The Instantiation Problem for Structural Realism

Ontic Structural Realism (OSR) is widely regarded as a natural metaphysical interpretation of contemporary physics. Quantum nonseparability, contextuality, and research programmes that reconstruct spacetime from deeper relational organisation all suggest that physical reality is fundamentally structural. OSR captures this shift by identifying reality with relational structure itself. A further question remains, however: how such structure exists as a concrete world rather than as formally specified structure alone. This paper develops what may be called the Instantiation Problem for Structural Realism. Physical theories articulate highly structured mathematical relations such as state spaces, symmetry groups, and dynamical constraints. Formal specification alone does not explain how such structure is present as a realised world. Removing intrinsic relata consequently leaves unresolved the distinction between abstract structure and concrete occurrence. Several responses within the structural realist literature are examined, including eliminative relationism, thin object proposals, and appeals to primitive physical existence. The paper argues that none satisfactorily explains the transition from formal structure to determinate actuality. An experiential grounding account is then proposed in which experiential manifestation provides the minimal ontological condition under which relational architecture exists as determinate occurrence. Experiential manifestation is understood in a minimal ontological sense referring to occurrent presence rather than to human or biological consciousness.