ST5: A 5-Valued Logic for Truth-Value Judgments Involving Vagueness and Presuppositions

摘要

Both presuppositional and vague expressions may yield non-classical truth-value judgments. Given that expressions of these kinds may combine together, I propose a single logical system intended to deal with them, which would account for our truth-value judgments. The system I propose is based on Cobreros&al's 3-valued system for vagueness, ST, which comes with a notion of assertoric ambiguity that I claim naturally deals with our non-classical judgments for vagueness. I show that the specificities of presuppositions with respect to truth-value judgments can be accounted for within this system if we add two logical values to it. I discuss a specific 5-valued system that I call ST5.