Online research in philosophy

This paper examines whether structural realism entails an anti-realist thesis about natural kinds. Structural Realism is the view that the scientific realist can only support a realist claim about the structure of reality rather than its objects. Ladyman (1998) (2002) & French & Ladyman (2003) motivate the claim that ontic structural realism eliminates ‘objects’ as a distinct ontological category, thereby eliminating any possibility of a metaphysical account of individual objects. This is empirically motivated by fundamental physics. Those inclined towards realism about the rest of the sciences (chemistry, biology, the medical sciences, economics and so on) might think the appeal of structural realism as a general metaphysics for all of the sciences limited. Nevertheless, recent literature argues that mature special sciences e.g. economics, can be equally described by mathematical/syntactic models making the appeal of structural realism a more general one for the metaphysics of all of the sciences. {Ross (2006)}. Given a commitment to ontic structural realism, if natural kinds are kinds of “object”, then anti-realism about natural kinds should follow. However, I examine two realist theses about natural kinds and argue that a commitment to structural realism is not straightforwardly inconsistent with either.

When it comes to name-calling, structural realists have heard pretty much all of it. Among the many insults, they have been called ‘empiricist anti-realists’ but also ‘traditional scientific realists’. Obviously the collapse accusations that motivate these two insults cannot both be true at the same time. The aim of this paper is to defend the epistemic variety of structural realism against the accusation of collapse to traditional scientific realism. In so doing, I turn the tables on traditional scientific realists by presenting them with a dilemma. They can either opt for a construal of their view that permits epistemic access to non-structural features of unobservables but then face the daunting task of substantiating a claim that seems to have little hope of being true or they can drop the requirement of epistemic access to non-structural features but then face a collapse to epistemic structural realism. There is thus only one well supported way to be a realist. No wonder then that many traditional scientific realists have over the years expressed views that are strikingly similar to epistemic structural realism. It is high time to let these epistemic structural realists out of the closet.

In his paper ``What is Structural Realism?'' James Ladyman drew a distinction between epistemological structural realism and metaphysical (or ontic) structural realism. He also drew a suggestive analogy between the perennial debate between substantivalist and relationalist interpretations of spacetime on the one hand, and the debate about whether quantum mechanics treats identical particles as individuals or as `non-individuals' on the other. In both cases, Ladyman's suggestion is that an ontic structural realist interpretation of the physics might be just what is needed to overcome the stalemate. The main thesis of this paper is that, whatever the interpretative difficulties of generally covariant spacetime physics are, they do not support or suggest structural realism. In particular, I hope to show that there is in fact no analogy that supports a similar interpretation of the metaphysics of spacetime points and of quantum particles.

We present a precise form of structural realism, called group structural realism , which identifies ‘structure’ in quantum theory with symmetry groups. However, working out the details of this view actually illuminates a major problem for structural realism; namely, a structure can itself have structure. This article argues that, once a precise characterization of structure is given, the ‘metaphysical hierarchy’ on which group structural realism rests is overly extravagant and ultimately unmotivated.

The epistemic form of structural realism asserts that our knowledge of the world is restricted to its structural features. Several proponents of this view assume that the world possesses non-structural features; features which, according to their view, cannot be known. In other words, they assume that there is, or, there ought to be (on the basis of normative arguments in epistemology), always a gap between our epistemological and ontological commitments. The ontic form of structural realism denies that this is, or ought to be, the case. Proponents of this view argue that the perfect alignment of epistemological and ontological commitments is a highly desirable metatheoretical feature. They argue this on the basis of the prima facie sensible principle that our ontological commitments ought never to overreach our epistemic ones. Naturally the issue of alignment transcends the debate between the epistemic and the ontic structural realists. Is it in principle impossible for there to be circumstances under which we ought to subscribe to the misalignment of epistemological and ontological commitments? What do the different answers to this question entail for ontic structural realism?

This chapter traces the development of structural realism within the scientific realism debate and the wider current of structuralism that has swept the philosophy of the natural sciences in the twentieth century.1 The primary aim is to make perspicuous the many manifestations of structural realism and their underlying claims. Among other things, I will compare structural realism’s various manifestations in order to throw more light onto the relations between them. At the end of the chapter, I will identify the main objections raised against the epistemic form of structural realism. This last task will pave the way for the evaluation of the structural realist answer to the main epistemological question, an evaluation that will be central to the rest of this dissertation.

In recent years Structural Realism has been revived as a compromise candidate to resolve the long-standing question of scientific realism. Recent debate over structural realism originates with Worrall's (1989) paper "Structural Realism: The best of Both Worlds". However, critics such as Psillos contend that structural realism incorporates an untenable distinction between structure and nature, and is therefore unworkable. In this paper I consider three versions of structural realism that purport to avoid such criticism. The first is Chakravartty's "semirealism" which proceeds by trying to show that structural realism and entity realism entail one another. I demonstrate that this position will not work, but follow Chakravartty's contention that structural realism need not imply that scientific knowledge can only be of mathematical structure. I advance from this conclusion to sketch a version of structural realism that is consistent with recent deflationary approaches to the scientific realism question. Finally, I consider a third approach to structural realism Ladyman's "metaphysical structural realism" which tries to avoid the difficulties of earlier versions by taking structure to be ontologically primary. I show that the deflationary approach to structural realism undermines the rationale behind Ladyman's approach.

'Structural realism' is a buzzword in the scientific realism debate. Various positions with diverse motivations fall under this label. A much advertised distinction is between epistemic and ontological forms of structuralism. This paper scrutinizes the alleged dichotomy between these two 'alternatives', and criticises the considerations that have been taken to motivate the ontic variety over the epistemic. I will argue that ontological structural realism is not called for within the traditional realism debate.

This paper sets out a moderate version of metaphysical structural realism that stands in contrast to both the epistemic structural realism of Worrall and the—radical—ontic structural realism of French and Ladyman. According to moderate structural realism, objects and relations (structure) are on the same ontological footing, with the objects being characterized only by the relations in which they stand. We show how this position fares well as regards philosophical arguments, avoiding the objections against the other two versions of structural realism. In particular, we set out how this position can be applied to space-time, providing for a convincing understanding of space-time points in the standard tensor formulation of general relativity as well as in the fibre bundle formulation.

Structural realism is a rather popular view in philosophy of science. As with many popular views, sprouting is never far behind. No sprout has had as much grip on the view’s image as ontic structural realism. Indeed its supporters have such a stranglehold that ‘structural realism’ has almost become a byword for their views. In this talk, I want to redress this imbalance by returning to structural realism’s humble epistemic beginnings to examine exactly what made the view so attractive in the first place. To this effect, I will reconstruct several arguments – some of which little known – proposed in the early part of the twentieth century in support of the epistemic version of structural realism. Not wanting to dwell too much on the past, I will then switch to more recent arguments both for and against the position. A careful evaluation of these arguments will hopefully provide useful information as to what form, if any, epistemic structural realism must take in order to be a viable alternative to its direct competitors, namely standard scientific realism and constructive empiricism.