking up earth to promote metal:
In practice, this rule denotes fortifying the spleen to treat disorders of the lung. The rule applies in cases of lung vacuity that occur in conjunction with spleen-stomach vacuity. Since the stomach and spleen are the source of the acquired constitution, and are the basis of Qi and blood formation, supplementing these organs is generally conducive to increasing the body’s resistance to disease. If we were to interpret “banking up earth to promote metal” through Five Elements theory to mean that supplementing the spleen is effective only in treating lung vacuity, the theory that the stomach and spleen are the basis of Qi and blood formation would to a certain extent be invalidated.
Metal and water promoting each other:
This guideline is derived from Five Elements principle that metal promotes water. In practice, the rule refers to lung-kidney Yin vacuity, where treatment is based chiefly on the method of enriching kidney Yin, and complemented by that of nourishing lung Yin. The disorder involves vacuity in two organs, so both are treated. This approach is not limited to the kidney and the lung; it may also be applied to other dual vacuity patterns. For example, kidney and heart Yin can be simultaneously diseased, as can kidney and heart Yang. An even more common example is kidney and liver Yin. All these conditions are treated by a dual approach. Because kidney Yang and kidney Yin are the root of the Yin and Yang of the whole body, treatments of dual disorders involving the kidney and another organ are primarily based on supplementing the kidney. This is an important principle of treatment in Chinese medicine.
Enriching water to moisten wood:
This is taken to mean nourishing kidney Yin to subdue liver Yang, a principle that is applied in the treatment of ascendant hyperactivity of liver Yang due to liver-kidney Yin vacuity. However, Five Elements theory fails to take account of the fact that kidney Yin is the root of the Yin of all viscera. Insufficiency of kidney Yin can produce not only ascendant hyperactivity of liver Yang characterized by dizziness and upbearing fire flush, but also upflaming of heart fire (characterized by palpitation, insomnia, profuse dreaming, and erosion of the nasal and oral mucosa). Accordingly, kidney Yin enrichment treats disorders stemming from both liver-kidney and heart-kidney Yin vacuity. The inherent relationships of the Yin and Yang aspects of the organs thus explain the supplementation of kidney Yin to subdue liver Yang or to clear heart fire. The axiom that the kidney is the source of all Yin means that kidney Yin has the definite functions of nourishing the Yin aspect of all the other organs, and of counteracting the Yang aspect of all the other organs. To claim that kidney Yin can moisten only the liver would be erroneous. In reality, this rule of thumb falls within the scope of “invigorating the governor of water to counteract the brilliance of Yang”.
Banking up earth to control water:
Treatment of water swelling by fortifying the spleen and boosting Qi is known as banking up earth to control water. Here, “water” refers not to the kidney, but to water-damp evil in the body. According to the correspondence between five elements and the five viscera, water can only represent the kidney and cannot refer to water-damp evil. Thus, banking up earth to control water only makes sense when rephrased as fortifying the spleen to disinhibit water.
To sum up, today it is generally held that the theories of Yin-Yang and Five Elements derived from practical experience are based on rudimentary dialectics and have been a positive force in the development of medical theory. As a consequence of historical conditions, however, they were necessarily incomplete. Although certain aspects of these theories still provide valuable guides for clinical practice, other aspects are unclear and are therefore incompatible with modern medicine. The accurate aspects must be preserved and the inaccurate aspects eliminated. Although the terms Yin and Yang are still in common use, the practice of referring to the organs by their corresponding element is dying out. It is thought that greater clarity is achieved by referring to the organs by their own names, even when discussing their interrelationships. Retaining only the theories that have practical value will do no damage to the theoretical body of Chinese medicine. Indeed, it will help to eliminate the constraints, develop Chinese Medicine further, and raise it to the standards of a modern science. The practical aspects of the Yin-Yang and Five Elements theories must be subject to practical analysis to separate the seed from the chaff. It would be wrong to think of these theories as entirely valid or invalid. What is required is honest analysis to select the best of past and present theory, and to use modern scientific methods in further research. Only then will China be able to develop Chinese medicine, and make its rightful contribution towards the development of a new medical and pharmacological science.