I work mainly on philosophy of language, philosophy of mind (including philosophy of psychology), and philosophy of logic. My current research concerns three topics: the nature of assertion; non-propositional varieties of representation; and the relation between computational and mental processes. Comments on all papers (especially unpublished drafts) are welcome.

Selected Bibliography

PUBLISHED PAPERS

• “Church’s Thesis and the Conceptual Analysis of Computability,” Notre Dame Journal of Formal Logic 
  
  Church’s thesis asserts that a number-theoretic function is intuitively computable if and only if it is recursive. A related thesis asserts that Turing’s work yields a conceptual analysis of the intuitive notion of numerical computability. I endorse Church’s thesis, but I argue against the related thesis. I argue that purported conceptual analyses based upon Turing’s work involve a subtle but persistent circularity.
  
  
• “Assertion and its Constitutive Norms,” Philosophy and Phenomenological Research

  Alston, Searle, Williamson, and many others advocate the restrictive model of assertion, according to which certain constitutive assertoric norms restrict which propositions one may assert. Sellars and Brandom advocate the dialectical model of assertion, which treats assertion as constituted by its role in the game of giving and asking for reasons. Sellars and Brandom develop a restrictive version of the dialectical model. I explore a non-restrictive version of the dialectical model. On such a view, constitutive assertoric norms constrain how one must react if an interlocutor challenges one’s assertion, but they do not constrain what one should assert in the first place.

• “A Linguistic Reason for Truthfulness,” in Truth and Speech Acts, ed. Dirk Greimann and Geo Siegwart

  This paper further develops the non-restrictive dialectical perspective. Many philosophers hold that truthfulness is somehow constitutive of assertion. I argue against this view while simultaneously attempting to ground truthfulness in assertion’s essential features. I argue that truthfulness is the prima facie best way to avoid decisive counter-arguments against what one says. Moreover, avoiding decisive counter-arguments is a constitutive goal of rational dialectic. Thus, while truthfulness is not constitutive of assertion, it is the rational default strategy for achieving a goal that is constitutive of assertion.

• “Shifting the Burden of Proof?" The Philosophical Quarterly

  Dialectical foundationalists, including Adler, Brandom, Leite, and Williams, claim that some asserted propositions do not require defense just because an interlocutor challenges them. By asserting such a proposition, the speaker shifts the burden of proof to her interlocutor. Dialectical egalitarians claim that all asserted propositions require defense when challenged. I elucidate the dispute between dialectical foundationalists and egalitarians, and I defend a broadly egalitarian stance against several prominent objections.

• “Epistemic and Dialectical Regress,” Australasian Journal of Philosophy

  Dialectical egalitarianism apparently generates a vicious “regress of justifications,” since an interlocutor can challenge the premises through which a speaker defends her original assertion, and so on ad infinitum. I argue that the putative regress is not worrisome and that egalitarianism can handle it quite satisfactorily. I also defend a positive view that combines an anti-foundationalist conception of dialectical interaction with a foundationalist conception of epistemic justification.

• “Predication and Cartographic Representation,” Synthese

  I argue that maps do not feature predication, as analyzed by Frege and Tarski. I take as my foil Casati and Varzi’s Parts and Places, which attributes predication to maps. I adduce intuitions about cartographic truth-conditions that militate against this attribution. I conclude that attaching a marker to map coordinates is a different mode of semantic composition than attaching a predicate to a singular term.

• “Cognitive Maps and the Language of Thought,” British Journal for the Philosophy of Science

  Fodor advocates a view of cognitive processes as computations defined over the language of thought (or Mentalese). Even among those who endorse Mentalese, considerable controversy surrounds its representational format. What semantically relevant structure should scientific psychology attribute to Mentalese symbols? Researchers commonly emphasize logical structure, akin to that displayed by predicate calculus sentences. To counteract this tendency, I discuss computational models of navigation drawn from probabilistic robotics. These models involve computations defined over cognitive maps, which have geometric rather than logical structure. They thereby demonstrate the possibility of rational cognitive processes in an exclusively non-logical representational medium. Furthermore, they offer much promise for the empirical study of animal navigation.

• "Chrysippus's Dog as a Case Study in Non-Linguistic Cognition," Philosophy of Animal Minds, ed. Robert Lurz. Cambridge: Cambridge
  University Press
  
  I critique an ancient argument for the possibility of non-linguistic deductive inference. The argument, attributed to Chrysippus, describes a dog whose behavior supposedly reflects disjunctive syllogistic reasoning. Drawing on contemporary robotics, I urge that we can equally well explain the dog's behavior by citing probabilistic reasoning over cognitive maps. I then critique various experimentally-based arguments from scientific psychology that echo Chrysippus's anecdotal presentation.
  
  

WORKS IN PROGRESS

• “Syntax and Semantics in Computation Theory”

  Philosophers almost invariably assume that computations are defined over semantically neutral entities: i.e., entities that lack any inherent meaning or content. I argue that this assumption derives no support from the mathematical theory of computation, as developed by Turing, Post, and others. The mathematical theory is perfectly consistent with computations defined over semantically permeated entities: i.e., entities that have their meanings or contents essentially. I support my position through detailed investigation of Turing machines defined over semantically permeated syntax. I conclude that contemporary discussion enshrines an overly narrow conception of computation as formal or “non-semantic.”

• “Against Structuralist Theories of Computational Implementation”

  Computational models are abstract entities that can be implemented or realized by physical systems. Structuralism about computational implementation holds that a physical system realizes a computational model just in the case the system exhibits a pattern of causal organization isomorphic to the model’s formal structure. I argue against structuralism through a series of counter-examples drawn from mathematics, computer science, and recursion theory. On my opposing view, computational implementation requires instantiating appropriate non-structural properties (including semantic properties) determined by the computational model.

• “Is Computation Formal?”

  The formal conception of computation, espoused by Egan, Fodor, Stich, and many others, holds that computational processes are not sensitive to semantic properties. The formal conception is quite popular, but it faces well-known difficulties. Accordingly, authors such as Block and Peacocke pursue a “semantically-laden” alternative, according which computation can be sensitive to semantics. Focusing on Peacocke’s account, I argue that the semantically-laden perspective likewise faces formidable obstacles.

• "Essential Meanings"
  
  An entity is semantically neutral if it lacks inherent meaning, content, or semantic properties. An entity is semantically permeated if it has its meaning essentially. The dichotomy between semantic neutrality and semantic permeation applies to natural language, mental representation, and formal logic. As emphasized by philosophers such as Plato, Aristotle, Ockham, Frege, Hilbert, Sellars, Putnam, Fodor, and Burge, fundamental questions turn on whether the relevant domain features semantically neutral or semantically permeated entities. I try to clarify this crucial dichotomy by offering a modal analysis. I then deploy my analysis to investigate whether the language of thought is semantically neutral or semantically permeated.
  
  

OTHER PUBLICATIONS

• Review of Christopher Gauker's Words without Meaning, Philosophical Review, Vol. 115, No. 1, January 2006, 121-124.
  
  
• "Convention,"Stanford Encyclopedia of Philosophy