We clarify Bohr’s interpretation of quantum mechanics by demonstrating the central role played by his thesis that quantum theory is a rational generalization of classical mechanics. This thesis is essential for an adequate understanding of his insistence on the indispensability of classical concepts, his account of how the quantum formalism gets its meaning, and his belief that hidden variable interpretations are impossible.

This book will be of particular interest to those philosophers, scientists, and mathematicians who are interested in the foundations of science.

Hempel's Dilemma is the claim that physicalism is an ill-formed thesis because it can offer no account of the physics that it refers to: current physics will be discarded in the future, and we don't yet know the nature of future physics. This article confronts the first horn of the dilemma, and argues that our knowledge of current physics is sufficient for offering a physicalist ontology of the mind. We have good scientific evidence that future physics will be irrelevant to (...) the mind-body problem because mental processes lie safely within the well-understood domains of applicability of current physical theories. (shrink)

Niels Bohr famously argued that a consistent understanding of quantum mechanics requires a new epistemic framework, which he named complementarity . This position asserts that even in the context of quantum theory, classical concepts must be used to understand and communicate measurement results. The apparent conflict between certain classical descriptions is avoided by recognizing that their application now crucially depends on the measurement context. ;Recently it has been argued that a new form of complementarity can provide a solution to the (...) so-called information loss paradox. Stephen Hawking argues that the evolution of black holes cannot be described by standard unitary quantum evolution, because such evolution always preserves information, while the evaporation of a black hole will imply that any information that fell into it is irrevocably lost---hence a "paradox." Some researchers in quantum gravity have argued that this paradox can be resolved if one interprets certain seemingly incompatible descriptions of events around black holes as instead being complementary. ;In this dissertation I assess the extent to which this black hole complementarity can be undergirded by Bohr's account of the limitations of classical concepts. I begin by offering an interpretation of Bohr's complementarity and the role that it plays in his philosophy of quantum theory. After clarifying the nature of classical concepts, I offer an account of the limitations these concepts face, and argue that Bohr's appeal to disturbance is best understood as referring to these conceptual limits. ;Following preparatory chapters on issues in quantum field theory and black hole mechanics, I offer an analysis of the information loss paradox and various responses to it. I consider the three most prominent accounts of black hole complementarity and argue that they fail to offer sufficient justification for the proposed incompatibility between descriptions. ;The lesson that emerges from this dissertation is that we have as much to learn from the limitations facing our scientific descriptions as we do from the successes they enjoy. Because all of our scientific theories offer at best limited, effective accounts of the world, an important part of our interpretive efforts will be assessing the borders of these domains of description. (shrink)

A proper understanding of black hole complementarity as a response to the information loss paradox requires recognizing the essential role played by arguments for the applicability and limitations of effective semiclassical theories. I argue that this perspective sheds important light on the arguments advanced by Susskind, Thorlacius, and Uglum—although ultimately I argue that their position is unsatisfactory. I also consider the argument offered by ’t Hooft for the breakdown of microcausality around black holes, and conclude that it relies on a (...) mistaken treatment of measurement collapse. There is, however, a legitimate argumentative role for black hole complementarity, exemplified by the position of Kiem, Verlinde, and Verlinde, that calls for a more subtle analysis of the limitations facing our effective theories. (shrink)

Belot, Earman, and Ruetsche (1999) dismiss the black hole remnant proposal as an inadequate response to the Hawking information loss paradox. I argue that their criticisms are misplaced and that, properly understood, remnants do offer a substantial reply to the argument against the possibility of unitary evolution in spacetimes that contain evaporating black holes. The key to understanding these proposals lies in recognizing that the question of where and how our current theories break down is at the heart of these (...) debates in quantum gravity. I also argue that the controversial nature of assessing the limits of general relativity and quantum field theory illustrates the significance of attempts to establish the proper borders of our effective theories. (shrink)

Belot, Earman, and Ruetsche dismiss the black hole remnant proposal as an inadequate response to the Hawking information loss paradox. I argue that their criticisms are misplaced and that, properly understood, remnants do offer a substantial reply to the argument against the possibility of unitary evolution in spacetimes that contain evaporating black holes. The key to understanding these proposals lies in recognizing that the question of where and how our current theories break down is at the heart of these debates (...) in quantum gravity. I also argue that the controversial nature of assessing the limits of general relativity and quantum field theory illustrates the significance of attempts to establish the proper borders of our effective theories. (shrink)

1. Petkov assumes that the standard relativistic interpretations of measurement procedures are to be respected, but this is precisely what 3D-er (the 3-dimensionalist) will deny. Petkov’s apparent contradictions are due to the fact that he considers an inconsistent mixture of 3D ontology and the standard interpretation of special relativity.

Presentations of black hole complementarity by van Dongen and de Haro, as well as by 't Hooft, suffer from a mistaken claim that interactions between matter falling into a black hole and the emitted Hawking-like radiation should lead to a failure of commutativity between space-like-related observables localized inside and outside the black hole. I show that this conclusion is not supported by our standard understanding of quantum interactions. We have no reason to believe that near-horizon interactions will threaten microcausality. If (...) these interactions reliably transfer information to the outgoing radiation, then this response to Hawking's information loss argument should amount to a version of the bleaching scenario. I argue that the challenge facing black hole complementarity is that of reconciling this commitment to bleaching with the expectation that the event horizon will be locally unremarkable. This challenge is most promisingly met by proposals that postulate a consistent account of the limitations of our local semi-classical theories, but no support is added to these postulates by appeals to verificationism or to the interactions considered by 't Hooft. (shrink)