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 A review of the early historical documents and literature of early Zen masters clearly reveals that they were well versed in numerous Mahāyāna Buddhist sūtras, including Madhyamaka.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 not been recognized by the government; however, in 2007, with 1.5 million followers, the Vietnamese Pure Land Buddhism Association (Tịnh Độ Cư Sĩ Phật Hội Việt Nam) received official recognition as an independent and legal religious organization. Thiền is the Sino-Xenic pronunciation of "Chan" (Japanese "Zen") and is derived ultimately from Sanskrit "dhyāna". The traditional account is that in 580, an Indian monk named Vinitaruci () traveled to Vietnam after completing his studies with Sengcan, the third patriarch of Chan Buddhism. This would be the first appearance of Thiền. The sect that Vinitaruci and his lone Vietnamese disciple founded would