The Structure of Permissibility under Radical Skepticism: From Assertion to Action

This study asks how theory can still guide action if radical skepticism rules out final guarantee and the subject cannot withdraw from action. It rejects the direct use of objects, premises, proof, norms, aims, and common standpoints unless their permissibility of use can be explained within current cognition. The central task is therefore not to secure final truth, but to construct a structure through which judgment, examination, assertion, and action-guidance can still operate under insufficient guarantee. The study first reconstructs assertion as a structure of permissibility rather than as a statement of object-truth. Through the assertion-structure, contents that exceed what judgment and examination directly provide may still enter current use under examinable and revisable conditions. On this basis, it constructs a premise-layer, then explains how candidate actions are minimally permitted or excluded through legitimacy, how aims are constructed from action-tendencies rather than given a priori, and how action-groups are selected through layer-by-layer screening, exclusion, and free choice where further distinction can no longer be made. The final part extends the structure to relations among subjects. Cooperation is not derived from common norms or good will, but from subjects changing one another’s conditions of aim-realization through feedback, deterrence, counteraction, withdrawal, and adjustment of trust. What is finally retained is not a fixed aim, self, or guarantee, but cognition’s structural capacity to judge, assert, organize aims, act, absorb feedback, and reconstruct itself within current cognition.