The Defeasibility Of Legal Reasoning

As a new kind of informal reasoning，the further research of defeasible reasoningplays an important role in the optimization of legal reasoning, the development oflegal argumentation theory, the ascension of judicial justice and consultative judicialpractice. Emphasis on or attach importance to "Defeasible", do not mean to make acomplete denial of the determinacy of legal reasoning, but to seek an appropriate,reasonable and fair judicial verdict by enhancing the legitimacy and persuasion of reasoningconclusion through dialogue, negotiation, debate and the complement of informationafter realizing the defeasibility of legal reasoning.The word "Defeasible" comes from an English word, which aims to illustrate theconclusion could be falsified, weakened, invalid or declared null and void, but it doesnot mean that it must be overthrown. Hart, John Pollock, Feinberg, Giovanna haveelucidated "Defeasible" from different angles, which make connotation and value of"Defeasible" more clear and abundant. And through an organic combination of legalreasoning and "Defeasible", there comes a new reasoning model， defeasiblereasoning.The birth and development of defeasible reasoning, is closely related to theevolution of legal reasoning, especially the criticism of realistic jurisprudence and theresponse of new analytical jurisprudence. The rise of non monotonic reasoning, thedevelopment of artificial intelligence, linguistic turn of philosophy and the activity ofthe legal argumentation, provide thinking method, practice areas, linguistic tool andjustification of legitimacy to the research of defeasible reasoning, which gained aboarder space neither from the formal logic nor the applicable fields.The three dimensions of research about the uncertainty of legal norms, the construction of legal facts and the defeasibility of reasoning conclusion, make us easyto go deep into the kernel of defeasible reasoning and chew the essence. Due to thefuzziness of language, the legal loophole, legal conflict and the judge’s personalpreferences, the specification of norm is uncertain (only in the relativesense).Generally, we can’t revivify or construct the legal facts clearly and accuratelyfor the restriction of limited exploring means of evidence and the procedural rules.Based on the foregoing reasons, the conclusion of reasoning always facing thechallenge of diversification, acceptability and reversibility.The defeasibility make us realize that legal reasoning is not conclusive orirreversible, although the syllogism reasoning can guarantee the legitimacy andrationalization of the conclusion in formal, the major and minor premises of thereasoning is likely to be questioned, which leads to the unreliable of the inferenceconclusion. Through the fully tap, dialogue, cross-examination, debate of the legalnorms and facts, and seriously considering of the new information, new factors andthe future possibility of the case, we can promote optimization of legal reasoning andthe development of legal argumentation on the one hand, and guarantee the judicialfairness and unjustly charged cases could be effectively avoided or timely corrected ingreatest possibility on the other hand.The emphasis on defeasible reasoning should be limited in some degree theexcessive pursuit of it may fall into legal skepticism (nihilism) or the fact agnostic.Which on the one hand leads to the indeterminacy of judicial verdict and weaken orerosion of the authority, dignity and res judicata of the judicial, on the other hand willinduce vexatious suit or rampant litigation, making it hard to settle disputes or recoverorder as soon as possible and overwhelming the already scarce and weak judicialresources，the stability and development of the order of rule of law was threatened.The fully study and controllable use of defeasible reasoning could provide new ideasand methods for the judicial practice, which will lead to a more fair, reasonable andacceptable judicial verdict.