If the prisoner convinces himself on each day, “I will be hanged today,” then it is not be possible to surprise him. Paradoxes like this tend to make implicit u

If the prisoner convinces himself on each day, “I will be hanged today,” then it is not be possible to surprise him. Paradoxes like this tend to make implicit use of assumptions regarding perfect rationality, deduction, and common knowledge, and I think the underlying problem here comes from a violation regarding these.