… if your beloved survived, prayer is unnecessary; whereas, if she didn’t survive, prayer will be ineffective …until we realize that, in this special context, backwards causation is a real possibility. Since God can literally see into the future, he may have foreseen your prayer at the time of the calamity and may have answered it in advance. In this case, your prayer reaches back into the past and causes God to act then. Amazingly then, as we saw, there is a point to praying, even though your beloved’s survival (or otherwise) is something that has already happened.
I have put this problem to a large number of people, both friends and students in class. To almost everyone it is perfectly clear and obvious what should be done. The difficulty is that these people seem to divide almost evenly on the problem, with large numbers thinking that the opposing half is just being silly.More recently, and rather notably, the longstanding British newspaper The Guardian challenged its avid readers to resolve Newcomb’s paradox and discovered much the same, as did a subsequent rigorous PhilPapers poll of professional philosophers. Both of these polls used the standard version of the paradox, which is explained in the Guardian piece, unlike the simple version I have used above, but this difference is negligible. Half a century on, people continue to be split on this most contemporary of paradoxes.