On Physics and Philosophy

Bernard d'Espagnat is Professor Emeritus of Physics at the University of Paris-Orsay, where he was director of the Laboratoire de Physique Theorique et Particules Elementaires (Laboratory of Theoretical Physics and Elementary Particles) from 1970 to 1987. His books in English include the classic "Conceptual Foundations of Quantum Mechanics" and "Veiled Reality".

• Preface to the English Edition xi Foreword 1 PART 1: PHYSICAL FACTS AND RELATED CONCEPTUAL PROBLEMS CHAPTER 1: Broad Overview 13 1-1. A General Picture 13 1-2. Some Useful Definitions 21 CHAPTER 2: Overstepping the Limits of the Framework of Familiar Concepts 32 2-1. Introduction 32 2-2. From Aristotle's Ontology to Descartes' Near Realism and Galilean Ontology 32 2-3. A Small Digression on Ontology 34 2-4. A Gradual Overstepping 37 2-5. Trajectories and Misleading "Pieces of Evidence" 38 2-6. On the Existence or Nonexistence of Hidden Things: Particles and Dirac's Sea 41 2-7. A "Fabricated" Ontology 46 2-8. Indications for What Follows 48 CHAPTER 3: Nonseparability and Bell's Theorem 51 3-1. Correlation at-a-Distance: Bell's Theorem 51 3-2. Locality and the Bell Theorem 58 3-3. Discussion and Philosophical Implications 71 CHAPTER 4: Objectivity and Empirical Reality 89 4-1. Strong Objectivity and Weak Objectivity (Alias Intersubjectivity) 89 4-2. The Measurement Problem and Empirical Reality 101 4-3. "Quantum Rules" and "von Neumann's Chain" 110 CHAPTER 5: Quantum Physics and Realism 113 5-1. Strong Objectivity and Realism 113 5-2. Intersubjective Agreement 127 5-3. Intersubjective Agreement and Empirical Reality 127 5-4. Conceptual Glimpses; Carnap, Quine, Primas; Relative Ontologies 129 CHAPTER 6: Universal Laws and the "Reality" Question 134 6-1. The "Theoretical Framework" Notion 134 6-2. Antiuniversalism and "Realism about Entities" 136 6-3. "Pythagorism" ("Einsteinism") 142 6-4. Remarks Concerning Two "Macrorealisms" 145 6-5. Quantum Mechanics as a Universal Theoretical Framework 146 6-6. Antirealism 148 CHAPTER 7: Antirealism and Physics; the Einstein-Podolsky-Rosen Problem; Methodological Operationalism 152 7-1. "Value of a Quantum Physical Quantity" in the Antirealist Framework 152 7-2. Operationalism (Alias "Instrumentalism") 156 7-3. On "Meaning" and "Prediction" 166 CHAPTER 8: Measurement and Decoherence, Universality Revisited 168 8-1. Introduction 168 8-2. Decoherence 177 8-3. Decoherence and State Robustness 189 8-4. The Everett-Zurek Semirealist Approach 190 8-5. Universality Revisited 192 CHAPTER 9: Various Realist Attempts 196 9-1. Introduction 196 9-2. On Our Intellectual Craving for Realism 196 9-3. The Broglie-Bohm Approach 199 9-4. The So-Called "Modal" Interpretation 206 9-5. The Heisenberg Representation: It Does Not, by Itself, Yield a Solution 209 9-6. Feynman's Reformulation and the Corresponding "Fabricated Ontology" 211 9-7. A "Realism of Signification" 216 9-8. Nonlinear Realist Quantum Theories 220 9-9. Outlook 222 CHAPTER 10: Schrodinger's Cat, Wigner's Friend, and Veiled Reality 225 10-1. Introduction 225 10-2. Of Pointers and Cats 225 10-3. Wigner's Friend 228 10-4. The Veiled Reality Hypothesis 236 PART 2: A PHILOSOPHICAL ANALYSIS CHAPTER 11: Science and Philosophy 249 11-1. The Impossible Split 249 11-2. Epistemology in the Late Twentieth Century 250 11-3. A Critical Glance at Some Claims 255 11-4. Physics and Linguistics 258 11-5. Sociologism 261 11-6. The End of Certainties? 