Quantum field theory (QFT) presents a genuine example of the underdetermination of theory by empirical evidence. There are variants of QFT—for example, the standard textbook formulation and the rigorous axiomatic formulation—that are empirically indistinguishable yet support different interpretations. This case is of particular interest to philosophers of physics because, before the philosophical work of interpreting QFT can proceed, the question of which variant should be subject to interpretation must be settled. New arguments are offered for basing the (...) interpretation of QFT on a rigorous axiomatic variant of the theory. The pivotal considerations are the roles that consistency and idealization play in this case. *Received June 2009; revised August 2009. †To contact the author, please write to: Department of Philosophy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; e‐mail: [email protected]. (shrink)

String theory promises to be able to provide us with a working theory of quantum gravity and a unified description of all fundamental forces. In string theory there are so called ‘dualities’; i.e. different theoretical formulations that are physically equivalent. In this article these dualities are investigated from a philosophical point of view. Semantic and epistemic questions relating to the problem of underdetermination of theories by data and the debate on realism concerning scientific theories are discussed. (...) Depending on ones views on semantic issues and realism different interpretations are possible of the dualities. (shrink)

This article investigates the implications of string theory for the conception of scientific theory confirmation. The classical understanding of theory confirmation is based on the assumption that scientific theory building is underdetermined by the available empirical data. Several arguments are presented, which suggest a devaluation of this ‘principle of scientific underdetermination’ in the context of string theory. An altered conception of scientific progress emerges that is not based on the notion of theory succession.

The underdetermination of theory by data argument (UD) is traditionally construed as an argument that tells us that we ought to favour an anti-realist position over a realist position. I argue that when UD is constructed as an argument saying that theory choice is to proceed between theories that are empirically equivalent and adequate to the phenomena up until now, the argument will not favour constructive empiricism over realism. A constructive empiricist cannot account for why scientists are (...) reasonable in expecting one theory to be empirically adequate rather than another, given the criteria he suggests for theory choice. (shrink)

This paper examines the epistemological significance of the present situation of underdetermination in quantum mechanics. After analyzing this underdetermination at three levels---formal, ontological, and methodological---the paper considers implications for a number of variants of the thesis of scientific realism in fundamental physics and reassesses Lakatos‘ characterization of progress in physical theory in light of the present situation. Next, this paper considers the implications of underdetermination for Weinberg’s ‘‘dream of a final theory.’’ Finally, the paper concludes (...) by suggesting how one might still think of realism and progress in fundamental physics despite the possibility of persistent underdetermination in quantum mechanics. (shrink)

Classical and quantum field theory provide not only realistic examples of extant notions of empirical equivalence, but also new notions of empirical equivalence, both modal and occurrent. A simple but modern gravitational case goes back to the 1890s, but there has been apparently total neglect of the simplest relativistic analog, with the result that an erroneous claim has taken root that Special Relativity could not have accommodated gravity even if there were no bending of light. The fairly recent acceptance (...) of nonzero neutrino masses shows that widely neglected possibilities for nonzero particle masses have sometimes been vindicated. In the electromagnetic case, there is permanent underdetermination at the classical and quantum levels between Maxwell's theory and the one-parameter family of Proca's electromagnetisms with massive photons, which approximate Maxwell's theory in the limit of zero photon mass. While Yang–Mills theories display similar approximate equivalence classically, quantization typically breaks this equivalence. A possible exception, including unified electroweak theory, might permit a mass term for the photons but not the Yang–Mills vector bosons. Underdetermination between massive and massless (Einstein) gravity even at the classical level is subject to contemporary controversy. (shrink)

I examine the argument that scientific theories are typically 'underdetermined' by the data, an argument which has often been used to combat scientific realism. I deal with two objections to the underdetermination argument: (i) that the argument conflicts with the holistic nature of confirmation, and (ii) that the argument rests on an untenable theory/data dualism. I discuss possible responses to both objections, and argue that in both cases the proponent of underdetermination can respond in ways which are (...) individually plausible, but that the best response to the first objection conflicts with the best response to the second. Consequently underdetermination poses less of a problem for scientific realism than has often been thought. (shrink)

