Coherent Flow and the Emergence of an Interior _A Dynamical Proof of the Physical Origin of Interiority_

A physical condition is required to determine when a system possesses an interior. This paper derives such a condition from the balance between internal restoration and environmental disruption. Let λ_self denote the rate at which a system restores and propagates its own structure, and λ_env the rate at which environmental interaction redistributes or disrupts that structure. The relation R = λ_self / λ_env defines a critical condition R★ separating two regimes of activity. When R P(S_t | E_t). In this regime, perturbations are resolved relative to the system’s own organization, establishing a reference frame defined from within. This produces self-measurement in a dynamical sense and generates a distinction between internally governed and externally imposed activity. An interior is identified with the condition in which a system’s states are defined relative to its own structure. Consciousness corresponds to the operation of a system within this regime, where persistence, temporal depth, unity, and self-reference arise as direct consequences of sustained coherent propagation. The coherence condition provides a minimal, substrate-independent criterion for the emergence of an interior without introducing additional primitives.