Yunmen Wenyan

Yunmen Wenyan (Japanese: Ummon Bun'en) was one of the major Chan masters of the Tang dynasty in China and founder of the Yunmen school, one of the five major schools of Chan, the Chinese tradition from which Zen developed. The dates of his birth and death are not entirely certain: he is generally placed around 864 and 949, although some sources give 862 as his birth year. He matters because his short, puzzling teachings became a central source for the koan tradition.

He was born near Suzhou, in Jiaxing, into a family named Zhang. As a young man he became a monk, and dissatisfied with the teaching he received, he sought out the master Muzhou Daoming, who according to a late tradition broke one of his legs over his persistence. Daoming sent him to Xuefeng Yicun on Mount Xianggu, under whom he studied for several years before reaching enlightenment. After his teacher's death he travelled widely and gained a reputation. The ruler of the Southern Han kingdom, Liu Yan, became his patron and appointed him abbot of the Lingshu monastery. Around 923, tired of the constant visitors, he asked the king to fund a new monastery on Mount Yunmen, which gave its name to his school.

His teaching was direct and often disconcerting. He answered with shouts, blows of a staff, or single words such as "Guan!", the so-called One Word Barriers. He is said to have discouraged the recording of his sayings, though that anecdote first circulated in the early twelfth century and its origin is doubtful. His brief, paradoxical remarks became material for koans, and several appear in later collections such as the Blue Cliff Record.

His school flourished for centuries and was eventually absorbed into the Linji school toward the end of the Southern Song dynasty. His influence lives on in Zen practice, in koan collections, and in the fascination he has held for teachers and writers in other times and places.