The Zuo Wang Lun 坐忘论

Zuo Wang Lun written by Sima Chengzhen in the Tang Dynasty, Zuo Wang Lun consists of one scroll, divided into seven sections: "Respect and Faith (1)", "Severing Attachments (2)", "Gathering the Mind (3)", "Simplifying Affairs (4)", "True Observation (5)", "Supreme Calm (6)", and "Attaining the Dao (7)". These sections outline seven steps and stages of cultivating the Dao, focusing on the practice of "sitting in forgetfulness" (zuo wang) and "gathering the mind" (shou xin) to eliminate desires.

The text argues that the initial stage of Dao cultivation requires sitting calmly, gathering the mind, and detaching from external realms—free from clinging to any objects—to enter a state of emptiness (xu wu), where the mind unites with the Dao. Since external realms are created by the mind, only by gathering the mind, keeping it untainted by mundane dust, and transcending the ordinary can one return to the innate nature of the mind, which is "calm" and "empty". This emphasis on stillness (zhu jing) profoundly influenced later Neo-Confucian scholars of the Song Dynasty.

The concept of "zuo wang" (sitting in forgetfulness) first appeared in Zhuangzi·The Great Ancestral Teacher. It was later elaborated by Wei-Jin metaphysics and Taoism; for example, the Taoist scripture Dongxuan Lingbao Dingguan Jing (Scripture on Stabilizing Observation of the Mystery-Penetrating Numinous Treasure) discusses stabilizing the mind with the principle of "extinguishing the restless mind but not the illuminating mind". Wu Zeng of the Southern Song Dynasty noted in Nenggai Zhai Manlu (Casual Notes from the Studio of Correction) that Sima Chengzhen’s Zuo Wang Lun drew inspiration from this idea.

Amid the Tang Dynasty’s prevalent practice of external alchemy (waidan), Sima Chengzhen integrated Lao-Zhuang thought with Buddhist methods of samādhi (zhi guan, "stopping and observing"), advocating "zuo wang" as a core practice. This played a pivotal theoretical role in Taoism’s shift from external alchemy to internal alchemy (neidan) and exerted a lasting influence on later Taoist internal alchemy traditions.

Zuo Wang Lun is included in the Zhengtong Daozang (Daoist Canon of the Zhengtong Reign) under the "Tai Xuan" section.