The logic of logical revision formalizing dummett's argument

Neil Tennant and Joseph Salerno have recently attempted to rigorously formalize Michael Dummett's argument for logical revision. Surprisingly, both conclude that Dummett commits elementary logical errors, and hence fails to offer an argument that is even prima facie valid. After explicating the arguments Salerno and Tennant attribute to Dummett, I show how broader attention to Dummett's writings on the theory of meaning allows one to discern, and formalize, a valid argument for logical revision. Then, after correctly providing a rigorous statement of the argument, I am able to delineate four possible anti-Dummettian responses. Following recent work by Stewart Shapiro and Crispin Wright, I conclude that progress in the anti-realist's dialectic requires greater clarity about the key modal notions used in Dummett's proof.     

Possibilities,models, and intuitionistic logic: Ian Rumfitt’s The boundary stones of thought

AIan Rumfitt's new book presents a distinctive and intriguing philosophy of logic, one that ultimately settles on classical logic as the uniquely correct one–or at least rebuts some prominent arguments against classical logic. The purpose of this note is to evaluate Rumfitt's perspective by focusing on some themes that have occupied me for some time: (i) the role and importance of model theory and, in particular, the place of counter-arguments in establishing invalidity, (ii) higher-order logic, and (iii) the logical pluralism/relativism articulated in my own recent *Varieties of logic*.     

Intuitionism,Meaning Theory and Cognition

Michael Dummett has interpreted and expounded upon intuitionism under the influence of Wittgensteinian views on language, meaning and cognition. I argue against the application of some of these views to intuitionism and point to shortcomings in Dummett's approach. The alternative I propose makes use of recent, post-Wittgensteinian views in the philosophy of mind, meaning and language. These views are associated with the claim that human cognition exhibits intentionality and with related ideas in philosophical psychology. Intuitionism holds that mathematical constructions are mental processes or objects. Constructions are, in the first instance, forms of consciousness or possible experience of a particular type. As such, they must be understood in terms of the concept of intentionality. This view has a historical basis in the literature on intuitionism. In a famous 1931 lecture Heyting in fact identifies constructions with fulfilled or fulfillable mathematical intentions. I consider some of the consequences of this identification and contrast them with Dummett's views on intuitionism.     

What Harmony Could and Could Not Be

The notion of harmony has played a pivotal role in a number of debates in the philosophy of logic. Yet there is little agreement as to how the requirement of harmony should be spelled out in detail or even what purpose it is to serve. Most, if not all, conceptions of harmony can already be found in Michael Dummett's seminal discussion of the matter in The Logical Basis of Metaphysics. Hence, if we wish to gain a better understanding of the notion of harmony, we do well to start here. Unfortunately, however, Dummett's discussion is not always easy to follow. The following is an attempt to disentangle the main strands of Dummett's treatment of harmony. The different variants of harmony as well as their interrelations are clarified and their individual shortcomings qua interpretations of harmony are demonstrated. Though no attempt is made to give a detailed alternative account of harmony here, it is hoped that our discussion will lay the ground for an adequate rigorous treatment of this central notion.     

Royaumont Revisited

Michael Dummett has claimed that the only way to establish communication between the analytic and Continental schools of philosophy is to go back to their point of divergence in Frege and the early Husserl. In this paper, I try to show that Dummett's claim is false. I examine in detail the discussions at the infamous 1958 Royaumont Colloquium on analytic philosophy. Many – including Dummett – believe that these discussions underscore the futility of attempting to bridge the gap between Continental and analytical philosophies in anything like their current shapes. I argue, however, that a close study of the Royaumont proceedings rather reveals how close some of the analytical speakers were to some of their Continental listeners.     

Knowledge of language in action

Knowledge of a language is a kind of knowledge, the possession of which enables a speaker to understand and perform a variety of linguistic actions in that language. In this paper, I pursue an agency-oriented approach to knowledge of language. I begin by examining two major agency-oriented models of knowledge of language: Michael Dummett's Implicit Knowledge Model and Jennifer Hornsby's Practical Knowledge Model. I argue that each of these models is inadequate for different reasons. I present an Acquaintance Knowledge Model, in which a speaker's knowledge of a language is a combination of the speaker's first-order linguistic ability and second-order acquaintance with his ability and actions.     

