SIMA CHENGZHEN (647–735; adult style, Ziwei; name in religion, Daoyin) was an eminent court Daoist and Shangqing patriarch of the Tang period (618–907). A native of Wen County in modern Henan province, Sima Chengzhen was a descendant of the Sima ruling family of the Jin dynasty (265–420) and of high regional officials under the Sui (581–618) and early Tang. Sima Chengzhen received his Daoist initiation from the Shangqing patriarch Pan Shizheng (587–684) at Mount Songshan, the Central Peak, in Henan. Pan, a counselor on Daoist doctrine to Emperor Gaozong (r. 650–684), transmitted to Sima the inspired fourth-century writings of the Shangqing scriptural corpus, as well as meditational and physiological techniques practiced by that movement. Sima Chengzhen succeeded his master as the twelfth patriarch of the Shangqing lineage. After a period of wandering, he lived in seclusion on Mount Tiantai in Zhejiang, where he assumed the epithet Boyun zi, Master White Cloud.

Sima...