Blackwell Reference Online

Extract

The concept of truth serves in logic not only as an instrument but also as an object of study. Eubulides of Miletus (fl. fourth century BCE), a Megarian logician, discovered the paradox known as ‘the Liar,’ and, ever since his discovery, logicians down the ages - Aristotle and Chrysippus, John Buridan and William Heytesbury, and Alfred Tarski and Saul Kripke, to mention just a few - have tried to understand the puzzling behavior of the concept of truth. In Eubulides’ paradox, it is supposed that a person X says What I am now saying is false. and he says nothing more. The supposition is plainly coherent, but it leads via highly plausible arguments to absurd conclusions. If what X says is true, then X's statement must be assessed to be false (because X claims to have said something false). But if what X says is false, then X's statement must be assessed to be true (because, again, X claims to have said something false). The truth of X's statement implies, therefore, its falsity, and the falsity of X's statement implies, in turn, its truth. The original supposition seems thus to imply a contradiction. The very simplicity of Eubulides’ paradox has provoked numerous simple ‘solutions’ of it. There is, for instance, the idea (put forward by Bar-Hillel and others) that the paradox is removed, and the entire problem solved, simply by noting that truth is a property of ... log in or subscribe to read full text