A Study On Carnap's Logical Semantics

Carnap opposed the traditional metaphysics view,and he thought that the only task of philosophy was to make a logical analysis of scientific language.By the influence of rejecting metaphysics,he studied logic.In addition,because of the transformation from extension at logic to intension at logic,Carnap's research on logic also transformed from syntax to semantics.Carnap's research on logical semantics was mainly influenced by Frege's distinction between sense and reference and Tarski's definition of true.Carnap constructed the semantic system S₁ which contains two parts:object language and semantic rules.Based on the semantic system,Carnap proposed the method of Extension and Intension.In this method,Carnap defined the basic concepts of L-true,equivalent and L-equivalent,and used these concepts to assign two different entities as expressions'extension and intension respectively.These expressions which appear individually include predicate expression,sentence expression and individual expression.In order to examine expressions that do not appear individually but in other types of expressions,we should link them with specific contexts.Carnap classified three distinct contexts:extension context,intension context and belief sentence context,and investigated the problem of expressions'interchangeable in these contexts.Carnap's logical semantics influences the development of logical research and philosophical research.First,the method of Extension and Intension he proposed overcomes the defects of the method of the Name-Relation,thus becoming the basic method in the research of logical semantics.Secondly,the method of Extension and Intension portrays its intension successfully,which is of great value for solving the analysis of paradoxes.Finally,Carnap's logical semantics also has an important influence on the related work of contemporary philosophers.