The first substance has Yin and Yang. This theory is the basis for feng shui and traditional Chinese Medicine as well as Chinese astrology. All things terrestrial and celestial fall into one of five groups, the Wu Xing (Five Elements). The five elements are:

The Five Elemental Energies (wu sing) represent the tangible activities of yin and yang as manifested in the cyclic changes of nature which regulate life on earth. Also known as the Five Movements (wu yun), they define the various stages of transformation in the recurring natural cycles of seasonal change, growth and decay, shifting climatic conditions, sounds, flavors, emotions, and human physiology. Each energy is associated with the natural element which most closely resembles its function and character, and from these elements they take their names. Unlike the Western and other systems of five elements, the Chinese system focuses on energy and its transformations, not on form and substance. The elements thus symbolize the activities of the energies with which they are associated.

As manifestations of yin and yang on earth, the Five Elemental Energies represent various degrees of 'fullness' and 'emptiness' in the relative balance of yin and yang within any particular energy system. An ancient Chinese text explains this principle as follows:

By the transformation of yang and its union with yin, the Five Elemental Energies of Wood, Fire, Earth, Metal, and Water arise, each within its specific nature according to its share of yin and yang. These Five Elemental Energies constantly change their sphere of activity, nurturing and counteracting one another so that there is a constancy in the transformation from emptiness to abundance and abundance to emptiness, like a ring without beginning or end. The interaction of these primordial forces brings harmonious change and the cycles of nature run their course. The Five Elemental Energies combine and recombine in innumerable ways to produce manifest existence. All things contain all Five Elemental Energies in various proportions.

Water is the elemental energy associated with winter, when a state of extreme yin prevails. Winter is the season of stillness and rest, during which energy is condensed, conserved, and stored. Water is a highly concentrated element containing great potential power awaiting release. In the human body, Water is associated with essential fluids such as hormones, lymph, marrow, and enzymes, all of which contain great potential energy. Its color is black, the color which contains all other colors in concentrated form. In nature, Water is dissipated by excess heat; in humans, Water energy is depleted by the 'heat' of stress and excess emotions. The way to conserve the potential energy of Water is to stay still and 'be cool'.

The next phase of the seasonal cycle is spring, during which the Wood element arises from the potential energy of Water, just as plants sprout from the ground in spring rains. This is the 'new yang' stage of the cycle. Wood energy is expansive, exhilarant, explosive. It is the creative energy of 'spring fever', awakening the procreative drive of sexuality. It is associated with vigor and youth, growth and development. In the human body, Wood energy is associated with the movement of muscles and the activity of tissues. Its color is green, the vibrant color of spring growth. Wood energy demands free statement and space for open expansion. Blocking it gives rise to feelings of frustration, anger, jealousy, and stagnation.

Just as spring develops naturally into summer, so the aggressive creative energy of Wood matures into the flourishing 'full yang' energy of Fire. This is the most overtly energetic phase of the cycle, during which the 'heat' of full yang energy is sustained. All life forms flourish in summer owing to the warm, stable glow of fire energy. Fire is related to the heart, which is the seat of human emotions and the organ whose constant warmth and pulse keeps blood and energy moving. Its color is red, the warm color of fire and blood. It is associated with love and compassion, generosity and joy, openness and abundance. If blocked it results in hypertension and hysteria, heart problems and nervous disorders.

Towards the end of summer comes an interlude of perfect balance during which Fire burns down and energy mellows, transforming itself into the elemental energy of Earth. Neither yin nor yang predominates during this period; insead they are in a state of optimum balance. This is the pivot of the cycle, the fulcrum between the yang energies of spring and summer and the yin energies of autumn and winter. The Five Elemental Energies hum in harmony at this time, providing a sense of ease, wellbeing, and completeness. The Earth energy of late summer is the phase and the feeling celebrated in the song 'Summertime, and the living is easy ...' Its color is yellow, the color of sun and earth, and in human anatomy it is associated with the stomach, spleen, and pancreas, which lie at the center of the body and nourish the entire system. If Earth energy is deficient, digestion is impaired and the entire organism is thrown off balance owing to insufficient nourishment and vitality.

