The ontic structural realist stance is motivated by a desire to do philosophical justice to the success of science, whilst withstanding the metaphysical undermining generated by the various species of ontological underdetermination. We are, however, as yet in want of general principles to provide a scaffold for the explicit construction of structural ontologies. Here we will attempt to bridge this gap by utilizing the formal procedure of quantization as a guide to ontic structure of modern physical theory. The example of non-relativistic particle mechanics will be considered and, for that case, it will be shown that a viable candidate for an ontic structural realism framework can be constituted in terms of the combination of a state-space with Poisson bracket structure, and a set of observables, with Lie algebra structure. 1 Introduction2 Formulation Underdetermination and Structural Ontologies3 Quantization and Structural Ontologies4 The Case of Non-relativistic Particle Mechanics 4.1 Formulation underdetermination 4.2 The classical ontology 4.3 Quantum theory and the generalized structural ontology 4.4 Interpretation of results5 Conclusion and Prospects
The ontic structural realist stance is motivated by a desire to do philosophical justice to the success of science, whilst withstanding the metaphysical undermining generated by the various species of ontological underdetermination. We are, however, as yet in want of general principles to provide a scaffold for the explicit construction of structural ontologies. Here we will attempt to bridge this gap by utilizing the formal procedure of quantization as a guide to ontic structure of modern physical theory. The example of non-relativistic particle mechanics will be considered and, for that case, it will be shown that a viable candidate for an ontic structural realism framework can be constituted in terms of the combination of a state-space with Poisson bracket structure, and a set of observables, with Lie algebra structure. 1 Introduction2 Formulation Underdetermination and Structural Ontologies3 Quantization and Structural Ontologies4 The Case of Non-relativistic Particle Mechanics 4.1 Formulation underdetermination 4.2 The classical ontology 4.3 Quantum theory and the generalized structural ontology 4.4 Interpretation of results5 Conclusion and Prospects
Three accounts of effective realism (ER) have been advanced to solve three problems for scientific realism: Fraser and Vickers (forthcoming) develop a version of ER about non-relativistic quantum mechanics that they argue is compatible with all the main realist versions (‘interpretations’) of quantum mechanics avoiding the problem of underdetermination among them; Williams (2019) and Fraser (2020b) propose ER about quantum field theory as a response to the problems facing realist interpretations; Robertson and Wilson (forthcoming) propose ER to deal with the dubious ontological status of the entities belonging to superseded theories. This paper argues for the unification of these proposals based on realism about modal structure and the idea of scale relativity of ontology developed by ontic structural realists. This solves problems some or all the accounts of ER face, especially that of making explicit in what way they are realist. Furthermore, we respond to a recent critique that has been raised against the ontic structural realist account of quantum mechanics that we employ.
The aim of this work is to study the ontological thesis defended by Ontic Structural Realism, which, in general, states that the ontological commitments should be focused in the relations and not on objects. This would be a more coherent realist stance towards modern physical theories. In first place we will study the ontological conception defended by the Ontic Structural Realism, which, broadly speaking, postulates that the ontological focus should be placed on relations rather than on objects. This, in turn, would constitute a realistic interpretation of the current physical theories. Secondly, as a possible defense to the position stated by Ontic Structural Realism, the concept of non-supervenient relations will be studied and it will be argued that it is this type of relations that acquires a fundamental character in Quantum Mechanics, as, for example, in phenomena such as the so-called quantum entanglement.
Scientific realism has traditionally maintained that our best scientific theories can be regarded as more or less true and as representing the world as it is (more or less). However, one of our very best current theories—quantum mechanics—has famously resisted such a realist construal, threatening to undermine the realist stance altogether. The chapters in this volume carefully examine this tension and the reasons behind it, including the underdetermination generated by the multiplicity of formulations and interpretations of quantum physics, each presenting a different way the world could be. Authors in this volume offer a range of alternative ways forward: some suggest new articulations of realism, limiting our commitments in one way or another; others attempt to articulate a ‘third way’ between traditional forms of realism and antirealism, or are critical of such attempts. Still others argue that quantum theory itself should be reconceptualised, or at least alternative formulations should be considered in the hope of evading the problems faced by realism. And some examine the nature of these issues when moving beyond quantum mechanics to quantum field theory. Taken together they offer an exciting new set of perspectives on one of the most fundamental questions in the philosophy of modern physics: how can one be a realist about quantum theory, and what does this realism amount to?
Abstract Ontic structuralism or ontic structural realism in the philosophy of physics can be broadly considered as an interpretative strategy providing a set of conceptual and metaphysical tools—or, more ambitiously, an ontological framework—in order to account for central features of current fundamental physics. This article aims to review the main structuralist interpretative moves in the context of our two best fundamental physical theories of matter and spacetime, namely, quantum theory (quantum mechanics and quantum field theory) and general relativity. We highlight in particular the structuralist understanding of permutation invariance, entanglement and nonlocality in quantum theory, and of the dynamical features of spacetime, (gauge‐theoretic) diffeomorphism invariance and background independence in general relativity.
According to scientific realism, science gives us an approximately true description of what the world is like. But what does it mean? In this chapter, we focus on the ontological and metaphysical aspects of this discussion. That is, we are concerned with the following questions: what there is, according to our best scientific theories? And how are these things that theories say exist? We start from the assumption that a genuine scientific realism must deal with these issues. Taking non-relativistic quantum mechanics as a case study, we discuss some of the challenges currently faced by a genuinely realistic stance. We argue, first, that in the ontological aspect, realists are in the same boat as science, that is, without sufficient epistemic justification to adopt the belief in the entities postulated by a single quantum theory, given that experience (currently) is not able to decide between rival theories; in the metaphysical aspect, realists also encounter problems with theory choice, given the possibility of associating more than one metaphysical theory with the description of the entities postulated by each quantum theory. The same goes for structuralist alternatives, since, even if we accept that scientific theories are committed to the existence of structures, but not objects, we still do not know what structures are, metaphysically. Finally, we move forward in the discussion with the meta-Popperian method, which serves to reduce the metaphysical alternatives associated with the ontological postulates of scientific theories. We may not know what the correct alternative is, but we have been able to progressively check which metaphysical alternatives are incompatible with each scientific theory.
In recent years, there has been a controversial debate in the literature regarding the choice among many interpretations of quantum mechanics. Based on certain realist desiderata, this debate has been partly addressed in the context of the choice between two opposite views about the mathematical space in which the fundamental ontology of this theory lives. Indeed, some scholars advocate a worldview in which this ontology lives in the abstract high-dimensional space, whilst others advocate a three-dimensional worldview, according to which the ontology lives in the physical space of our everyday experience. In this contribution, I will critically evaluate the tenability of solving the resulting underdetermination between the three/high-dimensional worldviews in the context of one particular quantum theory: the Bohmian approach. In so doing, I will be following two strategies: firstly, I will undermine the assumption that a set of theoretical or metaphysical virtues blocks the underdetermination problem associated with the mathematical space in which the fundamental Bohmian ontology lives; and secondly, I will propose a structural Bohmian interpretation through the use of dynamical symmetries (symplectic Lie groups), according to which the three/high-dimensional space distinction is just apparent as both spaces are grounded by the same dynamical, group-theoretic structure.