Celestial Principles Explored 天原发微

Authored by Bao Yunlong in the early Yuan Dynasty and revised by Fang Hui, this work was completed during the Yuanzhen reign period (1295–1296).

The version included in The Daozang has eighteen volumes and is classified under the Taiqing Section. There is also another version incorporated in the Siku Quanshu (Complete Library of the Four Treasuries).

This book expounds on astronomical phenomena and numerical principles. The author argued that since the Qin and Han dynasties, scholars who discoursed on heaven had either been constrained by divination techniques or fallen into emptiness, thus leaving the underlying relationship between heaven and humanity obscure and unclear. Therefore, based on The Great Commentary on the Zhouyi, he conducted extensive research and thorough investigation to compile this work. Divided into twenty-five chapters, the book discusses the substance and function of the Taiji, annual cycles, the beginning and end of all things, movement and stillness, yin and yang, the sun, the moon and stars, the twelve celestial divisions, the seventy-two pentads, the intercalation method, the Hetu (Yellow River Diagram) and Luoshu (Luo River Writing), the innate and acquired principles, leftward and rightward rotations, the origin of numbers, ghosts and spirits, transformation, and other topics. Each chapter first cites the theories of Song-dynasty Confucian scholars such as Zhou Dunyi, Shao Yong, the Cheng brothers, Zhang Zai, Zhu Xi and Cai Yuanding, followed by the author’s own insights. Rooted in the principles of the image-number Taoism-influenced Zhouyi studies, its core tenet is to elaborate on the Neo-Confucianism of the Chengs and Zhu Xi, with its ultimate tenet tracing back to Zhu Xi’s doctrine of reverence—a theoretical system closely associated with the five elements theory in traditional Chinese philosophy.