•  34
    Review of Symbolic Logic. forthcoming.
    It is widely thought that chance should be understood in reductionist terms: claims about chance should be understood as claims that certain patterns of events are instantiated. There are many possible reductionist theories of chance, differing as to which possible pattern of events they take to be chance-making. It is also widely taken to be a norm of rationality that credence should defer to chance: special cases aside, rationality requires that one's credence function, when conditionalized o…Read more
  •  2
    Book Review (review)
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 41 (1): 81-83. 2010.
  •  5
    Spacetime (edited book)
    Dartmouth Pub. Co.. 1996.
    This collection of articles on the theme of space and time covers such broad topics as the philosophy of spacetime, spacetime structure, spacetime ontology, the epistemology of geometry, and general relativity.
  •  85
    That Does Not Compute: David Lewis on Credence and Chance
    Philosophy of Science. forthcoming.
    Like Lewis, many philosophers hold reductionist accounts of chance (on which claims about chance are to be understood as claims that certain patterns of events are instantiated) and maintain that rationality requires that credence should defer to chance (in the sense that under certain circumstances one's credence in an event must coincide with the chance of that event). It is a shortcoming of an account of chance if it implies that this norm of rationality is unsatisfiable by computable agent…Read more
  •  146
    Ratbag Idealism
    In Yemima Ben-Menahem (ed.), Rethinking the Concept of Laws of Nature, . forthcoming.
    A discussion of the sense in which reality is mind-dependent for Kant and for David Lewis. Plus a lot about space-aliens (and a bit about pimple-worms).
  •  171
    Gravity and Grace
    Philosophers' Imprint 22 (1). 2022.
    This paper revisits the bearing of underdetermination arguments on scientific realism. First it argues that underdetermination considerations provide good reason to doubt that science is objective in the strong sense that anyone following the its methods will be led closer and closer to the truth about any given question within the purview of those methods, as more relevant data are considered. Then it argues that scientific realism is difficult to maintain in the absence of this sort of objecti…Read more
  •  204
    Absolutely No Free Lunches!
    Theoretical Computer Science. forthcoming.
    This paper is concerned with learners who aim to learn patterns in infinite binary sequences: shown longer and longer initial segments of a binary sequence, they either attempt to predict whether the next bit will be a 0 or will be a 1 or they issue forecast probabilities for these events. Several variants of this problem are considered. In each case, a no-free-lunch result of the following form is established: the problem of learning is a formidably difficult one, in that no matter what method …Read more
  •  19
    An Automatic Ockham’s Razor for Bayesians?
    Erkenntnis 84 (6): 1361-1367. 2019.
    It is sometimes claimed that the Bayesian framework automatically implements Ockham’s razor—that conditionalizing on data consistent with both a simple theory and a complex theory more or less inevitably favours the simpler theory. It is shown here that the automatic razor doesn’t in fact cut it for certain mundane curve-fitting problems.
  •  332
    An Automatic Ockham’s Razor for Bayesians?
    Erkenntnis 84 (6): 1361-1367. 2019.
    It is sometimes claimed that the Bayesian framework automatically implements Ockham’s razor—that conditionalizing on data consistent with both a simple theory and a complex theory more or less inevitably favours the simpler theory. It is shown here that the automatic razor doesn’t in fact cut it for certain mundane curve-fitting problems.
  • Geometry and Motion
    In Peter Clark & Katherine Hawley (eds.), Philosophy of Science Today, Clarendon Press. 2003.
  •  21
    Curve-Fitting for Bayesians?
    British Journal for the Philosophy of Science. 2016.
    Bayesians often assume, suppose, or conjecture that for any reasonable explication of the notion of simplicity a prior can be designed that will enforce a preference for hypotheses simpler in just that sense. Further, it is often claimed that the Bayesian framework automatically implements Occam's razor—that conditionalizing on data consistent with both a simple theory and a complex theory more or less inevitably favours the simpler theory. But it is shown here that there are simplicity-driven …Read more
  •  10
    I survey the options for understanding the nature of the wave-function in the setting of the relativistic collapse models recently developed by Tumulka. Some of the options involve surprising features, such as backwards causation or locality.
  •  184
    Chaos out of order: Quantum mechanics, the correspondence principle and chaos
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 28 (2): 147-182. 1997.
    A vast amount of ink has been spilled in both the physics and the philosophy literature on the measurement problem in quantum mechanics. Important as it is, this problem is but one aspect of the more general issue of how, if at all, classical properties can emerge from the quantum descriptions of physical systems. In this paper we will study another aspect of the more general issue-the emergence of classical chaos-which has been receiving increasing attention from physicists but which has largel…Read more
  •  353
    Synopsis and discussion: Philosophy of gauge theory
    with John Earman, Richard Healey, Tim Maudlin, Antigone Nounou, and Ward Struyve
    This document records the discussion between participants at the workshop "Philosophy of Gauge Theory," Center for Philosophy of Science, University of Pittsburgh, 18-19 April 2009.
  •  210
    Pre-socratic quantum gravity
    In Craig Callender & Nick Huggett (eds.), Physics Meets Philosophy at the Planck Scale, Cambridge University Press. pp. 213--55. 2001.
    Physicists who work on canonical quantum gravity will sometimes remark that the general covariance of general relativity is responsible for many of the thorniest technical and conceptual problems in their field.1 In particular, it is sometimes alleged that one can trace to this single source a variety of deep puzzles about the nature of time in quantum gravity, deep disagreements surrounding the notion of ‘observable’ in classical and quantum gravity, and deep questions about the nature of the e…Read more
  •  58
    From metaphysics to physics
    In Jeremy Butterfield & Constantine Pagonis (eds.), From Physics to Philosophy, Cambridge University Press. pp. 166--86. 1999.
