The celebrated Dreimännerarbeit by Born, Heisenberg and Jordan contains a matrix-mechanical derivation by Jordan of Planck’s formula for blackbody fluctuations. Jordan appears to have considered this to be one of his finest contributions to quantum theory, but the status of his derivation is puzzling. In our Dreimenschenarbeit, we show how to understand what Jordan was doing in the double context of a Boltzmannian approach to statistical mechanics and of the early ‘statistical interpretation’ of matrix mechanics.

In this paper I attempt to broaden Feyerabend scholarship by asking whether and how Feyerabend's philosophy of science, in particular his commitments to realism and pluralism about scientific theories as well as anarchism about scientific methods, is borne out in multidisciplinary research concerning the Leggett–Garg inequalities. These inequalities were derived explicitly to be a temporal analogue to Bell's inequalities: the viability of macroscopic realism is tested against the predictions of quantum mechanics by performing a series measurements on a macroscopic variable (...) of one system at different time intervals, then evaluating correlations among resultant values. In the nearly forty years since Leggett and Garg's paper, questions continue to be raised whether common tests of these inequalities reveal genuine violations or merely experimental disturbances. There is also much debate about what genuine violations in fact signify, if (as most agree) they are not straight-forwardly analogous to Bell tests. Taking this fascinating and as yet largely unsettled episode from physics as a case study, I derive three Feyerabendian lessons that demonstrate the relevance of his views even today. (shrink)

Grete Hermann was a pupil of mathematical physicist Emmy Noether, follower and co-worker of neo-Kantian philosopher Leonard Nelson, and an important intellectual figure in post-war German social democracy. She is best known for her work on the philosophy of modern physics in the 1930s, some of which emerged from intense discussions with Heisenberg and Weizsäcker in Leipzig. Hermann’s aim was to counter the threat to the Kantian notion of causality coming from quantum mechanics. She also discussed in depth the question (...) of ‘hidden variables’ and provided an extensive analysis of Bohr’s notion of complementarity. This volume includes translations of Hermann’s two most important essays on this topic: one hitherto unpublished and one translated here into English for the first time. It also brings together recent scholarly contributions by historians and philosophers of science, physicists, and philosophers and educators following in Hermann’s steps. Hermann's work places her in the first rank among philosophers who wrote about modern physics in the first half of the last century. Those interested in the many fields to which she contributed will find here a comprehensive discussion of her philosophy of physics that places it in the context of her wider work. (shrink)

I argue that quantum decoherence—understood as a dynamical process entailed by the standard formalism alone—carries us beyond conceptual aspects of non-relativistic quantum mechanics deemed insurmountable by many contributors to the recent quantum gravity and cosmology literature. These aspects include various incarnations of the measurement problem and of the quantum -to-classical puzzle. Not only can such problems be largely bypassed or dissolved without default to a particular interpretation, but theoretical work in relativistic arenas stands to gain substantial physical and philosophical insight (...) by incorporating decoherence phenomena. (shrink)

Prior analyses of Grete Hermann’s 1935 essay on the philosophical foundations of quantum mechanics have taken her central aim to be the recovery of an appropriately Kantian notion of causality from this new indeterministic physics. I argue that if one instead reads this essay as primarily an investigation into the meaning and implications of the relative nature of quantum mechanics—not only for physics, but also for fields as different as ethics—certain dimensions of her work appear with greater clarity. Among these (...) are her particular Kantian interpretation of Bohr’s complementarity and correspondence principles, her unique understanding of the quantum-classical divide, the failure of Kant’s a priori categories of space, time and causality to apply literally—even for obtaining classical natural knowledge, and the splitting of truth. (shrink)

Quantum decoherence is receiving a great deal of attention today not only in theoretical and experimental physics but also in branches of science as diverse as molecular biology, biochemistry, and even neuropsychology. It is no surprise that it is also beginning to appear in various philosophical debates concerning the fundamental structure of the world. The purpose of this article is primarily to acquaint non-specialists with quantum decoherence and clarify related concepts, and secondly to sketch its possible implications – independent of (...) particular interpretations of quantum mechanics – for broader philosophical debates. For example, decoherence shows that any method of parsing nature into levels or parts cannot be in principle but instead derives from our perception of the world as classical, a perception that is itself sustained by the process of decoherence. (shrink)

Recently I published an article in this journal entitled “Less interpretation and more decoherence in quantum gravity and inflationary cosmology” :1019–1045, 2015). This article generated responses from three pairs of authors: Vassallo and Esfeld :1533–1536, 2015), Okon and Sudarsky :852–879, 2016) and Fortin and Lombardi. In what follows, I reply to the criticisms raised by these authors.

