Cosmology and metaphysics are presented most directly in the first chapter of To Become a Sage. T'oegye chose for the first chapter of his Ten Diagrams the work that became the cornerstone of this area of Neo-Confucian thought, Chou Tun-i's Diagram of the Supreme Ultimate. The chapter includes both the diagram and Chou's own explanation of the diagram, along with further comments by Chu Hsi and by T'oegye. The Commentary on the chapter expands this with discussion of basic aspects of the framework of this cosmological vision. Sections of the commentary include:
On On Beginning with the "Diagram of the Supreme Ultimate"
The Relationship of Principle and Material Force
Principle as the Ultimate of Non‑Being and the Supreme Ultimate
The Supreme Ultimate and Material Force
The One and the Many.
Neo-Confucianism has been described as an "anthropo-cosmic" vision. This means that fundamental elements of Neo-Confucian anthropology, including psychology, ethics, spiritual cultivation are grounded in the categories and structure of the cosmology. Thus the full meaning of the cosmology becomes clear only when all these other areas are considered as well. Psychology, dealing with the dynamic structure and function of the mind-and-heart, is a particularly critical juncture of the cosmic and human dimensions of this vision. On this, see especially Chapter Six and Chapter Seven.