Zen is a subset of Buddhist tradition founded first in China and then later in Japan. The name of the sect derives from the Sanskrit dhyana [meditation]. In China the school early became known for making its central tenet the practice of meditation, rather than adherence to a particular scripture or doctrine.

The founder of Zen in China was the legendary Bodhidharma, who came to China from India in the late 5th cent. A.D. He taught the practice of "wall-gazing" and espoused the teachings of the Lanka-Vatara Sutra (whose chief doctrine is that of "consciousness-only"; see Yogacara), which he passed on to his successor Hui-k'o (487-593).

According to tradition, Hui-neng (638-713) became the sixth patriarch of Chinese Zen by superseding his rival in the intuitive grasp of the truth of enlightenment, even though he was illiterate. The Platform Sutra, attributed to Hui-neng, defines enlightenment as the direct seeing of one's "Original Mind" or "Original Nature," which is Buddha, and this teaching has remained characteristic of Zen. A number of teaching lineages arose after Hui-neng, all claiming descent from him, and teaching the method of "sudden enlightenment best known in the West by the term satori. In its formative period Zen was influenced by both Taoism and elements of Prajna-Paramita Buddhism.

The 8th and 9th cent. were the "golden age of Zen," producing such great masters as Ma-tsu, Nan-chuan, Huang-po, Lin-chi, and Chao-chou. The unique Zen teaching style developed, stressing oral instruction and using nonrational forms of dialogue, from which the later koan was derived. In some cases physical violence was used to jolt the student out of dependence on ordinary forms of thought and into the enlightened consciousness. Scholarly knowledge, ritual, and performing good deeds were considered of comparatively little spiritual value.

After the great persecution of Buddhism in 845, Zen emerged as the dominant Chinese sect, due partly to its innate vitality and partly to its isolation in mountain monasteries away from centers of political power. Two main schools of Zen, the Rinzai (Lin-chi) and the Soto (Ts'ao-tung), flourished and were transmitted to Japan in the 14th cent. The Rinzai sect placed greater emphasis on the use of the koan and effort to attain sudden enlightenment, while the Soto patriarch Dogen (1200-1253) emphasized sitting in meditation (zazen) without expectation and with faith in one's own intrinsic state of enlightenment or Buddha-nature.

The austere discipline and practical approach of Zen made it the Buddhism of the medieval Japanese military class. Zen monks occupied positions of political influence and became active in literary and artistic life. Zen monasteries, especially the main temples of Kyoto and Kamakura, were educational as well as religious centers.

The Zen influence on Japanese aesthetics ranges from poetry, calligraphy, and painting to tea ceremony, flower arrangement, and landscape gardening, particularly the distinctive rock-and-sand temple gardens. Japanese Zen declined in the 16th and 17th cent., but its traditional forms were revived by the great Hakuin (1686-1769), from whom all present-day Rinzai masters trace their descent. Zen thought was introduced to the West by the writings of D. T. Suzuki, and interest in the practice of Zen meditation blossomed after World War II, resulting in the establishment of Zen centers in many parts of the United States.