As Summer passes into Autumn, the energy of Earth transforms into Metal. During the Metal phase, energy once again begins to condense, contract, and draw inward for accumulation and storage, just as the crops of summer are harvested and stored in autumn for use in winter. Wastes are eliminated, like winnowing chaff from wheat, and only the essence is kept in preparation for the nonproductive Water phase of winter. If the harvest fails or falls short, there may not be sufficient energy stored during Water/winter to generate a strong and healthy cycle in the following Wood/spring. Metal energy controls the lungs, which extract and store essential energy from air and expel wastes from the blood, and the large intestine, which eliminates solid wastes while retaining and recycling water.

Its color is white, the color of purity and essence. Autumn is the season of retrospection and meditative insight, for shedding old skin and dumping the excess baggage of external attachments and emotions accumulated in summer, just as trees shed their leaves and bees drive drones from the hive at this time of year. Resisting this energy by clinging sentimentally to past attachments can cause feelings of melancholy, grief, and anxiety, which manifest themselves physiologically in breathing difficulties, chest pain, skin problems, and low resistance. Flu, colds, and other respiratory ailments are common indicators of blocked Metal energy, which is associated with the lungs. Just as Metal is a refined extract of Earth forged by Fire, so autumn is the season for extracting and refining essential lessons from the activities and experiences of summer, transforming them into the quiet wisdom of winter.

Like yin and yang, the Five elemental energies maintain their internal harmony through a system of mutual checks and balances known as 'creative' and 'control' cycles. Both these cycles, which counteract and balance one another, are in constant operation, maintaining the dynamic fields of polar forces required to move and transform energies. The creative cycle is one of generation, like the relationship between mother and child. Water generates Wood by nourishing its growth; Wood generates Fire by providing its fuel; Fire generates Earth by fertilizing it with ashes; Earth yields Metal by extraction and refinement; Metal becomes liquid like Water when it is melted.

Whenever a particular elemental energy grows too strong, it tends to exert an excessively stimulating influence over the following element in the creative cycle, like a domineering mother over a child, and at this point the element which controls the excessive energy kicks in to subjugate it and restore harmony. For example, if Wood flourishes to excess, providing so much fuel that Fire burns out of control, Metal steps in to cut down the supply of Wood and thereby reestablish normal balance. The creative and control cycles maintain constant harmony and balance among the Five elemental Energies.

An ancient Chinese adage says: 'A tree grows from the roots.' Yin and yang and the Five Elemental Energies form the main roots in the Taoist tree of health, and the entire edifice of traditional Chines medicine and physiology is based upon the foundation of these energy principles.

The Five Elemental Energies and their cycles provide a practical working model through which the interrelationships between the human body and the natural environment may be understood and controlled. They also illuminate the internal functional relationships between the body's various vital organs and explain how external elements such as foods and medicinal herbs influence the organs and their functions. All aspects of human health, including physiology and pathology, diagnosis and therapy, are rooted in this remarkably reliable system of polar forces and cyclic energy transformations.

The traditional Chinese view of human physiology differs significantly from the Western view in that the Chinese have always focused attention on the function rather than the form of the vital organs. The Western medical practice of studying human physiology based upon anatomical locations of various organs as revealed in dissected cadavers makes no sense to Chinese physicians, because cadavers have no living energy and their organs are not functional. How can a dead body reveal anything significant about the dynamics of living energy? Furthermore, in addition to their biological functions and anatomical locations, the Chinese concept of 'organs' also includes the specific type of energy that infuses each organ, as well as the energy meridians that channel organ energies to and from other parts of the body.

The second principle is that each of the six pairs of organs is governed by one of the Five Elemental Energies, with Fire controlling two pairs. The creative and control cycles of these energies orchestrate the functional relationships between the organs and determine how external environmental energies influence internal conditions. Internal conditions are in turn reflected externally by the color, tone, and texture of 'the five apertures and five tissues,' such as eyes and ears, skin and hair, which thus provide handy tools for diagnosing disease.

