Perhaps such a proposition is not expressible in any language that you or I speak, but – so a familiar story goes – it is decided by each world, so it plays just the role that other propositions do, so it counts as a proposition in the same way. In fact, we can see just how it counts as a proposition: given all the worlds in S, our proposition p says that the world is one of the worlds in S. It describes a way the world is, even if we have no means of picking out the set S, so it is a proposition.1...