    We discuss the relationship between the interpretative problems of quantum gravity and those of general relativity. We argue that classical and quantum theories of gravity resuscitate venerable philosophical questions about the nature of space, time, and change; and that the resolution of some of the difficulties facing physicists working on quantum theories of gravity would appear to require philosophical as well as scientific creativity.
  •  95
    The Hawking Information Loss Paradox: The Anatomy of a Controversy
    British Journal for the Philosophy of Science 50 (2): 189-229. 1999.
    Stephen Hawking has argued that universes containing evaporating black holes can evolve from pure initial states to mixed final ones. Such evolution is non-unitary and so contravenes fundamental quantum principles on which Hawking's analysis was based. It disables the retrodiction of the universe's initial state from its final one, and portends the time-asymmetry of quantum gravity. Small wonder that Hawking's paradox has met with considerable resistance. Here we use a simple result for C*-algeb…Read more
  •  88
    Substantivalists claim that spacetime enjoys an existence analogous to that of material bodies, while relationalists seek to reduce spacetime to sets of possible spatiotemporal relations. The resulting debate has been central to the philosophy of space and time since the Scientific Revolution. Recently, many philosophers of physics have turned away from the debate, claiming that it is no longer of any relevance to physics. At the same time, there has been renewed interest in the debate among phy…Read more
  •  77
    Determinism and ontology
    International Studies in the Philosophy of Science 9 (1). 1995.
    Abstract In the philosophical literature, there are two common criteria for a physical theory to be deterministic. The older one is due to the logical empiricists, and is a purely formal criterion. The newer one can be found in the work of John Earman and David Lewis and depends on the intended interpretation of the theory. In this paper I argue that the former must be rejected, and something like the latter adopted. I then discuss the relevance of these points to the current debate over the hol…Read more
  •  150
    An elementary notion of gauge equivalence
    General Relativity and Gravitation 40 (1). 2008.
    An elementary notion of gauge equivalence is introduced that does not require any Lagrangian or Hamiltonian apparatus. It is shown that in the special case of theories, such as general relativity, whose symmetries can be identified with spacetime diffeomorphisms this elementary notion has many of the same features as the usual notion. In particular, it performs well in the presence of asymptotic boundary conditions.
  •  338
    The principle of sufficient reason
    Journal of Philosophy 98 (2): 55-74. 2001.
    The paper is about the physical theories which result when one identifies points in phase space related by symmetries; with applications to problems concerning gauge freedom and the structure of spacetime in classical mechanics
  •  298
    In Ockham's Razors: A User's Guide, Elliott Sober argues that parsimony considerations are epistemically relevant on the grounds that certain methods of model selection, such as the Akaike Information Criterion, exhibit good asymptotic behaviour and take the number of adjustable parameters in a model into account. I raise some worries about this form of argument.
  •  75
    Geometric Possibility
    Oxford University Press UK. 2011.
    Gordon Belot investigates the distinctive notion of geometric possibility that relationalists rely upon. He examines the prospects for adapting to the geometric case the standard philosophical accounts of the related notion of physical possibility, with particular emphasis on Humean, primitivist, and necessitarian accounts of physical and geometric possibility. This contribution to the debate concerning the nature of space will be of interest not only to philosophers and metaphysicians concerned…Read more
  •  17
    Book reviews (review)
    International Studies in the Philosophy of Science 11 (3): 305-313. 1997.
    A review of Rob Clifton (ed.), Perspectives on Quantum Reality: Non-Relativistic, Relativistic, and Field-Theoretic
  •  1405
    Time in Classical and Relativistic Physics
    In Adrian Bardon & Heather Dyke (eds.), A Companion to the Philosophy of Time, Blackwell. pp. 185-200. 2013.
    This is a short, nontechnical introduction to features of time in classical and relativistic physics and their representation in the four-dimensional geometry of spacetime. Topics discussed include: the relativity of simultaneity in special and general relativity; the ‘twin paradox’ and differential aging effects in special and general relativity; and time travel in general relativity.
  •  101
    Why general relativity does need an interpretation
    Philosophy of Science 63 (3): 88. 1996.
    There is a widespread impression that General Relativity, unlike Quantum Mechanics, is in no need of an interpretation. I present two reasons for thinking that this is a mistake. The first is the familiar hole argument. I argue that certain skeptical responses to this argument are too hasty in dismissing it as being irrelevant to the interpretative enterprise. My second reason is that interpretative questions about General Relativity are central to the search for a quantum theory of gravity. I i…Read more
  •  81
    Time's Arrow and Archimedes' Point: New Directions for the Physics of Time (review)
    Philosophical Review 107 (3): 477. 1998.
    A review of Huw Price's Time's Arrow and Archimedes' Point
  •  536
    Quantum states for primitive ontologists: A case study
    European Journal for Philosophy of Science 2 (1): 67-83. 2012.
    Under so-called primitive ontology approaches, in fully describing the history of a quantum system, one thereby attributes interesting properties to regions of spacetime. Primitive ontology approaches, which include some varieties of Bohmian mechanics and spontaneous collapse theories, are interesting in part because they hold out the hope that it should not be too difficult to make a connection between models of quantum mechanics and descriptions of histories of ordinary macroscopic bodies. But…Read more
  •  210
    Dust, Time and Symmetry
    British Journal for the Philosophy of Science 56 (2): 255-291. 2005.
    Two symmetry arguments are discussed, each purporting to show that there is no more room for a preferred division of spacetime into instants of time in general relativistic cosmology than in Minkowski spacetime. The first argument is due to Gödel, and concerns the symmetries of his famous rotating cosmologies. The second turns upon the symmetries of a certain space of relativistic possibilities. Both arguments are found wanting.