Free Will After Determinism: Why Agency Survives the Death of Predictability

This paper presents a physically and computationally grounded model of free will that rejects metaphysical dualism and trivial compatibilism. By examining six structural constraints within our universe—computation, information storage, causal speed limits, recursive modeling, instrumental disturbance, and internal epistemic blindness—it demonstrates that perfect prediction is impossible even in a deterministic universe. Additionally, Section 3.7 argues that human actions remain irreproducible even when rehearsed, underscoring how agency emerges not from randomness but from systemic non-reproducibility. **Keywords:** free will, determinism, prediction limits, agency, computational limits, structural constraints, epistemic blindness, real-time decision making, irreproducibility, cognitive science.