The Wuliu Xianzong 伍柳仙宗

Wuliu Xianzong (The Orthodox Tradition of Immortals Wu and Liu) includes the following works: attributed to Wu Chongxu of the Ming Dynasty, Xianfo Hezong Yulu (Collected Sayings on the Unity of Immortals and Buddhas) in six volumes, Tianxian Zhengli Zhilun (Direct Discourse on the Orthodox Principles of Heavenly Immortals) in one volume, Tianxian Zhengli Qianshuo (Simple Explanation of the Orthodox Principles of Heavenly Immortals) in one volume, Jindan Yaojue (Essential Secrets of the Golden Elixir) in one volume, and Dandao Jiu Pian (Nine Essays on the Elixir Way) in one volume; as well as attributed to Liu Huayang of the Qing Dynasty, Huiming Jing (Scripture of Wisdom and Life) in one volume and Huayang Jinxian Zhenglun (Huayang's Verification of Golden Immortality) in one volume.

The works of these two authors were not originally compiled at the same time. It was not until the Qing Dynasty, when Deng Huiji, that their works were first collectively engraved and published under the title Wuliu Xianzong. Their alchemical methods are also known as the "Wuliu School" in the world.

The practices described in Wuliu Xianzong avoid metaphors, are relatively popular, and easily understandable to ordinary people. Moreover, the book strives to integrate the theories of Taoism, Buddhism, and Confucianism into a single system, discussing the principles of internal alchemy without sectarian biases, making it acceptable to both Buddhist and Taoist practitioners as well as the general public. Therefore, since the late Ming Dynasty, it has been widely circulated across regions, revered as a must-read for studying internal alchemy, taking precedence over other alchemical texts.

The alchemical methods outlined in Wuliu Xianzong are relatively clear. However, as "the great Dao is formless," the book contains excessive emphasis on active practices, overstresses techniques related to the "vitality" (ming), and clings to concrete forms. As a result, since its circulation, it has been criticized by some Taoist masters of alchemy. For example, Chen Yingning once said: "The two books Zhenglun (Verification) and Zhengli (Orthodox Principles) cannot be regarded as complete, yet they must be read." He also stated, "The Wuliu school is not of the highest order," and "The school of Tianxian Zhengli can be considered part of the heavenly origin tradition, but it is regrettable that it is too attached to tangible forms."He further noted,"The books of Wu Chongxu and Liu Huayang rigidly and explicitly divide the stages— 所谓百日筑基、七日过关、十月结胎、三年乳哺、九年面壁 (the so-called 'hundred days of foundation building,' 'seven days to pass the barriers,' 'ten months to form the embryo,' 'three years of nurturing,' and 'nine years of wall-gazing')—which, in reality, do not align with practice." Nevertheless, as a reference book for beginners studying internal alchemy, the value of Wuliu Xianzong is undeniable.