From External Authority to Internal Resonance: The Deepening of Kashin Theory in Medieval Waka 外的権威から内的感応へ——中世和歌における歌神論の深化

This article reconsiders the medieval Japanese theory of the waka deity (kashinron 歌神論) through a sustained comparison of Fujiwara no Shunzei (1114–1204) and the Tendai prelate Jien (1155–1225). Previous scholarship has tended to treat the two poets within separate analytical frames—Shunzei within Buddhist poetics, Jien within Tendai doctrinal history—leaving the structural transformation that links them largely unexamined. This study argues that Jien’s hundred-poem Sumiyoshi sequence in the Shūgyokushū can be read as enacting a systematic interiorization of the external authority structure that Shunzei articulated in the preface to the Senzai wakashū, and that this transformation can be reconstructed as a coherent religious phenomenology. Through close reading of the full hundred-poem sequence, this study proposes a heuristic sevenfold phenomenological model—Light, Voice, Wind, Wave, Knowledge, Silence, Eternity—traversed by four interlocking dimensions: the deity as soteriological consummation of the Dharma, kannō (感応, sympathetic resonance) as internal faith, hōraku (法楽) as total entrustment, and the auditory phenomenology of shinjin kōkan (神人交感). The study further proposes that this sevenfold structure can be understood as the temporal unfolding of the godai-gogyō (五大・五行) cosmology that Jien posits as inscribed in the 5-7-5-7-7 form of waka, offering a structural analogy between the pentadic grid of the verse and the experiential arc of the sequence. By grounding Jien’s kashinron in the prosodic form of waka, this study opens new methodological horizons for the comparative study of medieval poetic–religious thought.