The Ruyao jing (Mirror for Compounding the Medicine) is one of the most famous texts of Taoist Internal Alchemy, or Neidan. Written in the 10th century and attributed to Cui Xifan, it describes the foundations of Internal Alchemy in 20 short poems of four verses. Because of its symbolic and cryptic language, it has been subjected to different and sometimes conflicting interpretations. This book contains the first complete translation of the Ruyao jing and of the commentary by Wang Jie, who lived in the 14th century. Wang Jie - also known as Wang Daoyuan and as Hunran zi (Master of the Inchoate) - was a second-generation disciple of the great Neidan master, Li Daochun. His commentary is characterized by a strong connection between the doctrinal and the practical aspects of Neidan. The translator's notes provide details on the main technical terms and on the relation of this work to other important texts of Internal Alchemy, in particular the Cantong qi (Seal of the Unity of the Three) and the Wuzhen pian (Awakening to Reality). The book is vol. 1 in the "Masters" series of Golden Elixir Press. Contents: Introduction, p. vii Translation, p. 1 Five Poems by Wang Jie, p. 65 Chinese Text, p. 69 Glossary of Chinese Characters, p. 83 Works Quoted, p. 89