Today we have the accumulated and preserved knowledge of our ancestors as passed down through the ages to mull over. The origins of that knowledge are sometimes incomplete and sometimes are lost. The recorded, translated and preserved information we may think about and use for the purposes of education, research and practical application.

In Western science, a unified field theory is provided by the German professor Burkhard Heim (2). Contemporary science now describes the laws that show that matter and energy are the same things in different forms. This is not much different than the ancient Chinese concept of Qi. In any case, it must be remembered that theory and practice are, most of the time, two different things entirely.

Thus, from a Western view, the concept of qi may be thought to be a unified concept of matter and energy. Essential substances are material while functional activity is a manifestation of the directed use of the various forms of energy. What is described as the sum of human knowledge concerning matter and energy at the present time is more dialectic than the ancient Chinese concept of qi.

The Chinese character for "qi" is the same word that is used for air or gas, and it is thought to have the same properties as these substances. Qi may also be interpreted as the "life energy" or "life force," which flows within us. Sometimes, it is known as the "vital energy" of the body. Qi, Blood and Body Fluid are stated to be fundamental substances that maintain the vital activities of the human body. They are the material foundation for the physiological functions of the zang-fu organs, tissues and meridians.

What are the essential substances of the human body as stated by TCM?

1. Congenital essence - essence acquired from the parents and inherited
2. Acquired essence - essence derived from food and air

According to Wikipedia (3), essence is the attribute (or set of attributes) that makes an object or substance what it fundamentally is. Again, the emphasis is on the material. So, it appears that we have a fuzzy concept that may need clarification and elucidation. Qi is both material and energy according to TCM. So just what essential substances move and change in the human body? They are qi, blood and body fliud.

• QI

  TCM differentiates qualitative aspects of qi within the human body according to the source, function and distribution of qi (4). The terms utilized are Primary Qi, Pectoral Qi, Nutrient Qi and Defensive Qi. According to the source of the qi, they may be further classified into Congenital Qi and Acquired Qi. Primary Qi is derived from congenital essence (QE) and inherited from the parents; it is referred to as Congenital Qi. After birth, Pectoral Qi, Nutrient Qi and Defensive Qi are all derived from food essence and are therefore known as Acquired Qi.

  What may we say about Primary Qi? It is derived from the congenital essence, takes root in the Kidney and needs to be supplemented and nourished by the qi obtained from food essence, after birth. It stimulates and promotes the functional activities of the zang-fu organs and associated tissues.

  What may we say about Pectoral Qi? It is formed from a combination of Clean Qi that is inhaled by the Lungs and the qi of food essence. It is stored in the chest and has 2 main functions, to promote the lung's function of controlling respiration and to promote the heart's function of dominating the blood and blood vessels.

  What may we say about Nutrient Qi? It is derived from the qi of food essence that is produced by the Spleen and Stomach. It circulates in the vessels. Its primary function is to produce blood and to circulate with it.

  What may we say about Defensive Qi? It is derived from the qi of food essence. It circulates outside of the blood vessels. It functions to principally protect the body against external pathogenic factors but also to control the opening and closing of the pores to readjust body temperature, to moisten the skin and hair and to warm up the zang-fu organs.

  What may we say about Clear Qi? It is derived from the air. The lungs inhale Clear Qi and exhale Waste Qi. By inference then, Clear Qi may be oxygen and Waste Qi may be carbon dioxide.

  What may we say about Vital Qi? It is formed by a combination of the Qi of food essence, Clean Qi and Essential Qi stored in the Kidney. It is the qi of the meridians and the zang-fu organs.

  The TCM stated functions of qi are to promote, to warm, to defend, to regulate, to nourish and to be active. Here again, the concept is fuzzy due to overlap between form, function and energy flow.

  There will be a digression at this point to explain some concepts of contemporary human physiology that have relevance to the discussion of Qi. At first there will be a series of statements to remind the reader of certain general concepts. Then, an explanation will follow. The interaction of matter with other matter is by means of energy described loosely as "light". Energy may be dissipated through matter that arranges the matter into a lesser overall energetic state, as the most stable form of the matter undergoing interaction. Both organic and inorganic systems are subject to the same laws of physics. However, organic systems have special properties not available to inorganic systems. Energy may be temporarily captured and stored as high-energy chemical bonds in organic systems but not with inorganic systems.

