The Lorentz Transformation of Language: Indicative and Self-Expressive Spacetime in Yoshimoto Takaaki

Yoshimoto Takaaki’s theory of “indicative expression” and “self-expressive utterance” inherits the Cartesian coordinate structure of modern thought while reconstructing it as a dynamic linguistic field. In Descartes’ world, subject and object are arranged on orthogonal, absolute axes, and the observer stands outside, measuring the world from a fixed position. Yoshimoto’s schema likewise defines language through two intersecting axes: “indicative expression,” which points outward to the world, and “self-expression,” which reveals the inner state. Though this appears to form a static linguistic map, in reality the axes themselves fluctuate according to the intensity and social position of speech. Crucially, Yoshimoto’s linguistic space implicitly contains a structure analogous to Einstein’s Lorentz transformation. As the “velocity” of the speaker—social stance, emotional urgency, or genre of discourse—changes, the angle between self-expression and indicative expression tilts; the separation of inner and outer collapses, and linguistic spacetime bends. In this sense, Yoshimoto treated speech acts as frames of observation, conceiving language itself as a relativistic field. Though he lacked the mathematical formalism, he grasped intuitively that the social energy of words deforms the coordinates of time and space. Thus, the linguistic coordinate is no longer a fixed Cartesian plane but a Lorentz-like linguistic spacetime—an arena where interiority and exteriority dissolve and new forms of collectivity emerge.