The Polysystemic Nature of Chemical Theory: Toward an Epistemology for Engaging with Material Complexity

This article challenges the direct transfer of epistemological frameworks from physics to quantum chemistry. While the "Theory's Polysystemity" model offers a powerful analytical tool, the unique nature of chemical realities, with their hierarchical and contextual complexity, necessitates substantial adaptation of this model. We argue that chemical theory is necessarily an open and dynamic system of interconnected subsystems, where procedural, inferential, and approximative systems are as central as the nomological and ontological ones. Analyzing the case of Molecular Orbital Theory via this expanded framework, we illustrate how experimental or computational "surprise" (which we reconceptualize as "material response") does not constitute an anomaly, but rather an epistemological moment that reveals the network-like interaction between subsystems and drives their evolution This article aims to establish a chemical-specific epistemological foundation that acknowledges the particularity of its complexity and paves the way for historical and practical applications.