Adaptive Logic

Adaptive logic is a dynamic approach to reasoning that applies classical strategies by default but switches to paraconsistent or non-monotonic strategies locally when contradictions or abnormalities are detected. Developed primarily by the Belgian school led by Diderik Batens, adaptive logics treat inconsistency not as a global catastrophe but as a localized aberration to be contained and quarantined.

The central insight is pragmatic: most of our reasoning proceeds as if the world were consistent, and classical logic is the appropriate tool for this default assumption. When inconsistency arises — through error, incomplete information, or genuine paradox — adaptive logic 'adapts' by restricting the application of classical rules to the consistent fragment while isolating the contradictory premises. The result is a system that preserves classical strength where possible and paraconsistent resilience where necessary.

Adaptive logic is particularly relevant for reasoning in scientific contexts, where theories at the frontier often contain internal tensions that are resolved over time. Rather than forcing scientists to choose between classical rigidity and paraconsistent permissiveness, adaptive logic models the actual practice of working through inconsistency: identify the problem, bracket it, continue reasoning, and resolve it when possible. It is the logic of repair, not of revolution.