Book of Secret Correspondence

　　The full name of Yinfu Jing (Book of Secret Correspondence) is Huangdi Yinfu Jing (Yellow Emperor's Book of Secret Correspondence). It has altogether more than 300 Chinese characters. There has long been controversy about its author and the year it was written. It is said that Yinfu Jing was discovered by Li Quan, a famous Taoist of the Tang Dynasty (618-907) on Shaoshi Hukou cliff of Songshan Mountain in today's Henan Province, and then copies were made by writing and handed down to later generations.

　　According to Li Quan's explanation book Huangdi Yinfujing Shu (Explanation of Yellow Emperor's Book of Secret Correspondence), its contents can be concluded into two parts:

　　(1) First, it describes the observation of the nature and the objective laws of its developments and changes. So the movement of celestial bodies is the order of the nature, and the will of human beings must be consistent with the order of the nature. Second, the canon explains the changes of the heaven, the earth, people's life and death. In order to grasp the opportunity of success, a person should act in accordance with the nature. The canon thereafter describes the formation of natural disposition (acquired after birth) and the clever or clumsy quality of a person. It also explains the correct usage of ears, eyes and mouth, which follows the inter-promoting relation in the five elements to cultivate oneself.

　　(2) It first illustrates that achievements can be acquired as long as one person is devoted to something wholeheartedly, then emphasizes that it is necessary to master these subtle natural order of the nature according to circumstances.