Structural Realism

Recently, there has been a debate as to whether or not the principle of the identity of indiscernibles (the PII) is compatible with quantum physics. It is also sometimes argued that the answer to this question has implications for the debate over the tenability of ontic structural realism (OSR). The central aim of this paper is to establish what relationship there is (if any) between the PII and OSR. It is argued that one common interpretation of OSR is undermined if (...) the PII turns out to be false, since it is committed to a version of the bundle theory of objects, which implies the PII. However, if OSR is understood as the physical analogue of (sophisticated) mathematical structuralism then OSR does not imply the PII. It is further noted that it is (arguably) a virtue of OSR that it is compatible with a version of the PII for possible worlds. (shrink)

In this paper, a new account of empirical claims in structuralism is developed. Its novelty derives from the use that is made of the linguistic approach to scientific theories despite the presumed incompatibility of structuralism with that approach. It is shown how the linguistic approach can be applied to the framework of structuralism if the semantic foundations of that approach are refined to do justice to the doctrine of indirect interpretation of theoretical terms. This doctrine goes back to Carnap but (...) has been advanced until the present day without a proper semantic explanation. (shrink)

Primarily addressed to readers unfamiliar with the structuralist approach in philosophy of science, we introduce the basic concepts that the contributions to this special issue presuppose. By means of examples, we briefly review set-theoretic structures and predicates, the potential and actual models of an empirical theory, intended applications, as well as links and specializations that are applied, among others, in reconstructing the empirical claim associated with a theory element.

Ontic Structural Realism is a version of realism about science according to which by positing the existence of structures, understood as basic components of reality, one can resolve central difficulties faced by standard versions of scientific realism. Structures are invoked to respond to two important challenges: one posed by the pessimist meta-induction and the other by the underdetermination of metaphysics by physics, which arises in non-relativistic quantum mechanics. We argue that difficulties in the proper understanding of what a structure is (...) undermines the realist component of the view. Given the difficulties, either realism should be dropped or additional metaphysical components not fully endorsed by science should be incorporated. (shrink)

In the debate over scientific realism, attention has been given recently to a realist position referred to as structural realism. In this essay, I offer a version of this position and indicate how it addresses two standard forms of underdetermination argument posed by the anti-realist.

Radical Ontic Structural Realism (ROSR) claims that structure exists independently of objects that may instantiate it. Critics of ROSR contend that this claim is conceptually incoherent, insofar as, (i) it entails there can be relations without relata, and (ii) there is a conceptual dependence between relations and relata. In this essay I suggest that (ii) is motivated by a set-theoretic formulation of structure, and that adopting a category-theoretic formulation may provide ROSR with more support. In particular, I consider how a (...) category-theoretic formulation of structure can be developed that denies (ii), and can be made to do work in the context of formulating theories in physics. Keywords: structural realism, category theory, general relativity.. (shrink)

This dissertation consists of two parts. The first is on the relation between formalism and ontological commitment in the context of theories of spacetime, and the second is on scientific realism. The first part begins with a look at how the substantivalist/relationist debate over the ontological status of spacetime has been influenced by a particular mathematical formalism, that of tensor analysis on differential manifolds . This formalism has motivated the substantivalist position known as manifold substantivalism. Chapter 1 focuses on the (...) hole argument which maintains that manifold substantivalism is incompatible with determinism. I claim that the realist motivations underlying manifold substantivalism can be upheld, and the hole argument avoided, by adopting structural realism with respect to spacetime. In this context, this is the claim that it is the structure that spacetime points enter into that warrants belief and not the points themselves. ;In Chapter 2, an elimination principle is defined by means of which a distinction can be made between surplus structure and essential structure with respect to formulations of a theory in two distinct mathematical formulations and some prior ontological commitments. This principle is then used to demonstrate that manifold points may be considered surplus structure in the formulation of field theories. This suggests that, if we are disposed to read field theories literally, then, at most, it should be the essential structure common to all alternative formulations of such theories that should be taken literally. I also investigate how the adoption of alternative formalisms informs other issues in the philosophy of spacetime. ;Chapter 3 offers a realist position which takes a semantic moral from the preceding investigation and an epistemic moral from work done on reliability. The semantic moral advises us to read only the essential structure of our theories literally. The epistemic moral shows us that such structure is robust under theory change, given an adequate reliabilist notion of epistemic warrant. I call the realist position that subscribes to these morals structural realism and attempt to demonstrate that it is immune to the semantic and epistemic versions of the underdetermination argument posed by the anti-realist. (shrink)

