Skepticism, the view that reliable knowledge is beyond our grasp, has defied refutation throughout the history of philosophy. Professor Rudd argues that skepticism cannot be avoided as long as knowledge is considered purely as an intellectual matter, but that genuine knowledge can be established if it is thought of as being essecially tied to patterns of practical activity and to our emotional live. He outlines a provisional defense of skepticism, then relates it to work by Heidegger and Wittgenstein. Skepticism about "other minds" is dealt with by developing Wittgenstein's approach, with the result that we have to reject the assumption that true knowledge requires a detached observer. Finally, the author considers whether our knowledge of the physical world can be understood in a way analogous to our knowledge of other minds. Here he suggests that there are important similarities between Wittgenstein's reminders of the "expressive" character of our experience and Heidegger's account of ways in which we can experience the physical world "expressively".