Advocates of scientic realism typically respond to the challenge of the pessimistic meta-induction by turning to the history of science. The episode most frequently discussed is the shift from Fresnel's wave theory of light to Maxwell's electromagnetism. This particular history is taken to represent one of the hardest problems for the realist, for while it exhibits continuity on the empirical level, it simultaneously represents a dramatic shift in ontology. Thus, various authors have proposed methods for defeating the pessimistic meta-induction based (...) solely on consideration of the Fresnel-Maxwell case. In this paper, I present another case study from physics--Fermi's 1934 theory of beta-decay and the ensuing search for a universal description of weak interactions. I argue that the degree of success of two recent proposals for scientic realism--that of John Worrall (1989, 1994, 2007) and Juha Saatsi (2005)--changes importantly in light of this new case study. (shrink)

Within contemporary scientific and science-adjacent communities, it is generally accepted that quantum physics is our best theory. For this reason, it is understandable—and laudable—that scholars interested in questions at the intersection of science and theology wish to meaningfully engage with this physics. Recent work in foundations of physics has, however, importantly altered the landscape of quantum theory; in this article, my goal is to introduce these advances, then make an argument within this new landscape that I hope will be useful (...) for certain theological inquiries. Specifically, I shall argue from grounds of the physics itself that one may, with clear philosophical conscience, access the majority of quantum theory's tools, models, and explanations while maintaining an interpretation-neutral yet realist stance toward this physics. (shrink)

In this paper, we discuss various aspects of Heisenberg’s thought on hidden variables in the period 1927–1935. We also compare Heisenberg’s approach to others current at the time, specifically that embodied by von Neumann’s impossibility proof, but also views expressed mainly in correspondence by Pauli and by Schroedinger. We shall base ourselves mostly on published and unpublished materials that are known but little-studied, among others Heisenberg’s own draft response to the EPR paper. Our aim will be not only to clarify (...) Heisenberg’s thought on the hidden-variables question, but in part also to clarify how this question was understood more generally at the time. (shrink)

Recent discussions of structuralist approaches to scientific theories have stemmed primarily from Worrall's, in which he defends a position whose historical roots he attributes to Poincare. In the renewed debate inspired by Worrall, it is thus not uncommon to find Poincare's name associated with various structuralist positions. However, Poincare's structuralism is deeply entwined with both his conventionalism and his idealism, and in this paper we explore the nature of these dependencies. What comes out in the end is not only a (...) clearer picture of Poincare's position regarding structuralism, but also two arguments for versions of epistemic structuralism different in kind from that given by Worrall. (shrink)

Elise Crull claims that by invoking decoherence it is possible to obviate many “fine grained” issues often conflated under the common designation of measurement problem, and to make substantial progresses in the fields of quantum gravity and quantum cosmology, without any early incorporation of a particular interpretation in the quantum formalism. We point out that Crull is mistaken about decoherence and tacitly assumes some kind of interpretation of the quantum formalism.

Two recent papers appeared in FOOP disagree regarding the role played by decoherence in quantum physics. On the one hand, Elise Crull considers that decoherence, by itself, solves many conceptual problems in quantum physics, with no need of interpretative considerations. On the other hand, Antonio Vassallo and Michael Esfeld reply by correctly claiming that, although decoherence is a powerful tool to deal with conceptual problems, it does not dispense us from interpreting the formalism. In this brief note we want (...) to contribute to the debate with further considerations from another viewpoint. In this work we show that the discussions "decoherence versus interpretation" revolve around whether the theory of decoherence requires interpretive considerations to solve the measurement problem. In general, those discussions take the theory of decoherence for granted, as if it would not involve any difficulty. Therefore, they commonly focus on the "interpretation" wing: even in the case that the open system decoheres in a given basis, the whole closed system is still in a superposition and, thus, without an adequate interpretation, it cannot be said that the observables defined by that basis behave classically. Here we have focused on the "decoherence" wing: given the conceptual challenges that the theory must face and the alternative approaches to the orthodox view, the understanding of the very phenomenon of decoherence still requires a great deal of interpretive work. (shrink)

The Carol J. Adams Reader gathers together Adams's foundational and recent articles in the fields of critical studies, animal studies, media studies, vegan studies, ecofeminism and feminism, as well as relevant interviews and conversations in which Adams identifies key concepts and new developments in her decades-long work. This volume, a companion to The Sexual Politics of Meat (Bloomsbury Revelations), offers insight into a variety of urgent issues for our contemporary world: Why do batterers harm animals? What is the relationship between (...) genocide and attitudes toward other animals? How do activism and theory feed each other? How do race, gender, and species categories interact in strengthening oppressive attitudes? In clear language, Adams identifies the often hidden aspects of cultural presumptions. The essays and conversations found here capture the decades-long energy and vision that continue to shape new ways of thinking about and responding to oppression. (shrink)

J.S. Mill's plural voting proposal in Considerations on Representative Government presents political theorists with a puzzle: the elitist proposal that some individuals deserve a greater voice than others seems at odds with Mill's repeated arguments for the value of full participation in government. This essay looks at Mill's arguments for plural voting, arguing that, far from being motivated solely by elitism, Mill's account is actually driven by a commitment to both competence and participation. It goes on to argue that, for (...) Mill, much of the value of political participation lies in its unique ability to educate the participants. That ability to educate is not, however, a product of participation alone; rather, for Mill, the true educative benefits of participation obtain only when competence and participation work together in the political sphere. Plural voting, then, is a mechanism for allowing Mill to take advantage of the educative benefits that arise from the intersection of competence and participation. (shrink)

J M Tarrant; J. Wilson and B. Cowell on the Democratic Myth, Journal of Philosophy of Education, Volume 18, Issue 1, 30 May 2006, Pages 123–127, https://doi.org.

Thomas J.J. Altizer is one of the most important theologians of the twentieth and early twenty-first centuries, and all radical theology must pass through and be conversant with his work and the historical significance of his earlier contributions. This chapter presents Altizer’s essential ideas in a straightforward and accessible manner and provides a guide for the beginning reader.