STALNAKER’S THESIS IN CONTEXT

Abstract In this paper I present a precise version of Stalnaker’s thesis and show that it is both consistent and predicts our intuitive judgments about the probabilities of conditionals. The thesis states that someone whose total evidence is E should have the same credence in the proposition expressed by ‘if A then B ’ in a context where E is salient as they have conditional credence in the proposition B expresses given the proposition A expresses in that context. The thesis is formalised rigorously and two models are provided that demonstrate that the new thesis is indeed tenable within a standard possible world semantics based on selection functions. Unlike the Stalnaker–Lewis semantics the selection functions cannot be understood in terms of similarity. A probabilistic account of selection is defended in its place. I end the paper by suggesting that this approach overcomes some of the objections often levelled at accounts of indicatives based on the notion of similarity.