Due to its extraordinary predictive power and the great generality of its mathematical structure, quantum theory is able, at least in principle, to describe all the microscopic and macroscopic properties of the physical world, from the subatomic to the cosmological level. Nevertheless, ever since the Copen hagen and Gottingen schools in 1927 gave it the definitive formu lation, now commonly known as the orthodox interpretation, the theory has suffered from very serious logical and epistemologi cal problems. These shortcomings were immediately pointed out by some of the principal founders themselves of quantum theory, to wit, Planck, Einstein, Ehrenfest, Schrodinger, and de Broglie, and by the philosopher Karl Popper, who assumed a position of radical criticism with regard to the standard formulation of the theory. The aim of the participants in the workshop on Open Questions in Quantum Physics, which was held in Bari (Italy), in the Department of Physics of the University, during May 1983 and whose Proceedings are collected in the present volume, accord ingly was to discuss the formal, the physical and the epistemo logical difficulties of quantum theory in the light of recent crucial developments and to propose some possible resolutions of three basic conceptual dilemmas, which are posed respectively ~: (a) the physical developments of the Einstein-Podolsky-Rosen argument and Bell's theorem, i. e.

For three days in April of 1985, Cesena (Italy) was the scene of a national conference which was convened, by the Assessorato alia Cultura of this town under the auspices of the Societa Italiana di Logica e Filosofia delle Scienze (SILFS), in order to celebrate two historical milestones: the centenary of the birth of Niels Bohr, who was to become the leader of the orthodox, or Copenhagen, interpretation of quantum theory, and the fiftieth anniversary of the publication of the most influential challenge to this interpretation which was contained in the well-known paper coauthored by Einstein, Podolsky, and Rosen. The proceedings of the Cesena meeting, which are collected in the present volume, are intended to provide an exhaustive and panoramic view of the most recent investigations carried out by Italian scientists and philo sophers engaged in research on the foundations of quantum physics. What emerges is a critical review of, and alternative approaches to, the orthodox interpretation of the Copenhagen school."

Quantum mechanics has reached maturity as an a wesome scientific theory, and undeniably no experiment has so far produced any result conflic ting with its predictions. Nevertheless, an increasing number of scholars are seriously questioning the limits of this discipline's validity, a fact that is eloquently attested to by the four international conferences devoted to the foundations of quantum theory which were held in 1987 alone - in Joensuu, Vienna, Gdansk, and Delphi, respectively. There is an increa ing awareness that the founding fathers of quantum mechanics have left behind a theory which, though spectacularly successful in its applications, severely limits our intuitive understanding of the microworld, and that their reasons for doing so were at least partly arbitrary and open to question. The problem of the relationship between the existing quantum theory and objective reality at the atomic and subatomic levels can be tackled in essentially two ways: (i) One may focus attention on the formalism of the theory and attempt to deduce from it a coherent description of our measuring processes and a deeper understanding of the microworld. Oi) Alternatively, one may start from the experimental evidence and/or from models of the objective reality compatible with it and go on to inves tigate whether or not formalization of this knowledge can be accomodated within the broad confines of existing quantum theory."

Due to its extraordinary predictive power and the great generality of its mathematical structure, quantum theory is able, at least in principle, to describe all the microscopic and macroscopic properties of the physical world, from the subatomic to the cosmological level. Nevertheless, ever since the Copen hagen and Gottingen schools in 1927 gave it the definitive formu lation, now commonly known as the orthodox interpretation, the theory has suffered from very serious logical and epistemologi cal problems. These shortcomings were immediately pointed out by some of the principal founders themselves of quantum theory, to wit, Planck, Einstein, Ehrenfest, Schrodinger, and de Broglie, and by the philosopher Karl Popper, who assumed a position of radical criticism with regard to the standard formulation of the theory. The aim of the participants in the workshop on Open Questions in Quantum Physics, which was held in Bari (Italy), in the Department of Physics of the University, during May 1983 and whose Proceedings are collected in the present volume, accord ingly was to discuss the formal, the physical and the epistemo logical difficulties of quantum theory in the light of recent crucial developments and to propose some possible resolutions of three basic conceptual dilemmas, which are posed respectively ~: (a) the physical developments of the Einstein-Podolsky-Rosen argument and Bell's theorem, i. e.