Steven French

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.

Howard argues that the existence of unitarily inequivalent representations in Quantum Field Theory presents a problem for structural realism in this context. I consider two potential ways round this problem: 1), follow Wallace in adopting the 'naive' Lagrangian form of QFT with cut-offs; 2), adapt Ruetsche's 'Swiss Army Knife' approach. The first takes us into the current debate between Wallace and Fraser on conventional vs. algebraic QFT. The second involves consideration of the role of inequivalent representations in understanding spontaneous symmetry breaking and quantum statistics. In both cases, I suggest, the structural realist has sufficient room to manoeuvre

In the past thirty years, two fundamental issues have emerged in the philosophy of science. One concerns the appropriate attitude we should take towards scientific theories--whether we should regard them as true or merely empirically adequate, for example. The other concerns the nature of scientific theories and models and how these might best be represented. In this ambitious book, da Costa and French bring these two issues together by arguing that theories and models should be regarded as partially rather than wholly true. They adopt a framework that sheds new light on issues to do with belief, theory acceptance, and the realism-antirealism debate. The new machinery of "partial structures" that they develop offers a new perspective from which to view the nature of scientific models and their heuristic development. Their conclusions will be of wide interest to philosophers and historians of science.

The composition of objects is a much discussed issue in metaphysics. In this paper I look at various approaches to this issue in the context of two examples: the relationship between ‘everyday’ objects, such as tables, and their constituent physical entities, and the relationship between structures and objects, from the perspective of structural realism. My aims are first, to defend forms of eliminativism in both cases, whereby one can still make statements about the entities to be eliminated ; and second, to highlight some of the metaphysical moves that are available to the structuralist in articulating their ontology. In doing so I hope also to indicate how metaphysics and the philosophy of science can be brought into a more productive relationship.

Recent developments in the scientific realism debate have resulted in a form of ‘exemplar driven’ realism that eschews general ‘recipes’ and instead focuses on the specific, ‘local’ reasons for adopting a realist stance in particular theoretical contexts. Here I suggest that such a move highlights even more sharply the need for the realist to incorporate a health dose of metaphysics in her position, particularly when it comes to the theories associated with modern physics. Turning to another set of recent developments, having to do with the relationship between metaphysics and science, I argue that the exemplar driven realist can appropriate certain current metaphysical devices to help make concrete her commitments. Specifically I focus on a kind of exemplar based structural realism and examine the adequacy of, first, the determinables-determinate relationship as presented by Wilson and, second, Paul’s ‘one category ontology, as such devices within this framework.

Although Eddington's philosophy of physics has been subjected to critical re-evaluation in recent years, neither the exact nature of his structuralist views nor his response to criticism by the likes of Braithwaite have been made clear. In this paper I trace, in particular, the incorporation into Eddington's structuralism of the non-classical indistinguishability of quantum objects. His metaphysical view of such objects as the product of group-theoretical analysis is crucial for understanding his response to Braithwaite's criticisms of the whole structuralist endeavor. These criticisms closely resemble more recent attacks on structural realism in the philosophy of science. I conclude with a brief comparison between these more modern forms of structuralism and Eddington's.

Discussions of representation in science tend to draw on examples from art. However, such examples need to be handled with care given a) the differences between works of art and scientific theories and b) the accommodation of these examples within certain philosophies of art. I shall examine the claim that isomorphism is neither necessary nor sufficient for representation and I shall argue that there exist accounts of representation in both art and science involving isomorphism which accommodate the apparent counterexamples and, moreover, allow us to understand how “impossible” artistic objects and inconsistent scientific theories can be said to represent.

Department of History and Philosophy of Science. University of Cambridge, Free School Lane, Cambridge CB2 3RH This paper is concerned with the question of whether atomic particles of the same species, i. e. with the same intrinsic state-independent properties of mass, spin, electric charge, etc, violate the Leibnizian Principle of the Identity of Indiscernibles, in the sense that, while there is more than one of them, their state-dependent properties may also all be the same. The answer depends on what exactly the state-dependent properties of atomic particles are taken to be. On the plausible interpretation that these should comprise all monadic and relational properties that can be expressed in terms of physical magnitudes associated with self-adjoint operators that can be defined for the individual particles, then the weakest form of the Principle is shown to be violated for bosons, fermions and higher-order paraparticles, treated in first quantization *Some of the arguments inn this paper appeared in a thesis submited by one of us (S.F.) In partial fulfilment of the requirements for the PhD degree of the University of London, in 1984. entitled 'Identity and ‘Individuality in Classical and Quantum Physics’.