  The disciplines of biophysics, biochemistry and biology detail the concepts of the acquisition of food, its transformation into substances that the metabolism of the body uses for performing work and the elimination of waste products. It also details the use of gaseous oxygen for controlled burning within the body and the elimination of carbon dioxide as a waste product or the basis for the bicarbonate buffer system of the body fluids. In any case, what technology is able to measure is the transition of energy through all its states from high-energy chemical bonds into waste heat and more stable matter end products. All life on this Earth is dependent upon plant life for the production of high-energy chemical bonds as carbohydrates. All animal life burns these carbohydrate metastable high-energy biochemical bonds into low-energy stable carbon dioxide and water with a release of waste heat.

  So what conjectures may we make as to the TCM concepts of physiology in reference to the above information as regards to qi? Primary Qi may be likened to the neuroendocrine-adrenal gland system. Pectoral Qi may be likened to the respiratory function of the lungs. Nutrient Qi is the oxygen, sugars, proteins and lipids in the blood. Defensive Qi is the immune system and neuroendocrine system and their products. Congenital Qi is the inherited genetic system of the body as well as the bioscalar (7) energy imparted to the fertilized egg at conception. Acquired Qi is the energy derived from food by the metabolism of the body ultimately in the form of adenosine-tri-phosphate (ATP). Vital Qi is both the energy derived from high-energy biochemical bonds and the potential of all of the systems of the body to respond to change, i.e., rheostasis. This leaves the qi associated with the meridians to be discussed lastly as concepts concerning channel qi is rather difficult to explain and understand.

  The Qi associated with the meridians is imbued in the original egg that will make up the new individual. For a complete description of the origin of the meridian Qi, go to this reference (8). This is the basis of the statement that all life comes from pre-existing life. One possible route for means of travel is through the extracellular matrix of fascia and other connective tissues.

  The energies as described by masters of Qi Gong cannot be measured and followed by contemporary technical methods. Even in this context, the idea of Qi is a construct devised in order to explain what is experienced. The closest Western concept that equates with the TCM concept of Qi is that of bioscalar energy (9). In either case, information concerning vital energies is not well categorized due to the lack of technological capability to measure these energies.

• BLOOD

  The propelling force of Heart Qi is the basis of blood circulation while the Spleen Qi controls blood and prevents its extravasation (10). Blood is otherwise described as yin. In Western physiology, the heart system does not have a function independent of its component parts. The nervous elements control the heartbeat and the muscles utilize the energy derived from metabolism. The same is true of the Spleen; it houses the hemopoeitic system and utilizes energy derived from metabolism. Control of both systems is through the neuro-endocrine system via the autonomic nervous system and endocrine system and not some vital force.

• BODY FLUID

  The Qi of water is alluded to but not explained in the primary academic text of TCM (11). Body Fluid is described as yin. Water is a molecular substance that is able to arrange itself in order to retain information (12). Water has no intrinsic energy other than that contained in the bonds holding the molecules of oxygen and hydrogen together.

• YIN - YANG THEORY

  How does the above integrate with the TCM concepts of Yin-Yang? Yin and Yang (13) are stated to reflect the all the forms and characterisitcs existing in the universe. The theory of Yin-Yang does not itself refer to any concrete objective phenomena. It is, rather, a theoretical method for observing and analysing phenomena, a philosophical conceptualization. The application of Yin-Yang theory to the treatment of patients in TCM is basically a guide to diagnosis (14). Since the concept of Yin-Yang refers to a sliding scale between the two dicotomies, no actual component of the human body (whether it be energy or substance) exists as yin or yang in and of itself. In the experience of the author, this fact is seemingly forgotten by those practicing TCM. Even the primary text describes Qi as yang and Blood as yin and not as of a yin or yang like nature. A subtle distinction perhaps but extremely important in context.