Essence of the Taoist Canon

Each [element] resides in its own direction, but only Earth occupies the center. It distributes its flourishing power through the periods of Chen, Xu, Chou, and Wei The four "Earth" branches of the zodiac—Dragon, Dog, Ox, and Goat—which represent the transition periods at the end of each season., weaving together the beginning and the end of the year. Therefore, Wood relies on Earth to flourish, Fire relies on it to rest, Metal relies on it for birth, and Water relies on it for its foundation. These four elements all receive their efficacy from the power of Earth.

Yet this "Earth" permeates the entire universe; it has no single fixed location. Within the Kan (Water) trigram, it manifests as Wu Earth; within the Li (Fire) trigram, it manifests as Ji Earth. In the Central Palace, it is the combined Wu-Ji Earth, and within the four seasons, it is the Earth of the four branches. All of these are essentially the same substance.

How profound indeed! The poems of the Wuzhen Pian The "Chapters on Understanding Reality," a seminal 11th-century alchemical text by Zhang Boduan. state:

The text further says:

Without the harmonizing influence of True Earth, Yin and Yang would be blocked and separated (Pi) Referring to Hexagram 12, "Stagnation," where heaven and earth do not communicate., and Hard and Soft would be pulled apart, making it impossible to form the Elixir.

Alas! Lord Wei Wei Boyang composed this book to reveal the mysteries of this Way. His words are nothing other than a record of verified results and personal attainments. Fearing that his teachings might not gain the trust of later generations, he measured the divine brilliance of the Sun and Moon to establish his method and traced the principles of the I Ching hexagrams to provide proof. His presentation is both profound and luminously clear. How could he have fabricated baseless claims or given birth to useless theories merely to deceive and mislead those who come after?

Alchemical Cosmology Diagram

The diagram illustrates the "Twelve Earthly Branches" around the perimeter, showing the movement of time. At the core, the union of Sun (Li) and Moon (Kan) occurs within the axis of Heaven (Qian) and Earth (Kun), mediated by the Central Earth.