This version 1.2 presents the final publication version of Embodied Constructor Theory (ECT): Knowledge as a Constructor-Theoretic Physical Primitive. The paper develops ECT as a philosophical and computational framework in which knowledge is treated not as a passive representation, subjective belief, or late-stage emergent property, but as a constructor-theoretic physical primitive: the capacity by which physically possible transformations become stable, criticizable, repeatable, and expandable under constraints. The revised version shifts the center of gravity of ECT away from a Fristonian Free Energy / Active Inference foundation and toward a clearer Popper-Deutsch-Marletto formulation. Free Energy and Active Inference are retained only as historical and computational precursors, while the explanatory core is now expressed in terms of conjecture, criticism, counterfactual task structure, admissibility, embodied mediation, and the expansion of reliable task repertoires. This version also removes dependence on a Constructorial Mediation Boundary (CMB) as the central explanatory device. Instead, the theory is reformulated directly through the mathematical companion framework: mediated world-system interaction, internal conjecture Q, action tendency M, regulatory gain omega, and knowledge potential KP. Knowledge is thereby defined as accumulated constructorial capacity rather than as hidden probabilistic inference. A central clarification in v1.2 concerns Chiara Marletto’s constructor-theoretic account of life and knowledge. The paper now distinguishes explicitly between the conditional fragility of knowledge vehicles and the constructor-theoretic resilience of knowledge itself. This avoids the ambiguity that biological organisms, cells, lineages, or other local vehicles may be fragile while knowledge, in the constructor-theoretic sense, remains resilient insofar as it can contribute to its own preservation, copying, repair, or re-instantiation through appropriate constructors. The paper is intended as a philosophical companion and conceptual foundation for the mathematical framework presented in: Leon Mori, D. J. (2026). Knowledge as Explanatory Physical Capacity: Toward a Computable Architecture in Constructor-Theoretic Terms. Zenodo. https://doi.org/10.5281/zenodo.19626145
Dario Jesus Leon Mori (Thu,) studied this question.