The question of realism has become one of the most discussed in recent philosophy of science, and may be seen, at least to a certain extent, as the consequence of the decline of that too strict logico-analytical approach that was predominant in the period when this sector of philosophy knew its highest prestige (that is, approximately in the central decades of our century). This phenomenon may be considered as a gain or a loss according to different points of view. Some scholars see in it the resurrection of genuinely philosophical preoccupations, after a long parenthesis in which the attention was diverted by subtle and often Byzantine linguistic issues. Others estimate, on the contrary, that the previous approach had the merit of sticking to the concrete language of science, and of making the effort to investigate many of its actual methodological features, while the present moment in philosophy of science is characterized by debates (including that on realism) that are too generally (or generically) philosophical, and do not really matter for the doing and understanding of scientific practice. Yet the case of realism is one that can show how a significant philosophy of science ought to be articulated. First of all one may note that the cultural motivation and the concrete impulsion to the almost sudden explosion of philosophy of science as a specialized philosophical discipline was determined by the crisis of “classical” exact sciences between the end of the past and the beginning of the present century, and the philosophical problems that were immediately at the center of the discussion were precisely those that still characterize the realism debate of our days. Moreover, such problems were felt with particular strength by many scientists, and the most clear and interesting positions in the debate were taken by very serious, and even outstanding scientists (think of Mach, Duhem, Poincar(, Peano, Hilbert, Planck, Einstein, Bohr, Heisenberg, Schr(dinger, Born and several others), while no professional philosopher (with few notable exceptions, of which that of Russell is the most important) was able to significantly contribute to this debate for a long while (even the great Bergson said quite shallow things when he tried to come to terms with relativity theory). The happy situation of that time was made possible by the fact that a good philosophical background was a common feature in the education of scientists (in high schools and/or at the universities), so that they had the intellectual means for focussing on and discussing the philosophical problems emerging in their scientific practice. Later this was no longer the case: philosophers became more and more ignorant about science, and scientists about philosophy.

Yet this was not simply a matter of laziness: in fact contemporary science has become so complicated, that not only is it hardly possible to master its contents when one is not very seriously trained in it (even good scholars in a certain scientific field cannot master the advanced contents of other scientific fields), but this complication of science actually demands a far more complicated and elaborated set of philosophical instruments for a pertinent discussion of its philosophical issues. This in particular explains why the solutions proposed by those great scientists, already mentioned, from the beginning of our century are rather inadequate: the philosophical tools at their disposal (and which were part of their educational and cultural background) were too elementary to cope with the complexity of the new problems. This vindicates the importance of that specialized and technically complex way of doing philosophy of science that was characteristic of the logico-analytical tradition between the thirties and the sixties. Indeed it provided a lot of investigation tools that can be profitably used in the study of the philosophical issues imposed by contemporary science. However, a contact with concrete science must finally occur, and this may happen either when a philosopher of science equipped with this philosophical sophistication is also able to competently master the contents of the most advanced scientific theories or, at least, through an interdisciplinary dialogue between philosophers of science with a sufficient grasping of concrete scientific inquiry, and working scientists with a genuine interest in and a sufficient grasping of philosophical investigation. This is the situation that the present book tries to exemplify, and, accordingly, its content is divided into three parts. The first contains papers of a more general philosophical character, dealing with the issue of realism and anti-realism mainly along the lines that mark the philosophical features of this discussion (that is, questions connected with ontology, theory of knowledge, philosophy of language, though viewed in special connection with scientific knowledge). Since the consolidation of an anti-realist conception of the physical sciences seems to have been almost imposed by the lack of direct “access“ to the entities populating the micro-world, that are often called “unobservable” or “hidden,” a particular attention is paid to the investigation of this issue in the second part of this volume. The second part contains papers dealing with this topic, both from an historical and a theoretical point of view. Obviously, quantum physics is the most direct subject being considered in this discussion, and this makes it natural to pass to a more specialized (and technical) analysis of the question of realism in quantum physics, which constitutes the content of the third part of the book. According to the considerations outlined above, the authors of the papers shift from the field of philosophers to that of professional physicists when passing from the first to the last part of the volume, but in both cases a notable competence in the complementary field can be appreciated.

Several of the more generally-oriented papers of this book discuss the issue of realism laying stress primarily on the intellectual attitude which impulses the construction of science, rather than considering the results of scientific investigation. This is by no means strange, for it can be maintained that anti-realism was somehow a by-product of a certain historical deception regarding the results of modern science: after the admirable success of Newtonian physics, and the almost all-pervasive expansion of its concepts, models, paradigms, and mathematical approaches to the whole of physics during the l9th century, people were led to believe that science as such was able to provide mankind with absolute truth, endowed with well-established certainty. Truth being considered as the capability of science to tell us “how things really are,” this conception sufficiently supported a realist view of science, in the sense that it seemed to confirm that science is actually able to grant a true knowledge of reality (i.e., that its results justify our confidence in its realistic purport). The well-known crisis of the exact sciences (in particular of physics), which did not start with relativity and quantum mechanics, but was already announced by certain difficulties in the so-called “classical physics,” seemed to show that several claims of the accepted science were wrong (i.e., false), and therefore, that this science was not endowed with certainty. Hence it seemed obvious to conclude that we have to abandon also the realist conception which was supported by the original illusion that science is able to provide us with truth. But was this conclusion really justified, or was it rather too hasty?


The contributions contained in this book were presented and discussed as invited papers at two distinct meetings of similar thematic interest. The first was organized by the Italian Society for Logic and Philosophy of Science, in collaboration with the Istituto Italiano di Studi Filosofici, and took place in Naples in March 1992. The second was organized by the Association F. Gonseth, along with the Institut de la Méthode and the Swiss Society for Logic and Philosophy of Science, and took place in Bienne (Switzerland) in June 1993.