Journal of Philosophical Logic

, Volume 42, Issue 2, pp 285–315 | Cite as

An Inconsistency-Adaptive Deontic Logic for Normative Conflicts

  • Mathieu Beirlaen
  • Christian Straßer
  • Joke Meheus


We present the inconsistency-adaptive deontic logic DP r , a nonmonotonic logic for dealing with conflicts between normative statements. On the one hand, this logic does not lead to explosion in view of normative conflicts such as O A ∧ OA, O A ∧ PA or even O A ∧ ∼O A. On the other hand, DP r still verifies all intuitively reliable inferences valid in Standard Deontic Logic (SDL). DP r interprets a given premise set ‘as normally as possible’ with respect to SDL. Whereas some SDL-rules are verified unconditionally by DP r , others are verified conditionally. The latter are applicable unless they rely on formulas that turn out to behave inconsistently in view of the premises. This dynamic process is mirrored by the proof theory of DP r .


Deontic logic Normative conflicts Paraconsistent logic Inconsistency-tolerance Nonmonotonic logic Adaptive logic 


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Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Mathieu Beirlaen
    • 1
  • Christian Straßer
    • 1
  • Joke Meheus
    • 1
  1. 1.Centre for Logic and Philosophy of Science, Department of Philosophy and Moral SciencesGhent University (UGent)GhentBelgium

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