The Way of Highest Clarity was a Daoist religious movement that flourished for a thousand years in medieval China. This book explains its chief religious ideas and practices through three key texts, translated into English for the first time. The "Esoteric Biography of Perfected Purple Yang" documents the life of a Daoist saint who travels through China encountering a wealth of immortals and gods who aid him in his quest for transcendence. They transmit esoteric scriptures to him, including the "Central Scripture of the Nine Perfected," also translated here. This text explains a meditation technique that involves visualizing gods descending into the organs of the body at certain times of the year. The book also translates the preface to the "Perfect Scripture of the Great Grotto," a theological reflection on the practices of Highest Clarity, which connects the tradition back to the fundamental principles of the Dao. Together with the introductory essays on the concepts of nature, vision and revelation, the book provides an overview of a unique and fascinating religious imagination, which will be of interest to anyone who seeks a deeper understanding of China's cultural heritage.