Zen 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. Contrary to the popular image, literature does play a role in the Zen-training. Zen is deeply rooted in the teachings and doctrines of Mahāyāna Buddhism. "Unsui", Zen-monks, "are
Doctrinal background of Zen we conceive of is the result of the working of the five skandhas—results of perception, feeling, volition, and discrimination. The five skandhas together compose consciousness. The "things" we are conscious of are "mere concepts", not "Ding an sich". It took Chinese Buddhism several centuries to recognize that sunyata does not refer to "wu", "nothingness", nor does Buddhism postulate an undying soul. The influence of those various doctrinal and textual backgrounds is still discernible in Zen. Zen teachers still refer to Buddha-nature, but the Zen tradition also emphasizes that Buddha-nature "is" sunyata, the absence of an independent and substantial self. In