One of the hardest problems in the history of Western philosophy has been to explain whether and how experience can provide knowledge (or even justification for belief) about the objective world outside the experiencer's mind. A prominent brand of scepticism has precisely denied that experience can provide such knowledge. How, for instance (these sceptics ask) can I know that my experiences are not produced in me by a powerful demon (or, in a modern twist on that traditional Cartesian scenario, by a supercomputer)? This volume, originating from the research project on Basic Knowledge recently...