This lucid, informal, and very accessible discussion of Western thought takes the unique approach of interpreting skepticism -- i.e., doubts about knowledge claims and the criteria for making such claims -- as an important stimulus for the development of philosophy. The authors argue that practically every great thinker from the time of the Greeks to the present has produced theories designed to forestall or refute skepticism: from Plato to Moore and Wittgenstein. The influence of and responses to such 20th-century skeptics such as Russell and Derrida are also discussed critically.Popkin and Stroll review each major theory of philosophy chronologically and then further organize these theories into their respective subject areas: metaphysics, epistemology, ethics, political philosophy, and philosophy of religion. This is an outstanding introduction to the problems of philosophy by two eminent philosophers with a gift for presenting the history of ideas in a very lively and clear style.