Pragmatism and revisionism: James's conception of truth

Abstract

The paper argues that James's conception of truth is non‐revisionist, that is, it sanctions common use of the notion of truth, but criticizes foundation‐alist philosophical accounts of that notion. This interpretation conflicts with traditional interpretations of James such as Russell's and Moore's, and contemporary interpretations such as Dummett's, all of which are revisionist. To the extent that objections raised against James's pragmatism depend on such revisionist reading, this paper constitutes a defence of James. The paper argues, further, that non‐revisionism distinguishes James from logical positivism and contemporary verificationism, and that James seeks to defend rather than renounce metaphysics. On this issue the paper disagrees with Rorty, who ascribes to James an extreme anti‐metaphysical stance.     

What Is It to Make Clear the Working of Our Language?1

In The Logical Basis of Metaphysics, Dummett articulates and develops his “fundamental assumption” that the introduction rules for a logical constant determine its meaning. According to Dummett, logical laws in harmony with the introduction rules are justified, while logical laws not in harmony with the introduction rules are unjustified. This powerful picture enables Dummett to criticise certain aspects of our linguistic practice, such as the Law of Excluded Middle and the metaphysics of realism he believes it embodies, as not remaining responsible to the meanings of the logical constants. Against Dummett's fundamental assumption, I bring to bear what in the Tractatus Wittgenstein describes as his “fundamental thought” that the logical constants do not represent. Properly understood, Wittgenstein's point is that since the logical constants may be eliminated from the propositional signs of a fully precise logical notation, the constants do not express meanings to which our use of expressions containing the constants is responsible. I then apply Wittgenstein's fundamental thought to Dummett's proof‐theoretic notation to show that far from determining the meanings of the logical constants, the introduction rules merely allow the constants to be edited from certain inferences, leaving Dummett with no semantic kernel with which to criticise other sentences or inferences featuring the constants. Thus, his picture of what it is to make clear the working of our language collapses.     

Causes,Counterfactuals, and Non-Locality

In order to motivate the thesis that there is no single concept of causation that can do justice to all of our core intuitions concerning that concept, Ned Hall has argued that there is a conflict between a counterfactual criterion of causation and the condition of causal locality. In this paper I critically examine Hall's argument within the context of a more general discussion of the role of locality constraints in a causal conception of the world. I present two strategies that defenders of counterfactual accounts of causation can pursue to respond to Hall's challenge—including the adoption of a counterfactual condition that is sufficient for causal action-at-a-distance in place of Hall's ‘process’ condition—and conclude that Hall's argument against counterfactual accounts of causation is unsuccessful.     

Recognition,Freedom, and the Self in Fichte's Foundations of Natural Right

In this paper I present an interpretation of J. G. Fichte's transcendental argument for the necessity of mutual recognition (Anerkennung) in Foundations of Natural Right. Fichte's argument purports to show that, as a condition of the possibility of self‐consciousness, we must take ourselves to stand in relations of mutual recognition with other agents like ourselves. After reconstructing the steps of Fichte's argument, I present what I call the ‘modal dilemma’, which highlights a serious ambiguity in Fichte's deduction. According to the modal dilemma, the conclusion to Fichte's transcendental argument—that as a condition of the possibility of our self‐consciousness, we must recognize and be recognized by others—expresses either metaphysical or normative necessity. However, no normative conclusion follows from Fichte's premises, and the metaphysical claim that does follow from his argument appears to be implausibly strong. Thus the argument looks like a failure on either interpretation of the conclusion's modality. In the penultimate section of the paper, I propose a new interpretation of the argument that avoids the modal dilemma and provides a normative grounding of Fichte's concept of right.     

Reason,emotion, and love

Wittgenstein's private language argument is interpreted as an example of a kind of transcendental argument which, if valid, explains why a certain concept must possess certain features. Cognition and affect are shown to require each other by an application of Bennett's account of what beings capable of true cognition must be capable of, and the necessity of certain emotions to the existence of any rules in a community is argued in similar fashion. Hume's account of love and admiration being rejected, an account of love, intended to explain some of love's familiar features, is defended, and various proposed additions to the analysis are rejected. The idea of love is linked to those of value, agency, and the transcendental self by argument showing that each of these ideas requires all of the others. Finally, the idea of love is linked by a direct argument to that of the transcendental self.     

Deleuze's Use of Kant's Argument from Incongruent Counterparts

The aim of this paper is to explore Deleuze's use of Kant's argument from incongruent counterparts, which Kant uses to show the existence of what he calls an “internal difference” within things. I want to explore how Deleuze draws out an important distinction between the concept and the Idea, and provides an incisive account of his relationship to both the Kantian and Leibnizian projects. First, I look at Kant's use of the argument to provide a refutation of the Leibnizian account of space, before showing how this criticism in fact rests on the question of the conceptual determination of object. Second, I show how Deleuze develops a taxonomy of difference on the basis of his reading of Kant's argument. Finally, I look at what Deleuze sees as the limitations in Kant's understanding of this concept and Deleuze's attempt to overcome these limitations through the introduction of the notion of the Idea, which will provide a genetic and nonconceptual account of the object. In doing so, I show why Deleuze takes the formulation of an adequate account of difference to be one of the central aims of his own metaphysics.     

