Bulletproof Grandfathers, David Lewis, and 'Can't'-Judgements

Abstract

In this discussion piece, I argue that David Lewis fails to support his claim that (relative to one context) time-travelling Tim cannot kill his Grandfather in 1921. This result, in turn, undermines Lewis’s contextualist solution to the Grandfather Paradox—i.e. conceding that Tim can and cannot kill Grandfather, but relative to different contexts in each case. Show more