Since physicians in later generations frequently applied the five-element theory in their TCM books, it may take some time to diminish its application. GONG Zi-zhen, a distinguished scholar and poet in the Qing dynasty wrote a book entitled Fei Wu Xing Chuan, Against Five-Element Transformation) and expressed a strong argument against its use.

Zang Xiang, Zang-fu and Six Zang and Six Fu
The Zang are internal organs. The Xiang are external manifestations. I agree with the idea of replacing Zang Xiang with Zang Fu. The five Zang (heart, liver, spleen, lung, and kidney) and six fu [gallbladder, stomach, small intestine, large intestine, urinary bladder and Sanjiao organs have been commonly recognized in TCM. My new understanding of the five Zang and six fu organs are as follows.

Nao, brain)
Although TCM has considered the functions of the brain ever since the time of Nei Jing, the brain is not included as one of the five Zang organs. However, the Su Wen-Wu Zang Bie Lun, Chapter 21 of the Plain Questions) mentioned the brain as an "extraordinary fu organ". I, therefore, conclude that the brain is a special Zang or Fu. Although there was not much elaboration on this "extraordinary Fu organ" in the same chapter, information is scattered in sections on the Zang organs such as the heart and liver. Consequently, I'd like to list the brain as one of the five Zang organs, making six Zang organs in total. I believe that this new idea will be accepted by TCM practitioners.

The same chapter listed the brain and marrow as the first two "extraordinary Fu organs". However, the Su Wen-Wu Zang Sheng Cheng Pia, Chapter 10 of the Plain Questions) states that "all types of marrow relate to the brain". The marrow here seems to refer to the "spinal cord", since the Ling Shu-Hai Lun, Chapter 33 of the Miraculous Pivot) states that "the brain is the sea of marrow" and the Su Wen-Mai Yao Jing Wei Lun, Chapter 17 of the Plain Questions) clearly states that "brain-head houses the spirit and intelligence", indicating that the brain-Zang includes the brain and spinal cord.

In my opinion, some functions of the "heart" are governed by the brain. For instance, the heart-dominating mental activities and the heart-governing intelligence should be brain functions instead. I also think that the "seven emotions" (joy, anger, worry, thinking, sadness, fear and fright) are dominated by the brain. The liver's function in dominating the emotions should be ascribed to the brain as well.

Xin, (heart)
As mentioned above, the functions of dominating mental activities and intelligence should be ascribed to the brain. Does that mean the "heart" is not as important as before? The answer is absolutely no. The key function of the heart is to dominate the blood and blood vessels. The Su Wen-Wu Zang Sheng Cheng Plan states that "all blood pertains to the heart". The Su Wen-Wei Lun, the chapter 44 of the Plain Questions) states that "the heart dominates the blood and blood vessels of the body", and "blood circulates within the vessel without a stop", which is considered as the earliest description of blood circulation when compared with similar descriptions in Western medicine.

Fei, lung)
The lung mainly dominates respiration. The Su Wen-Wu Zang Sheng Cheng Pian states that "all kinds of qi pertain to the lung". Inhaled qi is called "clear qi" (natural qi). The composition of air remained unknown until the discovery of modern chemistry. It is understandable that the ancient Chinese did not make it clear that oxygen is the most important element in the air for the human body. Since the lung inhales oxygen into the blood vessels to supply it to the brain through the heart, its value is self evident. In addition, discharging the "turbid qi" is equally important. The relevant organs of the lung include the mouth and the nose, both connecting the body through the trachea. Since the lung is located at the upper part of the body and susceptible to infection, it is also called a "tender organ".

Gan, liver)
The liver dominates the free flow of qi and regulates the blood. However, its traditional function of dominating the emotions is actually a function of thebrain.

Pi, spleen)
The spleen dominates digestion and is closely related to the stomach.

Shen, kidney)
The kidney is very important in the basic theory of TCM. The role of the kidney is very different from that understood by Western medicine.

Unlike the kidney in Western medicine, the kidney in TCM is more extensive. It is generally believed that many conditions are associated with the kidney, because it is responsible for human growth, development, reprodUction and for supplementing the yang. Some people even think that the kidney is also responsible for osteoporosis and allergic reactions. It is not easy to understand the kidney in TCM in a scientific way.

First of all, the kidney dominates reproduction. Although the two functions (ejaculation and urination) of male genitalia were not observed through dissection or autopsy during the eastern Han dynasty to the Song and Qing dynasties, female genitalia and the carrier (uterus) of conception were observed. Formerly, people believed that the kidney dominates reproduction. The reproductive function of the kidney is inherited from the "congenital essence" of one's parents, which can then produce embryos to keep certain characteristics of one's parents. In my opinion, this is exactly what "the kidney is the congenital base" really means.

Secondly, the kidney is responsible for urinary function, along with the function of the urinary bladder in storing and discharging urine.

If the kidney dominates urogenital functions, can we place the TCM kidney into genitourinary functions? The answer is not clear. Despite some research achievements in the study of the kidney in TCM, further investigation is needed.

Six Fu Organs
The functions of the six Fu organs are absorption of food and discharge of wastes. The first five Fu organs are all connected with these functions. Sanjiao is mainly concerned with the distribution of the Zang-fu organs all over the body. Some people think that the concept of Sanjiao is not clear. Some think that Sanjiao generalizes the functional systems of the Zang-fu organs. Personally, I think that we can either keep it or reject it, or keep it temporarily.

