The fifth and last recognized patriarch of the Hua-yen school in China.as well as a widely admired Ch'an master. He received a standard Confucian (see Confucianism) education as a youth and was about to take the civil service examinations when he encountered the Ch'an monk Tao-yüan in 807. He was so impressed by him that he abandoned his career in order to join him. After a year of Ch'an study he read a commentary on the Hua-yen ching by Ch'eng-kuan (738–820), and switched his focus to Hua-yen studies. He travelled to the capital city of Lo-yang, where he studied with Ch'eng-kuan until the latter's death. His fame spread, and he was invited to lecture in the imperial palace and was subsequently given many honorific titles by the throne. His wide-ranging studies, coupled with his meditative experience, led him to criticize Ch'an's rejection of scriptures and oral teachings. As an alternative, he proposed that doctrinal study and Ch'an meditation mutually supported and reinforced each other, a theory called ‘doctrine and meditation leading to the same goal’ (chiao ch'an yi chih).
Aside from his Hua-yen lectures and writings, Tsung-mi wrote commentaries on other Mahāyāna scriptures as well as some original works. Perhaps most significantly, he proposed a theoretical framework to settle the lingering controversy over sudden andgradual enlightenment within the Ch'an school. He set forth a typology of cultivation and enlightenment that recognized the possibility of either suddenness or gradualness in both. This led him to postulate an ideal course of Ch'an practice as one marked by an initial experience of sudden enlightenment which was subsequently deepened by gradual cultivation; he criticized the Northern School for reversing these stages, which he thought left one's gradual cultivation without any foundation in an experiential realization of the nature of reality. However, he also criticized the heirs of the Southern School for having neglected the aspect of cultivation in favour of an all-sufficient experience of sudden enlightenment.