The connection between theories of truth and meaning is explored. Theories of truth and meaning are connected in a way such that differences in the conception of what it is for a sentence to be true are engendered by differences in the conception of how meanings depend on each other, and on a base of underlying facts. It is argued that this view is common ground between Davidson and Dummett, and that their dispute over realism is really a dispute in (...) the theory of meaning over holism and molecularism. The view offered is contrasted with influential pragmatist and modest views. (shrink)

This essay investigates whether or not we should think that the things we say are identical to the things our sentences mean. It is argued that these theoretical notions should be distinguished, since assertoric content does not respect the compositionality principle. As a paradigmatic example, Kaplan's formal language LD is shown to exemplify a failure of compositionality. It is demonstrated that by respecting the theoretical distinction between the objects of assertion and compositional values certain conflicts between compositionality and contextualism are (...) avoided. This includes the conflict between eternalism and the semantics of tense, the embedding problems for contextualism about epistemic modals and taste claims, and the conflict between direct reference and the semantics of bound pronouns (and monstrous operators). After presenting the theoretical picture which distinguishes assertoric content from compositional semantic value, some objections to the picture are addressed. In so doing, the objection from King (2003) stemming from apparent complications with the interaction of temporal expressions and attitude reports is assessed and shown to be non-threatening. (shrink)

We may try to explain proofs as chains of valid inference, but the concept of validity needed in such an explanation cannot be the traditional one. For an inference to be legitimate in a proof it must have sufficient epistemic power, so that the proof really justifies its final conclusion. However, the epistemic concepts used to account for this power are in their turn usually explained in terms of the concept of proof. To get out of this circle we may (...) consider an idea within intuitionism about what it is to justify the assertion of a proposition. It depends on Heyting’s view of the meaning of a proposition, but does not presuppose the concept of inference or of proof as chains of inferences. I discuss this idea and what is required in order to use it for an adequate notion of valid inference. (shrink)

I see the question what it is that makes an inference valid and thereby gives a proof its epistemic power as the most fundamental problem of general proof theory. It has been surprisingly neglected in logic and philosophy of mathematics with two exceptions: Gentzen’s remarks about what justifies the rules of his system of natural deduction and proposals in the intuitionistic tradition about what a proof is. They are reviewed in the paper and I discuss to what extent they succeed (...) in answering what a proof is. Gentzen’s ideas are shown to give rise to a new notion of valid argument. At the end of the paper I summarize and briefly discuss an approach to the problem that I have proposed earlier. (shrink)

According to a main idea of Gentzen the meanings of the logical constants are reflected by the introduction rules in his system of natural deduction. This idea is here understood as saying roughly that a closed argument ending with an introduction is valid provided that its immediate subarguments are valid and that other closed arguments are justified to the extent that they can be brought to introduction form. One main part of the paper is devoted to the exact development of (...) this notion. Another main part of the paper is concerned with a modification of this notion as it occurs in Michael Dummett’s book The Logical Basis of Metaphysics. The two notions are compared and there is a discussion of how they fare as a foundation for a theory of meaning. It is noted that Dummett’s notion has a simpler structure, but it is argued that it is less appropriate for the foundation of a theory of meaning, because the possession of a valid argument for a sentence in Dummett’s sense is not enough to be warranted to assert the sentence. (shrink)

This paper offers a new interpretation for Wittgenstein`s treatment of mathematical identities. As it is widely known, Wittgenstein`s mature philosophy of mathematics includes a general rejection of abstract objects. On the other hand, the traditional interpretation of mathematical identities involves precisely the idea of a single abstract object – usually a number –named by both sides of an equation.