Induction,indifference and guessing

Pragmatism in semantics is hampered by its proponents' tendency to tie understanding too closely to our mastery of epistemic practice. Both Brandom's inferentialist semantics and the anti-realist semantics championed by Dummett and Tennant amply illustrate this tendency. As a consequence, neither theory can successfully handle cases of the innocuously unknowable in which two sentences, though mutually consistent, nonetheless cannot be known to be true together. On Brandom's account, such sentences are treated as being mutually inconsistent after all. According to both Dummett's and Tennant's version of anti-realist semantics, we cannot know that there are any true sentences of this kind. Neither result is the least acceptable, whence either theory fails. The lesson to be learnt from this failure is that understanding should not be identified with the ability to reach warranted verdicts, but with the ability to think, where thinking is constitutively involved in, but nonetheless distinct from judging.     

Rational Action Entails Rational Desire: A Critical Review of Searle's Rationality in Action1

Abstract

In this paper I contest Searle's thesis that desire-independent reasons for action – ‘reasons that are binding on a rational agent, regardless of desires and dispositions in his motivational set’ – are inherent in the concept of rationality. Following Searle's procedure, I first address his argument that altruistic reasons for action inhere in the concept of rationality, and then examine his argument for his more general thesis. I conclude that a viable theory of rational action would be centered, not on the concept of desire-independent reasons, but rather on the concept of rational desire.     

Outflanking the vicious circle

Sir Michael Dummett unfairly criticises Frank Ramsey for advocating full-fledged realism as a way to escape the problem of vicious circularity. Instead Ramsey uses a more moderate approach that only requires a thin commitment to theoretical terms. In ‘Theories’, Ramsey details a method to substitute observational terms for the theoretical terms appearing in a theory, but its early advocates, Rudolf Carnap and Carl Hempel, recognised that the resulting ‘ramsey-sentence’ does not intend to fully remove the theoretical content of the original theory. Through a model-theoretic approach, Jaakko Hintikka clarifies how the ramsey-sentence is embedded in the original theory, and, thereby, retains a commitment to the theoretical content that governs the substituted observable terms. By understanding how ramsey-sentences relate to the original theory, we will see that Ramsey need not assert a full-fledged realism to address vicious circularity. Instead of committing to the existence of all theoretical concepts involved in the original theory, ramsey-sentences assert the existence of an unspecified object that satisfies the substituted observable terms, and this commitment is sufficient to escape vicious circularity. Through this process of definition, Ramsey sidesteps Dummett's charge of full-fledged realism, and suggests a more moderate position that is consistent with Dummett's emphasis on domain specification.     

On Tugendhat's Analysis of Heidegger's Concept of Truth

This paper responds to Tugendhat's well‐known and influential critique of Heidegger's concept of truth with the resources of Heidegger's texts, in particular §44 of Being and Time. To start with, Tugendhat's primary critical argument is reconstructed. It is held to consist firstly in the charge of ambiguity against Heidegger's formulations of his concept of truth and secondly in the claim that Heidegger's concept of truth is incompatible with an adequate concept of falsehood. It is shown that the supposedly ambiguous meanings are, on the one hand, in fact clearly distinguished by Heidegger and, on the other, that they merely amount to different extensions of the same meaning of truth. It is then shown how this concept of truth is indeed compatible with an adequate, albeit post‐metaphysical, concept of falsehood. Finally, the grounds of falsehood in the untruth of the existential of Verfallen are pursued and further objections are dismissed.     

Sartre and Bergson: A Disagreement about Nothingness

Abstract

Henri Bergson's philosophy, which Sartre studied as a student, had a profound but largely neglected influence on his thinking. In this paper I focus on the new light that recognition of this influence throws on Sartre's central argument about the relationship between negation and nothingness in his Being and Nothingness. Sartre's argument is in part a response to Bergson's dismissive, eliminativist account of nothingness in Creative Evolution (1907): the objections to the concept of nothingness with which Sartre engages are precisely those raised by Bergson. Even if Sartre's account of nothingness in its entirety is found to be flawed, I argue that the points he makes specifically against Bergson are powerful.

My discussion concludes with a brief examination of the wider philosophical background to Sartre's and Bergson's discussion of nothingness: here I point to some important aspects of Sartre's early philosophy, including some features of his conception of nothingness, that may testify to Bergson's positive influence on his thought.