This book introduces the reader to relevant logic and provides the subject with a philosophical interpretation. The defining feature of relevant logic is that it forces the premises of an argument to be really used in deriving its conclusion. The logic is placed in the context of possible world semantics and situation semantics, which are then applied to provide an understanding of the various logical particles and natural language conditionals. The book ends by examining various applications of relevant logic and (...) presenting some interesting open problems. It will be of interest to a range of readers including advanced students of logic, philosophical and mathematical logicians, and computer scientists. (shrink)

According to the dominant position among philosophers of language today, we can legitimately ascribe determinate contents to natural language sentences, independently of what the speaker actually means. This view contrasts with that held by ordinary language philosophers fifty years ago: according to them, speech acts, not sentences, are the primary bearers of content. François Recanati argues for the relevance of this controversy to the current debate about semantics and pragmatics. Is 'what is said' determined by linguistic conventions, or is it (...) an aspect of 'speaker's meaning'? Do we need pragmatics to fix truth-conditions? What is 'literal meaning'? To what extent is semantic composition a creative process? How pervasive is context-sensitivity? Recanati provides an original and insightful defence of 'contextualism', and offers an informed survey of the spectrum of positions held by linguists and philosophers working at the semantics/pragmatics interface. (shrink)

According to the logical pluralism of Beall and Restall, there are several distinct relations of logical consequence. Some critics argue that logical pluralism suffers from what I call the collapse problem: that despite its intention to articulate a radically pluralistic doctrine about logic, the view unintentionally collapses into logical monism. In this paper, I propose a contextualist resolution of the collapse problem. This clarifies the mechanism responsible for a plurality of logics and handles the motivating data better than the original (...) view. It is a major improvement that should be embraced by all logical pluralists. (shrink)

_Thoughts and Utterances_ is the first sustained investigation of two distinctions which are fundamental to all theories of utterance understanding: the semantics/pragmatics distinction and the distinction between what is explicitly communicated and what is implicitly communicated.

We describe and discuss several semantical views of linear logic. Our primary topic is game semantics, including modifications suggested by Abramsky, Jagadeesan, Hyland, Ong, and Japaridze. We also briefly discuss Girard's coherence spaces and de Paiva's Dialectica-like semantics.

We present in this article a new logical system inspired from linear logic. This system is designed in order to express causality and dynamism. The cut elimination theorem holds for this logic. Examples of applications are given.

We present in this article a new logical system inspired from linear logic. This system is designed in order to express causality and dynamism. The cut elimination theorem holds for this logic. Examples of applications are given.

Consequence is at the heart of logic; an account of consequence, of what follows from what, offers a vital tool in the evaluation of arguments. Since philosophy itself proceeds by way of argument and inference, a clear view of what logical consequence amounts to is of central importance to the whole discipline. In this book JC Beall and Greg Restall present and defend what thay call logical pluralism, the view that there is more than one genuine deductive consequence relation, a (...) position which has profound implications for many linguists as well as for philosophers. We should not search for one true logic, since there are many. (shrink)

Confusion in terms inspires confusion in concepts. When a relevant distinction is not clearly marked or not marked at all, it is apt to be blurred or even missed altogether in our thinking. This is true in any area of inquiry, pragmatics in particular. No one disputes that there are various ways in which what is communicated in an utterance can go beyond sentence meaning. The problem is to catalog the ways. It is generally recognized that linguistic meaning underdetermines speaker (...) meaning because of the need for disambiguation and reference assignment and because people can speak figuratively or indirectly. But philosophers and linguists are coming to recognize that these are not the only ways. The situation may be described in Gricean terms: the distinction between what is said and what is implicated is not exhaustive. Charting the middle ground between the two will require attending to specific examples, noting their distinctive features, and articulating the relevant concepts. That is what I aim to do here. The basic idea will be to distinguish not only the implied from the explicit but the implicit from the implied. (shrink)