The investigations on higher-order type theories and on the related notion of parametric polymorphism constitute the technical counterpart of the old foundational problem of the circularity of second and higher-order logic. However, the epistemological significance of such investigations has not received much attention in the contemporary foundational debate.We discuss Girard’s normalization proof for second order type theory or System F and compare it with two faulty consistency arguments: the one given by Frege for the logical system of the Grundgesetze and (...) the one given by Martin-Löf for the intuitionistic type theory with a type of all types.The comparison suggests that the question of the circularity of second order logic cannot be reduced to Russell’s and Poincaré’s 1906 “vicious circle” diagnosis. Rather, it reveals a bunch of mathematical and logical ideas hidden behind the hazardous idea of impredicative quantification, constituting a vast domain for foundational research. (shrink)

One of Etchemendy's arguments against the Tarskian and model‐theoretic notion of logical truth is based on a reduction principle according to which a universally quantified sentence is true if, and only if, all of its instances are logically true. The reduction of logical truth to mere truth reveals that the concept of validity at play in Tarski and in model‐theory relies upon extra‐logical assumptions. A similar reduction had already been put forward by Prawitz, although not with focus on extra‐logical assumptions. (...) Prawitz's reduction concerns rather the possibility of understanding the Tarskian and model‐theoretic approach as implying any epistemic modality. We take into account a possible strategy that an advocate of Tarski and model‐theory may use against Etchemendy's objection, and argue that this strategy fails with respect to Prawitz's criticism. This permits us to shed light upon a difference between Prawitz's and Etchemendy's standpoints: while Etchemendy's reduction shows that the Tarskian and model‐theoretic notion of logical truth cannot be understood as an adequate formal counterpart of truth‐preservation solely by virtue of logical form, Prawitz's reduction insists on the fact that truth‐preservation solely by virtue of logical form is insufficient for epistemic modality to obtain. (shrink)

This dialogue between Achilles and the Tortoise – in the spirit of those of Carroll and Hofstadter – argues against the idea, identified with the “traditional” interpretation of Aristotle’s “sea battle argument”, that future contingents are an exception to the Principle of Bivalence. It presents examples of correct everyday predictions, without which one would not be able to decide and to act; however, doing this is incompatible with the belief that the content of these predictions lacks a truth-value. The cost (...) of using a non-classical logic to cope with that may be too high for Stagirite’s defenders, and they would still need to explain why our ordinary predictions seem to have a binary truth-value. In the end, the paper suggests that the problem of future contingents – and of free will – is not a logical problem at all, but rather a limit on what an agent can believe before taking a decision. (shrink)

This paper gives attention to a special point in Brandom.

Many arguments that show p to be enthymematic (in an argument for q) rely on claims like “if one did not believe that p, one would not have a reason for believing that q.” Such arguments are susceptible to the neg-raising fallacy. We tend to interpret claims like “X does not believe that p” as statements of disbelief (X's belief that not-p) rather than as statements of withholding the belief that p. This article argues that there is a tendency to (...) equivocate in arguments for the enthymematicity of arguments (e.g., Lewis Carroll's paradox, Hume's problem) as well as in arguments for the enthymematicity of action explanations (e.g., arguments for psychologism and for explanatory individualism). The article concludes with a warning, because the equivocation is often helpful in teaching and because neg-raising verbs include philosophically vital verbs: desire, want, intend, think, suppose, imagine, expect, feel, seem, appear. (shrink)

Saul Kripke's thesis that ordinary proper names are rigid designators is supported by widely shared intuitions about the occurrence of names in ordinary modal contexts. By those intuitions names are scopeless with respect to the modal expressions. That is, sentences in a pair like (a) Aristotle might have been fond of dogs, (b) Concerning Aristotle, it is true that he might have been fond of dogs will have the same truth value. The same does not in general hold for definite (...) descriptions. If one, like Kripke, accounts for this difference by means of the intensions of the names and the descriptions, the conclusion is that names do not in general have the same intension as any normal, identifying description. However, this difference can be accounted for alternatively by appeal to the semantics of the modal expressions. On the account we suggest, dubbed 'relational modality', simple singular terms, like proper names, contribute to modal contexts simply by their actual world reference, not by their descriptive content. That account turns out to be fully equivalent with the rigidity account when it comes to truth of modal and non-modal sentence (with respect to the actual world), and hence supports the same basic intuitions. Here we present the relational modality account and compare it with others, in particular Kripke's own. (shrink)

Peter Pagin Is the principle of semantic compositionality compatible with the principle of semantic holism? The question is of interest, since both principles have a lot that speaks for them, and since they do seem to be in conflict. The view that natural languages have compositional structure is almost unavoidable, since linguistic communication by means of new combinations of words would be virtually incomprehensible otherwise. And holism too seems generally plausible, since the meaning of an expression is directly connected with (...) the way that expression interacts with other. (shrink)

