"Yi Xue" is an important work on Xiangshu Yi Xue in the Song Dynasty. It was a careful work by Wang Shi, a Neo-Confucian scholar in the Southern Song Dynasty. This book is based on the classics of "The Book of Changes" and combined with the Neo-Confucianism of Cheng and Zhu to systematically expound the principles of yin and yang changes, with special emphasis on the combination of hexagram deduction and meaning explanation. Wang Shi emphasized that "the Yi Dao is vast and all-encompassing" and advocated observing the relationship between heaven and man through the changes in hexagrams and lines, which provided a unique image-numerical analysis framework for later generations to study "The Book of Changes". The book's annotations on the "Xici" and "Shuo Gua" and other biographies demonstrate the academic characteristics of the Song Dynasty's "Yi Xue".
