Zen expected to become familiar with the classics of the Zen canon". A review of the early historical documents and literature of early Zen masters clearly reveals that they were well versed in numerous Mahāyāna Buddhist sūtras, including Madhyamaka. Especially the Lotus Sutra played a large role in the development of East Asian Buddhism, including Zen. Nevertheless, Zen is often pictured as anti-intellectual. This picture of Zen emerged during the Song Dynasty (960–1297), when Chán became the dominant form of Buddhism in China, and gained great popularity among the educated and literary classes of Chinese society. The use of koans, which
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