In the Chinese system, everything ultimately boils down to energy, a view which modern Western physics is beginning to verify. Therefore, the Chinese approach to human health and physiology accounts not only for the effects of obvious visible substances such as microbes and toxins, blood and bile, but also for the invisible and even more pervasive influences of emotions and energies that have a direct impact on the human energy system. As the energy therapist Dr. John Veltheim puts it: 'Science tells us that everything is energy and that matter is nothing more than energy in a different form.' The Five Elemental Energies and their cycles provide an intelligible formula for diagnosing and correcting the energy disorders that lie at the root of most human ailments, and for taking preventive measures to avoid such disruptions before they occur.

Since the Chinese view differs so significantly from the conventional Western view of human physiology, a brief review of each of the twelve vital organ systems and their functions according to traditional Chinese medical practice is in order here, so that Western readers may gain a proper working perspective on the subject. We'll run through the organs according to the Five Elemental Energies, first describing the associated 'solid' yin organs, then its 'hollow' yang partner.

The heart is called the 'King' of the organs. The Internal Medicine Classic states: 'The heart commands all of the organs and viscera, houses the spirit, and controls the emotions.' In Chinese, the word for 'heart' (hsin) is also used to denote 'mind'. When the heart is strong and steady, it controls the emotions; when it is weak and wavering, the emotions rebel and prey upon the heart/mind, which then loses its command over the body. Physiologically, the heart controls the circulation and distribution of blood, and therefore all the other organs depend upon it for sustenance. Thoughts and emotions influence the function of various organs via pulse and blood pressure, which are controlled by the heart, where emotions arise.

Internally, the heart is functionally associated with the thymus gland, which is located in the same cavity and forms a mainstay of the immune system. Extreme emotions such as grief and anger have an immediate suppressive effect on the immune system by inhibiting thymus function, a phenomenon that has long been observed but little understood in Western medicine.

Externally, the heart is related to the tongue, to which it is connected by the heart muscle. The color and texture of the tongue thus reflect the condition of the heart. Speech impediments such as stuttering and mutism are often caused by dysfunction or imbalance in heart energy. Facial complexion, which is a direct reflection of blood circulation, is also a major external indicator of heart function. Fire energy makes the heart the dominant organ of summer, during which season the heart must increase circulation to the surface in order to dissipate excess body heat.

Known as the 'Minister of Reception', the small intestine receives partially digested food from the stomach and further refines it, separating 'the pure from the impure', then assimilating the purified nutrients and moving the impure wastes onwards to the large intestine for elimination. Associated with the heart by Fire energy, the small intestine controls the more basic emotions, as reflected in the Chinese term duan chang ('broken intestines'), which is equivalent to the English term 'broken heart'. Its energy meridian runs into the head, where it influences the function of the pituitary gland, the 'master gland' whose secretions regulate growth, metabolism, immunity, sexuality, and the entire endocrine system.

The liver is called the 'General' or 'Chief of Staff' and is responsible for filtering, detoxifying, nourishing, replenishing, and storing blood. The liver stores large amounts of sugar in the form of glycogen, which it releases into the blood stream as glucose whenever the body requires extra infusions of metabolic energy. The liver receives all amino acids extracted from food by the small intestine and recombines them to synthesize the various forms of protein required for growth and repair of bodily tissues.

The liver controls the peripheral nervous system, which regulates muscular activity and tension. The inability to relax is often caused by liver dysfunction or imbalance in Wood energy. Liver energy also controls ligaments and tendons, which together with muscles regulate motor activity and determine physical coordination. Liver function is reflected externally in the condition of finger and toenails and by the eyes and vision. Blurry vision is often a result of liver malfunction rather than an eye problem, and even Western medicine recognizes the symptomatic yellow eyes of liver jaundice.

