The school of Ch'an Buddhism that acknowledged the T'ang-dynasty monk Lin-chi I-hsüan (d. 866) as its patriarch. During the later T'ang dynasty this school was relatively minor and was counted as one of the ‘Five Houses’ of Ch'an at the time. However, by the early years of the Sung dynasty (960–1279), it had risen to great prominence and became, along with the Ts'ao-tung school, one of the two major schools of Ch'an in China. During this period of its ascendancy, several monks from Japan.most notably Eisai (1141–1215), travelled to China and attained enlightenment (satori) under the tutelage of masters in the Lin-chi school, and transmitted the lineage back to Japan where it became known as Rinzai. The lineage of Lin-chi I-hsüan was carried forward by a centralized lineage from master to chief disciple for six generations, but during the seventh two masters came to prominence and established parallel lineages: Yang-ch'i Fang-hui (992–1049) and Huang-lung Hui-nan (1002–69). Both men were forceful and charismatic teachers, described respectively as the ‘tiger and dragon’ of Ch'an. The strength of these two lineages was recognized in the designation of the ‘Five Houses and Seven Schools’ of Ch'an at the time. However, by the end of the Sung period, the Huang-lung school declined while the Yang-ch'i school gained in strength.
Taking its major teaching methods from the example of Lin-chi himself and his teacher, Huang-po Hsi-yün (d. 850), the Lin-chi school emphasized the use of ‘crazy Ch'an’ or ‘shock Ch'an’ techniques during its early period. These methods included shouting directly into a student's ear, beating him, or giving seemingly nonsensical responses to questions. However, as the school gained in popularity and established new temples throughout China, the number of teachers who understood and could skilfully employ these techniques declined, and by the time of Yang-ch'i and Huang-lung, the school shifted its emphasis from the actual use of these methods to the recounting of stories depicting occasions when a teacher had used such a method and successfully prodded a student into enlightenment. These stories, or at least the critical portions of them, came to be collected into anthologies of ‘public cases’, or kung-an (Jap., kōan), and their use created a viable alternative to actual beating and shouting. A student could now meditate on the story under the guidance of a master and try to penetrate the sayings and actions of past masters and understand the enlightenment experience for themselves.
The use of ‘shock’ techniques and kōans stood in contrast to the methods of the other most popular school of Ch'an, Ts'ao-tung, which tended to emphasize ‘silent illumination’ (Chin., mo-chao Ch'an). This meant that the student did not use any particular method such as kōan study, because there was nothing to be gained: they were already fully enlightened Buddhas just as they were, and the point of meditation was simply to realize that fact. The controversy reached its height in the exchange between the Lin-chi school's Ta-hui Tsung-kao (1089–1163) and the Ts'ao-tung school's Hung-chih Cheng-chüeh (1091–1157) in which both argued for the superiority of their chosen practices. The literature that emanated from their argument helped to define and harden each school's position. Ironically, the terms ‘silent illumination Ch'an’ (Chin., mo chao ch'an) and ‘kōan-contemplation Ch'an’ (Chin., k'an hua ch'an) were first used in this debate as derogatory terms that each used to caricature his opponent's position, but later entered the vocabulary as standard designations for two equally valid modes of practice. However, in the real world beyond the literary remains of these two great minds, the goal-oriented activity of kōan contemplation appealed more to the artistic and military communities, who saw that the methods of the Lin-chi school produced tangible results, whereas Ts'ao-tung's ‘silent illumination’ simply rested on the platitude that there was no goal to attain. Therefore, Lin-chi outstripped Ts'ao-tung in its ability to draw support from the lay community. By the end of the Sung, Lin-chi had absorbed all of the other of the ‘Five Houses’ of Ch'an with the exception of Ts'ao-tung, but at the same time the ascendancy of Neo-Confucianism drew the interest of the Chinese intelligentsia away from Buddhism and into Confucian studies, and so during the post-Sung period, Lin-chi became marginalized along with the rest of Buddhism.