A Logical Study On The Inference Of Indirect Evidence

Indirect evidence widely exists in litigation cases,but how to reasonably use it to determine the facts of a case has become a major problem in legal practice.On the one hand,the use of indirect evidence has the risk of excessive "inference" which leads to wrong cases.Indirect evidence has the word "indirect",which is not as good as direct evidence,there is always a logical "jump" between indirect evidence and the facts to be proved,so more inference is needed,but each step of inference has the risk of leading to a wrong case;on the other hand,if indirect evidence is abandoned too carefully,there is also a wrong case caused by the fact that should be identified but not.From a logical point of view,both direct evidence and indirect evidence need to be inferred,and there is no priority between them in the power of proof.In practice,we all prefer direct evidence,and even exclude indirect evidence on the grounds that the proving power of direct evidence is greater than indirect evidence.The reason lies in the tension between the two purposes of evidence law.The principle of the best evidence is sometimes used to distribute the risk of error more fairly,but for the purpose of accurately determining the facts,the two are equal and there is no priority.The scope of indirect evidence is very broad,including almost all the existing types of evidence,because all evidence needs inference.The only difference between direct evidence and indirect evidence may be the length of its inference chain.Inference is the logical feature of indirect evidence,and indirect evidence inference is a special form of inference.To be exact,indirect evidence inference is a kind of plausible inference.Plausible inference is to deduce other plausible propositions from some plausible propositions.Before being attacked and weakened by other propositions,we can temporarily accept the proposition as true.The difference between them can be regarded as the difference between necessity and probability.Indirect evidence inference has the characteristics of probability,because the process from indirect evidence to facts to be proved always depends on generalization,which becomes the "glue" between indirect evidence and facts to be proved.Generalization is the proposition of probability,rather than the universal proposition that constitutes the major premise in deductive reasoning.Through plausible inference,the plausibility of evidential facts and generalization are transferred to the conclusion.From the micro level,indirect evidence inference consists of major premise,minor premise and conclusion.The major premise is generalization,the minor premise is evidential fact,and the conclusion is the fact to be proved.Generalization is the summary of human’s general experience,the knowledge base of human beings,the evidence fact is the most direct information indicated by indirect evidence,and the fact to be proved is the legal decomposition of the final fact to be proved.From the macro level,the single indirect evidence inference can use different argumentation schemata,and different argumentation schemata have different applicability in different types of dialogue.The relationship between the single indirect evidence and the final facts to be proved is expressed in the form of a chain of inference,and the conclusion of one inference becomes the premise of the next inference.The facts inferred from the single indirect evidence are called intermediate facts.Different intermediate facts and the final facts to be proved are combined in the way of demonstration.The argumentation structure is divided into combined argumentation and convergent argumentation.If two intermediate facts can independently support the final facts to be proved,then this argumentation is combined argumentation.If two intermediate facts must be combined to support the final facts to be proved,that is,without one intermediate fact,neither can support the final facts to be proved,then this argumentation is convergent argumentation.From the static point of view,the conclusion of indirect evidence inference is plausible.According to the theory of plausible inference,the plausibility is not expressed by probability,but by plausibility.The plausibility is cumulative and progressive,and the final facts to be proved can be determined on the basis of these indirect evidences after reaching a certain standard of proof.First,by analyzing the single indirect evidence inference,and then through different argumentation combinations,the final purpose of proving the final facts to be proved is achieved in the way of plausible inference.From the dynamic point of view,indirect evidence inference mainly occurs in the trial.Both parties of the trial argue with each other,and each party has the right to attack or weaken the other party’s indirect evidence inference.The intermediate parties may recognize,withdraw and refute the fact claims,so the fact finding is in a dynamic process,and the parties have the obligation to persuade the fact finding on the basis of abiding by the rules of debate in the trial.If the fact determiner finally finds that the fact claim of one party is more acceptable and forms inner conviction,then the final facts to be proved obtained by the winning party through indirect evidence inference will be proved.Based on the analysis and evaluation of indirect evidence inference,in order to make better use of indirect evidence to determine the facts of the case,we need some guidance of inference rules.Therefore,on the basis of the logical interpretation of the final rule of indirect evidence,this paper puts forward four suggestions on the inference rule of indirect evidence,one is to show the inference path of indirect evidence in a schema way;the other is to establish the inference of indirect evidence on a solid generalization;the third is to develop the inference of indirect evidence in the process of full argumentation;the fourth is to adhere to the principle of free proof and inner conviction.Finally,a classic case study is used to show the process of indirect evidence inference.