Deterministic models explain the persistence of systems but remain structurally blind to the origin of genuine change. This paper argues that while history and behavior appear inevitable in hindsight, such coherence is a retrospective illusion created by erasing the contingencies of bifurcation. I propose a framework of Structural Agency, where the individual functions as a non-derivable origin within a physically closed system. By distinguishing between physical realizability and structural derivability, I demonstrate that free will is not a metaphysical exception but a systemic property: the capacity of an agent to introduce a causal event that restructures the space of possibilities. Recognizing the individual as an origin does not violate physical closure; it completes the structural understanding of systems that deterministic frameworks, by definition, leave incomplete.
Claudio Bresciano (Mon,) studied this question.