According to one prominent view, current metaphysics is hopelessly disconnected from the implications of modern science and as a result should be abandoned forthwith (Ladyman and Ross 2007). Others have taken a more conciliatory stance, suggesting that the metaphysicians’ toolbox may yet yield devices that could prove useful to the philosopher of science (French and McKenzie 2012). In this book, Sider aims to contribute to the metaphysics of science by setting out an array of such tools and indicating which are (...) up to the job. More particularly, he wants to demonstrate the usefulness of certain ‘postmodal’ concepts, such as fundamentality, which is a promising tack, given that (Callender 2011), for example, has argued that it was the modal turn initiated by the likes of Kripke that is ultimately responsible for the disconnect. To illustrate his overall claim that the tools we deploy may help frame the issues that we take to be central to the metaphysics of science, Sider chooses to analyse various forms of structuralism, the view that we should take structure to be primary and the relevant entities to be secondary : nomic essentialism, which takes properties to be ‘bound up’ with laws (ibid., p. 23); structural realism, which holds, in its epistemic form, that all that we know about the world is its structure and, in the ontic alternative, that the world is, in some sense, structure; and comparativism about quantities, whereby quantities are ascribed to objects comparatively or relationally (ibid., p. 122). His conclusions are that no postmodal sense can be made of the first two, and so much the worse for them, whereas comparativism about quantities can unproblematically be stated in such terms (ibid., p. 119), and indeed, when it comes to ‘fundamentality’, at least, may well be this concept’s ‘Waterloo’ (ibid., p. 166). The worry some philosophers of science will have is that Sider’s arguments are driven more by his metaphysics than the relevant science and the issues that he identifies don’t quite map onto those they take to be central. (shrink)

According to one prominent view, current metaphysics is hopelessly disconnected from the implications of modern science and as a result should be abandoned fort.

The overaraching goal of this paper is to elucidate the nature of superselection rules in a manner that is accessible to philosophers of science and that brings out the connections between superselection and some of the most fundamental interpretational issues in quantum physics. The formalism of von Neumann algebras is used to characterize three different senses of superselection rules (dubbed, weak, strong, and very strong) and to provide useful necessary and sufficient conditions for each sense. It is then shown how (...) the Haag–Kastler algebraic approach to quantum physics holds the promise of a uniform and comprehensive account of the origin of superselection rules. Some of the challenges that must be met before this promise can be kept are discussed. The focus then turns to the role of superselection rules in solutions to the measurement problem and the emergence of classical properties. It is claimed that the role for “hard” superselection rules is limited, but “soft” (a.k.a. environmental) superselection rules or N. P. Landsman’s situational superselection rules may have a major role to play. Finally, an assessment is given of the recently revived attempts to deconstruct superselection rules. (shrink)

The ontological status of theories themselves has recently re-emerged as a live topic in the philosophy of science. We consider whether a recent approach within the philosophy of art can shed some light on this issue. For many years philosophers of aesthetics have debated a paradox in the (meta)ontology of musical works (e.g. Levinson [1980]). Taken individually, there are good reasons to accept each of the following three propositions: (i) musical works are created; (ii) musical works are abstract objects; (iii) (...) abstract objects cannot be created. However it seems clear that, if one wants to avoid inconsistency, one cannot commit to all three. Following up recent developments courtesy of Cameron ([2008a]), we consider how one might respond to the corresponding set of propositions in the (meta)ontology of scientific theories. 1 Introduction2 Setting up the Problem3 What to Reject? 3.1 Scientific theories are not created? 3.2 Scientific theories are not abstract objects? 3.3 Abstract objects can be created?4 A Fourth Way: Truth-maker Theory5 Objections and Replies 5.1 What are the truth-makers? 5.2 Objections from World 3 5.3 Fictionalism 5.4 Concrete/abstract6 Conclusion. (shrink)

We put forward a possible new interpretation and explanatory framework for quantum theory. The basic hypothesis underlying this new framework is that quantum particles are conceptual entities. More concretely, we propose that quantum particles interact with ordinary matter, nuclei, atoms, molecules, macroscopic material entities, measuring apparatuses, in a similar way to how human concepts interact with memory structures, human minds or artificial memories. We analyze the most characteristic aspects of quantum theory, i.e. entanglement and non-locality, interference and superposition, identity and (...) individuality in the light of this new interpretation, and we put forward a specific explanation and understanding of these aspects. The basic hypothesis of our framework gives rise in a natural way to a Heisenberg uncertainty principle which introduces an understanding of the general situation of ‘the one and the many’ in quantum physics. A specific view on macro and micro different from the common one follows from the basic hypothesis and leads to an analysis of Schrödinger’s Cat paradox and the measurement problem different from the existing ones. We reflect about the influence of this new quantum interpretation and explanatory framework on the global nature and evolutionary aspects of the world and human worldviews, and point out potential explanations for specific situations, such as the generation problem in particle physics, the confinement of quarks and the existence of dark matter. (shrink)

In this paper I contend that standard quantum theory has a minimal interpretation, on which all physicists agree. That interpretation is sufficient for every application of quantum theory and it has been confirmed by a countless number of experiments. However, it provides neither an overall picture of the quantum world nor an intended ontology for quantum theory. For those reasons, several full interpretations have been proposed in order to complete the minimal interpretation. I then argue that those interpretations –which are (...) empirically equivalent, but mutually incompatible- are metaphysical ventures that cannot be confirmed by any conceivable experience. Moreover, I claim that the program of finding the ontology for quantum theory rests on the false assumption that there is a unique ontology compatible with each physical theory. I conclude that there is no direct path either from the formalism of quantum theory to its intended ontology, or from determinate metaphysical assumptions to the quantum formalism. (shrink)