In the hands of philosopher Daniel Dennett, every aspect of human thought, from complex decision-making right through to the sense of self, receives a computational interpretation. Thought and consciousness, then, is indeed a reality and a tangible one at that. Wittgenstein set out in particular to undermine those seductive theories about mind and consciousness that philosophers since Descartes have puzzled and battled over. Unfortunately, many scientists have not appreciated Wittgenstein’s work.