This book is the first in the five-volume series entitled Practical Traditional Chinese Medicine and Pharmacology. It addresses, in plain and readable English, the concepts and interrelationship as well as clinical application of the basic philosophical elements of traditional Chinese medicine such as yin and yang and five elements. The author also explains physiology, pathology, etiology, diagnostic methodology, and syndrome differentiation as understood in traditional Chinese medicine through a discussion of the zang-fu (internal) organs and the channels and collaterals. Stress is placed on the importance of holistic treatment based on an accurate diagnosis. Thus the reader can learn the methods of understanding disease from the vantagepoint of traditional Chinese medicine and obtain knowledge of its basic theories.