Semi-realism offers a metaphysics of science based on causal properties. Insofar as these are understood in terms of dispositions for specific relations that comprise the concrete structure of the world it can be regarded as a form of structural realism. And insofar as these properties are 'sociable' and cohere into the groupings that comprise the particulars investigated by science, it captures the underlying intuition behind forms of entity realism. However, I shall raise concerns about both these features. I shall suggest that dispositionalism is not an appropriate metaphysics for modern physics and that 'sociability' should be understood in terms of the coherence revealed by symmetry principles. I hope to show how we can retain the virtues of semi-realism while dispensing with the problematic elements by recasting it in more thoroughly structuralist terms

Although much of its history has been neglected or misunderstood, a structuralist 'tendency' has re-emerged within the philosophy of science. Broadly speaking, it consists of two fundamental strands: on the one hand, there is the identification of structural commonalities between theories; on the other, there is the metaphysical decomposition of objects in structural terms. Both have been pressed into service for the realist cause: the former has been identified primarily with Worrall's 'epistemic' structural realism; the latter with Ladyman's 'ontic' form. And both raise important issues of general interest within the philosophy of science and metaphysics, respectively. The former invites questions regarding the identification and appropriate representation of these commonalities; the latter touches on different views regarding the nature of objects, the constitutive role of properties and the seat of causal powers. Both strands have recently come under critical fire. It is my intention to present a unified account of the 'structuralist tendency' which emphasizes the dual roles of structure as representational and constitutive, and to indicate how the more acute critical remarks can be dealt with

The current state of the relationship between metaphysics and the philosophy of science might appear to be one best described as ‘hostility on both sides’. In an attempt to bridge this gap, French and McKenzie have suggested a two fold strategy: on the one hand, if metaphysics is to be taken to have something direct to say about reality, the implications of physics need to be properly appreciated; on the other, one does not have to agree with the claim that a prioristic metaphysics should be dismissed or even discontinued, since we should value scientifically disinterested metaphysics as a ‘toolbox’ for philosophers of science. It is in the context of this strategy that I want to approach the issue of understanding the symmetry principles that feature in the Standard Model of modern physics. I shall suggest that the dispositional analysis of laws is incapable of accommodating such principles. However, there are other tools in the metaphysical toolbox that one can draw upon to help capture the nature of such symmetries corresponding to the second part of the above strategy.

Dispositionalist accounts of scientific laws are currently at the forefront of discussions in the metaphysics of science. However, Mumford has presented such accounts with the following dilemma: if laws are to have a governing role, then they cannot be grounded in the relevant dispositions; if on the other hand, they are so grounded, then they cannot perform such a role. Mumford’s solution is drastic: to do away with laws as metaphysically substantive entities altogether. Dispositionalist accounts are also deficient in that they either make no mention of the significant role of symmetries in science, or attempt to inappropriately eliminate this role. Here we shall attempt to motivate a structuralist view of laws by showing how it evades Mumford’s dilemma and accommodates the role of symmetry principles. In addition we shall consider how this view deals with a number of issues that dispositionalism finds problematic and indicate how the supposed necessity of laws and the explanation of relevant counterfactuals look from this structuralist perspective.

Within the philosophy of science there has been a great deal of rather vague talk about the 'heuristic fruitfulness' (or what Peirce called the 'esperable uberty') of theories. It is my aim in the present paper to add some precision to these discussions by linking this 'fruitfulness' to the satisfaction of certain heuristic criteria. In this manner the demarcation between 'discovery' and 'pursuit' becomes blurred. As a case study, I present the competition between the paraparticle and colour models of quarks in the late 1960s. I argue that the eventual appraisal of the latter as the more fruitful of the two was based on the incorporation of a particular symmetry principle, regarded as a heuristic guideline, rather than on non-epistemic factors concerning 'cognitive resources' and the like.