Sankyū reading of Dōgen and the triadic nature of experience

This paper argues that Dōgen's philosophy should be understood through the inseparable unity of Buddha-nature, expression (dōtoku), and practice-realisation (shushō), not as distinct doctrines but as co-constitutive dimensions of reality's continuous self-manifestation. Through close reading of key Shōbōgenzō fascicles, particularly “Busshō,” “Uji,” and “Genjōkōan,” I demonstrate how post-Meiji analytical approaches (kenkyū) have fragmented Dōgen's essentially holistic thought by imposing Western metaphysical categories. Recovering the traditional sankyū (participatory investigation) method reveals how Dōgen's texts function performatively, requiring embodied engagement rather than propositional analysis. This triadic reading shows Buddha-nature as dynamic field rather than metaphysical substrate, expression as reality's direct self-articulation rather than representation, and practice-realisation as world-confirmed actualisation rather than goal-seeking. The implications extend beyond Buddhist studies: Dōgen offers an ecological ontology where value is intrinsic to relational networks, a non-representational semantics, and an ethics of care grounded in recognising our co-constitution with the natural world.