Inquiry Of Deontic Logic Tolerating Normative Conflicts

When faced with multiple norms that cannot be implemented at the same time,it can be considered as a normative conflict.In Standard Deontic Logic,normative conflicts are regarded as logical contradictions that cannot exist.However,they seem to be commonplace in daily life.If normative conflict is possible,then some normative deduction systems that are different from Standard Deontic Logic and applicable for reasoning in normative conflicts are attractive theoretical choice.In the first chapter,normative conflict and typical deontic paradox are analyzed from the perspectives of constitution and solution,trying to distinguish them and get rid of the research perspective of normative conflict as a kind of deontic paradox.After that,several main attitudes towards normative conflict in deontic logic are sorted out and introduced,and supports for the position of normative conflict is possible are provided to some extent.In the second chapter,through the analysis of two important semantics of Standard Deontic Logic,why Standard Deontic Logic cannot tolerate normative conflicts are explained from the semantic perspective.The third chapter,from the syntactic perspective,L.Goble’s three requirements for deontic logic systems to tolerate normative conflicts are expounded.According to the requirements,some deontic logic systems that try to tolerate normative conflicts are investigated syntactically and semantically.In addition,some problems in L.Goble’s DPM are pointed out.There is a tension between the core principle used by DPM and its basic position of tolerating the normative conflicts,which also lays hidden problems for the approaches of adaptive logic that is followed.In chapter four,some of the more radical approaches are investigated.The approaches under the paraconsistent logic have a common difficulty that cannot be overcame.In these deontic logic systems,Deontic Disjunctive Syllogism does not hold,which causes these approaches are too weak to tolerate normative conflicts adequately.Under the approaches of nonmonotonic logic,the default deontic logic utilizing default logic,which set out by J.F.Horty,can deal with reasonings in many simple normative conflicts,but it is too sensitive to the expressions of norms as premises,and when facing normative conflicts that are not direct conflicting,the reasoning ability it shows is still too weak.At the same time,lacking of proof theory is also a serious shortcoming.C.Stra（?）er,M.Beirlaen and L.Goble et al.set out some adaptive deontic logics by utilizing adaptive logic to nonmonotonically enhance some previous systems that were too weak.These deontic logics benefit from adaptive logic that can temporarily use some "problematic" principles,which can deal with the reasonings of various normative conflicts more flexibly,and can adequately tolerate normative conflicts at technical level.However,whether utilizing the resources of adaptive logic to tolerate normative conflicts is an appropriate solution remains to be considered.In this approach,normative conflicts are set as abnormalities,assuming that normative conflicts are not usual existence,which is contrary to the original motivation to tolerate normative conflicts,in which the tension is more pronounced than in DPM.