AP-017: The Toulmin Isomorphism — A Formal Correspondence Between Scientific Validation and Universal Epistemic Structure

This paper establishes a formal correspondence between the six components of Toulmin's model of argumentation (1958) and the stages of hierarchical validation in the experimental life sciences. Six bijective mappings are identified that preserve functional roles, compositional structure, and failure modes. A unified probabilistic formulation — P(conclusion | premises, model, data) — is proposed that subsumes both frameworks. Implications for the design of epistemic validation systems, including AI systems requiring structured justification of conclusions, are discussed. The correspondence suggests that Toulmin's model may function as a structural attractor for any sufficiently rigorous validation process. Part of the Alexandria Papers series by Laboratorios Alexandria.