EN
Tichý’s solution of two basic kinds of liar paradox is based on the ramified theory of types, which is his own explication of the original proposal of Russell’s. This ramified theory of types is used for the rigorously explained concept of ‘languages’ and the languages in question seem to be similar, in hierarchy at least, to Tarski’s languages. But Tichý avoided the disadvantages of Russell’s and Tarski’s solutions of the liar paradoxes, and he in fact stands between them, at the golden mean. The main point is that Tichý’s own solution is in no way ad hoc because he first provided a crucial reason for hierarchies and only then refuted the paradox. Any language L is construed as mapping from expressions to (logically-explicated) meanings. Because no function is allowed to be among its own values, the name of language L, i.e. ‘L’ (and then any other containing ‘L’), is thus meaningless in L (‘L’ is meaningful only in the metalanguage of L, i.e. ML; but again, ‘ML’ is not meaningful in ML). No sentence is true simpliciter, the truth of a sentence is relative to what it says (means) in a given language. The disambiguated liar sentence contains ‘truth in L’, thus it is clearly meaningless in L. Since a meaningless sentence cannot be true or false, the liar paradox cannot arise. After a detailed exposition and, above all, a thorough defence of Tichý’s approach, we successfully apply the method of his solution to other known kinds of liar paradox.