Abstract

Two purported proofs of the incoherence of vague identity are considered. First gareth evans's attempt is criticized and reformulated to overcome certain formal difficulties. Despite the reformulation, However, Evans's proof is demonstrated invalid in accord with a supervaluational approach. Next nathan salmon's attempt is evaluated. Here the problem is salmon's implicit assumption of a version of leibniz's law which is stronger than that strictly guaranteed by the law as it is given in classical logic. The question is raised on what grounds this stronger version is to be considered a logical law: without it the proof fails