Chin'gak Hyesim

Chin'gak Hyesim (1178–1234) was the foremost student of Bojo Jinul and the master who firmly established hwadu (keyword) practice as the central method of Korean Seon. He entered monastic life as a young man and studied under Jinul at Suseonsa, where his penetrating insight earned him recognition as Jinul's dharma heir. After Jinul's death in 1210, Hyesim assumed leadership of the Suseonsa community and served as its second director, expanding the community and deepening its practice standards.

Hyesim's principal contribution was shifting the emphasis of Korean Seon from Jinul's balanced approach of meditation-and-doctrine toward a more intensive focus on hwadu investigation, the practice of concentrating on the critical phrase of a koan until conceptual thinking is utterly exhausted and awakening breaks through. He compiled the first Korean collection of hwadu cases and wrote extensive commentaries guiding practitioners through the method. This emphasis on hwadu became the defining feature of Korean Seon practice and remains so to the present day. Hyesim also played an important role in Korean literary history, producing significant collections of poetry and prose that demonstrate the integration of contemplative depth with literary accomplishment.