Weyl Curvature as the Unique Freely Reconstructible Gravitational Structure

This work establishes a uniqueness result for gravitational structureunder minimal constraints on physical meaning and observational access. Physical distinctions are restricted to operative distinguishabilityand causal accessibility, without assumptions on field equations,symmetry, boundary conditions, or dynamics. Under these constraints, point-local geometric quantities,instantaneous states, and curvature components fixed by intersectingnon-gravitational sources are excluded as carriers of independentgravitational content. Applying these exclusions to the algebraic decomposition of spacetimecurvature shows that the Weyl tensor is the only tensorial structurethat remains freely reconstructible from admissible observation.All standard gravitational phenomena arise as direct corollaries. Any gravitational observable not reducible to Weyl-mediatedreconstruction would falsify the result.