Abstract

According to orthodox semantics, to know the meaning of a sentence is to know its truth-conditions. Against this view I observe that we typically do not know the truth-conditions of the sentences we understand. We do not know the truth-conditions, for instance, of empty definite descriptions, non-declaratives, subjunctive conditionals, causal ascriptions, belief ascriptions, probability statements, figurative language, category mistakes, normative judgments, or vague statements. Appealing to tacit knowledge does not help, for the problem goes beyond our inability to articulate complete truth-conditions: even full knowledge of the world’s condition would leave us unable to say whether an arbitrary sentence was true or false.