Manuel Rebuschi

Implicit versus Explicit Knowledge in Dialogical Logic

A dialogical version of (modal) epistemic logic is outlined, with an intuitionistic variant. Another version of dialogical epistemic logic is then provided by means of the S4 mapping of intuitionistic logic. Both systems cast new light on the relationship between intuitionism, modal logic and dialogical games.

Epistemology, Context, and Formalism

The main purpose of the present volume is to advance our understanding of the notions of knowledge and context, the connections between them and the ways in which they can be modeled, in particular formalized a question of prime importance and utmost relevance to such diverse disciplines as philosophy, linguistics, computer science and artificial intelligence and cognitive science. Bringing together essays written by world-leading experts and emerging researchers in epistemology, logic, philosophy of language, linguistics and theoretical computer science, the book examines the formal modeling of knowledge and the knowledge-context link at one or more of three intersections - context and epistemology, epistemology and formalism, formalism and context and presents a novel range of approaches to the current discussions that the connections between knowledge, language, action, reasoning and context continually enlivens. It develops powerful ideas that will push the relevant fields forward and give a sense of the new directions in which mainstream and formal research on knowledge and context is heading.

IF and Epistemic Action Logic

This paper is a tentative discussion about the alleged opposition between van Benthem’s account of logic games (Epistemic Action Logic, EAL) and Hintikka’s IF first-order logic. Both logics provide a specific viewpoint on the relationship between logic and games, especially games of imperfect information. Arguing for a cooperative vs. competitive strategy, we will combine EAL and IF logic and obtain natural formulations of the existence of a uniform winning strategy for the verifier in an evaluation game. One of the upshots of the combination IF-EAL is a well known result usually put forward about IF-languages, namely that a sentence is equivalent to its truth-conditions, formulated in a new frame.

Schizophrenic Conversations and Context Shifting

The present article deals with pathological conversations involving individuals diagnosed as schizophrenic. An interdisciplinary study accounted for discontinuities occurring in such conversations and prior analyses revealed the importance of underspecification. Conversational interpretation and context thus both play crucial roles in schizophrenic discourse. Building on this premise and inspired by previous analyses of fictional discourse, this work presents an experimental analysis of schizophrenic discourse using pragmatic context.

Knowing Necessary Truths

How account for the intuitive difference between simply knowing a necessary proposition, and knowing that it is a necessary truth? In the paper it will be shown that two-dimensional semantics does not do the job in an adequate way. A solution is provided which is based on Hintikka’s worldlines. Assuming a slight extension of the syntax, modal epistemic logic can thus deal with classical puzzles like knowledge of identities.

Reasoning About Knowledge in Context

In this paper we lay out the conceptual and technical foundations of a general framework that will allow us to talk and reason about the connections between knowledge and context. Based on the notion of “contextual models” !contextual , a first section on “static formalism ” will make it possible to capture using the same language and the same semantics , a number of epistemological positions amongst those most prominent in the recent philosophical literature on knowledge , and to investigate the logical properties and connections they end up attaching to their respective notions of knowledge and context . This “static” component is augmented with a “dynamic” formalization of context based on a simplified version of Discourse Representation Theory, which will allow us to account for the contribution of epistemic statements to the evolution of the “score” of a conversation about knowledge .

Le Moi comme un objet intentionnel. Une sémantique de «je» sans engagement ontologique

Les attitudes de se sont generalement considerees comme constituant une classe particuliere d’attitudes de re. Cet article propose une analyse differente, qui s’appuie sur la notion d’attitude de objecto et qui evite un engagement ontologique envers le sujet. La proposition elabore l’idee de Hintikka d’une logique epistemique dite de seconde generation, qui introduit un marqueur syntaxique permettant d’exprimer des relations d’independance entre certaines constantes logiques. De cette semantique resulte une conception du Moi, denotation de «je», comme un objet simplement intentionnel.

Extended Game-Theoretical Semantics

A new version of Game-Theoretical Semantics (GTS) is put forward where game rules are extended to the non-logical constants of sentences. The resulting theory, together with a refinement of our criteria of identity for functions, provide the technical basis for a game-based conception of linguistic meaning and interpretation.