Belief Worlds and Epistemic Possibilities :: Philosophy Philosophical Essays

Belief Worlds and Epistemic Possibilities ABSTRACT: This paper develops an individualistic, belief-based account for a limited class of epistemic possibility statements. Section I establishes the need for such an account by reviewing a recent version of the majority view (the "Relevant Community Account") and contesting two key assumptions. I argue that some epistemic possibilities are belief-based-contra the assumption that all are knowledge-based. Against the assumption that all epistemic possibility statements are analyzable in terms of the speaker's "relevant community," I contend that the truth value of some statements is a function of the speaker's epistemic states alone. Section II develops an alternative account designed to capture those internal, individual statements. Modeling belief sets as "belief worlds," I explain our epistemic processes in terms of an ability to shift attention among our various belief worlds. Ever since G. E. Moore set out to explain the phrase "it's not certain that" and ended up offering a definition of epistemic possibility, ordinary uses of epistemic modal sentences have commanded more attention. A number of more recent accounts-which I'll call the "Moorean accounts"-follow Moore by analyzing all statements having the form "It's possible that p" uniformly. Their analysis is uniform in that they make two assumptions: first that some community is relevant in every case, and second that every statement is analyzable in terms of knowledge. I think that both assumptions are false, so one thing I'll do today is to suggest truth conditions for statements failing of both assumptions-"individual, doxastic possibility statements." I will have time to contest only the first assumption, though, and will therefore help myself to my conclusion regarding the second; I will assume that the locution "It's possible that p" is not restricted to expressions of epistemic, that is, knowledge-based possibility, but may be used to express doxastic or belief-based possibility as well. The first assumption-that some community is relevant to every use of "It's possible that p"-will be my main concern, then. To make the assumption in its stronger form, as Ian Hacking and Paul Teller do, is to treat all uses of "It's possible that p" as statements to be translated as "For all we know, p." But the locution "It's possible that p" is used not only for statements of that sort-for, in my terminology, "community statements"-but also for what I'll call "individual statements"-statements properly translated as "For all I know, p." The assumption that some community is relevant to every use of "It's possible that p" is also made by Keith DeRose, but in a weaker form.