Olaf Müller’s book develops a new case for underdetermination, and, as he is focusing on theories of a ‘limited domain’, this assumes the containability of the theories. First, the paper argues that Müller’s theory of darkness is fundamentally Newtonian, but for Newton’s optical theory the type of theoretical structure Müller adopts is problematic. Second, the paper discusses seventeenth-century challenges to Newton, changes in the proof-structure of Newton’s optical theory, and how these affect Müller’s reconstruction. Müller’s book (...) provides empirically equivalent theories, yet the historical theories were not empirically equivalent, and the same experiments were used to extract different bodies of evidence to rebut the opponent. Third, Goethe’s multi-layered critique of Newton’s experimental proof is investigated, including his developmental account of prismatic colours, the role of experimental series in rejecting Newton’s observations, and his incorporation of the ‘limited domain’ of prismatic colours in a broader framework. Two key elements of Goethe’s method, polarity and strengthening are discussed in contrast to Müller, who only utilises polarity in his account. Finally Neurath’s attempts to come to grips with the optical controversies and the prism-experiments with ‘blurred edges’ are recalled. Müller also discusses in detail some of these experiments and heavily draws on Quine. Neurath developed Duhem’s and Poincaré’s conventionalist insights and had good reasons to be pessimistic about theory-containment. Their differences provide some additions to the history of the Duhem–Quine thesis. (shrink)

The anti-exceptionalist debate brought into play the problem of what are the relevant data for logical theories and how such data affects the validities accepted by a logical theory. In the present paper, I depart from Laudan's reticulated model of science to analyze one aspect of this problem, namely of the role of logical data within the process of revision of logical theories. For this, I argue that the ubiquitous nature of logical data is responsible for the proliferation of (...) several distinct methodologies for logical theories. The resulting picture is coherent with the Laudanean view that agreement and disagreement between scientific theories take place at different levels. From this perspective, one is able to articulate other kinds of divergence that considers not only the inferential aspects of a given logical theory, but also the epistemic aims and the methodological choices that drive its development. (shrink)

The goal of this article is to show that the structuralist approachprovides a powerful framework for the analysis of certain holistic phenomena in empirical theories.We focus on two aspects of holism. The first refers to the involvement of comprehensive complexes of hypothesesin the theoretical treatment of systems regarded in isolation. By contrast, the second refers to thecorrelation between the theoretical descriptions of different systems. It is demonstrated how these two aspectscan be analysed by making use of the structuralist notion of (...) theory-nets, and how they are reflected by a refinedversion of the Ramsey sentence. Furthermore, it is argued that there exists a tight correlation between theoccurrence of these two holistic phenomena, a specific form of underdetermination of terms which occur in thefundamental principles of an empirical theory, and the shaping of the theory's protective belt. After having dealtwith these questions in abstracto, the relevance of these considerations for a better understanding of the dynamicsof empirical theories is demonstrated in a concrete case study. It refers to the role holistic phenomenaplayed in the investigation of the anomalous advance of Mercury's perihelion and in the various attempts to eliminate this anomaly. (shrink)

The empirical underdetermination of theories is a philosophical problem which until the last century has not seriously troubled actual science. The reason is that confirmation does not depend only on empirical consequences, and theoretical virtues allow to choose among empirically equivalent theories. Moreover, I argue that the theories selected in this way are not just pragmatically or aesthetically better, but more probably true. At present in quantum mechanics not even theoretical virtues allow to choose among many competing theories and (...) interpretations, but this is because none of them possess those virtues to a sufficient degree. However, first, we can hope for some future advancement. Second, even if no further progress came forth, all the most credited competitors agree on a substantial core of theoretical assumptions. Therefore underdetermination does not show that we cannot be realist on unobservable entities in general, but at most that in particular fields our inquiry may encounter some de facto limits. (shrink)

Advocates of the "strong programme" in the sociology of knowledge have argued that, because scientific theories are "underdetermined" by data, sociological factors must be invoked to explain why scientists believe the theories they do. I examine this argument, and the responses to it by J.R. Brown (1989) and L. Laudan (1996). I distinguish between a number of different versions of the underdetermination thesis, some trivial, some substantive. I show that Brown's and Laudan's attempts to refute the sociologists' argument fail. (...) Nonetheless, the sociologists' argument falls to a different criticism, for the version of the underdetermination thesis that the argument requires, has not been shown to be true. (shrink)

