I am amazed and delighted by the many excellent responses to my call for arguments about religion. These will be very helpful to me as I prepare for my debate with Dinesh D’Souza. Keep them coming!
Commenters also had a lot to say about the puzzle of the absent-minded driver. It seems to me that some of the analyses falter by being less than crystal clear about their assumptions: How much can the driver remember (e.g., if he updates his strategy at the first intersection and then arrives at the second, does he remember his original strategy or his updated strategy?), how much he can commit to (e.g. if he updates his strategy at the first intersection, can he commit to sticking to the new strategy at the second? can he commit to the method of updating he’ll use at the second?), how much he can anticipate (e.g. what does he believe about his future updates?), how smart he is (can he use his knowledge of his current strategy to figure out whether he’s already updated and hence what intersection he’s at?) and how sneaky he is (e.g. might he purposely adopt a bad strategy in order to trick his future self into updating to a good one?). I have what I think is a useful way of forcing puzzlers to be explicit about their assumptions, and had planned to post it on Monday, but I keep revising it, so it might be a few more days.