A Possible-Worlds Solution to the Puzzle of Petitionary Prayer

Abstract

If the thing he prays for doesn’t happen, then that is one more proof that petitionary prayers don’t work; if it does happen, he will, of course, be able to see some of the physical causes which led up to it, and `therefore it would have happened anyway’, and thus a granted prayer becomes just as good a proof as a denied one that prayers are ineffective. -- CS Lewis, The Screwtape Letters