Within the philosophy of science, the realism debate has been revitalised by the development of forms of structural realism. These urge a shift in focus from the object oriented ontologies that come and go through the history of science to the structures that remain through theory change. Such views have typically been elaborated in the context of theories of physics and are motivated by, first of all, the presence within such theories of mathematical equations that allow straightforward representation of the (...) relevant structures; and secondly, the implications of such theories for the individuality and identity of putative objects. My aim in this talk is to explore the possibility of extending such views to biological theories. An obvious concern is that within the context of the latter it is typically insisted that we cannot find the kinds of highly mathematised structures that structural realism can point to in physics. I shall indicate how the model-theoretic approach to theories might help allay such concerns. Furthermore, issues of identity and individuality also arise within biology. Thus Dupre has recently noted that there exists a ‘General Problem of Biological Individuality’ which relates to the issue of how one divides ‘massively integrated and interconnected’ systems into discrete components. In response Dupre advocates a form of ‘Promiscuous Realism’ that holds, for example, that there is no unique way of dividing the phylogenetic tree into kinds. Instead I shall urge serious consideration of those aspects of the work of Dupre and others that lean towards a structuralist interpretation. By doing so I hope to suggest possible ways in which a structuralist stance might be extended to biology. (shrink)

Humean Supervenience is a metaphysical model of the world according to which all truths hold in virtue of nothing but the total spatiotemporal distribution of perfectly natural, intrinsic properties. David Lewis and others have worked out many aspects of HS in great detail. A larger motivational question, however, remains unanswered: As Lewis admits, there is strong evidence from fundamental physics that HS is false. What then is the purpose of defending HS? In this paper, we argue that the philosophical merit (...) of HS is largely independent of whether it correctly represents the world’s fundamental structure. In particular, we show that insofar as HS is an apt model of the world’s higher-level structure, it thereby provides a powerful argument for reductive physicalism and explains otherwise opaque inferential relations. Recent criticism of HS on the grounds that it misrepresents fundamental physical reality is, therefore, beside the point. (shrink)

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. (shrink)

The paper has three parts. In the first part ExtOSR, an extended version of Ontic Structural Realism, will be introduced. ExtOSR considers structural properties as ontological primitives, where structural properties are understood as comprising both relational and structurally derived intrinsic properties or structure invariants. It is argued that ExtOSR is best suited to accommodate gauge symmetry invariants and zero value properties. In the second part, ExtOSR will be given a Humean shape by considering structures as categorical and global. It will (...) be laid out how such structures serve to reconstruct non-essential structural kinds and laws. In the third part Humean structural realism will be defended against the threat of quidditism. (shrink)

We set out a fundamental ontology of atomism in terms of matter points. While being most parsimonious, this ontology is able to match both classical and quantum mechanics, and it remains a viable option for any future theory of cosmology that goes beyond current quantum physics. The matter points are structurally individuated: all there is to them are the spatial relations in which they stand; neither a commitment to intrinsic properties nor to an absolute space is required. The spatial relations (...) change. All that is needed to capture change is a dynamical structure, namely dynamical relations as expressed in terms of the dynamical parameters of a physical theory. (shrink)

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. (shrink)

This paper tries to reconstruct Ernst Cassirer's potential reception of the EPR argument, as exposed by Einstein in his letter to Cassirer of March 1937. It is shown that, in conformity with his transcendental epistemology taking the conditions of accessibility as constitutive of the quantum object, Cassirer would probably have rejected the argument. Indeed, Cassirer would probably not have subscribed to its separability/local causality presupposition (which goes against his interpretation of the quantum formalism as a self-suf!cient condition constitutive of the (...) quantum object, without any reliance on spatial intuition), nor to its completeness requirement (as his partial endorsement of Bohr's complementarity, and his rejection of the Kantian "idea of complete determination", illustrate). By rejecting both of its premises, Cassirer's philosophy of physics thus enables to escape the EPR dilemma, and exhibits what, in Kantian terms, might be called a "negative utility" with respect to physical science. A further investigation of the anti-reductionist utility of Cassirer's systematic philosophy with respect to physics and other "symbolic forms" is !nally suggested. (shrink)

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. (shrink)

Chakravartty and others have pressed that the defender of scientific realism needs to supply a metaphysical story, most saliently a modal story, of how knowledge of the unobservable can be possible. Here I consider the challenge the problem of theory change poses to theories of modal metaphysics.

Dispositional Essentialism and Ontic Structural Realism aim to account for modality. Dispositional Essentialism takes properties to account for laws. In particular, it takes determinate properties to account for laws of nature, which are determinable. Ontic Structural Realism does the reverse. According to Steven French, Ontic Structural Realism takes laws and symmetries to be part of the fundamental structure of the world. Determinate properties are “dependent” on laws. The core difference between Dispositional Essentialism and Ontic Structural Realism’s accounts of modality is (...) the direction of the dependence between properties and laws. As a result, French describes Ontic Structural Realism as a reverse-engineering of Dispositional Essentialism, and Chakravartty differentiates them by saying that Dispositional Essentialism gives a bottom-up account of modality whereas Ontic Structural Realism’s is top-down. Both views face significant problems. The main problems these views face stem from relational individuation. Properties are individuated by their relations to further properties. As such, it is hard to see how they can be metaphysically prior to those relations as per Dispositional Essentialism. Equally, laws are relations between properties. As such, it is hard to see how they could be metaphysically prior to the properties they relate as per Ontic Structural Realism. Both properties and laws seem dependent on each other. By requiring one to come first and explain the other, dispositional essentialists and ontic structural realists end up in a chicken-egg scenario. I propose a hybrid between Dispositional Essentialism and Ontic Structural Realism. My hybrid view does away with the dogma of ontological priority between properties and laws. Instead, properties and laws symmetrically depend. I argue that my hybrid view is the way out of the chicken-egg-property-law conundrum. It paves a new way for making sense of modality from a structuralist perspective. (shrink)