This paper criticizes the attempt to found the epistemological doctrine that all theories are evidentially underdetermined on the thesis that all theories have empirically equivalent rivals. The criticisms focus on the role of auxiliary hypotheses in prediction. It is argued, in particular, that if auxiliaries are underdetermined, then the thesis of empirical equivalence is undecidable. The inference from empirical equivalence to the underdetermination of total theories would seem to survive the criticisms, because total theories do not require auxiliaries to (...) yield observational consequences. It is shown that, nevertheless, underdetermination cannot be established for total theories. (shrink)

It is often possible to know what a speaker intends to communicate without knowing what they intend to say. In such cases, speakers need not intend to say anything at all. Stanley and Szabó's influential survey of possible analysis of quantifier domain restriction is, therefore, incomplete and the arguments made by Clapp and Buchanan against Truth Conditional Compositionality and propositional speaker-meaning are flawed. Two theories should not always be viewed as incompatible when they associate the same utterance with different propositions, (...) as there may be many ways to interpret speakers that are compatible with their intentions. (shrink)

After a thorough examination of the claim that "the underdetermination of theory by evidence forces us to seek sociological explanations of scientists' cognitive choices", Samir Okasha concludes that the only significant problem with this argument is that the thesis of underdetermination is not adequately supported. Against Okasha, I argue (1) that there is a very good reason to question the inference from the underdetermination of a theory to a sociological account of that theory's acceptance, (...) and (2) that Okasha's own objection to the argument is too weak. (shrink)

Compositionality and semantic innocence seem intuitively plausible constraints on a semantic theory. It has, however, proved notoriously difficult to respect both principles within a single framework. In this paper I argue that their apparent incompatibility derives from an overly-strong formulation of the principles. I propose an alternative weaker formulation which allows for both principles to be respected within a single semantic framework while satisfying the intuitions which motivate the two principles.

Quine has attempted to support his indeterminacy thesis by invoking the assumption that two different physical theories could both be compatible with all possible data. His argument ought to work even if the translation of non-Theoretical sentences is determinate. But this enables us to see that the underdetermination of theory need not produce any indeterminacy in the translation of theory.

It is a familiar fact in the practice of science that the available observational evidence may not decide between rival hypotheses or theories. For instance, at the time of Copernicus it was widely held that his theory and the Ptolemaic theory did not differ in their predictions in regard to the available astronomical data. This situation can be illustrated by an analogy. Imagine a finite number of dots on a page of paper representing the available evidence. It will (...) always be possible to draw more than one curve connecting the points. How do we decide which curve or theory to adopt? A standard response is to look to some area where the theories make different predictions. We then seek new evidence, perhaps by conducting an experiment, to determine which theory's prediction is correct and opt tentatively for that one. If it is not feasible to gather this evidence, we can be agnostic for the moment on the question of which it is best to adopt. Or, more likely, we will look to factors other than tit with the data to assist us in resolving the matter (see pragmatic factors in theory acceptance). We will call this phenomena weak Underdetermination of theories, or WUT. (shrink)

In this paper, I reconstruct an argument of Aristidis Arageorgis against empirical underdetermination of the state of a physical system in a C*-algebraic setting and explore its soundness. The argument, aiming against algebraic imperialism, the operationalist attitude which characterized the first steps of Algebraic Quantum Field Theory, is based on two topological properties of the state space: being T1 and being first countable in the weak*-topology. The first property is possessed trivially by the state space while the latter (...) is highly non-trivial, and it can be derived from the assumption of the algebra of observables’ separability. I present some cases of classical and of quantum systems which satisfy the separability condition, and others which do not, and relate these facts to the dimension of the algebra and to whether it is a von Neumann algebra. Namely, I show that while in the case of finite-dimensional algebras of observables the argument is conclusive, in the case of infinite-dimensional von Neumann algebras it is not. In addition, there are cases of infinite-dimensional quasilocal algebras in which the argument is conclusive. Finally, I discuss Porrmann's construction of a net of local separable algebras in Minkowski spacetime which satisfies the basic postulates of Algebraic Quantum Field Theory. (shrink)

According to the underdetermination thesis, all evidence necessarily underdetermines any scientific theory. Thus it is often argued that our agreement on the content of mature scientific theories must be due to social and other factors. Drawing on a long standing tradition of criticism, I shall argue that the underdetermination thesis is little more than speculation based on an impoverished account of induction. A more careful look at accounts of induction does not support an assured underdetermination or (...) the holism usually associated with it. I also urge that the display of observationally equivalent theories is a self-defeating strategy for supporting the underdetermination thesis. The very fact that observational equivalence can be demonstrated by arguments brief enough to be included in a journal article means that we cannot preclude the possibility that the theories are merely variant formulations of the same theory. (shrink)

Investigation of the use of intervention data in estimating parameters in a Bayesian network.

