Many scientific theories purport to describe empirically inaccessible aspects of the world. The agenda of foundational physics is more ambitious still: to characterize the world at the level of 'primitive ontology'. In this pursuit it often posits new and peculiar physical features, a proclivity aided by the abstract, mathematical way in which foundational theories are framed. But how do we decipher their physical content, and in particular the accounts of primitive ontology they offer, and why think that content is true? This dissertation explores the relationship between these questions -- between the problem of ontological interpretation in foundational physics and the nature of scientific realism. I do not argue for a unified account. Rather, I examine three contexts in which their interactions are particularly interesting and philosophically significant. First, I consider the role scientific methodology plays in a prominent naturalistic defense of scientific realism: the no-miracles argument. The most sophisticated form of this argument rests on the broad claim that successful scientific methodology is irredeemably theory dependent. I examine the nature of this theory dependence within the context of Maxwell's development of electromagnetism, and argue that the presence of competing ontological interpretations undermines the realist's attempt to draw sweeping epistemic conclusions from methodological success. I next consider the concept of theoretical reformulation and how it applies to the claim that Lagrangian dynamics is a reformulation of (part of) Newtonian dynamics. How should this claim be understood in light of the fact that the world is non-classical? What can this tell us about the concept of theory reformulation itself, which plays a central role in arguments against scientific realism? I provide an analysis of theory reformulation in terms of counterfactual interpretative judgments, and then cast doubt on its justification in the classical case by developing a non-Newtonian interpretation of Lagrangian dynamics. Finally, I consider whether competing ontological interpretations raise underdetermination problems for realism about foundational physics. After first re-formulating the underdetermination argument to avoid recent objections that it fails to pose any distinctive threat, I suggest a formulation of realism that vitiates the underdetermination threats posed by competing ontological interpretations.
Many scientific theories purport to describe empirically inaccessible aspects of the world. The agenda of foundational physics is more ambitious still: to characterize the world at the level of 'primitive ontology'. In this pursuit it often posits new and peculiar physical features, a proclivity aided by the abstract, mathematical way in which foundational theories are framed. But how do we decipher their physical content, and in particular the accounts of primitive ontology they offer, and why think that content is true? This dissertation explores the relationship between these questions -- between the problem of ontological interpretation in foundational physics and the nature of scientific realism. I do not argue for a unified account. Rather, I examine three contexts in which their interactions are particularly interesting and philosophically significant. First, I consider the role scientific methodology plays in a prominent naturalistic defense of scientific realism: the no-miracles argument. The most sophisticated form of this argument rests on the broad claim that successful scientific methodology is irredeemably theory dependent. I examine the nature of this theory dependence within the context of Maxwell's development of electromagnetism, and argue that the presence of competing ontological interpretations undermines the realist's attempt to draw sweeping epistemic conclusions from methodological success. I next consider the concept of theoretical reformulation and how it applies to the claim that Lagrangian dynamics is a reformulation of (part of) Newtonian dynamics. How should this claim be understood in light of the fact that the world is non-classical? What can this tell us about the concept of theory reformulation itself, which plays a central role in arguments against scientific realism? I provide an analysis of theory reformulation in terms of counterfactual interpretative judgments, and then cast doubt on its justification in the classical case by developing a non-Newtonian interpretation of Lagrangian dynamics. Finally, I consider whether competing ontological interpretations raise underdetermination problems for realism about foundational physics. After first re-formulating the underdetermination argument to avoid recent objections that it fails to pose any distinctive threat, I suggest a formulation of realism that vitiates the underdetermination threats posed by competing ontological interpretations.
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?
The central aim of this thesis is to present a new kind of realism that is driven not from the traditional realism/anti-realism debate but from the practice of physicists. The usual debate focuses on discussions about the truth of theories and their fit with nature, while the real practices of the scientists are forgotten. The position I shall defend is called 'phenomenological realism': theories are merely tools to construct other theories and models, including phenomenological models; phenomenological models are the vehicles of representation. The realist doctrine was recently undermined by the argument from the pessimistic meta-induction, also known as the argument from scientific revolutions. I argue that phenomenological realism is a new kind of scientific realism which can overcome the problem generated by the argument from scientific revolutions, and which depend on the scientific practice. The realist tried to overcome this problem by suggesting various types of theory dichotomy. I claim that different types of dichotomy presented by realists did not overcome the problem, these dichotomies cut through theory vertically. I argue for a different kind of dichotomy between high level theoretical abstractions and low-level theoretical representations. I claim that theoretical work in physics have two distinct types depending on the way they are built these are: theoretical models which built depending on a top-down approach and phenomenological models which are built depending on a bottom-up approach, this dichotomy cuts the division along a horizontal line between low and high level theory. I present two case studies. One from superconductivity where I contrast the BCS theory of superconductivity with the phenomenological model of Landau and Ginzburg. I show how in that field of physics the historical developments favoured phenomenological models over high-level theoretical abstraction. I show how the BCS theory of superconductivity was constructed, and why it was accepted as the fundamental theory of superconductivity, and how later failed to account for new kinds of superconductors. I contrast that with the building of the widely accepted phenomenological model of superconductivity. The other case study is a fresh look at the Bohr-Einstein debate. I think that the main difference between Bohr and Einstein was their position from how theoretical work ought to be conducted in physics. Einstein always sought the mathematical clarity and simplicity, he adopted a top-down approach toward theoretical work, while Bohr insisted on a bottom-up approach. (author)
