•  1218
    A teaching document I've used in my courses on truth and on incompleteness. Aimed at students who have a good grasp of basic logic, and decent math skills, it attempts to give them the background they need to understand a proper statement of the classic results due to Gödel and Tarski, and sketches their proofs. Topics covered include the notions of language and theory, the basics of formal syntax and arithmetization, formal arithmetic (Q and PA), representability, diagonalization, and the incom…Read more
  •  1088
    This is a completely informal presentation of the ideas behind the diagonal lemma. One really can't see this important result from too many different angles. This one aims at getting the main idea across. (For the cognoscenti, it is in the spirit of Quine's treatment in terms of "appended to its own quotation".)
  •  1309
    Frege’s Theorem: An Introduction
    The Harvard Review of Philosophy 7 (1): 56-73. 1999.
    A brief, non-technical introduction to technical and philosophical aspects of Frege's philosophy of arithmetic. The exposition focuses on Frege's Theorem, which states that the axioms of arithmetic are provable, in second-order logic, from a single non-logical axiom, "Hume's Principle", which itself is: The number of Fs is the same as the number of Gs if, and only if, the Fs and Gs are in one-one correspondence
  •  1194
    Semantic Accounts of Vagueness
    In J. C. Beall (ed.), Liars and Heaps, Oxford University Press Uk. pp. 106-27. 2004.
    Written as a comment on Crispin Wright's "Vagueness: A Fifth Column Approach", this paper defends a form of supervaluationism against Wright's criticisms. Along the way, however, it takes up the question what is really wrong with Epistemicism, how the appeal of the Sorities ought properly to be understood, and why Contextualist accounts of vagueness won't do.
  •  2022
    Discusses Frege's formal definitions and characterizations of infinite and finite sets. Speculates that Frege might have discovered the "oddity" in Dedekind's famous proof that all infinite sets are Dedekind infinite and, in doing so, stumbled across an axiom of countable choice.
  •  831
    Die Grundlagen der Arithmetik, 82-3
    with George Boolos
    In Matthias Schirn (ed.), The Philosophy of Mathematics Today, Clarendon Press. pp. 407-428. 1998.
    A close look at Frege's proof in "Foundations of Arithmetic" that every number has a successor. The examination reveals a surprising gap in the proof, one that Frege would later fill in "Basic Laws of Arithmetic".
  •  137
    Perhaps the most important argument against deflationism is the so-called Success Argument: The success of certain behavioral strategies depends upon the truth of a person's beliefs. If so, then the notion of truth appears to play an important role in psychological explanation, contradicting the central thesis of deflationism. I argue here that this type of argument poses a particularly difficult problem for disquotationalism, but that the important case concerns the role that the falsity of a p…Read more
  •  646
    Disquotation, Translation, and Context-Dependence
    In Ernest Lepore & David Sosa (eds.), Oxford Studies in Philosophy of Language, 3, Oxford University Press. pp. 99-128. 2023.
    It has been known for some time that context-dependence poses a problem for disquotationalism, but the problem has largely been regarded as one of detail: one that will be solved by the right sort of cleverness. I argue here that the problem is one of principle and that extant solutions, which are based upon the notion of translation, cannot succeed.
  •  1255
    What Bar-On and Simmons call 'Conceptual Deflationism' is the thesis that truth is a 'thin' concept in the sense that it is not suited to play any explanatory role in our scientific theorizing. One obvious place it might play such a role is in semantics, so disquotationalists have been widely concerned to argued that 'compositional principles', such as (C) A conjunction is true iff its conjuncts are true are ultimately quite trivial and, more generally, that semantic theorists have misconce…Read more
  •  3024
    How Not To Watch Feminist Pornography
    Feminist Philosophical Quarterly 7 (1). 2021.
    This paper has three goals. The first is to defend Tristan Taromino and Erika Lust (or some of their films) from criticisms that Rebecca Whisnant and Hans Maes make of them. Toward that end, I will be arguing against the narrow conceptions that Whisnant and Maes have of what `feminist' pornography must be like. More generally, I hope to show by example why it is important to take pornographic films seriously as films if we're to understand their potential to shape, or mis-shape, socio-sexual nor…Read more
  •  851
    Disquotationalism is the view that the only notion of truth we really need is one that can be wholly explained in terms of such trivialities as: “Snow is white” is true iff snow is white. The 'Classical Disquotational Strategy' attempts to establish this view case by case, by showing that each extant appeal to truth, in philosophical or scientific explanations, can be unmasked as an appeal only to disquotational truth. I argue here that the Classical Strategy fails in at least two cases: attribu…Read more
  •  211
    Reply to Hintikka and Sandu: Frege and Second-Order Logic
    Journal of Philosophy 90 (8): 416-424. 1993.
