"Volume II, The Great Treatise" is a series of essays dating from 300 BCE that explain the view, principles, and practices associated with the Yijing.

Readers of "The Great Treatise" will find a structured, rigorous, and thorough presentation of the elements needed to fully appreciate the genius of the Yijing. "The Great Treatise" provides clear instruction on many levels: it presents the spiritual and philosophical principles that generate the ontological processes, hierarchy, culture, and ethics of the Yijing. It carefully defines key terms and explains the functions of the various parts of the hexagram texts. It correlates these terms, the text, and the technique of divination to how the manifest world and human society emerge from the primordial realms of Heaven and Earth, and the Dao.

It provides examples of how to interpret and apply the text to the challenges faced by leaders. It recounts how the hexagram images functioned as archetypes that the Ancestral Sovereigns used to invent the tools that made human civilization possible. It outlines a vision of human society in harmony with Heaven, Earth, and natural ecology, and that supports the lives and spiritual paths of humanity.

Overall, it provides virtuous readers the tools and understanding they need to receive "Heavenly assistance" from the text of the Yijing. In this way it offers profound training for leaders who must meet the challenges of the modern world.

The text of the Yijing assumes a sophisticated reader already conversant with the contents of a text like the "Great Treatise." Without the benefit of a guide like "The Great Treatise," readers struggle to grasp the Yijing's overarching principles, although these principles' footprints are found everywhere in the rich landscape of the 64 hexagrams.