Structural Realism

Real Patterns in Physics and Beyond (2024)

To appear in forthcoming volume on real patterns, edited by Tyler Millhouse, Steve Petersen, and Don Ross, to be published by MIT Press.

I apply Dennett's `real patterns' idea to the ontology of physics, and specifically to the puzzle of how to relate the very different ontologies one finds at different scales in physics (e.g. particles vs continua, or fields vs particles). I argue that real patterns provide part but not all of the answer to the puzzle, and locate the rest of the answer in the structural-realist idea that ontology in general is secondary to (mathematically-presented) structure. I make some suggestions for the application of these ideas outside physics, including in the philosophy of mind context that motivated Dennett's original proposal.

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Learning to Represent: Mathematics-first accounts of representation and their relation to natural language (2024)

Currently online-only.

I develop an account of how mathematized theories in physics represent physical systems, in response to the frequent claim that any such account must presuppose a non-mathematized, and usually linguistic, description of the system represented. The account I develop contains a circularity, in that representation is a mathematical relation between the models of a theory and the system as represented by some other model --- but I argue that this circularity is not vicious, in any case refers in linguistic accounts of meaning and representation, and is simply a consequence of the fact that we have no unmediated, representation-independent access to the world.

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Functionalism fit for physics (2023)

(Eleanor Knox and DW) In submission.

We put the recent flurry of interest in functionalism in philosophy of physics into context by considering functionalism's roots in philosophy of mind. There we identify two types of functionalism, which we call 'causal-role' and 'constitutive' functionalism: the former is a defeasible reductive hypothesis, while the latter, when true, is analytically so, and is not itself reductive. We argue through case studies that it is the constitutive notion of functionalism that is the better fit to physics.

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Stating Structural Realism: mathematics-first approaches to physics and metaphysics (2021)

In J. Hawthorne (ed.), Philosophical Perspectives volume 36: Metaphysics (Wiley-Blackwell, 2022), 345-37

I respond to the frequent objection that structural realism fails to sharply state an alternative to the standard predicate-logic, object / property / relation, way of doing metaphysics. The approach I propose is based on what I call a `math-first' approach to physical theories (close to the so-called `semantic view of theories') where the content of a physical theory is to be understood primarily in terms of its mathematical structure and the representational relations it bears to physical systems, rather than as a collection of sentences that attempt to make true claims about those systems (a `language-first' approach). I argue that adopting the math-first approach already amounts to a form of structural realism, and that the choice between epistemic and ontic versions of structural realism is then a choice between a language-first and math-first view of \emph{metaphysics}; I then explore the status of objects (and properties and relations) in fundamental and non-fundamental physics for both versions of math-first structural realism.

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Protecting cognitive science from quantum theory (2004)

Behavioral and Brain Sciences 27 (2004), pp. 636-637

The relation between micro-objects and macro-objects advocated by Kim is even more problematic than Ross & Spurrett (R&S) argue, for reasons rooted in physics. R&S's own ontological proposals are much more satisfactory from a physicist's viewpoint but may still be problematic. A satisfactory theory of macroscopic ontology must be as independent as possible of the details of microscopic physics.

(Note: Behavioral and Brain Sciences is an interdisciplinary journal in the psychology/cognitive science/AI/philosophy-of-mind nexus. It typically publishes a "target article", several dozen short responses, and then a reply from the authors of the target article. This is my reply to D. Ross and D. Spurrett, What to say to a skeptical metaphysician: A defense manual for cognitive and behavioral scientists, BBS 27 (2004) pp. 603-627.)