David Papineau presents a controversial view of human reason, portraying it as a normal part of the natural world, and drawing on the empirical sciences to illuminate its workings. In these six interconnected essays, he discusses both theoretical and practical rationality, and shows how evolutionary theory, decision theory, and quantum mechanics offer fresh approaches to some long-standing problems. This volume gathers together five essays on related topics that the author has published in various journals since 1997. In addition, chapter 5 (on causality) is entirely new. Chapter 4 on probability was originally written in collaboration with Helen Beebee. The book succeeds at presenting an articulated and coherent view in various areas of epistemology and philosophy of science, treating a series of issues ranging from the foundations of decision theory and probability to various interesting problems in the cognitive sciences. – The first three chapters center on classical epistemological issues as well as on certain aspects of the evolution of cognition. Together they present a forceful and original naturalistic account, which, at times, is directly at odds with widespread philosophical views on the nature of content, knowledge and the aims of inquiry. The last three chapters on probability, causation and quantum mechanics form another cohesive part of the book. Even when the topics discussed in these last three chapters are of a more technical nature, they are presented in a very accessible and readable manner. – Contents : Preface; Introduction. – 1. Normativity and Judgement; – 2. The Evolution of Knowledge; – 3. The Evolution of Means-End Reasoning; – 4. Probability as a Guide to Life (co-authored with Helen Beebee); – 5. Causation as a Guide to Life; – 6. Uncertainty Decisions and the Many-Minds Interpretation of Quantum Mechanics.