Denis Bonnay

Quine est célèbre pour sa critique de la notion d’analyticité, mais il en a également proposé des substituts définissables en termes behavioristes. Cet article examine la question de savoir si de tels substituts peuvent ou non jouer un rôle épistémologique, en les comparant avec des tentatives récentes de réhabilitation de l’a priori. Il apparaît que la caractérisation de ce qu’est une définition acceptable en termes behavioristes est cruciale, et qu’un élargissement de la classe des comportements linguistiques pertinents peut ouvrir la voie à une réhabilitation substantielle de l’analyticité.Quine is famous for his critics against the notion of analyticity used in epistemology and philosophy of science by philosophers of the Vienna circle. However, Quine has also proposed alternative definitions of the notion, which would be acceptable from a behaviorist perspective. In this paper, I address the question whether such alternative definitions can play any epistemologically significant role, by comparing them with recent attempts at a new defense of a priori knowledge. The upshot is that the answer cruccially depends on what is an acceptable definition in a behaviorist perspective. It might well be that an epistemologically significant notion of analyticity can be based upon a broad enough characterization of linguistic behavior.

Providing a principled characterization of the distinction between logical and non-logical expressions is a longstanding issue in the philosophy of logic. In the Logical Syntax of Language, Carnap proposes a syntactic solution to this problem, which aims at grounding the claim that logic and mathematics are analytic. Roughly speaking, his idea is that logic and mathematics correspond to the largest part of science for which it is possible to completely specify by "syntactic" means which sentences are valid and which are not. Despite a renewed interest in the philosophical benefits of analyticity, both inside and outside of Carnap scholarship, Carnap's definition of logical expressions seems to have drawn too little attention. I shall argue that it is worth a second look. More precisely, my aim will be to defend this idea against some technical problems faced by Carnap's way of implementing it and against Quinean attacks on syntax-based conventionalism. Section 1 presents Carnap's definition in the context of Logical Syntax of Language, that is, how exactly the definition works, and why Carnap needs it. In section 2, I review three challenges that have been raised in the literature, and I propose to revise the definition accordingly. I argue that its modified version is immune to the previous challenges, and, to some extent, immune to new challenges as well. In the last section, I suggest that the definition has a philosophical interest of its own, because standard Quinean objections are not as conclusive as one might think when attention is paid to the fact that Carnap requires complete syntactic specification of validities.

Williamson's margin for error semantics for knowledge implies that knowledge cannot systematically imply knowledge of one's knowledge. Each new iteration of knowledge requires what is known to remain true in worlds that are further and further away from the initial context of evaluation, including worlds where the proposition can no longer be true. In previous work, it was argued that this tension can be solved by means of a richer, two-dimensional semantics for knowledge, called Centered Semantics. This chapter shows that Centered Semantics can be translated into a standard semantics with actuality operators. It discusses the contextualist implications of the semantics, in particular, regarding the knowledge a subject might have of her margins of error.

The standard relation of logical consequence allows for non-standard interpretations of logical constants, as was shown early on by Carnap. But then how can we learn the interpretations of logical constants, if not from the rules which govern their use? Answers in the literature have mostly consisted in devising clever rule formats going beyond the familiar what follows from what. A more conservative answer is possible. We may be able to learn the correct interpretations from the standard rules, because the space of possible interpretations is a priori restricted by universal semantic principles. We show that this is indeed the case. The principles are familiar from modern formal semantics: compositionality, supplemented, for quantifiers, with topic-neutrality.

Since the ground-breaking contributions of M. Dummett (Dummett 1978), it is widely recognized that anti-realist principles have a critical impact on the choice of logic. Dummett argued that classical logic does not satisfy the requirements of such principles but that intuitionistic logic does. Some philosophers have adopted a more radical stance and argued for a more important departure from classical logic on the basis of similar intuitions. In particular, J. Dubucs and M. Marion (?) and (Dubucs 2002) have recently argued that a proper understanding of anti-realism should lead us to the so-called substructural logics (see (Restall 2000)) and especially linear logic. The aim of this paper is to scrutinize this proposal. We will raise two kinds of issues for the radical anti-realist. First, we will stress the fact that it is hard to live without structural rules. Second, we will argue that, from an anti- realist perspective, there is currently no satisfactory justi cation to the shift to substructural logics.

The problem of logical constants consists in finding a principled way to draw the line between those expressions of a language that are logical and those that are not. The criterion of invariance under permutation, attributed to Tarski, is probably the most common answer to this problem, at least within the semantic tradition. However, as the received view on the matter, it has recently come under heavy attack. Does this mean that the criterion should be amended, or maybe even that it should be abandoned? I shall review the different types of objections that have been made against invariance as a logicality criterion and distinguish between three kinds of objections, skeptical worries against the very relevance of such a demarcation, intensional warnings against the level at which the criterion operates, and extensional quarrels against the results that are obtained. I shall argue that the first two kinds of objections are at least partly misguided and that the third kind of objection calls for amendment rather than abandonment.

The standard semantic definition of consequence with respect to a selected set X of symbols, in terms of truth preservation under replacement (Bolzano) or reinterpretation (Tarski) of symbols outside X, yields a function mapping X to a consequence relation ⇒x. We investigate a function going in the other direction, thus extracting the constants of a given consequence relation, and we show that this function (a) retrieves the usual logical constants from the usual logical consequence relations, and (b) is an inverse to—more precisely, forms a Galois connection with—the Bolzano-Tarski function.