Scientific Realism and Anti-Realism

We said earlier that it’s not of much interest to try to place Niels Bohr into classification schemes that have been devised by analytic philosophers in the past fifty years. For example, the question “was Bohr a Humean about laws of nature?” can hardly be given a clear answer, since Bohr’s context was so different from that of contemporary analytic philosophers.¹

Nonetheless, the question “was Niels Bohr a scientific realist?” is a little more interesting — especially since anti-realists are thought to be people with a somewhat negative attitude toward science and its authority to pronounce on philosophical issues.² What’s more, although analytic philosophers have tried to give various precise definitions of realism and anti-realism, those words do come up in earlier philosophy, and that seem to pick out some kind of genuine difference, at least in general attitude. For example, Harald Høffding (Bohr’s teacher) gave a lecture titled “On realism in science and faith” at the University of Copenhagen in 1882 (more than twenty years before Bohr began his studies).

We know now, it is true, that the often expressed scepticism with regard to the reality of atoms was exaggerated. (Bohr 1934, p 93)

Without doubt, Bohr’s philosophical views have shaped the way generations of physicists think about quantum mechanics, but they have also, in the eyes of an increasing number, discouraged and stifled progress. Bohr argued that it is wrong to think that the task of physics is to find out how nature is – or to know the ‘real essence of the phenomena’ — but rather to concern itself only with what we can say about nature: the ‘aspects of our experience’. [Note: No citation here. Presumably Al Khalili is basing this claim on rumors that were fostered by some things that Aage Petersen said about Bohr’s view.] These two opposing views, the first ontological and the second epistemo- logical, can in fact both be correct: what a physicist should be able to say about nature, even at the quantum scale, should be the same as how nature is, or as close to it as we can get, but always trying to edge closer. This ‘realist’ view is one that I have always found myself siding with in the end, despite having serious doubts now and again. (Al-Khalili 2020, p 122)

A realist (with respect to a given theory or discourse) holds that (1) the sentences of that theory are true or false ; and (2) that what makes them true or false is something external — that is to say, it is not (in general) our sense data, actual or potential, or the structure of our minds, or our language, etc. (Putnam 1979, pp 69-70)

Science aims to give us, in its theories, a literally true story of what the world is like ; and acceptance of a scientific theory involves the belief that it is true. (Van Fraassen 1980, p 8)

Back in the day, particular instances of realism were a pretty straightforward matter. … But a completely different account of what it takes to be “real realist” emerges in several of these papers. (Maudlin 2007)