The meaning of scientific propositions is not always expressible in terms of observable phenomena. Such propositions involve generalizations, and also terms that are theoretical constructs. I study here how to assess the meaning of scientific propositions, that is, the specific import of theoretical terms. Empiricists have expressed a concern that scientific propositions, and theoretical terms, should always be, to some degree, related to observable consequences. We can see that the former empiricist criterion of meaning only implies for theoretical terms not (...) to be definable in terms of observable, but that their use put a constraint on the observable consequences of a theory. To that effect, Ramsey's method of formal elimination of theoretical terms can be an interesting tool. It has faced important logical objections, which have mostly been addressed with respect to the problem of the ontological commitment of the second-order quantification they imply. I show here that these criticisms can be overcome, and that there can be a successful Ramsey elimination of theoretical terms with first order sentences, making Ramsey's method a relevant tool to assess the empirical meaning of scientific propositions. (shrink)

In this paper, inspired by the late twentieth century developments in philosophy of science, I propose an ontological scheme to accommodate the scientifically-informed anti-substantivalist views of the self. I call the position structural realist theory of the self. More specifically, I argue that SRS provides a middle ground for bringing a metaphysical reconciliation between the two recurring, and apparently competing forms of such anti-substantivalist views, i.e., eliminativism and pluralism. The notion of the structural self, as the underpinning pattern that is (...) the subject of the ontological commitments in SRS, is not as cumbersome as the orthodox substantivalist notion, and yet accounts for the relation of the different aspects and elements of the self by integrating them structurally into a central unifying pattern of selfhood. I use the experimental studies of Northoff et al. about the processing of the self-related stimuli in the cortical midline structure of the brain, to argue that the underlying pattern of the selfhood could be sought at the level of information processing. I also add a programmatic suggestion about how the different situated, experiential and extended aspects of the selfhood could be structurally incorporated into this underlying pattern. (shrink)

There is good reason to believe that scientific realism requires a commitment to the objective modal structure of the physical world. Causality, equilibrium, laws of nature, and probability all feature prominently in scientific theory and explanation, and each one is a modal notion. If we are committed to the content of our best scientific theories, we must accept the modal nature of the physical world. But what does the scientific realist’s commitment to physical modality require? We consider whether scientific realism (...) is compatible with Humeanism about the laws of nature, and we conclude that it is not. We specifically identify three major problems for the best-systems account of lawhood: its central concept of strength cannot be formulated non-circularly, it cannot offer a satisfactory account of the laws of the special sciences, and it can offer no explanation of the success of inductive inference. In addition, Humeanism fails to be naturalistically motivated. For these reasons, we conclude that the scientific realist must embrace natural necessity. (shrink)

Recent discussions of structuralist approaches to scientific theories have stemmed primarily from Worrall's, in which he defends a position whose historical roots he attributes to Poincare. In the renewed debate inspired by Worrall, it is thus not uncommon to find Poincare's name associated with various structuralist positions. However, Poincare's structuralism is deeply entwined with both his conventionalism and his idealism, and in this paper we explore the nature of these dependencies. What comes out in the end is not only a (...) clearer picture of Poincare's position regarding structuralism, but also two arguments for versions of epistemic structuralism different in kind from that given by Worrall. (shrink)

This paper explores varieties of scientific structuralism. Central to our investigation is the notion of `shared structure'. We begin with a description of mathematical structuralism and use this to point out analogies and disanalogies with scientific structuralism. Our particular focus is the semantic structuralist's attempt to use the notion of shared structure to account for the theory-world connection, this use being crucially important to both the contemporary structural empiricist and realist. We show why minimal scientific structuralism is, at the very (...) least, a powerful methodological standpoint. Our investigation also makes explicit what more must be added to this minimal structuralist position in order to address the theory-world connection, namely, an account of representation. (shrink)

The focus of this paper is the recent revival of interest in structuralist approaches to science and, in particular, the structural realist position in philosophy of science . The challenge facing scientific structuralists is three-fold: i) to characterize scientific theories in ‘structural’ terms, and to use this characterization ii) to establish a theory-world connection (including an explanation of applicability) and iii) to address the relationship of ‘structural continuity’ between predecessor and successor theories. Our aim is to appeal to the notion (...) of shared structure between models to reconsider all of these challenges, and, in so doing, to classify the varieties of scientific structuralism and to offer a ‘minimal’ construal that is best viewed from a methodological stance. (shrink)

In the present paper the attempt is made for the first time to formalize the modern theory of elementary particles based on the structuralist approach. To this end, the description within the scope of the so-called standard model is considered. In the physics of elementary particles the term ‘standard model’ denotes the summary of theories which describe the various elementary building blocks of matter as well as their interactions between each other. This model represents one of the most successful theories (...) in physics, particularly because of the impressive experimental confirmation. Hence a structuralist reconstruction of it is a challenging task. (shrink)

Paper on structural realism and how its problems lend support to some kind of panpsychism.

