Common ground and epistemic reasoning: a cognitive-pluralist approach

In challenging the common ground theory of speech acts, Levinson poses a further, cognitive challenge: How can interlocutors keep track of all the conversational elements that must be stored in common ground, given the taxing demands of producing and understanding language in the naturally fast pace of conversation? In response to this challenge, I propose to adopt a cognitive-pluralist approach to common ground, which I illustrate with three pragmatic phenomena that require more or less efficient mechanisms for epistemic reasoning.