Features And Changes Of Carnap's Logical Syntax

R.Carnap's logical syntax is a milestone in the history of logic and philosophy. Following Leibniz and Wittgenstein, Carnap agrees with solving philosophical issues by logical method. Using formal symbolic logic as a tool, with rigorous logical analysis for language, he constructs a formal and scientific language, which is a legitimate language applicable to each science. It is the logical syntax of language. Since the introduction of symbolic logic, logical syntax clearly shows formal feature. Affected by Wittgenstein, Carnap insists that a proposition:the discussion on logical syntax will not involve the meaning of language. No reference to meaning is involved in the result of formalizing, and is an important prerequisite for formal implementation. In addition, Carnap's logical syntax gets himself positioned as a universal and sciencetic of language which is necessarily intersubjective.Adopting the language as a logical calculus, the rules of logic as the syntax's rules, Carnap establishes a formal theory of language, completing Leibniz's idea of "common language ". He creates a new situation for formal language, and by the means of linking solving of philosophical problem and logic in strict sense, Carnal achieves the great linguistic turn in the contemporary philosophy.In fact, logical syntax is foundation of the logical semantics. Tarski's logical semantics shows to Carnap the necessity and possibility of the semantics. Tarski's definition of "truth" makes him finally confirmed that only semantics is what he is after. The logical truth is essentially a semantic notion, only in the semantics can be given the appropriate definition. Compared with Tarski, he understands the semantics more on the intention semantics. In the semantics, Carnap uses method of extension-intention to describe a variety of expressions'intentions and extensions. This approach describes formal intention's concept in history of logical for the first time, pioneers the study of logical semantics situation. Carnap makes great achievements in his lifetime.His thoughts is ambitious, profound, but also has limitations. For example, he can not give a general definition of "true" in result of the position of positivism in the syntactic stage; in the latter of his academic career, he transfers to the field of inductive logic, resulting in semantic research achievement has not been further carried forward.