COMMON GROUND AND MODAL DISAGREEMENT

ABSTRACT: The common ground in an inquiry consists of what the participants agree on, at least for the sake of the inquiry. The relations between the factual and linguistic components of common ground are notoriously difficult to trace. I clarify them by exploring how modal disagreements – disagreements about how things might be – interact with the linguistic and the factual common ground. I argue that modal agreement is essential to common ground of any kind. KEY WORDS: common ground, possible worlds, semantics I will begin my discussion of common ground and modal disagreement with an illustration of the complex interactions between beliefs about meaning and beliefs about the facts. Andy, Bob and Charles are discussing American politics, when Andy says, ‘Cheney is a vet. He served in Vietnam. ’ Bob and Charles dispute this, both saying ‘What? Cheney is not a vet. ’ But while Andy and Bob mean veteran by ‘vet’, Charles means veterinarian. We know how to describe these disagreements, and even what it takes to resolve them. Andy and Bob agree on the meaning of ‘Cheney is a vet’, but disagree about the facts while Andy and Charles disagree about the meaning of that sentence, but may otherwise agree on the facts. But now along comes Donald who says