The key figure in the Caodong school was founderDongshan Liangjie. Some attribute the name "Cáodòng" as a union of "Dongshan" and "Caoshan", the latter from one of Dongshan's Dharma-heirs, Caoshan Benji;. However, the "Cao" much more likely came from Cáoxī, the "mountain-name" of Huineng, the Sixth Ancestor of Chan, as Caoshan was of little importance unlike his contemporary and fellow Dharma-heir, Yunju Daoying. The school emphasised sitting meditation, and later "silent illumination" techniques.
History
The Caodong school was founded by Dongshan Liangjie and his Dharma-heir Caoshan Benji. Dongshan traced back his lineage to Shitou Xiqian, a contemporary of Mazu Daoyi. Sayings to the effect that Shitou and Mazu were the two great masters of their day date from decades after their respective deaths. Shítóu's retrospective prominence owes much to the importance of Dongshan Liangjie. Shítóu does not appear to have been influential or famous during his lifetime: In the 11th century the Caodong-school nearly extinguished. Dayang Jingxuan, the last descendant of the Caodong-lineage passed on his dharma-transmission via Fushan Fayuan, a teacher from the Linji school, to Fayuan's student Touzi Yiqing, who was born five years after Jingxuan's death. During the Northern Song the Caodong was not successful in the social elite. The Linji school and Yunmen school dominated Chán. It was Touzi Yiqing's student Furong Daokai who was a successful monastic, and revived the Caodong school. His dharma "grandson" Hongzhi Zhengjue became very successful among elite literati in the Southern Song, when the Imperial Court decreased their influence on society, and Chán schools became dependent on elite literati for support. This success drew opposition of Dahui Zonggao, who promoted the Hua Tou method of koan-study as an accessible means for Chán-practice, and attacked the silent illumination of Hongzhi. In 1227 Dōgen Zenji, a former Tendai student, studied Caodong Buddhism under Tiantong Rujing, and returned to Japan to establish the Sōtō sect. His lineage incorporates not only the dharma-transmission via Fushan Fayuan, but also Linji dharma-transmissions via Eisai and his student Myozen, a teacher of Dogen, and the Linji dharma-transmission of Dahui Zonggao via the Nōnin school.
Lineage chart
via Shitou the Caodong traces back its origins to Huineng.