Are theories ‘underdetermined by the evidence’ in any way that should worry the scientific realist? I argue that no convincing reason has been given for thinking so. A crucial distinction is drawn between data equivalence and empirical equivalence. Duhem showed that it is always possible to produce a data equivalent rival to any accepted scientific theory. But there is no reason to regard such a rival as equally well empirically supported and hence no threat to realism. Two theories are (...) empirically equivalent if they share all consequences expressed in purely observational vocabulary. This is a much stronger requirement than has hitherto been recognised— two such ‘rival’ theories must in fact agree on many claims that are clearly theoretical in nature. Given this, it is unclear how much of an impact on realism a demonstration that there is always an empirically equivalent ‘rival’ to any accepted theory would have—even if such a demonstration could be produced. Certainly in the case of the version of realism that I defend—structural realism—such a demonstration would have precisely no impact: two empirically equivalent theories are, according to structural realism, cognitively indistinguishable. (shrink)

The aim of this paper is to show that science, understood as pure research, ought not to be affected by non-epistemic values and thus to defend the traditional ideal of value-free science. First, we will trace the distinction between science and technology, arguing that science should be identified with pure research and that any non-epistemic concern should be di­rected toward technology and technological research. Second, we will examine different kinds of values and the roles they can play in scientific research (...) to argue that science understood as pure research is mostly and in any case ought to be value-free. Third, we will consider and dismiss some widespread arguments that aim to defend, especially at a normative level, the inevitable value-ladenness of science. Finally, we will briefly return to the connections among science, technology, and values. (shrink)

The main theme is that theorizing serves empirical prediction. This is used as the core of a counter to contemporary anti-realist arguments. Different versions of the thesis that data underdetermines theory are identified and it is shown that none which are acceptable differentiates between theory selection and prediction. Criteria sufficient for the former are included amongst those necessary for the latter; and obviously go beyond mere compatibility with data.Special attention is given to causal process theories. It is argued (...) that the only empirically equivalent alternatives which can be constructed to any theory of this kind must be parasitic on that theory; so a choice for the original theory can not be avoided. Once this is established, a positive case for taking a realist position can be developed. (shrink)

This paper surveys the status of scientific realism in relation to quantum physics, focusing on the problem of underdetermination.

The underdetermination of scientific theory choice by evidence is a familiar but multifaceted concept in the philosophy of science. I answer two pressing questions about underdetermination: “What is underdetermination?” and “Why should we care about underdetermination?” To answer the first question, I provide a general definition of underdetermination, identify four forms of underdetermination, and discuss major criticisms of each form. To answer the second question, I then survey two common uses of underdetermination (...) in broader arguments against scientific realism and in support of the use of values in scientific theory choice. I conclude that philosophers should also care about underdetermination because it impacts scientists in their practice. (shrink)

Structural realism is sometimes said to undermine the theory underdetermination (TUD) argument against realism, since, in usual TUD scenarios, the supposed underdetermination concerns the object-like theoretical content but not the structural content. The paper explores the possibility of structural TUD by considering some special cases from modern physics, but also questions the validity of the TUD argument itself. The upshot is that cases of structural TUD cannot be excluded, but that TUD is perhaps not such a terribly (...) serious anti-realistic argument. (shrink)

In 1991 Larry Laudan and Jarret Leplin proposed a solution for the problem of empirical equivalence and the empirical underdetermination that is often thought to result from it. In this paper we argue that, even though Laudan and Leplin’s reasoning is essentially correct, their solution should be accurately assessed in order to appreciate its nature and scope. Indeed, Laudan and Leplin’s analysis does not succeed in completely removing the problem or, as they put it, in refuting the thesis of (...) underdetermination as a consequence of empirical equivalence. Instead, what they show is merely that science possesses tools that may eventually lead out of an underdetermination impasse. We apply their argument to a real case of two empirically equivalent theories: Lorentz’s ether theory and Einstein’s special relativity. This example illustrates the validity of Laudan and Leplin’s reasoning, but also shows the importance of the reassessment we argue for. (shrink)

According to the no miracles argument, scientific realism provides the only satisfactory explanation of the predictive success of science. It is argued in the present article that a different explanatory strategy, based on the posit of limitations to the underdetermination of scientific theory building by the available empirical data, offers a more convincing understanding of scientific success.

