The implication is – as indeed described in the sources – that one lets go of all kinds of intentional and reactive patterns and comes to rest in oneness with spirit and is ready to merge completely with Dao. (Kohn 2010:1)   The "Zuowanglun" is associated with six contemporaneous texts by Daoist mediation masters from the "Chongxuan" 重玄 "Twofold Mystery" and Shangqing "Highest Clarity" Schools. Sima Chengzhen led an influential school of Buddho-Daoist mediation centered on Mount Tiantai, which was also the headquarters of the Tiantai school of Buddhism. The (early 8th century) "Dingguanjing" 定觀經 "Scripture on Concentration and Observation", or "Dongxuan lingbao dingguanjing" 洞玄靈寶定觀經 "Scripture on Concentration and Observation of the Numinous Treasure from the Cavern Mystery", appears three times in the Daoist Canon: as an appendix to the "Zuowanglun" edition, as a separate text (DZ 400, tr. Kohn 2010:163-173), and in the "Yunji Qiqian" anthology. This 49-stanza text outlines the psychological transition from an ordinary perspective with emotions and desires to a mental state of stability and quietude (Kohn 2010:65). The popular "Dingguanjing" was summarized under the title "Guanmiaojing" 觀妙經 "Scripture on Concentration on the Mystery" (DZ 326). The "Cunshen lianqiming" 存神鍊氣銘 "Inscription on Visualizing Spirit and Refining Qi" (DZ 834, tr. Kohn 2010:174-178) is attributed to the Daoist physician and alchemist Sun Simiao (d. 682). This text first records five phases in taming the mind and seven stages in transforming the body into immortality, which the "Zuowanglun" appendix and "Dingguanjing" repeat. The "Tianyinzi" 天隱子 "[Book of the] Master of Heavenly Seclusion" was allegedly transmitted by Wu Yun 吳筠 (d. 778) and edited by Sima Chengzhen, who wrote the "Oral Instructions" postface.