It is worth noting that the I Ching, which originated during the Shang and Zhou periods, recognized earlier that the world develops through the interaction of the two forces of yin and yang, and contains a reasonable core of simple dialectics. Philosophers of the time used it to explain changes in nature, for example, in 780 B.C., Bo Yang Fu used the phrase "Yang can't come out of its ambush, and Yin can't evaporate" to explain why earthquakes occur; in 654 B.C., Shuxing used the phrase "the matter of yin and yang" to explain the meteorite within the territory of the State of Song, and in the same period, the five elements of the I Ching were used to explain the development of the world. Coupled with the emergence of the doctrine of the five elements in this period, progressive medical doctors in the long-term accumulation of medical knowledge on the basis of yin and yang and five elements to elucidate the physiological and pathological mechanisms of the human body, such as the medical and the proposed "six qi disease," to yin, yang, wind, rain, obscurity, Ming out of order to explain the causes of disease, marking the budding of the theory of simple medicine.