Through its association with Wood energy, the liver governs growth and development, drive and desires, ambitions and creativity. Obstruction of liver energy can cause intense feelings of frustration, rage, and anger, and these emotions in turn further disrupt liver energy and suppress liver function, in a vicious self-destructive cycle.

Known as the 'Honorable Minister', the gall bladder is in charge of the 'Central Clearing Department'. It secretes the pure and potent bile fluids required to digest and metabolize fats and oils, and its energy provides muscular strength and vitality. It works with the lymphatic system to clear toxic byproducts of metabolism from the muscular system, thereby eliminating muscular aches and fatigue. In the Chinese system, the common tension headache is caused by obstruction in the gallbladder meridian, which runs up over the shoulders and back of the neck to the top of the head and forehead. Hence such headaches are usually accompanied by neck and shoulder tension.

The gall bladder governs daring and decisiveness. In Chinese, the word for 'daring' is da dan ('big gall'). The English language also acknowledges this psychophysiologic relationship with the phrase 'a lot of gall'. An old Chinese adage states: 'The gall bladder is daring, the heart is careful', which reflects the stimulating generative influence of Wood to Fire.

In Chinese medicine, the function of the spleen organ-energy system includes the pancreas. Called the 'Minister of the Granary', the spleen and pancreas control extraction and assimilation of nutrients from food and fluids by providing the digestive enzymes and energy required by the stomach and small intestine. They regulate the quantity and quality of blood in circulation and coordinate with the kidneys to control fluid balance throughout the system. Spleen energy commands extraction of energy from stomach to lungs, where it is blended with energy from air to form True Human Energy. The spleen directly influences and is reflected by the tone and condition of muscle tissue. Weak limbs and muscular atrophy are indications of deficient spleen energy.

Spleen and pancreas condition is reflected externally by the color and tone of the lips: Reddish moist lips indicate strong spleen function; pale dry lips are a sign of weak spleen function. The mouth is the spleen's external aperture, and temperamental moodiness is its associated emotion. The Chinese term for 'bad temper' is 'bad spleen energy', a psychophysiologic association also reflected in the English term 'splenetic'.

The stomach is called the 'Minister of the Mill' and is also known as the 'Sea of Nourishment'. Because it is responsible for providing the entire system with postnatal energy from the digestion of food and fluids, it is regarded as the 'Root of Postnatal Life'. In addition to digesting bulk foods and fluids and moving them onwards to the small intestine for extraction and assimilation of nutrients, the stomach also extracts pure postnatal energy from foods and fluids, and in coordination with spleen energy it transports this food energy through the meridian system to the lungs, where it combines with air energy from breathing. This is a function of the stomach not acknowledged in Western medicine, which focuses only on the biochemistry of digestion and does not recognize the bioenergetic aspect.

Governed by pivotal Earth energy, the stomach is responsible for extracting and balancing all Five Elemental Energies from foods and fluids ingested through the mouth, which it shares with the spleen as its external aperture. Any dysfunction of the stomach results in an immediate deficiency or imbalance in the nourishing energy channeled from the stomach to other organs. "Pivotal" means center as the center is one of the 5 cardinal directions..

Known as the 'Prime Minister', the lungs control breath and energy and assist the 'King' heart with the circulation of blood. The Internal Medicine Classic states: 'Energy is the commander of blood; when energy moves, blood follows. Blood is the mother of energy; where blood goes, energy follows.' This intimate relationship between breath and pulse, blood and energy, is the basis of Chinese breathing exercises.

Breathing controls cellular respiration, and shallow irregular breathing is therefore a major cause of low vitality and insufficient metabolism. The lungs also control the skin, which 'breathes' via the opening and closing of pores and is responsible for adjusting body temperature through perspiration and shivering. The skin is where the radiant energy of resistance emanates, forming the first line of defense against noxious environmental energies such as heat and cold. Flu and the common cold are caused by impairment of radiant skin energy's capacity to resist external invasion, and symptoms of these diseases usually settle in the lungs and bronchial tract. Pallid skin and poor complexion are common indications of weak lungs. The nose is the external aperture of the lungs and the gate of breath. A clogged or runny nose is another indicator of ailing lungs.

