Structural Admissibility as a Pre-Explanatory Condition in Scientific Reasoning

Scientific explanations typically begin with models that describe the behaviour of systems through equations, algorithms, or rules of interaction. However, most scientific disciplines implicitly assume that the states being analysed already belong to a valid system. This paper argues that such assumptions conceal a prior structural condition governing scientific reasoning: admissibility. Within the Paton System framework, a system state must satisfy governing constraints that permit its membership and continuation within a system before explanatory models can meaningfully operate. The paper formalises this requirement as a pre-explanatory admissibility layer that determines whether system states are structurally permitted to exist and persist prior to scientific explanation. By identifying admissibility as a prerequisite for scientific reasoning, the Paton System clarifies the structural boundary between possible description and valid explanation. This interpretation connects structural admissibility with broader discussions in philosophy of science concerning the conditions that make scientific explanation possible.