Most of my research is focussed on representation, idealization, and the nature of models in scientific theorizing, and on metaphysical issues in the interpretation of quantum mechanics, though I'm also working on a paper on overdetermination and mental causation.

Below are some descriptions of forthcoming papers and works in progress, and in most cases you can download the most recent complete draft. Comments are very welcome.

Representation, Idealization, and Models

"Missing Systems and the Face Value Practice." Descriptions of missing systems are passages of scientific text which look just like accurate descriptions of systems from the domain of inquiry, but which are known not to be. (This includes, but is not limited to, descriptions of idealized systems.) The face value practice is the practice of talking and thinking as though there are things which fit such descriptions nonetheless. I focus on the way in which various philosophical accounts of models, modelling, representation, idealization, theory structure, and scientific methodology rely on the face value practice, and ask whether such a reliance can be made to seem legitimate, in a way which will support the weight of the philosophical accounts in question. A good part of the discussion is devoted to exploring the question of whether descriptions of missing systems should be taken to be semantically and pragmatically on a par with descriptive passages in works of fiction.

This paper is forthcoming in Synthese. The version attached here was written as a talk, and given under the title "Models and Idealized Systems." I'll post the version I'm preparing for publication when I've finished the current round of revisions.

"Models and the Semantic View", the short version (forthcoming in the proceedings of the 2004 Philosophy of Science Association Meetings). I begin by distinguishing two notions of model, the notion of a truth-making structure and the notion of a mathematical model (in one specific sense). I then argue that although the models of the semantic view have often been taken to be both truth-making structures and mathematical models, this is in part due to a failure to distinguish between two ways of truth-making; in fact, the talk of truth-making is best excised from the view altogether. The result is a version of the semantic view which is better supported by the direct evidence offered for it, better equipped to achieve its avowed aims, and, I think, closer to the intentions of the original proponents of the view in many ways, despite some of their own declarations to the contrary. And this leaves us in a better position to assess the semantic view. (I then go on to offer arguments against the semantic view in one of my pipeline papers, “Mathematical Models and Propositional Models” - see the description of the really long version of "Models and the Semantic View", below.)

"Models, the Semantic View, and Scientific Representation". This is a longer version of "Models and the Semantic View", and is essentially the version I gave at the PSA. After presenting the arguments contained in the short version, I go on to explore the ramifications of my claims about the semantic view for structural realism and for structuralism about science. So although you might want to look at this for a less dense presentation of the arguments found in the short version of "Models and the Semantic View," the main reason for taking a look would be to read the extra material contained in the last two sections (pp. 24-29), which I had to excise from the Philosophy of Science version for reasons of space.

"Models and the Semantic View", the really long version. The short paper of the same title listed above is in fact a descendant of just section 2 of this paper, along with improved versions of some supporting material from section 1 and the introduction. My plan is to shape a separate paper out of section 1 and section 3.

Section 1 contains a taxonomy of models which needs a little expanding, but which is, I hope, quite useful. The aim of the taxonomy is to be comprehensive in the sense that it contains all the objects picked out, or purportedly picked out, by all the widespread and coherent uses of the term 'model' to be found in the philosophy of science literature. (On its bolder days, it aims to contain all the things scientists pick out when they use the term, too.) I think it comes close to succeeding in this aim, and I hope to improve it so that it comes even closer. (One outstanding issue is to think about how computer models and computer simulations fit in, or how the taxonomy can be modified so that they do.) This is not intended to be a comprehensive taxonomy of notions of model - there are plenty of notions of model to be found in the literature which are neither used nor mentioned in the laying out of this taxonomy. The hope is just that the objects picked out by all coherent such notions in fact fall into one of the categories in this taxonomy. (Of course, that aim could be achieved all too easily in various trivial ways, but the rest of the paper makes it clear that the distinctions employed in this taxonomy are philosophically useful ones.)

With this taxonomy and the arguments of section 2 (now to be found in the short paper listed above) in place, I go on in section 3 to argue that the semantic view is ill-equipped to provide an account of a central scientific use of the term 'model', and that a notion of model quite alien to the semantic view is better suited to the task. (I now think that one of the arguments I give for the first claim rests on a modal fallacy, but I do give others, too.) This is the notion of a model as a set of propositions (not sentences) the members of which together form a representation of a system, or a type of system, under study. I go on to explore the idea of taking a theory to be a collection of such propositional models, and to look at the advantages for the philosophy of science of employing the notion of a propositional model in our theorising.

The working title of the resulting paper (composed, more or less, of reworked versions of sections 1 and 3 of this paper) is "Mathematical Models and Propositional Models."

Please note that as this paper has been around for a little while, various of the bibliographical entries will need updating, and I'll probably end up expanding the bibliography, too.