Logical pluralism is the view that there is more than one correct logic. This very general characterization gives rise to a whole family of positions. I argue that not all of them are stable. The main argument in the paper is inspired by considerations known as the “collapse problem”, and it aims at the most popular form of logical pluralism advocated by JC Beall and Greg Restall. I argue that there is a more general argument available that challenges all variants (...) of logical pluralism that meet the following three conditions: that there are at least two correct logical systems characterized in terms of different consequence relations, that there is some sort of rivalry among the correct logics, and that logical consequence is normative. The hypothesis I argue for amounts to conditional claim: If a position satisfies all these conditions, then that position is unstable in the sense that it collapses into competing positions. (shrink)

Gricean pragmatics. Saying vs. implicating ; Discourse and cooperation ; Conversational implicatures ; Generalised vs. particularised ; Cancellability ; Gricean reasoning and the pragmatics of what is said -- The standard recipe for Q-implicatures. The standard recipe ; Inference to the best explanation ; Weak implicatures and competence ; Relevance ; Conclusion -- Scalar implicatures. Horn scales and the generative view ; Implicatures and downward entailing environments ; Disjunction : exclusivity and ignorance ; Conclusion -- Psychological plausibility. Charges of psychological (...) inadequacy ; Logical complexity ; Abduction ; Incremental processing ; The intentional stance ; Alternatives ; Conclusion -- Nonce inference or defaults?. True defaults ; Strong defaultism ; Weak defaultism ; Contextualism ; Conclusion -- Intentions, alternatives, and free choice. Free choice ; Problems with the standard recipe ; Intentions first ; Free choice explained ; Comparing alternatives ; Two flavours of Q-implicature ; Conclusion -- Embedded implicatures : the problems. The problems ; Varieties of conventionalism ; Against conventionalism ; Conclusion -- Embedded implicatures : a Gricean approach. Disjunction ; Belief reports ; Factives and other presupposition inducers ; Indefinites ; Contrastive construals and lexical pragmatics ; Conclusion. (shrink)

Logical pluralism is the claim that different accounts of validity can be equally correct. Beall and Restall have recently defended this position. Validity is a matter of truth-preservation over cases, they say: the conclusion should be true in every case in which the premises are true. Each logic specifies a class of cases, but differs over which cases should be considered. I show that this account of logic is incoherent. Validity indeed is truth-preservation, provided this is properly understood. Once understood, (...) there is one true logic, relevance logic. The source of Beall and Restall’s error is a recent habit of using a classical metalanguage to analyse non-classical logics generally, including relevance logic. (shrink)

In a famous and controversial paper, B. H. Slater has argued against the possibility of paraconsistent logics. Our reply is centred on the distinction between two aspects of the meaning of a logical constant *c* in a given logic: its operational meaning, given by the operational rules for *c* in a cut-free sequent calculus for the logic at issue, and its global meaning, specified by the sequents containing *c* which can be proved in the same calculus. Subsequently, we use the (...) same strategy to counter Quine's meaning variance argument against deviant logics. In a nutshell, we claim that genuine rivalry between (similar) logics *L* and *L'* is possible whenever each constant in *L* has the same operational meaning as its counterpart in *L'* although differences in global meaning arise in at least one case. (shrink)

I discuss paradoxes of implication in the setting of a proof-conditional theory of meaning for logical constants. I argue that a proper logic of implication should be not only relevant, but also constructive and nonmonotonic. This leads me to select as a plausible candidate LL, a fragment of linear logic that differs from R in that it rejects both contraction and distribution.

Dialetheism is the view that some contradictions are true. This is a view which runs against orthodoxy in logic and metaphysics since Aristotle, and has implications for many of the core notions of philosophy. Doubt Truth to Be a Liar explores these implications for truth, rationality, negation, and the nature of logic, and develops further the defense of dialetheism first mounted in Priest's In Contradiction, a second edition of which is also available.

I defend the view that the truth conditions of the ordinary indicative conditional are those of the material conditional. This is done via a discussion of assertability and by appeal to conventional implicature rather than conversational implicature.

Logic, Logical connectives, Verbal disputes, Proof theory, Non-classical logic.

The aim of the present book is to give a comprehensive account of the ‘state of the art’ of substructural logics, focusing both on their proof theory and on their semantics (both algebraic and relational. It is for graduate students in either philosophy, mathematics, theoretical computer science or theoretical linguistics as well as specialists and researchers.