Perspectives of Physical Realism

Gregor Schiemann

Realism in Context: The Examples of Lifeworld and Quantum Physics Lifeworld realism and quantum-physical realism are taken as experience-dependent conceptions of the world that become objects of explicit reflection when confronted with context-external discourses. After a brief sketch of the two contexts of experience—lifeworld and quantum physics—and their realist interpretations, I will discuss the quantum world from the perspective of lifeworld realism. From this perspective, the quantum world—roughly speaking—has to be either unreal or else constitute a different reality. Then, I invert the perspective and examine the lifeworld from the standpoint of quantumphysical realism. This conception of the lifeworld has gained momentum from new research results in recent decades. Despite its experiential basis, quantum-physical realism bears an ambiguity akin to that of lifeworld realism. While the perspectival inversion serves to highlight the problem, it also contributes to an improved understanding of lifeworld-realism.

A. J. Leggett

Nora Berenstain

Privileged-perspective realism (PPR) is a version of metaphysical realism that takes certain irreducibly perspectival facts to be partly constitutive of reality. PPR asserts that there is a single metaphysically privileged standpoint from which these perspectival facts obtain. This chapter discusses several views that fall under the category of privileged-perspective realism. These include presentism, which is PPR about tensed facts, and non-multiverse interpretations of quantum mechanics, which the chapter argues, constitute PPR about world-indexed facts. Using the framework of the bird perspective and the frog perspective, it argues that PPR views are motivated by the assumption that the frog perspective is metaphysically primary. The chapter considers case studies of metaphysical interpretations of special relativity and quantum mechanics in order to demonstrate that such motivations for PPR are non-naturalistic. It considers psychological factors that motivate the appeal of PPR views and offers naturalistic explanations of why we should not expect them to lead to good metaphysics of science.

Jean Staune

Daniel James Robertson

The debate between Arthur Fine and Alan Musgrave is well known amongst those involved in the scientific realism debate and centres upon two papers that are quite often found together in philosophy of science anthologies. Reading them like this gives the very strong impression the Musgrave is the victor which is the commonly held view. In this thesis, I wish to overturn this view by placing Fine's paper in context, namely as part of a larger work on the history and philosophy of quantum physics. Fine's book, The Shaky Game: Einstein, Realism and Quantum Theory, gives us good reason to believe that quantum physics significantly undermines the whole scientific realism debate, and as such, has strongly influenced Fine's development of the Natural Ontological Attitude, which is as Fine believes a middle ground between realism and anti-realism. The present thesis evaluates the Natural Ontological Attitude from a physicist's perspective and defends Fine against Musgrave's reply to the extent that it demonstrates that Musgrave would do well to read Fine's paper in context. That said, just as Fine in his youth hoped that a quantum realist position will one day be found, so I also possess this aspiration; and so, despite my concluding that Fine is justified in holding to NOA, I argue furthermore that NOA is but a precursor to a potential quantum structural realist position. After showing that structural realism is worthy of consideration by using it to counter Fine's objections to scientific realism, I analyse the results of quantum physics in an attempt to understand what it can tell us about reality in the quantum realm. Eliminativist Ontic Structural Realism holds great promise as a quantum realism contender, and as such, it inspired the questions regarding individuality and reality that are discussed in the final main chapter. I thus resuscitate hope that the cause of the quantum realist is not yet lost.

Fritz Rohrlich