  Van Inwagen himself applies the modal skepticism a bit differently. It could be that he accepts a theory of knowledge relevantly similar to that of David Lewis on which one must rule out all relevant, or in van Inwagen's case “real,” possibilities, but there is another way to take it. He tells a story according to which the world has the amount and distribution of evils we think it has and God exists which, he says, is a “real, possibility,” that is, something that might be true for all we know. The idea of a real possibility is best illustrated by what a TV lawyer would call an “alternative theory of the crime” (van Inwagen, in discussion) which is plausible enough to cause doubt, in the sense of inability to assent, to the proposition that the accused is guilty.