A theory of permission based on the notion of derogation
This paper, based on the author's doctoral thesis [Norms and norm-dynamics. Philosophy Department, University of Bergen, Norway (2008)], proposes a major modification of the treatment of positive permission in the framework of input/output logics. When a normative code contains an explicit permission that is inconsistent with the set of all its obligations, input/output logic under its present formulation [\textit{D. Makinson} and \textit{L. van der Torre}, ``Permission from an input/output perspective'', J. Philos. Log. 32, No.~4, 391--416 (2003; Zbl 1028.03017)] treats the code as a whole as inconsistent. The author proposes to avoid such explosion by prioritizing positive permissions over obligations, by means of an AGM-style belief contraction on the obligations. This step, accompanied by certain other changes in the formulation designed to avoid a contested property of `input weakening', leads to formal concepts of `exemption' and `antithetic' (positive) permission in a normative system, introduced to replace the Makinson/van der Torre notions of static and dynamic (positive) permission respectively. The paper then examines the precise relationship between the two new kinds of positive permission, as well as with the explicitly given positive permissions and the negative ones.
scientific article; zbMATH DE number 5720214