《易說》Vol. 3

This is the table of contents for the Daoist classic Yi Shuo (Discourse on the Changes), authored by the venerated Sovereign Fu You (one of the Eight Immortals, Lü Dongbin, known by his Daoist name Chunyangzi). The entire work elucidates the profound philosophy of the Yijing (Book of Changes) through diagrammatic explanations, primarily containing the following content:

The opening section presents the two ancient mystical diagrams—the Hetu (River Chart, said to be borne by the dragon-horse from the Yellow River) and the Luoshu (Luo Writing, carried by the divine turtle from the Luo River). It then systematically analyzes the evolutionary process from the origin of the cosmos to the generation of all things: the Xiantian Hunji Tu (Diagram of Primordial Undivided Unity, the state before cosmic differentiation), Yuanji Tu (Diagram of Primordial Qi), Lingji Tu (Diagram of Spiritual Awakening), and Taiji Tu (Diagram of the Supreme Ultimate, depicting the division of Yin-Yang).

The middle section provides detailed diagrams of core Yijing concepts: the dynamic and static principles of the Zhongji (Central Equilibrium, the balancing point of Yin-Yang), the transformative logic of Shaoji (Lesser Yang and Lesser Yin), the essence of Taiyang (Great Yang) and Taiyin (Great Yin), and the relationship of the Sancai (Three Powers: Heaven, Earth, and Humanity). It particularly correlates the Xiantian Bagua (Fu Xi’s Eight Trigrams) with the numerology of the Luoshu, and the Houtian Bagua (King Wen’s Eight Trigrams) with the Hetu’s mathematical principles.

The latter part delves into the characteristics of Yin-Yang odd and even numbers, the process by which the Liangyi (Two Modes) generate the Sixiang (Four Symbols: Lesser Yang, Greater Yang, Lesser Yin, Greater Yin), which then evolve into the Eight Trigrams, as well as the cosmic mechanism of Qiankun (Heaven and Earth) opening and closing. Finally, it elaborates on the legendary accounts of Fu Xi creating the Yijing based on the Hetu and Yu the Great composing the Hongfan (Great Plan) according to the Luoshu. The work concludes with practical systems such as the circular and square arrangements of the sixty-four hexagrams, the interaction of Gangrou (firm and yielding, representing Yin-Yang dynamics), their correspondence with solar terms, and the relationship between Lülü (musical pitch) and the waxing and waning of Yin-Yang.