    Hintikka and Sandu had argued that 'Frege's failure to grasp the idea of the standard interpretation of higher-order logic turns his entire foundational project into a hopeless daydream' and that he is 'inextricably committed to a non-standard interpretation' of higher-order logic. We disagree.
  •  1501
    The Birth of Semantics
    Journal for the History of Analytical Philosophy 8 (6): 1-31. 2020.
    We attempt here to trace the evolution of Frege’s thought about truth. What most frames the way we approach the problem is a recognition that hardly any of Frege’s most familiar claims about truth appear in his earliest work. We argue that Frege’s mature views about truth emerge from a fundamental re-thinking of the nature of logic instigated, in large part, by a sustained engagement with the work of George Boole and his followers, after the publication of Begriffsschrift and the appearance of c…Read more
  •  1930
    Pornography and accommodation
    Inquiry: An Interdisciplinary Journal of Philosophy 64 (8): 830-860. 2021.
    ABSTRACT In ‘Scorekeeping in a Pornographic Language Game’, Rae Langton and Caroline West borrow ideas from David Lewis to attempt to explain how pornography might subordinate and silence women. Pornography is supposed to express certain misogynistic claims implicitly, through presupposition, and to convey them indirectly, through accommodation. I argue that the appeal to accommodation cannot do the sort of work Langton and West want it to do: Their case rests upon an overly simplified model of …Read more
  •  752
    The Logical Strength of Compositional Principles
    Notre Dame Journal of Formal Logic 59 (1): 1-33. 2018.
    This paper investigates a set of issues connected with the so-called conservativeness argument against deflationism. Although I do not defend that argument, I think the discussion of it has raised some interesting questions about whether what I call “compositional principles,” such as “a conjunction is true iff its conjuncts are true,” have substantial content or are in some sense logically trivial. The paper presents a series of results that purport to show that the compositional principles for…Read more
  •  2017
    Solving Frege's puzzle
    Journal of Philosophy 109 (1-2): 132-174. 2012.
    So-called 'Frege cases' pose a challenge for anyone who would hope to treat the contents of beliefs (and similar mental states) as Russellian propositions: It is then impossible to explain people's behavior in Frege cases without invoking non-intentional features of their mental states, and doing that seems to undermine the intentionality of psychological explanation. In the present paper, I develop this sort of objection in what seems to me to be its strongest form, but then offer a response to…Read more
  •  1079
    Formal Arithmetic Before Grundgesetze
    In Philip A. Ebert & Marcus Rossberg (eds.), Essays on Frege's Basic Laws of Arithmetic, Oxford University Press. pp. 497-537. 2019.
    A speculative investigation of how Frege's logical views change between Begriffsschrift and Grundgesetze and how this might have affected the formal development of logicism.
  •  971
    The Basic Laws of Cardinal Number
    In Philip A. Ebert & Marcus Rossberg (eds.), Essays on Frege's Basic Laws of Arithmetic, Oxford University Press. pp. 1-30. 2019.
    An overview of what Frege accomplishes in Part II of Grundgesetze, which contains proofs of axioms for arithmetic and several additional results concerning the finite, the infinite, and the relationship between these notions. One might think of this paper as an extremely compressed form of Part II of my book Reading Frege's Grundgesetze.
  •  2095
    Logicism, Ontology, and the Epistemology of Second-Order Logic
    In Ivette Fred Rivera & Jessica Leech (eds.), Being Necessary: Themes of Ontology and Modality from the Work of Bob Hale., Oxford University Press. pp. 140-169. 2018.
    In two recent papers, Bob Hale has attempted to free second-order logic of the 'staggering existential assumptions' with which Quine famously attempted to saddle it. I argue, first, that the ontological issue is at best secondary: the crucial issue about second-order logic, at least for a neo-logicist, is epistemological. I then argue that neither Crispin Wright's attempt to characterize a `neutralist' conception of quantification that is wholly independent of existential commitment, nor Hale's …Read more
  •  337
    One of the earliest discussions of the so-called 'bad company' objection to Neo-Fregeanism, I show that the consistency of an arbitrary second-order 'contextual definition' (nowadays known as an 'abstraction principle' is recursively undecidable. I go on to suggest that an acceptable such principle should satisfy a condition nowadays known as 'stablity'.
  •  881
    Cognitive Hunger: Remarks on Imogen Dickie's Fixing Reference
    Philosophy and Phenomenological Research 95 (3): 738-744. 2017.
