In so far as philosophers can agree about anything, a majority would agree that the two most influential philosophers of the twentieth century were Ludwig Wittgenstein and Martin Heidegger. Both possessed unmatched philosophical profundity, both challenged and overturned fundamental areas of philosophical discourse and both changed philosophy forever. Both were charismatic teachers who generated and inspired a legion of followers and both spawned trajectories of philosophical research which remain vital to this day. And one of them – Martin Heidegger – supported the most evil regime in history.