Why Defeasible Deontic Logic needs a Multi Preference Semantics
نویسندگان
چکیده
There is a fundamental difference between a conditional obligation being violated by a fact, and a conditional obligation being overridden by another conditional obligation. In this paper we analyze this difference in the multi preference semantics of our defeasible deontic logic DEFDIODE. The semantics contains one preference relation for ideality, which can be used to formalize deontic paradoxes like the Chisholm and Forrester paradoxes, and another preference relation for normality, which can be used to formalize exceptions. The interference of the two preference orderings generates new questions about preferential semantics.
منابع مشابه
Possible World Semantics for Defeasible Deontic Logic
Defeasible Deontic Logic is a simple and computationally efficient approach for the representation of normative reasoning. Traditionally defeasible logics are defined proof theoretically based on the proof conditions for the logic. While several logic programming, operational and argumentation semantics have been provided for defeasible logics, possible world semantics for (modal) defeasible lo...
متن کاملDynamic Normative Reasoning Under Uncertainty: How to Distinguish Between Obligations Under Uncertainty and Prima Facie Obligations
The deontic update semantics is a dynamic semantics for prescriptive obligations based on Veltman's update semantics, in which the dynamic evaluation of connicts of hierarchic obligations naturally leads to defeasibility. In this paper we use this dynamic semantics to study the diagnostic problem of defeasible deontic logic. For example, consider a defeasible obligationòught to be done' togethe...
متن کاملDefeasible Deontic Reasoning
This paper combines a system of deontic logic with a system for default reasoning to analyze a notorious philosophical problem: Chisholm’s Paradox. The basic approach is to write deontic rules with explicit exceptions, but we also consider the extent to which a set of implicit exceptions can be derived from the underlying deontic semantics.
متن کاملContrary-to-Duty Obligations
We investigate under what conditions contrary-to-duty (CTD) structures lacking temporal and action elements can be given a coherent reading. We argue, contrary to some recent proposals, that CTD is not an instance of defeasible reasoning, and that methods of nonmonotonic logics are inadequate since they are unable to distinguish between defeasibility and violation of primary obligations. We pro...
متن کاملRepresenting business contracts in RuleML
This paper presents an approach for the specification and implementation of translating contracts from a human-oriented form into an executable representation for monitoring. This will be done in the setting of RuleML. The task of monitoring contract execution and performance requires a logical account of deontic and defeasible aspects of legal language; currently such aspects are not covered b...
متن کامل