In this essay, I offer a critical evaluation of Hilary Putnam's writings on epistemology and philosophy of science, in particular his engagement with interpretative problems in quantum mechanics. I trace the development of his thinking from the late 1960s when he adopted a strong causal-realist position on issues of meaning, reference, and truth, via the "internal realist" approach of his middle-period writings, to the various forms of pragmatist, naturalized, or "commonsense" epistemology proposed in his latest books. My contention is that (...) Putnam's retreat from a full-fledged realist outlook has been prompted in large part by his belief that it cannot possibly be reconciled with the implications of quantum mechanics for our understanding of processes and events in the subatomic domain. However, I suggest, this response should be seen as premature given the range of as-yet unresolved problems with quantum mechanics on the orthodox (Copenhagen) interpretation and also the existence of an alternative account - David Bohm's hidden-variables theory - which perfectly matches the established predictive-observational results while providing a credible realist ontology. I also examine Putnam's case for adopting a nonstandard (three-valued) "quantum logic" in relation to the thinking of other philosophers - Michael Dummett among them - who have espoused a more global or doctrinaire version of anti-realism. I conclude that Putnam's early (causal-realist) position is by no means untenable in light of the various arguments that he now takes as counting decisively against it. (shrink)

In this essay I set out to place Derrida's work – especially his earlier books and essays – in the context of related or contrasting developments in analytic philosophy of science over the past half-century. Along the way I challenge the various misconceptions that have grown up around that work, not only amongst its routine detractors in the analytic camp but also amongst some of its less philosophically informed disciples. In particular I focus on the interlinked issues of realism versus (...) anti-realism and the scope and limits of classical logic, both of which receive a detailed, rigorous and sustained treatment in his deconstructive readings of Husserl, Austin and others. Contrary to Derrida's reputation as a exponent of anti-realism in its far-gone ‘textualist’ form and as one who merely plays perverse though ingenious games with logic I show that those readings presuppose both a basically realist conception of their subject-matter and a strong commitment to the protocols of bivalent logic. These he applies with the utmost care and precision right up to the point – unreachable except by way of that procedure – where they encounter certain problems or anomalies that cannot be resolved except by switching to a different logic. Philosophy of science in the analytic mainstream might benefit greatly from a closer acquaintance with Derrida's thinking on these topics, as it might from a knowledge of his likewise rigorous thinking-through of the antinomy between structure and genesis as it bears upon issues in the history of scientific thought. (shrink)

This paper is about the relationship between two questions: the question of what the objects of assertion are and the question of how best to theorise about ‘shifty’ phenomena like modality and tense. I argue that the relationship between these two questions is less direct than is often supposed. I then explore the consequences of this for a number of debates in the philosophy of language.

Richard Heck has recently drawn attention on a new version of the Liar Paradox, one which relies on logical resources that are so weak as to suggest that it may not admit of any “truly satisfying, consistent solution”. I argue that this conclusion is too strong. Heck's Liar reduces to absurdity principles that are already rejected by consistent paracomplete theories of truth, such as Kripke's and Field's. Moreover, the new Liar gives us no reasons to think that (versions of) these (...) principles cannot be consistently retained once the structural rule of contraction is restricted. I suggest that revisionary logicians have independent reasons for restricting such a rule. (shrink)

It is sometimes held that rules of inference determine the meaning of the logical constants: the meaning of, say, conjunction is fully determined by either its introduction or its elimination rules, or both; similarly for the other connectives. In a recent paper, Panu Raatikainen (2008) argues that this view - call it logical inferentialism - is undermined by some "very little known" considerations by Carnap (1943) to the effect that "in a definite sense, it is not true that the standard (...) rules of inference" themselves suffice to "determine the meanings of [the] logical constants" (p. 2). In a nutshell, Carnap showed that the rules allow for non-normal interpretations of negation and disjunction. Raatikainen concludes that "no ordinary formalization of logic ... is sufficient to `fully formalize' all the essential properties of the logical constants" (ibid.). We suggest that this is a mistake. Pace Raatikainen, intuitionists like Dummett and Prawitz need not worry about Carnap's problem. And although bilateral solutions for classical inferentialists - as proposed by Timothy Smiley and Ian Rumfitt - seem inadequate, it is not excluded that classical inferentialists may be in a position to address the problem too. (shrink)