"Idealization and Abstraction: A Framework," from Correcting the Model: Idealization and Abstraction in the Sciences (Rodopi, 2005), which I co-edited with Nancy Cartwright. (Published under the name Jones.) The paper contains a systematic set of proposals for clarifying talk of idealization and abstraction in both models and laws, degrees of idealization and abstraction, and idealization and abstraction as processes. I take as fundamental the distinction between idealizations as misrepresentations, and abstractions as mere omissions (where, in context, the word 'mere' adds an important qualification), and discuss other characteristic features of idealizations and abstractions. I examine the similarities and differences of my proposals to those found in the work of Cartwright and McMullin. And with the framework I propose in place, I distinguish three ways in which idealization can occur in laws and our employment of them – there are quasi-laws, idealized laws, and ideal laws.

Metaphysics and Quantum Theory

"Holism and Nonsupervenience in Quantum Mechanics" (under revision for BJPS). I argue that although part-whole relations in quantum-mechanical systems are indeed metaphysically striking, the most promising of current approaches to understanding talk of holism in quantum mechanics are inadequate in certain important ways. I also argue that there is a suggestive connection between the instantiation of peculiar part-whole relations in quantum mechanics and the appearance of nonlocal correlations.

The final version of this paper will contain a discussion of an alternative reading of the proposal (due, independently, to Paul Teller and Richard Healey) that holism in quantum mechanics is nonsupervenience of a certain sort than the reading discussed in the version posted here. The proposal we get on the alternative reading has more room to manoeuvre in the face of the objections I present to the first reading, but we come to see, nonetheless, that it can be maintained in the face of those objections only if we are willing to take on a significant range of non-trivial interpretive and metaphysical commitments.

"Dispositions and Quantum Mechanics". I begin by (i) formulating a series of underexplored and interrelated questions about dispositions and the interpretation of quantum mechanics, (ii) pointing out the ways in which dispositions make an appearance in a variety of interpretations of the theory, and (iii) arguing that the way in which they do so suggests that irreducible dispositions are an almost unavoidable feature of the quantum-mechanical picture of the physical world. Finally, I put irreducible dispositions to work in reinterpreting the Bohm theory; the effect is to eliminate certain problematic features of the ontology of that theory as it is standardly understood.

In the final version, I intend to supplement this defence of dispositions by moving outside the specific context of the interpretation of quantum mechanics to raise a new objection to what I take to be the most promising deflationary account of physical dispositions in general (the “functionalist” account). I also plan to address some recent debates over the question of whether the features of the standard Bohmian ontology I take to be obviously problematic in this version are, in fact, really problematic after all (including arguments put forward by Brad Monton and Peter Lewis).

This version was written as a talk, and does not yet contain diagrams. The reader who is familiar with the literature in the philosophy of QM will, I hope, be able to figure things out from the text alone.

And...

"Overdetermination, Mental Causation, and the Staggered Firing Squad: Problems with the Case for Compatibilism." A recent defence of compatibilism about mental causation, due to Karen Bennett (in "Why the Exclusion Problem Seems Intractable, and How, Just Maybe, To Tract It"), rests on a claim to the effect that certain counterfactuals provide a necessary condition on the presence of overdetermination. The claim in question is, as Bennett notes, quite widely accepted – both Lewis and Kim have committed themselves to it, for example. (Lewis, in fact, builds it into his definition of 'overdetermination.') I show that the claim is false (or that a definition of 'overdetermination' which guarantees it will fail to capture the intuitive notion we are after), and that the attempt to repair Bennett’s defence of compatibilism draws attention to the work being done by the assumption that when overdetermination threatens, the supervenience of one sufficient cause on another removes any cause for concern. I then argue that this latter assumption, too, is false, by identifying something missing from the list of candidates Ted Sider considers in "What's So Bad about Overdetermination?" What emerges, amongst other things, is a more accurate identification of the price we have to pay for nonreductive physicalism if we want to hold on to the causal completeness of physical and the causal efficacy of the mental.

The interest of this paper is twofold: both as a critique of Bennett’s defence of compatibilism, which is appealing in itself, and as showing that lots of people have been wrong in making a certain assumption about the counterfactuals which are licensed by a claim of overdetermination (or, as the case may be, in adopting a definition of overdetermination which guarantees such licensing, and then treating the definition as adequately capturing the phenomenon we are trying to capture). That assumption has played a role in the attempt to develop adequate accounts of the nature of causation, as well as in the debate over mental causation.

Selected older publications

“Against Experimental Metaphysics” (with Rob Clifton), in P.A. French, T.E. Uehling, Jr., and H.K. Wettstein (eds.), Midwest Studies in Philosophy, vol. XVIII, 1993, pp. 295-316. Notre Dame: University of Notre Dame Press.

“Weakening the Locality Assumptions in Algebraic Nonlocality Proofs” (with Andrew Elby), Physics Letters A, 1992, 171: 11-16.

“Some Difficulties for Clifton, Redhead and Butterfield’s Recent Proof of Nonlocality,” Foundations of Physics Letters, August 1991, 4: 385-393, with a response by Clifton et al.

“How to Hunt Quantum Causes” (with Nancy Cartwright), Erkenntnis, July 1991, 35: 205-231.