Breathing directly controls the autonomous nervous system, and this relationship is the basis for almost every system of yoga and meditation. By regulating the autonomous nervous system and governing energy and pulse, breathing forms a direct bridge between body and mind and may be utilized to keep the two in balance.

The large intestine is called the 'Minister of Transportation'. It controls the transformation of digestive wastes from liquid to solid state and transports the solids onwards and outwards for excretion through the rectum. It plays a major role in the balance and purity of bodily fluids and assists the lungs in controlling the skin's pores and perspiration. Coupled with the lungs by Metal energy, the large intestine depends on the lungs for movement via the expansion and contraction of the diaphragm, which works like a pump to give impetus to peristalsis by regulating abdominal pressure. Thus sluggish bowels may be stimulated and constipation cured by deep diaphragmic breathing and by tonifying lung energy. Conversely, congested lungs and clogged bronchial passages may be cleared by purging the bowels.

Known as the 'Minister of Power', the kidney is regarded as the body's most important reservoir of essential energy. The original prenatal energy (yuan chee) which forms the basis of life is stored in the kidney organ-energy system, which is why the kidneys are also known as the 'Root of Life'. In the Chinese view, the kidney organ system also includes the adrenal glands, which consist of the adrenal medulla and the adrenal cortex. These glands sit like hats on top of the kidneys and secrete a wide range of essential hormones that regulate metabolism, excretion, immunity, sexual potency and fertility. Destruction of the adrenal cortex is fatal. The kidney system also includes what the Chinese call the 'external kidneys': The testicles in men and the ovaries in women. Thus the kidneys control sexual and reproductive functions and provide the body's prime source of sexual vitality, which the Chinese regard as a major indicator of health and immunity.

The kidneys themselves are responsible for filtering waste metabolites from the blood and moving them onwards to the bladder for excretion in urine. Along with the large intestine, the kidneys control the balance of fluids in the body. In addition, they regulate the body's acid-alkaine balance (pH) by selectively filtering out or retaining various minerals.

The kidneys control the growth and development of bones and nourish the marrow, which is the body's source of red and white blood cells. Weak kidney energy is therefore a prime cause of anemia and immune deficiency. The Chinese view the spinal cord and the brain as forms of marrow, and therefore poor memory, inability to think clearly, and backache are all regarded as indicators of impaired kidney function and deficient kidney energy.

Kidney vitality is reflected externally by the condition of head and body hair and is associated with the aperture of the ears. Tintinitus (ringing ears) is thus a sign of kidney dysfunction. The kidneys are the seat of courage and willpower, and therefore any impairment in kidney energy results in feelings of fear and paranoia. Intense fear can cause involuntary urination, a phenomenon also known to Western medicine.

The bladder is called the 'Minister of the Reservoir' and is responsible for storing and excreting the urinary waster fluids passed down from the kidneys. As an organ the bladder has only this function, but as an energy system the bladder is intimately related to the functions and balance of the autonomous nervous system. That's because the bladder energy meridian runs along the back of the body from head to heel, with two parallel branches flowing along each side of the spinal column. These four branches of the bladder meridian exert a direct influence on the sympathetic and parasympathetic trunks of the autonomous nervous system, whose condition of modern life, over activates the sympathetic system, causing tension and pain along the spine and its periphery. This tension and pain may be relieved by stimulating the flow of energy along the spinal branches of the bladder meridian. Such stimulation induces total relaxation by switching the autonomous nervous system over to the restful, restorative parasympathetic mode. Chinese massage therapy focuses primarily on these four spinal branches of the bladder meridian because of their direct influence over the autonomous nervous system, which regulates all the body's basic vital functions.