According to logical inferentialists, the meanings of logical expressions are fully determined by the rules for their correct use. Two key proof-theoretic requirements on admissible logical rules, harmony and separability, directly stem from this thesis—requirements, however, that standard single-conclusion and assertion-based formalizations of classical logic provably fail to satisfy :1035–1051, 2011). On the plausible assumption that our logical practice is both single-conclusion and assertion-based, it seemingly follows that classical logic, unlike intuitionistic logic, can’t be accounted for in inferentialist terms. In (...) this paper, I challenge orthodoxy and introduce an assertion-based and single-conclusion formalization of classical propositional logic that is both harmonious and separable. In the framework I propose, classicality emerges as a structural feature of the logic. (shrink)

Históricamente, en los principales análisis filosóficos sobre el concepto de ‘verdad’ estuvo implícita lo que hoy se conoce como la teoría correspondentista de la verdad, la cual puede ser trazada desde Aristóteles hasta Immanuel Kant. A principios del siglo XIX, los detractores de la teoría correspondentista de la verdad comenzaron a argumentar, entre otras cosas, que esta postura es oscura, demasiado estrecha y autocomplaciente o argumentativamente circular. No obstante, en el ámbito científico algunos defensores de ciertas posturas realistas de la (...) ciencia han considerado que la verdad es la meta cognoscitva más importante de la actividad científica. Este estudio se realizó para establecer la plausibilidad de este argumento realista. Mediante el análisis de la validez de algunos argumentos de tipo ontológico, semántico y epistémico propuestos por algunos defensores de distintas versiones del llamado ‘Realismo Científico’, con los que se intenta relacionar el éxito empírico y predictivo de las mejores teorías científicas con la verdad, se muestra que, desde un punto de vista lógico, parece difícil confirmar que tales teorías nos proporcionen conocimiento confiable del mundo natural. Se sugiere que los científicos no son agentes confirmadores; sino agentes probabilísticos, esto es, agentes que buscan calcular la probabilidad con la que un hacedor de verdad convierte en verdadero a un portador de verdad con el que la ciencia comunica sus resultados. (shrink)

I am very happy indeed to contribute to this series of lectures, especially because I owe most of my training in philosophy to Elizabeth Anscombe, whose work has given the series its name. I am deeply indebted to the marvellous generosity of her teaching, to the example she set me of an unrelentingly thorough and serious thinker, to the unobtrusive way she introduced me to Wittgenstein's later philosophy. Through Elizabeth Anscombe I also made the acquaintance of my friend Philippa Foot, (...) whose work in moral philosophy has, over decades and more than anyone else's, influenced my own. I hope it will be possible to recognize in what I am going to say here not indeed the excellence but at least traces of the beneficial influence of both these philosophers. (shrink)

Contemporary interpretations of Zhuangzi’s 莊子 philosophy as adumbrating a relativist position are legion. However, what is the scope and nature of the relativism that can be gleaned from a comprehensive analysis of relevant passages in the Zhuangzi? In this essay, I shall explain Zhuangzi’s alleged relativist position as motivated from a primary concern about disagreement. He in effect claims that since any disputant can foresee her assertion to be refuted by an opponent, the recourse to a higher tribunal in adjudicating (...) the debate is futile. The consequence of an apparent lack of justification for assertion is, in my opinion, what needs elucidation. For example, is “truth relativism” an apt label for the nature of assertion in a debate without the verdict of a judge? Or, is it more appropriate to shun the concept of truth altogether in our explanation? I deem the contemporary explanation of Zhuangzi’s relativism either trivializes disputation or fails to account for the difference between a claim’s being right and being acceptable. Hence, I shall argue that without the intrusion of a judge as an arbiter of truth, the kind of disputation Zhuangzi practices promulgates faultless disagreement, which does not appeal to the correctness of any perspective in a comparative or absolute sense. In this understanding, Zhuangzi’s advice of harmonizing with both right and wrong is indeed a viable alternative to relativism and dogmatism, both of which do not properly take heed of the point of disagreeing in a disputation. (shrink)

