Caodong school
Sōtō is the Japanese line of the Chinese Caodong school, which was founded during the Tang Dynasty by Dongshan Liangjie. The Sōtō-school has de-emphasized kōans since Gentō Sokuchū (circa 1800), and instead emphasized on shikantaza. Dogen, the founder of Soto in Japan, emphasized that practice and awakening cannot be separated. By practicing shikantaza, attainment and Buddhahood are already being expressed. For Dogen, zazen, or shikantaza, is the essence of Buddhist practice. Gradual cultivation was also recognized by Dongshan Liangjie.