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 and Australia. In 1995, he and his organization split with Sanbo Kyodan in response to reorganization of the latter following Yamada's death. The Pacific Zen Institute led by John Tarrant, Aitken's first Dharma successor, continues as an independent Zen line. There are also Zen teachers of Chinese Chán, Korean Seon, and Vietnamese Thien. In 1962, Hsuan Hua moved to San Francisco's Chinatown, where, in addition to Zen, he taught Chinese Pure Land, Tiantai, Vinaya, and Vajrayana Buddhism. Initially, his students were mostly ethnic Chinese, but he eventually attracted a range of followers. Sheng-yen first visited the United States in 1978