Daoxin. （580-651） Chinese Chan monk， traditionally counted as the fourth patriarch of the traditional Chan lineage from Bodhidharma. His family name was Sima 司马. He began to study Buddhism at the age of fourteen， taking up the robe and bowl nine years later. He was active in his teaching， and is thought to be greatly responsible for much of the earlier popularization of Ch'an. He was nicknamed "the Great Physician Chan Master" 大医禅师. Teacher of Pomnang （法朗; fl. 632-646） one of the earliest Korean monks to transmit Chan to Korea.