Despite Quine's recurrent claims to the contrary, the idea is still widespread that indeterminacy of translation is a special case of underdetermination of theories. In this paper we explain how indeterminacy differs from underdetermination, and in what ways such gifted Quine scholars as Gemes and Bergström went astray.

Various forms of underdetermination that might threaten the realist stance are examined. That which holds between different 'formulations' of a theory (such as the Hamiltonian and Lagrangian formulations of classical mechanics) is considered in some detail, as is the 'metaphysical' underdetermination invoked to support 'ontic structural realism'. The problematic roles of heuristic fruitfulness and surplus structure in attempts to break these forms of underdetermination are discussed and an approach emphasizing the relevant structural commonalities is defended.

The extra value of novel confirmation over accommodation is explained based on an analysis of the underdetermination of scientific theory building. Novel confirmation can provide information on the number of possible scientific alternatives to a predictively successful theory. This information, in turn, can raise the probability that the given theory is true or will be empirically viable in the future.

The Polish researcher in the field of logic and philosophy, Jan Woleński, in one of his recent articles, "Metalogical Observations About the Underdetermination of Theories by Empirical Data," logically formalized two weak and strong versions of the underdetermination of theories by empirical data (or UT by abbreviation) and with these formalization has metalogically analyzed these two versions. Finally he has deducted that the weak version is defensible while the strong version is not. In this paper we will critically (...) study Woleński’s analysis of the strong version of UT. (shrink)

Duhem—Quine underdetermination plays a constructive role in epistemology by pinpointing the impact of non-empirical virtues or cognitive values on theory choice. Underdetermination thus contributes to illuminating the nature of scientific rationality. Scientists prefer and accept one account among empirical equivalent alternatives. The non-empirical virtues operating in science are laid open in such theory choice decisions. The latter act as an epistemological test tube in making explicit commitments to how scientific knowledge should be like.

Four empirically equivalent versions of general relativity, namely standard GR, Lorentz-invariant gravitational theory,and the gravitational gauge theories of the Lorentz and translation groups, are investigated in the form of a case study for theory underdetermination. The various ontological indeterminacies (both underdetermination and inscrutability of reference) inherent in gravitational theories are analyzed in a detailed comparative study. The concept of practical underdetermination is proposed, followed by a discussion of its adequacy to describe scientific progress.

In this paper, I argue (i) that there are certain methodological practices that are epistemically significant, and (ii) that we can test for the success of these practices empirically by examining case-studies in the history of science. Analysing a particular episode from the history of medicine, I explain how this can help us resolve specific cases of underdetermination. I conclude that, while the anti-realist is (more or less legitimately) able to construct underdetermination scenarios on a case-by-case basis, he (...) will have to abandon the strategy of using algorithms to do so, thus losing the much needed guarantee that there will always be rival cases of the required kind. (shrink)

Several feminist philosophers of science have tried to open up the possibility that feminist ethical or political commitments could play a positive role in good science by appealing to the Duhem-Quine thesis and underdetermination of theories by observation. I examine several different interpretations of the claim that feminist values could play a legitimate role in theory justification and show that none of them follow from a logical gap between theory and observation. Finally, I sketch an alternative approach (...) for defending the possibility that feminist political commitments could play a legitimate role in science. (shrink)

This paper examines the underdetermination between the Ptolemaic, Copernican, and the Tychonic theories of planetary motions and its attempted resolution by Kepler. I argue that past philosophical analyses of the problem of the planetary motions have not adequately grasped a method through which the underdetermination might have been resolved. This method involves a procedure of what I characterize as decomposition and identification. I show that this procedure is used by Kepler in the first half of the Astronomia Nova, (...) where he ultimately claims to have refuted the Ptolemaic theory, thus partially overcoming the underdetermination. Finally, I compare this method with other views of scientific inference such as bootstrapping. (shrink)