Preference Defeasible Deontic Logic

Deontic logic, also referred to as the logic of obligation or imperative, is thelogical study of the structures and effective patterns of normative reasoning. vonWright had said that deontic logic is the most problematic branch of logicphilosophical study. For exist different kinds of obligation conflicts in imperativereasoning. The most straightforward methods dealing with obligation conflicts is tointroduce the preference and defeasible relation between obligations, so that we canestablish preference-based deontic and defeasible deontic logic. Preference relationcan be differentiated two kinds. One is relation of specificity of fact which is used forstandarding condition of application. The obligation conflicts can be solved by setingup Deontic logic with reasoning of general knowledge or logical technology which isproduced in the field of artificial intelligence or computer. Another is ideal relationof standarding real situation, seting up deontic logic based on preference semantic.But the two kinds of deontic logic both have limitations. Defeasible deontic logic canonly deal with exception obligation reasoning; Preference-based deontic logic canonly deal with of country-to-duty obligation reasoning. When we combine them, theproblem of more complex preference is going to come out for their affecting eachother. Meanwhile some technology problems need to being solved aboutpreference-based deontic logic. The first, preference relation for sorting obligationsrequire assumption meet self-reflexive, transitive, and strong connectivity. In fact, theassumption is too strong, and cannot deal with the strong preference problem. Anotherproblem is that it cannot deal with conflicts of deontic which has symmetry andcannot compare. We call the kind of obligation conflict as deontic dilemma, anddeontic dilemma usually lead to serious deontic explosion, it means doing anythingbecome duty. The other way of deal with obligation conflicts is that building frame ofdeontic argumentation or priority relation of judging conflict by consumer ‘self, theway is logic of anti-complete form in essence. The paper insists on the basic point of view: normative reasoning that Deonticlogic studies is not only reasoning based on logical relation of obligation, is not onlyreasoning based on real situation fit condition of standard’s application yet, alsoneeds reasoning based on the form depict obligation is violated, reasoning based onexceptional obligation. We call the later four kinds of reasoning as reasoning withnorms. Studding reasoning with norms is not only because main pattern of normativereasoning is specific obligation application based on specific fact situation, andrealizes function of restriction, guidance, valuation that obligation treat subject, butalso because obligation itself has dependence of context, and complex of contextmainly exists in the course of obligation application, and it is basic reason whichleads to conflict of deontic. The Standard Deontic Logic just ignores dependence ofcontext, and leads to logicality are too strong. After that, Deontic logic which manylogicians found through making principle of deontic invalid, such as MinimalDeontic Logic is too weak, and makes some reasoning pattern desirable invalid.Therefore, founding defeasible characteristic of Deontic logic which establishreasoning of obligation become necessity. But all the dontic logic which wediscussed above can’t fully establish different pattern of normative reasoning.The paper use for reference from the theories above, and combine them, andThink the conflict of obligation doesn’t lead to collapse of logical system, and maylook power of restrain which embodies rules of Deontic of conflict as proving tobe. If not exsiting confliction, we shall applicate corresponding rule of reasoning ofobligation. If exsiting confliction, can applicate corresponding rule with sometechnology restrict, the technology is adaptive logic.The paper is based on adaptive logic, found Adaptive Dyadic Deontic Logic.ALCDPM is established as three groups<limit logic, abnormal sets, minimalabnormal set>, and limited logic which is founded on the base of two groupsDeontic logic of Lou Goble、Christian Stra er is system CDPM.2f which embodiesrule of fact detachment of different pattern of reasoning.on the base, we foundabnormal sets which establish differet rule of fact detachments, by basing oncharacteristic of different pattern of reasoning and making a distinction betweeninherent obligations and guiding obligations. The least abnormal tactics choice can guarantee to found pattern of reasoning of reasoning of obligation on the situation ofexsiting confliction. The main idea is explaining premise set correctly, throughprocess of developmental proving, application of deontic with condition. Whenabnormality doesn’t come out, can obtain a result as the same as obligation DeonticLogic. When abnormality come out, can abolish result which isn’t wanted on the baseof means marked, and avoid explosion of Deontic. Characteristic the system is: firstly,it can establish reasoning of malfeasance, reasoning of Deontic dilemma, reasoning ofexception obligation, reasoning of contained obligation. Secondly,it is strict systemof form, can establish condition of application of deontic rule as a part of proving, letproving itself add corresponding conduction of application not by consumer self.Thirdly, adaptive logic we choke is obligation form adaptive logic. When limited logicwe choke has self-reverse, transmit, tight handle, monotonous, can easily prove it hascorresponding quality. Compare with the close semantic field, ALCDPM has qualityof dependence, complete.fourthly, through application with condition not completelyeliminate rule of demotic inheritance、polymerization rule and so on, makeALCDPM retain merit of obligation Deontic Logic. Meanwhile establish defeasiblecharacteristic of reasoning of obligation through development proving. Fifthly,through making rule of fact separate and Deontic separate valid with condition, canfully establish reasoning of obligation and reasoning of application of obligation.Sixthly, through leading in two new deontic operators, establish a strictly deonticlogic relation. Through establish different abnormality, and found rule of reasoningwhich is applicated to different pattern of reasoning of obligation, can differentiatedreasoning of obligation of different pattern.