    The main focus of my comments is the role played in Dickie's view by the idea that "the mind has a need to represent things outside itself". But there are also some remarks about her (very interesting) suggestion that descriptive names can sometimes fail to refer to the object that satisfies the associated description.
  •  615
    The Frontloading Argument
    Philosophical Studies 175 (10): 2583-2608. 2018.
    Maybe the most important argument in David Chalmers’s monumental book Constructing the World is the one he calls the ‘Frontloading Argument’, which is used in Chapter 4 to argue for the book’s central thesis, A Priori Scrutability. And, at first blush, the Frontloading Argument looks very strong. I argue here, however, that it is incapable of securing the conclusion it is meant to establish.
  •  195
    Finitude and Hume’s Principle
    Journal of Philosophical Logic 26 (6): 589-617. 1997.
    The paper formulates and proves a strengthening of ‘Frege’s Theorem’, which states that axioms for second-order arithmetic are derivable in second-order logic from Hume’s Principle, which itself says that the number of Fs is the same as the number ofGs just in case the Fs and Gs are equinumerous. The improvement consists in restricting this claim to finite concepts, so that nothing is claimed about the circumstances under which infinite concepts have the same number. ‘Finite Hume’s Principle’ al…Read more
  •  1698
    Frege and semantics
    Grazer Philosophische Studien 75 (1): 27-63. 2007.
    In recent work on Frege, one of the most salient issues has been whether he was prepared to make serious use of semantical notions such as reference and truth. I argue here Frege did make very serious use of semantical concepts. I argue, first, that Frege had reason to be interested in the question how the axioms and rules of his formal theory might be justified and, second, that he explicitly commits himself to offering a justification that appeals to the notion of reference. I then discuss the…Read more
  •  3042
    Gareth Evans has argued that the existence of vague objects is logically precluded: The assumption that it is indeterminate whether some object a is identical to some object b leads to contradiction. I argue in reply that, although this is true—I thus defend Evans's argument, as he presents it—the existence of vague objects is not thereby precluded. An 'Indefinitist' need only hold that it is not logically required that every identity statement must have a determinate truth-value, not that some …Read more
  •  1468
    The Sense of Communication
    Mind 104 (413). 1995.
    Many philosophers nowadays believe Frege was right about belief, but wrong about language: The contents of beliefs need to be individuated more finely than in terms of Russellian propositions, but the contents of utterances do not. I argue that this 'hybrid view' cannot offer no reasonable account of how communication transfers knowledge from one speaker to another and that, to do so, we must insist that understanding depends upon more than just getting the references of terms right.
  •  3271
    Meaning and Truth-conditions
    In Dirk Greimann & Geo Siegwart (eds.), Truth and Speech Acts: Studies in the Philosophy of Language, Routledge. pp. 349--76. 2012.
    Defends the view that understanding can be identified with knowledge of T-sentences against the classical criticisms of Foster and Soames.
  •  203
    Grundgesetze der arithmetic I §10
    Philosophia Mathematica 7 (3): 258-292. 1999.
    In section 10 of Grundgesetze, Frege confronts an indeterm inacy left by his stipulations regarding his ‘smooth breathing’, from which names of valueranges are formed. Though there has been much discussion of his arguments, it remains unclear what this indeterminacy is; why it bothers Frege; and how he proposes to respond to it. The present paper attempts to answer these questions by reading section 10 as preparatory for the (fallacious) proof, given in section 31, that every expression of Frege…Read more
  •  1389
    Truth and disquotation
    Synthese 142 (3): 317--352. 2005.
    Hartry Field has suggested that we should adopt at least a methodological deflationism: [W]e should assume full-fledged deflationism as a working hypothesis. That way, if full-fledged deflationism should turn out to be inadequate, we will at least have a clearer sense than we now have of just where it is that inflationist assumptions ... are needed. I argue here that we do not need to be methodological deflationists. More pre-cisely, I argue that we have no need for a disquotational truth-predic…Read more
  •  1451
    Is Frege's Definition of the Ancestral Adequate?
    Philosophia Mathematica 24 (1): 91-116. 2016.
    Why should one think Frege's definition of the ancestral correct? It can be proven to be extensionally correct, but the argument uses arithmetical induction, and that seems to undermine Frege's claim to have justified induction in purely logical terms. I discuss such circularity objections and then offer a new definition of the ancestral intended to be intensionally correct; its extensional correctness then follows without proof. This new definition can be proven equivalent to Frege's without an…Read more