Predecessor Concepts and Successor Postulates: A Leibnizian Case Study in Invariance, Actuality, and First-Person Givenness

Title: Predecessor Concepts and Successor Postulates: A Leibnizian Case Study in Invariance, Actuality, and First-Person Givenness This paper develops a predecessor/successor methodology for reconstructing historically significant concepts under contemporary “Quinean discipline”: successor claims must earn their keep by playing an indispensable role in our best total theory, rather than by deference to tradition or theological authority. As a case study, the paper reconstructs Leibniz’s God-concept as a role-cluster and asks which parts of that cluster can be preserved as disciplined successor postulates. The result is a “successor package” consisting of three connected commitments: (S) Invariance / structural objectivity: the demand that physical description be fixed only up to appropriate symmetries, with surplus structure treated as non-ontological. (A) Selective actuality: actuality is not merely an indexical (“this world”), but involves a selection-role that cannot be reduced to Lewis-style indexical semantics. (C) First-person givenness: an anti-eliminativist constraint on a total theory, sharpened into a structural underdetermination argument. If physical description is specified only up to symmetries, the same structural slack that (S) treats as non-ontological can reappear as slack in identity-claims about givenness—so the identification of first-person givenness with purely physical structure is not fixed by the physical theory alone. The paper also explains why the stronger “full agency” cluster is not defended here: under Quinean discipline, abductive appeal is not yet sufficient to establish role-indispensability. DOI: 10.5281/zenodo.18651094 (An AI-use disclaimer is included in the manuscript.)