Gilbert Harman teaches at Princeton University, USA. He has published on statistical learning theory and moral philosophy as well as reasoning and recently co-edited A Companion to W. V. O. Quine (Wiley Blackwell)

Originally published in 1990. This study takes us through the argument for the possibility of scepticism, including looking at sense data and considering memory and perception.

Preface 1. Skepticism and Epistemology 2. The Warranted-True-Belief Conception 3. Hypothetic Inference 4. Psychological Concepts 5. Sense Data 6. The Definition of Knowledge 7. The Possibility of Skepticism