Rip van Winkle and the retention of ‘today’-belief: a puzzle

Abstract

Can a subject who expresses a belief with ‘today’ on a given day, and subsequently loses track of time, retain and re-express that belief on a future, potentially distant day? Since Kaplan’s tentative remarks on Rip Van Winkle, it has become popular to answer this question in the positive. However, a remarkably simple variation of the Rip Van Winkle story can show that this kind of view leads to a puzzling dilemma: either subjects cannot re-express a belief with utterances of ‘today’ on the same day, or else they may rationally exhibit conflicting stances toward the same ‘today’-belief. This result may be seen as supporting the claim that retention of ‘today’-belief over time requires the tracking of days. Yet it may also spur further research into the capacities involved in belief retention and re-expression to solve the puzzle.