Despite this strong suppression from the government, and vehement ideological opposition from Korean Neo-Confucianism, Seon Buddhism continued to thrive intellectually. An outstanding thinker was "Gihwa" (己和; (Hamheo Deuktong 涵虚得通) 1376–1433), who had first studied at a Confucian academy, but then changed his focus to Buddhism, where he was initiated to the "gwanhwa" tradition by "Muhak Jacho" (無學自超; 1327–1405). He wrote many scholarly commentaries, as well as essays and a large body of poetry. Being well-versed in Confucian and Taoist philosophies, Giwha also wrote an important treatise in defense of Buddhism, from the standpoint of the intrinsic unity of the three teachings, entitled the "Hyeonjeong non". In the tradition of earlier philosophers, he applied "che-yong" ("essence-function") and "Hwaeom" ("sa-sa mu-ae", "mutual interpenetration of phenomena").