My aim in this dissertation is to defend a realist interpretation of quantum mechanics.Firstly, I present considerations based on certain general features of theories in the natural sciences which indicate that realism affords a better account of those theories than instrumentalism.In particular, I consider certain issues surrounding the cognitive status of theories, including the role of models, the status of scientific explanation, and the referential character of theoretical terms.Secondly, I develop a detailed realist theory of measurement based on the notion of quantity terms as designators of objective properties of, and relations among, existing entities.I contrast this with the leading instrumentalist theories of measurement, and I argue that the realist theory is the better account of both the logic and practice of scientific measurement.Finally, I consider a number of objections to realism that arise because of certain theoretical features peculiar to quantum mechanics.In the course of this discussion, I consider crucial experimental evidence for the "dual" nature of microentities, various criteria of reality proposed by philosophers of science, the peculiar features of quantum mechanical measurement, and the status of causality in quantum mechanics.I argue that while certain realist viii ix interpretations of the quantum theory, namely the wave and wavicle interpretations, are unsatisfactory, an interpreta tion which construes micro-entities as existing particles is a tenable account.CHAPTER I ignored the considerations which arise at those more general levels of inquiry, but one can not adequately assess the status of quantum mechanics with respect to both realism and instrumentalism apart from those considerations.In the second two chapters of the dissertation, I shall argue that realist interpretations of quantitative theories in the natural sciences are preferable to instrumentalist interpretations.Then in the remainder of the dissertation, I shall go on to argue that realism is tenable at the quantum mechanical level despite the features peculiar to that theory.CHAPTER II THE COGNITIVE STATUS OF THEORIES transitions from one set of experiential statements to another.This view is in marked contrast to that of the realist who regards such terms as referential.This divergence in opinion between realists and instrumentalists about the referential character of theoretical terms leads to a related dispute over the role of models in the inter pretation of scientific theories.Before contrasting the various philosophical positions on this issue, it will be necessary to sort out different senses of the term "model."Upon inspecting the literature surrounding this dispute, it seems that much of the controversy about the role of models stems from a failure to make such distinctions.I will begin this task by distinguishing between 13 model-structures and model-objects.A model-structure is a definitely specifiable schema of mathematical-logical relationships which is exhibited by and can be abstracted from a set of objects.Any set of objects which exhibits a model-structure constitutes a set of model-objects.With respect to any particular scientific theory, there may be a variety of model-objects that scientists employ for various purposes.For example, in the kinetic theory of gases, one can distinguish the following.Firstly, there is the set of molecules themselves, the theoretical entities which we shall 13.For further detail in this regard, see Henry C. Byerly, "Model-Structures and Model-Objects," British Journal for the Philosophy of Science.Vol. 20, 1969, pp.135-144.i In fact, if one were to make that claim, I do not see how it could be supported without again falling prey to Maxwell's criticism cited above.And if one is simply troubled by the "ontological risk" involved in asserting the existence of theoretical entities because of the tentativeness of the corresponding theories, it should be noted that the risk of being wrong is a small price to pay for the potentially deeper understanding of nature that scientific theories afford us in the light of realist commitments.
Contemporary fundamental physics combines extraordinary empirical success with the per-sistence of unresolved foundational difficulties. While theoretical frameworks continue to in-crease in formal sophistication, certain classes of conceptual problems remain stable acrosssuccessive developments. This paper argues that this situation reflects a structural feature ofscientific methodology rather than a collection of isolated technical shortcomings.The central claim is that a methodological asymmetry between formal and ontological el-ements of scientific theories gives rise to a structural catch–22. Formal structures are readilyrevised, extended or elaborated, whereas ontological commitments that delimit a theory’s do-main of applicability are typically held fixed and remain implicit. As a result, foundationalproblems that originate at the level of interpretive structure cannot be resolved within the spaceof admissible responses, leading instead to formal complication or interpretive proliferation.Against this background, foundational paradoxes are not treated here as primary targetsof resolution but as diagnostic indicators of this structural constraint. The paper develops asystematic classification of paradox formation across fundamental physics, identifying five recur-ring mechanisms of ontological misalignment: boundary-region effects, illicit domain extension,projection conflation, temporal category errors and interpretive overloading. These mechanismsrecur across diverse theoretical contexts and account for the persistence of otherwise disparateparadoxes.The papers contribution is methodological and diagnostic: to clarify the structural conditionsunder which certain classes of foundational problems arise and persist and to show how makingontological commitments explicit can expand the space of coherent scientific description withoutundermining empirical rigor. The analysis also highlights how prevailing publication practicestend to reinforce the structural dynamics identified here.
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
In previous chapters we argued that the empirically successful formalism of quantum mechanics supports equally well two mutually incompatible general ontologies: the inherently indeterministic and generally accepted Copenhagen interpretation and Bohm's completely deterministic one. This underdetermination of the interpretation by the formalism is not simply an apparent one of two equivalent theories since there is no way to translate the terms of one of these ontologies into those of the other. This case could be seen as presenting a challenge to the scientific realist who seeks from successful scientific theories a true representation of the world. Furthermore, we suggest that the actual historical competition between these theories and the selection of Copenhagen over Bohm illustrate that such an historically contingent process is not meaningfully distinct from the rational reconstruction and logical judgment of the victorious theory. What is deemed successful and put on offer by the scientific community for the philosopher of science to justify after the fact is itself a contingent and nonunique product. UNDERDETERMINATION The origin of the underdetermination of scientific theories, what we refer to here as the so-called Duhem–Quine thesis, is typically located in Pierre Duhem's The Aim and Structure of Physical Theory (first published in 1906). There Duhem was quite explicit about what he took to be the basis for judging whether or not a given physical theory is acceptable.