Abstract: According to Luciano Floridi (2008) , informational structural realism provides a framework to reconcile the two main versions of realism about structure: the epistemic formulation (according to which all we can know is structure) and the ontic version (according to which structure is all there is). The reconciliation is achieved by introducing suitable levels of abstraction and by articulating a conception of structural objects in information-theoretic terms. In this essay, I argue that the proposed reconciliation works at the expense (...) of realism. I then propose an alternative framework, in terms of partial structures, that offers a way of combining information and structure in a realist setting while still preserving the distinctive features of the two formulations of structural realism. Suitably interpreted, the proposed framework also makes room for an empiricist form of informational structuralism (structural empiricism). Pluralism then emerges. (shrink)

Scientific change has two important dimensions: conceptual change and structural change. In this paper, I argue that the existence of conceptual change brings serious difficulties for scientific realism, and the existence of structural change makes structural realism look quite implausible. I then sketch an alternative account of scientific change, in terms of partial structures, that accommodates both conceptual and structural changes. The proposal, however, is not realist, and supports a structuralist version of van Fraassen’s constructive empiricism (structural empiricism).

This article develops an analogy proposed by Stachel between general relativity (GR) and quantum mechanics (QM) as regards permutation invariance. Our main idea is to overcome Pooley's criticism of the analogy by appeal to paraparticles. In GR, the equations are (the solution space is) invariant under diffeomorphisms permuting spacetime points. Similarly, in QM the equations are invariant under particle permutations. Stachel argued that this feature—a theory's ‘not caring which point, or particle, is which’—supported a structuralist ontology. Pooley criticizes this analogy: (...) in QM the (anti-)symmetrization of fermions and bosons implies that each individual state (solution) is fixed by each permutation, while in GR a diffeomorphism yields in general a distinct, albeit isomorphic, solution. We define various versions of structuralism, and go on to formulate Stachel's and Pooley's positions, admittedly in our own terms. We then reply to Pooley. Though he is right about fermions and bosons, QM equally allows more general types of particle symmetry, in which states (vectors, rays, or density operators) are not fixed by all permutations (called ‘paraparticle states’). Thus Stachel's analogy is revived. (shrink)

Abstract. I argue that pessimistic meta-induction (PMI) seems to point an ontological priority of the relations over the objects of the scientific theories of the kind suggested by French and Ladyman (French and Ladyman 2003). My strategy will involve a critical examination of epistemic structural realism (ESR) and historical case-study: the prediction of Zeeman’s effect in Lorentz’s theory of electron.

The number of positions identified with structural realism in philosophical debates about scientific knowledge has grown significantly in the past decade, particularly with respect to the metaphysical or ‘ontic’ approach (OSR). In recent years, several advocates of OSR have proposed a novel understanding of it in order to side-step a serious challenge faced by its original formulation, eliminative OSR. I examine the conceptual basis of the new, noneliminative view, and conclude that it too faces a serious challenge, resulting in a (...) dilemma for ontic structuralists regarding the ontological status of objects and properties, and the relative “ontological priority” of these entities with respect to the relations in which they stand. (shrink)

I consider the idea of a structure of fundamental physical particles being causal. Causation is traditionally thought of as involving relations between entities—objects or events—that cause and are affected. On structuralist interpretations, however, it is unclear whether or how precisely fundamental particles can be causally efficacious. On some interpretations, only relations exist; on others, particles are ontologically dependent on their relations in ways that problematize the traditional picture. I argue that thinking about causal efficacy in this context generates an inevitable (...) pattern of reasoning. To assess the cogency of a given structuralist proposal one must take a stand with respect to a significant metaphysical challenge. Two options then emerge: skepticism about the form of structuralism at issue; or a dissolution of the challenge by means of a contentious ontological primitive. I contend that the choice between these options cannot be forced on scientific or philosophical grounds alone. (shrink)