In making assertions one takes on commitments to the consistency of what one asserts and to the logical consequences of what one asserts. Although there is no quick link between belief and assertion, the dialectical requirements on assertion feed back into normative constraints on those beliefs that constitute one's evidence. But if we are not certain of many of our beliefs and that uncertainty is modelled in terms of probabilities, then there is at least prima facie incoherence between the normative (...) constraints on belief and the probability-like structure of degrees of belief. I suggest that the norm-governed practice relating to degrees of belief is the evaluation of betting odds. (shrink)

In this paper, I hope to provide an account of the conditions of moral realism whereby there are still significant metaphysical commitments made by the realist which set the view apart as a distinct position in the contemporary meta-ethical landscape. In order to do so, I will be appealing to a general account of what it is for realism to be true in any domain of experience, whether it be realism about universals, realism about unobservable scientific entities, realism about artifacts, (...) and so forth. (shrink)

Various natural deduction formulations of classical, minimal, intuitionist, and intermediate propositional and first-order logics are presented and investigated with respect to satisfaction of the separation and subformula properties. The technique employed is, for the most part, semantic, based on general versions of the Lindenbaum and Lindenbaum–Henkin constructions. Careful attention is paid to which properties of theories result in the presence of which rules of inference, and to restrictions on the sets of formulas to which the rules may be employed, restrictions (...) determined by the formulas occurring as premises and conclusion of the invalid inference for which a counterexample is to be constructed. We obtain an elegant formulation of classical propositional logic with the subformula property and a singularly inelegant formulation of classical first-order logic with the subformula property, the latter, unfortunately, not a product of the strategy otherwise used throughout the article. Along the way, we arrive at an optimal strengthening of the subformula results for classical first-order logic obtained as consequences of normalization theorems by Dag Prawitz and Gunnar Stålmarck. (shrink)

The validity of argument by disjunctive syllogism has been denied by proponents of relevant and paraconsistent logic. DS is stigmatised for its role in inferences — most notably C.I. Lewis's derivation of that fallacy of irrelevance ex falso quodlibet — that involve both it and other rules of inference governing disjunction, or, to speak more precisely, other rules of inference taken to apply to the very same disjunction that obeys DS. In avoiding these inferences the road less travelled is to (...) deny the identity rather than to deny DS: what follows is, then, an exercise in disjoining disjunctions. (shrink)

This article begins by outlining some of the history—beginning with brief remarks of Quine's—of work on conditional assertions and conditional events. The upshot of the historical narrative is that diverse works from various starting points have circled around a nexus of ideas without convincingly tying them together. Section 3 shows how ideas contained in a neglected article of de Finetti's lead to a unified treatment of the topics based on the identification of conditional events as the objects of conditional bets. (...) The penultimate section explores some of the consequences of the resulting logic of conditional events while the last defends it. (shrink)

Cora Diamond has recently criticised as mere legend the interpretation of a quip of Ramsey's, contained in the epigraph below, which takes him to be objecting to or rejecting Wittgenstein's Tractarian distinction between saying and showing. Whilst I agree with Diamond's discussion of the legend, I argue that her interpretation of the quip has little evidential support, and runs foul of a criticism sometimes made against intuitionism. Rather than seeing Ramsey as making a claim about the nature of propositions, as (...) Diamond does, we should understand him as making a claim about the grammar of the logical connectives. Such a view coheres with the extant evidence of the nature of Wittgenstein's and Ramsey's 1929 philosophical encounters. It is also compatible with attributing to Ramsey a recognition of Wittgenstein's distinction and with denying that criticising it is the lesson of the quip. (shrink)

Logical realism is the view that there is logical structure in the world. I argue that, if logical realism is true, then we are deeply ignorant of that logical structure: either we can’t know which of our logical concepts accurately capture it, or none of our logical concepts accurately capture it at all. I don’t suggest abandoning logical realism, but instead discuss how realists should adjust their methodology in the face of this ignorance.

