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.

We first introduce structural realism as a position in the metaphysics of science, pointing out the way in which this position replaces intrinsic properties with relations so that it amounts to a holistic in contrast to an atomistic metaphysics. We argue in favour of a moderate version of structural realism that puts objects and relations on the same ontological footing and assess the general philosophical arguments for this position. The second section shows how structural realism gains support from quantum physics. The third section explains how structural realism can be applied to the metaphysics of space-time.

In the last decade, structural realism has been presented as the most promising strategy for developing a defensible realist view of science. Nevertheless, controversy still continues in relation to the exact meaning of the proposed structuralism. The stronger version of structural realism, the so-called ontic structural realism, has been argued for on the basis of some ideas related to quantum mechanics. In this paper, I will first outline these arguments, mainly developed by Steven French and James Ladyman, then challenge them, putting a particular emphasis on a metaphysical principle (the Principle of the Identity of the Indiscernibles) which, even though it is crucial for the whole argument, hasn''t been, in my opinion, clearly stated and examined yet. My overall view will be that a weaker version of the form of realism we are considering is more plausible – namely, epistemic structural realism.

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.

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.

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.

Ontic structural realists hold that structure is all there is, or at least all there is fundamentally. This thesis has proved to be puzzling: What exactly does it say about the relationship between objects and structures? In this article, I look at different ways of articulating ontic structural realism in terms of the relation between structures and objects. I show that objects cannot be reduced to structure, and argue that ontological dependence cannot be used to establish strong forms of structural realism. At the end, I show how a weaker, but controversial, form of structural realism can be articulated on the basis of ontological dependence.

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.

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?

The epistemological version of structural realism, proposed by Cao Tianyu, has great influence in the philosophy of science. Syntheses has published a special volume discussing the topic. Cao criticizes anti-realism, as well as the epistemic and ontic versions of structural realism. From the concepts of structure, ontology, and construction, he analyzes the objectivity of scientific theories as having five aspects: construction, historicity, holism, revision, and revolution. This paper systematically analyzes and comments on Cao's structural realism. The author agrees with his criticism of the under-determination thesis, is neutral to his argument against ontological discontinuity, and questions his universal language argument.