Approximation Is Not Ontology_ Literal Branching, Metaphor, and the Deterministic Requirement in Quantum Foundations

This paper audits the internal consistency of ontological claims made by the Many-Worlds Interpretation of quantum mechanics. Restricting itself to premises explicitly asserted in the literature, it examines whether strict unitarity, determinism, and literal permanent branching can be jointly maintained. The analysis isolates a necessary substitution from approximate to exact orthogonality in decoherence-based branching accounts and shows that this substitution is not licensed by unitary dynamics. As a result, literal branching contradicts determinism, while emergent or metaphorical formulations avoid contradiction only by abandoning ontological commitment. No alternative interpretation is proposed, and no modification to quantum mechanics is asserted. The paper functions solely as a consistency audit of interpretive claims.