Structural realism has recently re-entered mainstream discussions in the philosophy of science. The central notion of structure, however, is contested by both advocates and critics. This paper briefly reviews currently prominent structuralist accounts en route to proposing a metaphysics of structure that is capable of supporting the epistemic aspirations of realists, and that is immune to the charge most commonly levelled against structuralism. This account provides an alternative to the existing epistemic and ontic forms of the position, incorporating elements of (...) both. Structures are here identified with relations between first order, causal properties: properties that confer specific dispositions for relations. This form of structuralism constitutes an explicit proposal for what seem implicit structuralist tendencies in sophisticated but more traditional characterizations of realism. An outline of the proposal's response to the anti-realist's pessimistic induction on the history of scientific theories is considered. (shrink)

This paper explores the consequences of the two most prominent forms of contemporary structural realism for the notion of objecthood. Epistemic structuralists hold that we can know structural aspects of reality, but nothing about the natures of unobservable relata whose relations define structures. Ontic structuralists hold that we can know structural aspects of reality, and that there is nothing else to know—objects are useful heuristic posits, but are ultimately ontologically dispensable. I argue that structuralism does not succeed in ridding a (...) structuralist ontology of objects. (shrink)

The intuition of the naı¨ve realist, miracle arguments notwithstanding, is countered forcefully by a host of considerations, including the possibility of underdetermination, and criticisms of abductive inferences to explanatory hypotheses. Some have suggested that an induction may be performed, from the perspective of present theories, on their predecessors. Past theories are thought to be false, strictly speaking; it is thus likely that present-day theories are also false, and will be taken as such at an appropriate future time.

It is claimed in the structural realism in philosophy of science that scientists aim to preserve the true structure, represented by the equations in their models. We reinterpret structural realism as a doctrine involving representation. Proving the existence of a representation theorem secures the problem of lacking independent criteria for identification between structure and non?structure. This paper argues that a similar realist view of structure can be found in the theory of consumption in which the Fisherian framework of intertemporal choices (...) is regarded as the true structure of the consumption function. Unlike the passive strategy of inducing the structure contained in structural realism, economists define structure in terms of invariance under intervention. Such a definition serves as a crucial device to examine and develop models for the adequacy of representing the structure of the consumption functions. JEL Classification: B22, B41, C50, E21. (shrink)

Several recent authors identify structural realism about scientific theories with the claim that the content of a scientific theory is expressible using its Ramsey sentence. Many of these authors have also argued that so understood, the view collapses into empiricist anti-realism, since an argument originally proposed by Max Newman in a review of Bertrand Russell’s The analysis of matter demonstrates that Ramsey sentences are trivially satisfied, and cannot make any significant claims about unobservables. In this paper I argue against both (...) of these claims. Structural realism and Ramsey sentence realism are, in their most defensible versions, importantly different doctrines, and neither is committed to the premises required to demonstrate that they collapse into anti-realism.Keywords: Ramsey sentence; Structural realism; Structuralism; Scientific realism. (shrink)

In his Analysis of Matter, Russell advocated an epistemic form of Epistemic Structural Realism which held that our knowledge of the external world is structural. This approach has been criticised by M.H.A. Newman, 137–148, 1928) and Stathis Psillos, S13–S24, 2001). The paper aims to reconstruct Russell’s version of ESR, and defend its experimental and philosophical plausibility. The basic assumption is that without getting a viable experimental handle on the linkage between the structure of perceptions and causal structure of the stimuli, (...) the so called upward path to SR couldn’t be defended conclusively. In this vein, the paper explores the resources of the recent experimental theories of perception. These help establishing a structuralist account of the perception, and provide an account for the causal linkage between the structure of perceptions and the structure of the stimuli. I argue that it is possible to settle for objectivity of this linkage according to the criteria of comprehensiveness, simplicity, and above all rationality, in a way that meets the standards of the scientific realists. (shrink)

Retention of structure across theory change has been invoked in support of a ‘structural’ alternative to more traditional entity-based scientific realism. In that context the transition from Newtonian mechanics to the Special Theory of Relativity is often regarded as a very significant instance of structural preservation, or retention, associated with correspondence-based recovery. The joint derivation, from a small set of elementary and ontologically neutral assumptions, of both the Galilei and the Lorentz transformation exemplifies the virtues of structural approaches to the (...) foundations of physical theories. The common origination of the resulting two relativistic frameworks sheds light on both the successes and the limitations of correspondence claims. However, the cognitive-operational character of the basic assumptions lends no support to the structural realist’s ‘inference to the best explanation’. (shrink)

