Symmetry is one of the central organizing concepts of modern mathematics and physics. It appears in Noether’s theorem as variational invariance, in Galois theory as algebraic automorphism, in differential Galois theory as solution-space symmetry, in gauge theory as internal field invariance, and in spatial physics as translational and rotational invariance. Yet these theories usually begin after symmetry has already been formalized. They rarely ask the deeper ontological question: what makes a transformation a symmetry rather than merely a transformation? This paper proposes that symmetry is not primitive. Symmetry is the formal appearance of conserved coherence under admissible transformation. A transformation becomes a symmetry only when the governing coherence relation of a system remains preserved through that transformation. The preceding papers in this sequence established three results: first, Noetherian symmetry is derived from conservation of coherence; second, Noetherian, Galois, and differential Galois symmetries are branches of closure-preserving transformation; third, the infratier framework supplies the pre-symmetry persistence skeleton in which conserved coherence differentiates into a fifteen-generator closure envelope. The present paper synthesizes these results into a general ontology of symmetry. The full hierarchy is: conservation of coherence -> infratier persistence -> closure-sector differentiation -> fifteen-generator envelope -> closure-preserving transformation -> symmetry -> invariant structure -> physical law The central conclusion is that symmetry is conserved coherence made visible through transformation. In this sense, symmetry is not merely a mathematical tool or descriptive convenience. Symmetry is the grammar of persistence.
Philip Lilien (Tue,) studied this question.