Both Natsume Sōseki and Yoshimoto Takaaki, while engaging with the “psychic phenomenon,” constructed within their respective theories a perpendicular structure between F and f.

 Both Natsume Sōseki and Yoshimoto Takaaki, while engaging with the “psychic phenomenon,” constructed within their respective theories a perpendicular structure between F and f. F represents the social or institutional dimension of reference; f the primary movement of emotion or impulse. In Sōseki’s Theory of Literature, the flow of feeling (fₛ) intersects with linguistic and stylistic norms (Fₛ), producing an aesthetic equilibrium. Rhythm and metaphor modulate this angle of intersection, creating for the reader a sense of “mind made medium.”

Yoshimoto’s Theory of Expression likewise defines self-expression (fᵧ) and referential expression (Fᵧ) as independent bases, where beauty arises in the band of resonance between them—neither excessive nor deficient. What unites them is the maintenance of a dynamic orthogonality (F ⊥ f), through which expression E(F, f) is temporally optimized. Beauty is thus neither the sum nor the difference of F and f, but the illumination born from their tension—the brief radiance at the moment when meaning is about to come into being.