Turning away from entities and focusing instead exclusively on ‘structural’ aspects of scientific theories has been advocated as a cogent response to objections levelled at realist conceptions of the aim and success of science. Physical theories whose (predictive) past successes are genuine would, in particular, share with their successors structural traits that would ultimately latch on to ‘structural’ features of the natural world. Motives for subscribing to Structural Realism are reviewed and discussed. It is argued that structural retention claims lose (...) their force if one gives up merely historical readings of the transition from Galilean-relativistic classical mechanics to the ‘special’ theory of relativity, heeding instead basic requirements that lead to their common derivation. Further cause for scepticism is found upon realising that the basic mathematical framework of quantum theory essentially reflects its predictive purpose, without any necessary input, be it of a ‘structural’ kind, from the physical world. (shrink)

Physics appears to be in a unique position to withstand antirealist attacks, especially ‘pessimistic induction’ arguments. Such resilience provides an incentive for embracing a ‘structural’ variant of scientific realism. Nevertheless, an examination of the physics-mathematics relationship suggests that whatever determines the success of modelling endeavours lends scant support to structural realism. A closer look at conceptual prerequisites of joint ab initio derivations of (i) Galilean and ‘special’ relativity theories and (ii) classical and ‘quantal’ probabilistic frameworks also fosters scepticism about a (...) major claim of structural realists: that mathematical features of theoretical frameworks – those, in particular, which determine their predictive efficiency – are ultimately rooted in ‘structural’ aspects of the natural world. Further concerns with the central tenets of structural realism are finally briefly addressed, and the question of possible non-instrumentalist alternatives is raised. (shrink)

I examine Carrier’s and Ladyman’s structural realist explanation of the predictive success of phlogiston chemistry. On their account, it succeeds because phlogiston chemists grasped that there is some common unobservable structure of relations underlying combustion, calcification, and respiration. I argue that this SR account depends on assuming the truth of current chemical theory of oxidation and reduction, which provides a better explanation of the success of phlogiston theory than SR provides. I defend an alternative version of inference-to-the-best-explanation scientific realism which (...) I call ‘Best Current Theory Realism’ and argue that it can answer the pessimistic meta-induction. (shrink)

In my review of Steven French's The structure of the world. Metaphysics & Representation. OUP, Oxford, 2014 I argue that the author is forced to navigate between the Scilla of Tegmark’s Pitagoreanism (2008) and the Carybdis of “blobobjectivism” (Horgan and Potrč 2008), namely the claim that the whole physical universe is a single concrete structurally complex but partless cosmos (a “blob”).

The main aim of our paper is to show that interpretative issues belonging to classical General Relativity (GR) might be preliminary to a deeper understanding of conceptual problems stemming from on-going attempts at constructing a quantum theory of gravity. Among such interpretative issues, we focus on the meaning of general covariance and the related question of the identity of points, by basing our investigation on the Hamiltonian formulation of GR. In particular, we argue that the adoption of a peculiar gauge-fixing (...) within the canonical reduction of ADM metric gravity may yield a new solution to the debate between substantivalists and relationists, by suggesting a \emph{tertium quid} between these two age-old positions. Such a third position enables us to evaluate the controversial relationship between entity realism and structural realism in a well-defined case study. After having indicated the possible developments of this approach in Quantum Gravity, we discuss the structuralist and holistic features of the class of spacetime models that are used in the above mentioned canonical reduction. (shrink)

Ladyman, Ross and their collaborators (Spurrett is a co-author of two chapters, Collier of one) begin their book with a ferocious attack on "analytic metaphysics", as it is currently practiced. Their opening blast claims that contemporary analytic metaphysics 'contributes nothing to human knowledge': its practitioners are 'wasting their talents', and the whole enterprise, although 'engaged in by some extremely intelligent and morally serious people, fails to qualify as part of the enlightened pursuit of objective truth, and should be discontinued' (vii). (...) They set out on a 'mission of disciplinary rescue' in the spirit of Hume and the logical positivists, in which a fair proportion of philosophy as currently practiced -- as they realize, their critique applies far beyond the boundaries of metaphysics proper -- will be consigned to the flames. (shrink)