In endorsing a conventionalism about the rules of sport, Morgan fails (according to his critics) to ground the normativity of such rules, especially once the historical specificity of their invention and implementation is granted. But how can normativity be grounded in the contingencies of the sporting practices of particular times and places? In particular, do Morgan’s concerns with dependence on ‘conventions’ flow only from the choice of options apparently on offer: roughly the choice between a realism (to reflect ‘facts of (...) the matter’) and a conventionalism in the ‘norm-based’ version that I urge is misguided. Exploring some of the variety of occasions for the operation of normativity in sporting contexts, and acknowledging their occasion-sensitivity, shows this to be a false dichotomy. In this light, the paper elaborates a Morgan-style conclusion by drawing a parallel with language-use to conclude that rule-following in sport has all the grounding it could get—and that, as with normativity for language-use, this is all the grounding one needs. (shrink)

, Rudolf Carnap became a chief proponent of the doctrine that the statements of intuitionism carry nonstandard intuitionistic meanings. This doctrine is linked to Carnap's ‘Principle of Tolerance’ and claims he made on behalf of his notion of pure syntax. From premises independent of intuitionism, we argue that the doctrine, the Principle, and the attendant claims are mistaken, especially Carnap's repeated insistence that, in defining languages, logicians are free of commitment to mathematical statements intuitionists would reject. I am grateful to (...) Nathan Carter, Gary Ebbs, Janet Folina, Luise Prior McCarty, Stewart Shapiro, Neil Tennant, Christopher Tillman, Beth Tropman, Wen-fang Wang, and two anonymous referees for their comments and suggestions. CiteULike Connotea Del.icio.us What's this? (shrink)

Different notions of analysis have been both theorized and put to use in early analytic philosophy. Two of them stand out: connective analysis and analysis as paraphrase. The latter played a central role in the development of analytic philosophy from Frege to Quine and beyond. With the advent of formal semantics of natural language in the 1970s, paraphrase came to be characterizable as translation into a formal “target language”. While I claim that the method cannot achieve its original philosophical aims, (...) I insist that, in spite of them, it is far from being a theoretically empty operation and that it lives on in some contemporary philosophical enterprises. (shrink)

Logic is usually thought to concern itself only with features that sentences and arguments possess in virtue of their logical structures or forms. The logical form of a sentence or argument is determined by its syntactic or semantic structure and by the placement of certain expressions called “logical constants.”[1] Thus, for example, the sentences Every boy loves some girl. and Some boy loves every girl. are thought to differ in logical form, even though they share a common syntactic and semantic (...) structure, because they differ in the placement of the logical constants “every” and “some”. By contrast, the sentences Every girl loves some boy. and Every boy loves some girl. are thought to have the same logical form, because “girl” and “boy” are not logical constants. Thus, in order to settle questions about logical form, and ultimately about which arguments are logically valid and which sentences logically true, we must distinguish the “logical constants” of a language from its nonlogical expressions. (shrink)

Research into logical syntax provides us the knowledge of the structure of sentences, while logical semantics provides a window into uncovering the truth of sentences. Therefore, it is natural to make sentences and truth the central concern when one deals with the theory of meaning logically. Although their theories of meaning differ greatly, both Michael Dummett’s theory and Donald Davidson’s theory are concerned with sentences and truth and developed in terms of truth. Logical theories and methods first introduced by G. (...) Frege underwent great developments during the past century and have played an important role in expanding these two scholars’ theories of meaning. (shrink)

Here is a distinction that appears very simple, looks compelling and seems to be deeply rooted in our reflections on learning. The distinction is between activities of learning that involve training and those that involve reasoning. In the former, the pupil is a passive recipient of habits of mind and action. The mechanism by which they acquire these habits is mimesis, not reasoning. In contrast, learning by reasoning involves considerable mental activity by the pupil who has to work out what (...) to think and do. The very mechanism by which the pupil learns is her own capacity to reason, to things work out for herself. In this paper I argue that there is no basis for this distinction. I argue that, contrary to the dominant empiricist thinking about such things, learning by reasoning is the only credible form of learning. I start with a brief characterisation of the distinction and an account of why it seems so compelling. In §2 I review the empirical evidence from developmental psychology for a rationalist account of language learning as learning by reasoning. In §§3 and 4 I provide a philosophical argument against the place of training and in favour of a rationalist model of learning by reasoning. (shrink)

On the most prominent account, understanding what was said is always propositional knowledge of what was said. I develop a more minimal alternative, according to which understanding is sometimes a distinctive attitude towards what was said—to a first approximation, entertaining what was said. The propositional knowledge account has been supported on the basis of its capacity to explain testimonial knowledge transmission. I argue that it is not so supported.

