Abstract

When knowledge is being doubted one way to express this doubt is by a counterfactual. Typically this counterfactual quotes some elements of the actual case or a case considered as actual and dodges the connection between proposition believed and what makes that proposition true. For example, when Descartes states his dreaming skepticism case, he gives us instances where he has previously been lying in his bed fast asleep while dreaming that he is awake. What triggers the loss of knowledge in Descartes’ case is that if he were asleep, he would still believe that he is sitting by the fire, holding a paper in his hand etc. The fact that he cannot distinguish between his dream-state and awake-state entails that he doesn’t know in the awake-state, considered as actual, either. So, a description of counterfactual possibilities that can be used to doubt knowledge in a possibility considered as actual has to make the truth of p indistinguishable from the falsity of p. Any possibility that falls under this description will be called transparent. Here is a definition: For any possibility W and any proposition believed p, W is transparent iff, in W the truth of p is indistinguishable from the falsity of p