III. Five-Phase Concept is the direct basis for determining five animals and its movements.

“The law of five phases and the opposition of yin and yang decide all relations, movements and transformations of everything in the world.” Due to the driving efforts by the yin-yang school, Five-Phase Concept as a world outlook achieved rapid development, and became a dominant mode of world recognition in the Han dynasty. It can be said that, Hua Tuo managed to surpass the previous life nurturing masters and created a complete and systematic method of conduction and body building, it was inseparable from the “Five-Phase mode of world cognition”.

(I) Taking five as the total number of items is enlightened by the Five-Phase theory.

Before Hua Tuo, there was no fixed number. For instance, Zhuangzi · Ingrained Ideas mentioned only two items, namely "bear hanging” and “bird stretching”; Huainanzi · Seminal Breath and Spirit mentioned six items, namely "bear hanging”, “bird stretching”, "wild duck bathing”, “monkey pawing”, "strigidae glaring” and “tiger looking backward”.

According to the deduction on the basis of the age when the “two items” in Zhuangzi · Ingrained Ideas were produced, the “two items” should be a product of yin-yang thinking. In other words, bear is on the earth and stands for Yin, while bird is in the sky and stands for Yang; "bear hanging" is conducted in front of the abdomen and so it stands for Yin, while "bird stretching” is conducted behind the back and so it stands for Yang; bear represents walking beasts, while bird represents flying birds. By analogy, "six items", "eight items" and "five items" should also be in consistency with ancient diversified cognitive schemata. However, the yin-yang and five-phase theory as the explanatory mode for explaining everything in the world was finally fixed and inherited in medicine science, but has disappeared gradually in other fields. The reason is that yin-yang and five-phase theory more correctly explained those physiological and pathological phenomena. On the contrary, "six qi" and "Eight Diagrams" failed to be inherited in medical field, because they have no higher rationality than the yin-yang and five-phase theory upon explaining physiological and pathological phenomena. Therefore, Hua Tuo created and designed Wu Qin Xi by taking five as the total number of items, which should result from his enlightenment from the five-phase theory, and should be a specific application of the mode of five-phase theory.

(II) Five animals were selected according to the corresponding relationship between the physical features of five kinds of animals and the five internal organs (heart, liver, spleen, lungs and kidneys) of human beings.

As aforementioned, Hua Tuo realized that: exercise could reach both the internal and the external; “wavering” of human body could enable the “grain qi in zang-fu organs to disappear”, and promote “qi-blood circulation in blood vessels, hence prevent arising of diseases”. Therefore, when he selected the five kinds of animals, he should proceed from analyzing the featurs of postures and movements of animals, and then pertinently selected the animals with special significance and its characteristic movements as the objects of imitation, which was a specific embodiment of the thinking mode of “Analogizing from the Similarity of the Appearances” in ancient Chinese culture.

Upon making selection, it also related to ancient people’s dialectical thinking on "conformity” and “inversion". “Conformity”, refers to conforming to the way of nature; “inversion”, refers to inverting the humanizing trend of human beings themselves and returning to nature. Specifically for human body building exercise, “conformity” should refer to conforming to physiological rule of human body, whereas human physiological rule should be in consistency with that of animals, which we also call “instinct”; “inversion” should refer to strenthening human's abilities which are not often applied in daily life but are necessary to health and longevity, whereas such abilities can be learned and acquired from animals. Therefore, as Hua Tuo selected such five animals as tiger, deer, bear, monkey and bird, his selection should be based on the following consideration:

First, he was enlightened by some biomimetic exercise methods already existing at that time. The most direct ones should be the six animals mentioned in Huainanzi. Through comparison of the five animals (namely tiger, deer, bear, monkey and bird) selected by Hua Tuo and the six animals (namely bear, bird, wild duck, monkey, strigidae and tiger) in Huainanzi, we can find that two animals “wild duck” and “strigidae” are not included in the five animals selected by Hua Tuo, and both these two animals belong to the “category of birds”, so we could guess that Hua Tuo might merge them into one category of “bird”, however, he added another animal “deer”. Thus, each animal represents one category. Such selection results from the fact that Hua Tuo saw the special values for body building which different animals have.

（By Wang Jinghao）