Tarski’s Definition Of Truth And Its Philosophical Value

Tarski’s semantic theory of truth and Godel’s incompleteness theorem and the Turing machine and the decision problem are known as the three major achievements of modern logic in terms of philosophy in 20th century. In order to hold the classical intuition of truth of Aristotle, Tarski presented creatively by the means of logical analysis and semantic analysis to make the word "true sentence" a materially adequate、formally correct definition in formal language. He also made famous hierarchy of language, created a semantic system in the modern sense, and thus showed the world the extraordinary charm of semantics, which have a broad and far-reaching impact on philosophy.The achievements of semantic theory of truth in mathematics and logic has been recognized, but in other aspect has triggered heated debate. One of the biggest controversy is whether semantic theory of truth is the correspondence theory of truth. Based on this debate, author create the paper. Firstly, considered the correspondence theory of truth and coherence theory of truth to be a representative of the traditional theory, the paper describes the traditional theory of truth and its problems, and distinguishes the two concepts definition of truth and the standard of truth. Secondly the paper describes how Tarski defined "truth". Tarski proposed the adequacy condition, namely the conditions all acceptable definition of truth should meet. Adequacy condition includes materially adequate and formally correct definition. Tarski then selected "satisfactory" as the intermediate concept to define "truth", and defined "satisfactory" in recursive method. Finally Tarski will "truth" as "satisfactory" extreme circumstances, got the definition of "truth":A closed sentence in object language is true, if and only if, it is satisfied by all sequences. At last, based on the definition of the concept of "satisfactory", the paper argues that the semantic theory of truth is the modern form of correspondence theory, because the concept of "satisfactory" precisely describes how to correspond which is difficult to explain in traditional correspondence theory. On the other hand, the semantic theory of truth and coherence theory is irrelevant.After Tarski, through the development of philosophers and linguists, many new theory of truth have been produced, such as deflationary theory of truth and reductionism. In comparison to these theories of truth, Tarski’s theory of truth is transcendent. Because the most modern theory of truth is to express their basic thoughts by an important concept in Tarlski’s theory,that is T equation. Therefore, understanding the semantic theory of truth is also of great significance to the study of other truth theory.