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 A review of the early historical documents and literature of early Zen masters clearly reveals that they were well versed in numerous Mahāyāna Buddhist sūtras, including Madhyamaka.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
Buddhism in Vietnam (, "Collection of Outstanding Figures of the Zen Garden") has been the dominant text used to legitimize Thiền lineages and history within Vietnam. However, Cuong Tu Nguyen's "Zen in Medieval Vietnam: A Study and Translation of the Thien Tap Anh" (1997) gives a critical review of how the text has been used to create a history of Zen Buddhism that is "fraught with discontinuity". Modern Buddhist practices are not reflective of a Thiền past; in Vietnam, common practices are more focused on ritual and devotion than the Thiền focus on meditation. Nonetheless, Vietnam is seeing a steady growth in Zen