263 CHAPTER 12: Materialisms 265 12-1. Introduction 265 12-2. Dialectical Materialism 265 12-3. The So-Called "Scientific" Materialism 266 12-4. "Neomaterialism" and Physics 272 12-5. The Purely Philosophical Aspects of Neomaterialism 276 12-6. Materialism and Wisdom 281 CHAPTER 13: Suggestions from Kantism 282 13-1. Introduction 282 13-2. A Look at Kantism 282 13-3. Facing the Refusal of the Independent Reality Notion 291 13-4. Kant and Our Contemporaries 306 CHAPTER 14: Causality and Observational Predictability 312 14-1. Introduction 312 14-2. Causes and Laws 312 14-3. Determinism and Causality 315 14-4. Determinism and Chaos 316 14-5. Quantum Indeterminacy 319 14-6. Predictability and Reliability Revisited 326 14-7. The Influence Notion Revisited 330 CHAPTER 15: Explanation and Phenomena 333 15-1. Introduction 333 15-2. The Notion of Explanation 333 15-3. Back to the "Explanatory Power of Predictive Rules" Question 342 15-4. Empirical Reality and Abstractions, Explanation, and Empirical Causality 344 15-5. The Rainbow Analogy 347 15-6. Removing the "Paradox of the Dinosaurs" 351 15-7. The "False Explanation" Question 352 CHAPTER 16: Mind and Things 354 16-1. Empiricism, Positivism, and So On 354 16-2. Phenomenalism 355 16-3. Ambiguities about Innatism 366 16-4. Poincare, Conventionalism, and Structural Realism 368 CHAPTER 17: Pragmatic-Transcendental versus Veiled Reality Approaches 376 17-1. Introduction 376 17-2. Replies to Michel Bitbol's and Herve Zwirn's Objections 376 17-3. The Pragmatic-Transcendental Approach 396 17-4. A Few Notes on Zwirn's Approach 402 CHAPTER 18: Objects and Consciousness 405 18-1. Introduction 405 18-2. Truth: Definitions and Criteria 406 18-3. Objects and "Orders," or "Levels," of Reality 408 18-4. A Few Remarks Concerning Sensations 411 18-5. On the Question of the Plurality of Minds 426 CHAPTER 19: The "Ground of Things" 429 19-1. Introduction 429 19-2. Mystery, Affectivity, and Meaning 429 19-3. Do Things Have a "Ground"? Pro and Con Received Arguments 434 19-4. Some Consequences of the Evolution of Physics 443 19-5. The Veiled Reality Conception Reexamined 449 APPENDIX 1: The Bell Theorem 465 A. Proof 465 B. A Simplified Proof 470 C. A Glance at the Experimental State of Things 473 D. Historical Comments and a Short Bibliography 474 APPENDIX 2: Consistent Histories, Counterfactuality, and Bell's Theorem 477 APPENDIX 3 Correlation-at-a-Distance in the Broglie-Bohm Model 483 References 485 Name Index 493 Subject Index 497

"Bernard d'Espagnat eschews the technical philosophical and mathematical jargon ... while nonetheless getting deeply into the consistency and plausibility of significant metaphysical claims. For all collections on the philosophy of science... Highly recommended."--Choice "In this valuable work, Bernard d'Espagnat brings his considerable expertise in contemporary physics to bear on the difficult philosophical issues arising from the current understanding of the subatomic domain."--Thomas Oberdan, Isis "Written in a very readable style, without an overload of mathematical equations, Of Physics and Philosophy unfolds the exotic features of quantum physics to the accompaniment of philosophical commentary. It is without doubt a work of immense scholarship, and will probably hold its own till the mysteries in the field are adequately understood. D'Espagnat's scholarship is helping understand the bizarre implications of quantum theory in investigating everything from free will and the paranormal to the enigma of consciousness."--Sudhirendar Sharma, Caravan