Is linguistic understanding a form of knowledge? I clarify the question and then consider two natural forms a positive answer might take. I argue that, although some recent arguments fail to decide the issue, neither positive answer should be accepted. The aim is not yet to foreclose on the view that linguistic understanding is a form of knowledge, but to develop desiderata on a satisfactory successor to the two natural views rejected here.

According to Rosenthal’s Higher-Order Thought (HOT) theory of consciousness, first-order mental states become conscious only when they are targeted by HOTs that necessarily represent the states as belonging to self. On this view a state represented as belonging to someone distinct from self could not be a conscious state. Rosenthal develops this view in terms of what he calls the ‘thin immunity principle’ (TIP). According to TIP, when I experience a conscious state, I cannot be wrong about whether it is (...) I who I think is in that state. We first suggest that TIP is a direct consequence of the HOT theory. Next we argue that somatoparaphrenia—a pathology in which sensations are sometimes represented as belonging to other people—shows that TIP can be violated. This violation of TIP in turn shows that the HOT theory’s claim that conscious states are necessarily represented as belonging to self is in error. Rosenthal’s attempt to account for pathological cases is found to be inadequate when applied to somatoparaphrenia, and other possible defenses are also shown to be incapable of preserving TIP. We further conclude by suggesting that the HOT theory’s failing in this regard is not a failing that is peculiar to this theory of consciousness. (shrink)

What we can call asymmetric disagreement occurs when one agent is in disagreement with another, but not vice-versa. In this paper, I give an example of and develop a framework for understanding this phenomenon. One pivotal feature of my example is that one of the agents in the scenario has a belief about what might be the case—a might-belief. I show that a traditional account of might-beliefs and disagreement cannot explain the initially surprising phenomenon of asymmetric disagreement. In order to (...) provide an explanation, I develop a dynamic account of might-beliefs and a corresponding account of disagreement. I close by exploring a choice point for our account—showing that the simple dynamic account has some controversial (though, perhaps, true) consequences. I explore how revisionary notions of validity, inconsistency, and disagreement can allow us to avoid these consequences if we wish. (shrink)

The focus of this paper are Dummett's meaning-theoretical arguments against classical logic based on consideration about the meaning of negation. Using Dummettian principles, I shall outline three such arguments, of increasing strength, and show that they are unsuccessful by giving responses to each argument on behalf of the classical logician. What is crucial is that in responding to these arguments a classicist need not challenge any of the basic assumptions of Dummett's outlook on the theory of meaning. In particular, I (...) shall grant Dummett his general bias towards verificationism, encapsulated in the slogan 'meaning is use'. The second general assumption I see no need to question is Dummett's particular breed of molecularism. Some of Dummett's assumptions will have to be given up, if classical logic is to be vindicated in his meaning-theoretical framework. A major result of this paper will be that the meaning of negation cannot be defined by rules of inference in the Dummettian framework. (shrink)

This paper discusses proof-theoretic semantics, the project of specifying the meanings of the logical constants in terms of rules of inference governing them. I concentrate on Michael Dummett’s and Dag Prawitz’ philosophical motivations and give precise characterisations of the crucial notions of harmony and stability, placed in the context of proving normalisation results in systems of natural deduction. I point out a problem for defining the meaning of negation in this framework and prospects for an account of the meanings of (...) modal operators in terms of rules of inference. (shrink)

The problem of negative truth is the problem of how, if everything in the world is positive, we can speak truly about the world using negative propositions. A prominent solution is to explain negation in terms of a primitive notion of metaphysical incompatibility. I argue that if this account is correct, then minimal logic is the correct logic. The negation of a proposition A is characterised as the minimal incompatible of A composed of it and the logical constant ¬. A (...) rule based account of the meanings of logical constants that appeals to the notion of incompatibility in the introduction rule for negation ensures the existence and uniqueness of the negation of every proposition. But it endows the negation operator with no more formal properties than those it has in minimal logic. (shrink)