This article explores the TCM essence by extensive comparative study of eastern-western philosophy,science and technology history,medical science and so on,making deep-going comparative study on systems of TCM and western medicine by ontology and methodology.It shows that observation and classifi cation plays an important role in western medicine,and western medicine is an experience science that emphasizes on life regularity from the aspect of texture-function of human body.But in TCM,it is observation and mode reasoning plays an important role,and TCM is a theoretic science emphasizing on phenomenon-state of human body.

Determinacy is the aim that human search during the course ofrecognition.But with the development ofscience, human discover that indeterminacy is the essence ofthe world.The contingency and randomness ofbiomutation indicate that there are many indeterminacy during the course oflife movement and changes ofdiseases.In ancient, the Chinese people grasped the movement and change rules ofobjective objects by mode reasoning under the condition ofindeterminacy and diversity.They applied the mode reasoning into TCM to study the multivariate life state ofhuman body, and to grasp the movement and change rules oflife and diseases.

How did Inner Canon of Huangdi(Huangdi Nei Jing) get the numerous thinking quintessences of Dao,Fa,Ru,Mo,Ming,Yin-yang,Nong and Bing etc to establish the TCM theory system? In the middle and end stages of the Warring States Period,the Ji Town School established by government official of Qi state marshaled numerous schools of Dao,Fa,Ru,Mo,Ming,Yin-yang,Nong and Bing etc,developed face to face academic communication,a hundred schools of thought contend,brought about the naissance of Huang Lao Neodoxy,which adopted the numerous thinking quintessence.It established the integration view of "heaven,earth and human",developed the thought style of understanding human rules according to the order of nature,and influenced numerous thoughts at that time and settled as the tradition thought style of the Chinese nation.Huangdi(Huangdi Nei Jing) brought the integration view of "heaven,earth and human" into the theory framework,to draw the the thought style of understanding human rules according to the order of nature,found the academic essence of TCM.

By studying Chinese medicine with judgement standard of scientific discipline of scientific epistemology, it is found that Chinese medicine takes physiological and pathological phenomenon as well as the life state reflected by them during the process of life activities of human body as research object. The method of speculating the interior change from the exterior manifestations is adopted. The discipline has a team of professional scientists that have clear research direction, academic institution, publications, and educational facilities. Chinese medicine is different from western medicine that takes structure and tissues of human body and their functions as study object, as well as adopts anatomical and experimental methods. Chinese medicine and western medicine are two branches of medical science. So, Chinese medicine should ascertain its nature as “Phenomenon-State Medicine”, and foot “Phenomenon-State Medicine” in medical science as a discipline, set up rational faith scientifically and further develop Chinese medicine according to the intrinsic law of “Phenomenon-State Medicine”.

What kind of science is TCM? How to develop TCM that consistent with its inherent rule? To solve this problem,we should establish dimension research area of TCM,set up science of "theory study of TCM",evolve dimension research of TCM.We can gather a body of scholars of TCM that not only master TCM theory but also possess knowledge structure in terms of philosophy,logic,science philosophy and science epistemology et al,formation academic society,carry out research,discussion and argument.So to make clear that what kind of science is TCM,what are its theoretical structure,essential characteristic and developing rule,which aspect of biotic phenomenon,research method and thought does it study.In that way to recognize investigative aim of TCM science,establish rationality belief of science community of TCM,so as to accelerate us to choice TCM research thought that accord with its own inherent rule,advance clinical therapeutic effect and develop foundational theory of TCM.

The thought of "verification" in Inner Canon of Huangdi includes "verifying through comparison" and "verifying through result",which ensures the truth of medical experience,theoretical results and recognition of Chinese medicine.Therefore,"verification" is a important concept and category of verifying criterion of truth in theoretical system of TCM.

Traditional Chinese medicine is not much of a experience fact delineation and record on human body vital movement,disease process and disease therapeutics,but a theory explanation on experience fact though making observed medical phenomenon come down to general law and principle;a dialectic-analogy logic system formed by applying logical thinking law of Chinese people to tidy up medical experience knowledge;a theory medical science formed by a concept-category system organized by a series of different decks of theory categories,which has highly self-support nature in interior of theory whole and logic consistency between propositions.

Views of "Integrated whole of heaven,earth and man","Derive the theory of the human body from natural environment" and "Xing-ming Ying-yin" combined with medical practice were origins of traditional Chinese medicine theory.On the premise of ensuring internal coordination of the whole theory in accordance with the logic of proposition,physicians kept on enriching connotation,validating hypothesis and using the theories in practice,made traditional Chinese medicine theory has scientific conformation of medical model of "environment-body and spirit",logic system of "dialectical-analogize" and subject character of "manifestation-state ".

Qi was a basic concept of material existence in Chinese ancient philosophy.Qi was the flowing and microscopic existence in pre-qin dynasty,which was different from liquid and solid.Qi was the important conception of the flowing and microscopic existence in Inner Canon of Huangdi,which constructed the medical theory and explained the nature,human body,physiology and pathology.Thus,it made the TCM theory belong to materialistic epistemology.Qi explained the existence of life material which could not be cognized at that time,this made TCM theory do not need to study what material was,but to study what the changes of material were,then promoted the progress of medical science.

Yin-yang in ancient Chinese philosophy originally meant two kinds of qi,yin was cold and yang was warm.Its extended meaning originated from Yizhuan was two aspects opposite to each other during the whole world.In Inner Canon of Huangdi, the category of yin-yang was more than generalization of the law of the unity of opposites in nature,the basic principles of yin-yang were further revealed,which was the major content of the yin-yang theory of TCM.Thinking pattern of physicians through the ages had been effected by the yin-yang theory for more than two thousand years,which made TCM theory has a dialectical thinking mode.Therefore,a theoretical system of medicine with the property of dialectical logic was set up.