Diagnostic Methods of Diseases
There are four diagnostic methods in TCM, namely inspection, auscultation and olfaction, inquiry and pulse-taking. Just as stethoscopes, sphygmomanometers and thermometers are frequently used in Western medicine, I think that these four diagnostic methods can be used in both TCM and Western medicine. As biochemical assays, ECG, X-rays, CT and MRI are all part of this methodology, they can also be used in both TCM and Western medicine. The real purpose is to diagnose, prevent and treat any potential disorders rapidly and accurately. Further investigations are needed on more issues of TCM basic theory.

INVESTIGATION OF THE BASIC THEORY OF CHINESE HERBS
Along with the basic theory of TCM, a treatment theory has developed as well. The earliest treatment was acupuncture, and shortly after, Chinese herbal therapy. The earliest existing medicinal book is Wu Shi Er Bing Fang, Prescriptions for Fifty-two Types of Diseases) unearthed in Han tomb number 3 in Changsha Mawangdui (tomb of the son of Li Cang of the western Han dynasty, buried in 168 BC, or the 12th year of Han Wen Di). Written in the calligraphy of Qin Xiao Zhuan on silk, the book listed fifty-two types of diseases with several formulas for each disease, but it did not mention any theory on Chinese herbs.

The basic theory on Chinese herbs was first recorded in the Nei Jing, but in a very simple way. Complete discussions were not recorded until the completion of the Shen Nong Ben Cao Jing at the end of eastern Han dynasty. Since the original copy had been lost, TAO Hong-jing in the Liang dynasty compiled the Ben Cao Jing Ji Zhu along with the Ming Yi Bie Lu, Extra Records of Distinguished Physicians). However, this book became very rare in the Song dynasty. Fortunately, the government in the Song dynasty recompiled this book as the Zheng Lei Ben Cao. The three generations of emperors in the Song dynasty (SONG Tai zu, SONG Hui zong and SONG Gao zong) valued medicine. Without their efforts, we would not have the Shen Nong Ben Cao Jing and the Zheng Lei Ben Cao today. The Ben Cao Gang Mu by LI Shi-zhen in the Ming dynasty provided the most systematic descriptions of the theory of Chinese herbs. The investigation of the basic theory of Chinese herbs is therefore based on this book.

This article discusses only the core theory. The theory on the nature of herbs includes the four qi, the five tastes, characteristics and meridian-tropism, and the absence or presence of toxic substances. The theory on the composition of the herbs includes the coordination of the seven effects in compatibility with the monarch, minister, assistant and guide.

The four qi include cold, hot, warm and cool. The five tastes include sour, salty, sweet, bitter and acrid. The characteristics and meridian-tropism indicate specific Zang-fu organs. Although this generalization in ancient times was good enough, it needs to keep pace with the times. The structure of chemical compositions of many herbs is clear, although certain types of herbs may be bitter at first and may turnsweet following changes of a certain group or even with a three-dimensional position change of the same group. These observations belong to my scope of expertise and of other pharmaceutical chemists, and please forgive me for not giving detailed discussion in this regard. When it comes to meridian-tropism, the Pharmacopoeia of the People's Republic of China says that one herb can enter two or three meridians.

The characteristics and meridian-tropism of herbs also needs to keep pace with the times. LI Shi-zhen also thought that the "four qi and five tastes" should be modified, but "it's too difficult to change". The absence or presence of toxic substances is important to medicinal herbs. The best-quality medicinal herbs are usually nontoxic. The medicinals that can strengthen the body constitutions are considered good ones. However, the medicinals with a little bit of toxicity may be helpful to the treatment of diseases. The medicinals having risks outweighing benefits are not advised to be used. One of the arguments of Chinese herbal theory is to add some detoxifying herbs when using toxic ones. In addition, scientific preparations may also act to reduce the  toxic effects.

The coordination of the seven effects in compatibility should be taken as the first priority in the theory on the composition of herbs. The seven effects include using alone, mutually reinforcing, assisting, incompatibility, inhibition, detoxifying and antagonism. In recent years, some scholars listed contraindications of the eighteen compatible medicaments. A single herb formula was also recorded in the Shang Han Za Bing Lun, Treatise on Febrile and Miscellaneous Diseases), which was completed not long after the Shen Nong Ben Cao Jing. The "coordination of seven effects in compatibility" should also keep pace with the times.

A single-herb formula should always be advocated. A compound formula is much more
difficult. A compound formula may only contain two herbs. Some formulas in the Shang Han Za Bing Lun only contain two or three herbs. Generally, a compound formula consists of the monarch, minister, assistant and guide, or one monarch medicinal, two minister medicinals, three assistant ones and four guiding ones or one monarch medicinal, three minister ones and nine assistants or guiding ones. The big compound formulas in recent years even contain twenty medicinals or more, sometimes up to seventy. As a result, even those who made the prescriptions cannot tell which one is the monarch, which one is the minister and which ones are just assistants. Actually, there are many compound formulas in Western medicine. In summary, we need to investigate whether it is really necessary to decide or classify the monarch, minister, assistant and guide. Antagonism and synergism are very similar to the"coordination in compatibility" in TCM. I do not mean to accommodate TCM to Western medicine, but I do mean to emphasize the characteristics of TCM theory.Since I'm not an expert in TCM, for possible errors, any suggestions or comments are welcome.

Acknowledgements
The author thanks Professor HAN Chou-ping, College of International Education, Shanghai University of Traditional Chinese Medicine for the earlier English translation of this paper and Professor Karl W.K. Tsim of the Hong Kong University of Science and Technology for the lingual revision of this paper.                        
                                                    (Received October 30, 2008)
                                                              Edited by TAO Bo