Dhyāna in Buddhism "silent illumination." This became the source of some differences in practice between the Línjì and Cáodòng schools. A kōan, literally "public case", is a story or dialogue, describing an interaction between a Zen master and a student. These anecdotes give a demonstration of the master's insight. Koans emphasize the non-conceptional insight that the Buddhist teachings are pointing to. Koans can be used to provoke the "great doubt", and test a student's progress in Zen practice. Kōan-inquiry may be practiced during zazen (sitting meditation), kinhin (walking meditation), and throughout all the activities of daily life. Kōan practice is particularly emphasized by
Buddhism in the United States (1927), he became a visible expositor of Zen Buddhism and its unofficial ambassador to Western readers. In 1951, Daisetz Teitaro Suzuki returned to the United States to take a visiting professorship at Columbia University, where his open lectures attracted many members of the literary, artistic, and cultural elite. In the mid-1950s, writers associated with the Beat Generation took a serious interest in Zen, including Gary Snyder, Jack Kerouac, Allen Ginsberg, and Kenneth Rexroth, which increased its visibility. Prior to that, Philip Whalen had interest as early as 1946, and D. T. Suzuki began lecturing on Buddhism at Columbia in 1950.