HARMONIOUS RULES FOR IDENTITY

Abstract

AbstractLogical inferentialists claim that the meanings of the logical constants are given by their inference rules. To rule out tonk-like expressions, it is often demanded that pairs of inference rules must be harmonious. The usual inference rules for the identity predicate are not harmonious, but most inferentialists want identity to be logical. Stephen Read has tried to formulate alternative, harmonious inference rules for identity. It will be proved, however, that his rules are precisely as strong as the old rules and that, because the old rules are not harmonious (as Read argues), nor are his. Further, it will be shown that no sound rules will be any improvement. Identity remains in need of satisfactory inferentialist treatment.