Embedding Epistemic Modals

Seth Yalcin has pointed out some puzzling facts about the behaviour of epistemic modals in certain embedded contexts. For example, conditionals that begin 'If it is raining and it might not be raining, …' sound unacceptable, unlike conditionals that begin 'If it is raining and I don't know it, …'. These facts pose a prima facie problem for an orthodox treatment of epistemic modals, according to which they express propositions about the knowledge of some contextually specified individual or group. This paper develops an explanation of the puzzling facts about embedding within an orthodox framework. According to orthodoxy, words like 'might' and 'possible' admit " epistemic " uses, on which 'it might be the case that ϕ' and 'it is possible that ϕ' express roughly the same thing as 'S does not know that not-ϕ', or 'S is not in a position to know that not-ϕ', for some contextually relevant individual or group S. 1 Seth Yalcin (2007) has introduced some new data that seem to challenge this equivalence. The data involve certain embedded occurrences of sentences like (1)a and (1)b: (1) a. It is raining and it might not be raining b It is raining and I don't know that it is raining 1 Read quotations that include Greek variables as quasi-quotes.