Norwood Russell Hanson was one of the most important philosophers of science of the post-war period. Hanson brought Wittgensteinian ordinary language philosophy to bear on the concepts of science, and his treatments of observation, discovery, and the theory-ladenness of scientific facts remain central to the philosophy of science. Additionally, Hanson was one of philosophy¿s great personalities, and his sense of humor and charm come through fully in the pages of Perception and Discovery.
Perception and Discovery, originally published in 1969, is Hanson¿s posthumous textbook in philosophy of science. The book focuses on the indispensable role philosophy plays in scientific thinking. Perception and Discovery features Hanson¿s most complete and mature account of theory-laden observation, a discussion of conceptual and logical boundaries, and a detailed treatment of the epistemological features of scientific research and scientific reasoning. This book is of interest to scholars of philosophy of science, particularly those concerned with Hanson¿s thought and the development of the discipline in the middle of the 20^th century. However, even fifty years after Hanson¿s early death, Perception and Discovery still has a great deal to offer all readers interested in science.

Introduction.- Part 1. Provocations and Restraints: 1. On Philosophizing-and Some Logical Distinctions.- 2. Defining Conceptual Boundaries.- 3. Measuring and Counting: More Boundaries.- Part 2. The Act of Scientific Seeing: 4. There Is More to Seeing than Meets the Eye.- 5. Seeing the Same Thing.- 6. Seeing and Seeing As.- 7. Seeing As and Seeing That.- 8. Seeing, Saying, and Knowing.- 9. Spectacles behind the Eyes.- 10. Can We See Facts?.- 11. Facts and Seeing That.- Part 3. Perplexity: the Process of Experimental Research: 12. Waves, Particles, and Facts.- 13. Hypotheses Facta Fingunt.- 14. Scientific Simplicity and Crucial Experiments.- 15. The Systematic Side of Science.- 16. Discovering Causes and Becauses.- 17. What Happens as a Rule.- 18. Theory-Laden Language.- 19. The Scientists' Toolbox.- 20. Laws, Truths, and Hypotheses.- 21. Principles as Platitudes.- Part 4. Probability and Probable Reasoning in Science.- 22. Frequencies and the Mathematics of Probability.- 23. Using and Interpreting the Probability Calculus.- 24. Elements of Statistical Technique.- 25. The Principle of Uniformity Revisited.- Editor's Epilogue.- Index.