The Tanzi Huashu 谭子化书 Master Tan's Book of Transformation

Tanzi Huashu (Master Tan's Book of Transformation) was written by Tan Qiao, a Taoist scholar of the late Tang and Five Dynasties period. His courtesy name was Jingsheng, and he was a native of Quanzhou, Fujian.

Tan Qiao inherited Laozi's thoughts, believing that all things in the world originate from xu (emptiness) and eventually return to xu. After completing Huashu, he gave it to Song Qiqiu of the Southern Tang Dynasty, asking him to write a preface for its dissemination.

Tanzi Huashu is divided into six chapters: "Daohua" (Transformation of the Dao), "Shuhua" (Transformation of Techniques), "Dehua" (Transformation of Virtue), "Renhua" (Transformation of Benevolence), "Shihua" (Transformation of Food), and "Jianhua" (Transformation of Frugality), totaling six volumes with 110 sections, each titled with two characters.

The highest philosophical category discussed in the book is "taixu" (the Great Emptiness), which is equivalent to xu, as stated: "The Great Emptiness is but emptiness." All things in the world gradually emerge from xu through transformation and eventually return to xu. On one hand, natural forms are generated from xu: "Emptiness transforms into spirit, spirit into qi (vital energy), qi into blood, blood into form, form into infant, infant into child, child into youth, youth into adulthood, adulthood into old age, old age into death, and death returns to emptiness" (Daohua·Sheng Si [Transformation of the Dao: Life and Death]).

The concept of "taixu" in this book was adopted by the Northern Song philosopher Zhang Zai, who further equated it with qi and put forward the proposition that "taixu is qi," demonstrating its influence on later Song-Ming Neo-Confucianism.

The book also inherits the idea from Yinfu Jing (Classic of the Hidden Symbol): "Heaven and earth steal from all things, all things steal from humans, and humans steal from all things." It argues: "Heaven and earth steal from the Great Emptiness to exist; humans and creatures steal from heaven and earth to exist; the worms in the intestines steal the flavors from me to exist" (Daohua·Tiandi [Transformation of the Dao: Heaven and Earth]). "Thus, the noble person preserves essence and qi, stores soul and spirit, restrains tastes, forbids desires, and belittles external wealth and honor" in pursuit of "heaven and earth growing old while I remain unyielding."

Its highest cultivation realm is "nurturing emptiness," as stated: "The ancient sages explored the origin of the Dao and the end of obstruction, attained the source of creation, forgot form to nurture qi, forgot qi to nurture spirit, forgot spirit to nurture emptiness" (Daohua). Those who can nurture emptiness will achieve clarity and penetration, reaching a state where "the tangible and intangible interpenetrate, things and self are unified, birth has no beginning, and death has no end. Those who understand this Dao cannot have their form destroyed or their spirit dissipated" (Daohua·Long Hu [Transformation of the Dao: Dragon and Tiger]).

This theory of "things obstructing while emptiness penetrates" directly influenced the Neo-Confucian Zhou Dunyi's idea that "things are impenetrable, but spirit enlivens all things."