A Research On Cohen's Theory Of Inductive Grading

This paper discusses three main problems. Firstly, the backgrounds of Cohen's theory of inductive grading is introduced. It comes from two aspects of motivation: one is the shock of Popper's scientific falsification, and another is the problems in theory of Hempel's explanation.Next, the theories on inductive grading of Cohen are divided into two parts—inductive support grading, and grading after adding them of probability.When analyzing the theory of Cohen's inductive support-grading, this paper begins with the definition of inductive-support, then it introduces an important concept of"relevant variables", adding it to the idea of inductive support grading. Cohen suggested negative principle, disjunction principle in the inductive support-grading syntax. They have two characteristics, which are regarded as important distinctions between non-Pascalian probability logic and Pascalian probability logic.When elaborating the inductive grading, which are added with probability, it illustrates how to determine the grading of inductive probability by examples. In the following contex, the characters of probability in inductive grading theory are analyzed. At the end of this part, the rules are contrasted of probability calculus between Cohen and Carnap.At last, Cohen's inductive grading is evaluated objectively. They are divided into three aspects: monotone, openness, initiative. As for the significance, the inductive grading inherits thinking of Bacon's experiment, partially solving Humes's problem. Certainly, there are also disadvanges for Cohen's inductive grading. That is, its weakness can be seen weak when we compare relevant variable which is definite in different scope. In addition, Cohen over-relied on method of exclusion, ignored the enumeration method and the individual differences in the evidence are also disadvantages for his theory. Inductive grading theory is of great importance status in Cohen's inductive system. The reasons why we analyze it are to explore the value of its methodology, so that it can guide our practice scientifically.