Abstract

The denitional feature of Tarski's theory of truth will be the subject of this paper. In fact, addition, multiplication and divisibility were well-known mathematical concepts before the accurate Peano formalization. Analogously, the Tarski's metatheory could be an accurate formalization of ‘ x is a formula’, ‘x is the reference/sense of y’ and ‘x is a true sentence’, all them introduced by definition. However, ‘x is a true sentence’, because of the paradoxes, cannot be an accurate formalization of truth predicate of ordinary language. The question is: which concept of truth does the tarskian ‘x is a true sentence’ formalize? The answer is simple and not new, but its meanders are informative and enlightening.