Known as the 'King's Bodyguard', the pericardium is the heart's protective sack. Although it is not recognized as an organ in Western physiology, it is regarded in Chinese medicine as a Fire-energy organ whose special function is to protect the heart. Not only does the pericardium provide the heart with physical protection, its energy also protects the heart from damage and disruption by excessive emotional energies generated by the other organs, such as anger from the liver, fear from the kidneys, and grief from the lungs. In the Chinese system of health, extreme outbursts of the Seven Emotions are regarded as powerful disruptors of internal energy balance and major causes of disease. Without the pericardium to protect it, the heart would be subject to injury from the radical fluctuations in energy caused by every emotional up and down of the day.

The pericardium also helps regulate circulation in the major blood vessels that run in and out of the heart. Emotionally, pericardium energy is related to the loving feelings associated with sex, thereby linking the physical and emotional aspects of sexual activity. It does this by moderating the raw sexual energy of the kidneys with the all embracing love generated by the heart.

This organ-energy system, which is not recognized in Western physiology, is called the 'Minister of Dykes and Dredges' and is responsible for the movement and transformation of various solids and fluids throughout the system, as well as for the production and circulation of nourishing energy (ying chee) and protective energy (wei chee). It is not a single self-contained organ, but rather a functional energy system involved in regulating the activities of other organs. It is composed of three parts, known as 'burners', each associated with one of the body's three main cavities: Thorax, abdomen, and pelvis. An ancient Chinese medical text states: 'The Upper Burner controls intake, the Middle Burner controls transformation, the Lower Burner controls elimination.'

The Upper Burner runs from the base of the tongue to the entrance to the stomach and controls the intake of air, food, and fluids. It harmonizes the functions of heart and lungs, governs respiration, and regulates the distribution of protective energy to the body's external surfaces.

The Middle Burner runs from the entrance to the stomach down to its exit at the pyloric valve and controls digestion by harmonizing the functions of stomach, spleen, and pancreas. It is responsible for extracting nourishing energy from food and fluids and distributing it via the meridian system to the lungs and other parts of the body.

The Lower Burner runs from the pyloric valve down to the anus and urinary tract and is responsible for separating the pure from the impure products of digestion, absorbing nutrients, and eliminating solid and liquid wastes. It harmonizes the functions of liver, kidney, bladder, and large and small intestines and also regulates sexual and reproductive functions. Some medical researchers believe that the Triple Burner is associated with the hypothalamus, the part of the brain which regulates appetite, digestion, fluid balance, body temperature, heartbeat, blood pressure, and other basic autonomous functions.

While each organ in the body has its own unique structure, anatomical location, and biological activity, it is their functional interaction as a complete organic system that counts in the Chinese system of health care. Harmony among the Five Elemental Energies of the organs and balance between their yin and yang aspects form the foundation for health and vitality, while functional disharmony and energy imbalance are the prime causes of disease and debility. Unlike modern Western medicine, which treats diseases of individual organs based upon isolated symptomatic disorders, Chinese diagnosis and therapy are based on the functional interrelationships between all the organs as a whole system, in which diseases are often traced to root causes far removed from where the obvious symptoms appear. Focusing on function rather than form requires a thorough understanding of how the human energy system operates, and this in turn enables the physician to track down root causes of disease and effect lasting cures, rather than simply providing symptomatic relief.

Just as each season and each organ is governed by one of the Five elemental Energies, so each medicinal herb in the Chinese pharmacopoeia is associated primarily with one of the Five Energies, and this association is indicated by the herbs' dominant flavor. The energy and flavor of the herb determine its 'natural affinity' (GUI jing) for the organ associated with the same energy, as well as its therapeutic effect on that organ, as follows:

The Five Flavors are also used in traditional Taoist 'Five Elements' cooking, which combines various foods and condiments according to the creative and control cycles of the Five Elemental Energies and their natural affinities with associated organs. Thus sour foods are prescribed for weak livers but proscribed for overactive livers, owing to their affinity for the Wood energy of the liver. Pungent Metal-energy foods stimulate the lungs and large intestine, salty Water-energy foods have a diuretic effect on the kidneys and bladder, and so forth.