While recent publications on Chinul have done much to create a solid basis for the study of the later Korean Son tradition, one may, in reading these works, be left with the impression that through Chinul, Son and Kyo were thoroughly combined and that scriptural study was forever after an integral part of the training of a Korean monk. But in fact, on a basis of examination of their writings and teaching records, we can see that Son monks for nearly two centuries after Chinul all but ignored systematic scriptural study or exegesis, and returned to a relatively non-textual stance, characteristic of Chinese Lin-chi (Kor. Imje) Ch'an. This pattern of disproportionate emphasis on classical Imje practice methods was broken by Hamho Tukt'ong (1376-1433, often referred to by scholars his posthumous name Kihwa), who is one of Korean Buddhism's more prolific writers and scriptural exegetes, and whose essays and commentaries had a significant impact on the subsequent history of the tradition.
Kihwa's writings are permeated with allusions of, references to, and influence from his well-known predecessors Wonhyo and Chinul. Like them, he attempted an actualization of the Hwaom (Ch. Hua-yen) principle of interpenetration in the actual structure of Buddhist practice. Most important in this regard is his revivification of the project of the amalgamation of Son and Kyo Buddhism initiated by Chinul, which is done primarily through his v O ka hae solui, where he argues strongly for the identity of Son and Kyo principles. Interpenetration is also an important concept in his commentaries on the Yuan chiao ching and the Yung-chia chi, where he also endeavors for a blended presentation of doctrine and meditation. In his Hyon chong non, Kihwa carries out a project of interreligious harmonization reminiscent of Wonhyo's hwajaeng, wherein he uses the Hua-yen principle of interpenetration to argue for the fundamental parallels in doctrine between the "Three Teachings" of Buddhism, Confucianism and Taoism. Through the examination of selected translations of the above works, we may gain a clear view of the significance of Kihwa's place in Korean Buddhism as a thinker who had deeply grasped the essentials of the most influential antecedent Korean and Chinese philosophers and who was able to re-enliven these for posterity.
I. Introduction II. Background on Kihwa III. Interpenetration/non-obstruction as Applied Principle in the Woks of Wonhyo and Chinul IV. The Kumgang panyaparamilgyong o ka hae solui: Kihwa's understanding of the unity of Son and Kyo through the Diamond Sutra V. The Meditation Manuals: Kihwa's Commentaries on the Comilation of Yung-chia and the Sutra of Perfect Enlightment VI. Kihwa's Introduction to the Sutra of Perfect Enlightment VII. Kihwa's Defense of Buddhism VIII. Conclusion: Kihwa--Son based scholar of interpenetration