Bernard d'Espagnat, Emeritus Professor at the University of Paris, Orsay, was born in Fourmagnac, France, on August 22, 1921. He received his Ph.D. in physics from the Sorbonne in 1950. He was a research physicist at the French National centre for Scientific Research, at the Fermi National Accelerator labouratory in Chicago, at the Niels Bohr Institute in Copenhagen, and at CERN in Geneva. In 1959, d'Espagnat joined the University of Paris, where he was professor at both the Paris and Orsay campuses. Professor d'Espagnat was director of the labouratoire de Physique Theorique et Particules Elementaires, Orsay, from 1970 to 1987. In 1996 he was elected into the Institut de France (Académie des Sciences morales et politiques) as a philosopher of science.

• Editor’s Foreword , 1999 Special Preface , Vita , Pedro’s Debate (Preface to Second Edition) , Preface (To First Edition) , Elements of Quantum Mechanics , Matter Waves , Superposition and Linearity , Statement of the Rules , Comments , Alternative Formulations , Density Matrices and Mixtures , The Density Matrix Formalism , Mixtures , Quantum Nonseparability , The Einstein-Podolsky-Rosen Problem , Possible Views on Nonseparability , Individuals, Ensembles, States , The “Hidden Variables” Approach , Direct Study of Some Principles , Aspects of the Problem of Retrodiction , Measurement Theories , Elements of Measurement Theory , Classical Properties , Macroscopic Instruments , Of Cats and Pointers , Nonideal Measurements: Small Influence of Outside World , Knowledge and the Physical World , Reality and Objects , Positivism , Bohr and Heisenberg , Wigner’s Friend , The Relativity of States , Summary and Outlook , Summary , Outlook

Bernard d'Espagnat, Emeritus Professor at the University of Paris, Orsay, was born in Fourmagnac, France, on August 22, 1921. He received his Ph.D. in physics from the Sorbonne in 1950. He was a research physicist at the French National centre for Scientific Research, at the Fermi National Accelerator labouratory in Chicago, at the Niels Bohr Institute in Copenhagen, and at CERN in Geneva. In 1959, d'Espagnat joined the University of Paris, where he was professor at both the Paris and Orsay campuses. Professor d'Espagnat was director of the labouratoire de Physique Theorique et Particules Elementaires, Orsay, from 1970 to 1987. In 1996 he was elected into the Institut de France (Académie des Sciences morales et politiques) as a philosopher of science.

• Editor’s Foreword , 1999 Special Preface , Vita , Pedro’s Debate (Preface to Second Edition) , Preface (To First Edition) , Elements of Quantum Mechanics , Matter Waves , Superposition and Linearity , Statement of the Rules , Comments , Alternative Formulations , Density Matrices and Mixtures , The Density Matrix Formalism , Mixtures , Quantum Nonseparability , The Einstein-Podolsky-Rosen Problem , Possible Views on Nonseparability , Individuals, Ensembles, States , The “Hidden Variables” Approach , Direct Study of Some Principles , Aspects of the Problem of Retrodiction , Measurement Theories , Elements of Measurement Theory , Classical Properties , Macroscopic Instruments , Of Cats and Pointers , Nonideal Measurements: Small Influence of Outside World , Knowledge and the Physical World , Reality and Objects , Positivism , Bohr and Heisenberg , Wigner’s Friend , The Relativity of States , Summary and Outlook , Summary , Outlook

Bernard d'Espagnat, Emeritus Professor at the University of Paris, Orsay, was born in Fourmagnac, France, on August 22, 1921. He received his Ph.D. in physics from the Sorbonne in 1950. He was a research physicist at the French National centre for Scientific Research, at the Fermi National Accelerator labouratory in Chicago, at the Niels Bohr Institute in Copenhagen, and at CERN in Geneva. In 1959, d'Espagnat joined the University of Paris, where he was professor at both the Paris and Orsay campuses. Professor d'Espagnat was director of the labouratoire de Physique Theorique et Particules Elementaires, Orsay, from 1970 to 1987. In 1996 he was elected into the Institut de France (Académie des Sciences morales et politiques) as a philosopher of science.

• Editor’s Foreword , 1999 Special Preface , Vita , Pedro’s Debate (Preface to Second Edition) , Preface (To First Edition) , Elements of Quantum Mechanics , Matter Waves , Superposition and Linearity , Statement of the Rules , Comments , Alternative Formulations , Density Matrices and Mixtures , The Density Matrix Formalism , Mixtures , Quantum Nonseparability , The Einstein-Podolsky-Rosen Problem , Possible Views on Nonseparability , Individuals, Ensembles, States , The “Hidden Variables” Approach , Direct Study of Some Principles , Aspects of the Problem of Retrodiction , Measurement Theories , Elements of Measurement Theory , Classical Properties , Macroscopic Instruments , Of Cats and Pointers , Nonideal Measurements: Small Influence of Outside World , Knowledge and the Physical World , Reality and Objects , Positivism , Bohr and Heisenberg , Wigner’s Friend , The Relativity of States , Summary and Outlook , Summary , Outlook