Séance du 5 avril

Jeudi 5 avril, 11h-13h
Salle D. Corbin

A Dynamic Logic of Interrogative Inquiry

Yacin Hamami

(Vrije Universiteit Brussel)

Abstract :

In this talk, I will propose a dynamic-epistemic analysis of the different epistemic operations constitutive of the process of interrogative inquiry, as described by Hintikka's Interrogative Model of Inquiry (IMI). I will develop a dynamic logic of questions for representing interrogative steps, based on Hintikka's treatment of questions in the IMI, along with a dynamic logic of inferences for representing deductive steps, based on the tableau method. I will then merge these two systems into a dynamic logic of interrogative inquiry which articulates a joint treatment of questions and inferences, providing thereby a unified framework representing the informational dynamics of interrogative inquiry.

I will provide sound and complete axiomatic systems for the three dynamic logics that I introduce, I will compare the framework with existing approaches and I will finally propose several directions for further works. This work is meant as a first step towards linking the IMI with the field of dynamic logics of information and rational agency.

Séance du 15 mars

Jeudi 15 mars, 11h-13h.

Salle Corbin

Husserl on Intentional Attitudes

Giuliano Bacigalupo

Abstract:

In my presentation, I start by addressing the semantics developed by Husserl in his lecture Alte und Neue Logik (1908/9), which may be labelled as "sheres semantics". In the second part, I rely on this semantics as an interpretation grid for Husserl's analysis of intentional attitudes in Ideen I (1913) and argue for an interpretation of the noema as reference to non-actual objects or, what is tantamount to the same, to a non-actual sphere. Thirdly, I address Husserl's discussion of a prosteriori identities in the third section of Ideen I and how this bears on the previous discussion, especially on the notion of object simpliciter. Finally, I turn on the vexed question wether Husserl is a Fregean.

Séance du 16 février

Jeudi 16 février, 11h-13h

Salle Corbin

Playing with or without a list of announcements?

Sébastien Magnier

Abstract:

In a previous presentation, I have argued that a public announcement does not correspond to any conditional connectives. But in fact there are algorithms of translation that turn any public announcement in a conditional way. These translations do not yield an immediate material implication of annoucement propositions. They give us complex or embedded conditionals whose complexity directly depends of the post-condition of the announcement operator. Now, our aim is to compare the dialogues with those propositions (the one with the public announcement operator on the one hand and its corresponding translation on the other hand). As we shall see, such a study underlines the meaning of the list of announcements. This list represents the story of the commitment of the players. It emphasizes the two distinct levels: play and strategy level which occur in the dialogical framework. The comparison between them also suggests some improvements of the rule (SR-A.1) that will probably entail a weakening of the formal rule.

Séance du 2 février 2012

Jeudi 2 février, 11h-13h

Against the so-called “fictional nature” of Law

Juliele Sievers

Abstract:

In my presentation I will try once more to attack the notion of fiction in Law, this time by using some elements of Amie Thomasson’s artefactual theory and Hans Vaihinger’s Philosophy of As-If. Since the first lecture of those works seems to give the idea that norms have the same characteristics of fictions, I will present some arguments against this interpretation. One of them refers to the multiplicity of interpretations of the term “fiction”, which often leads to confusion in its use. Starting by comprehending that the definition of fiction in Literature, in Science and in Law has totally different aspects will lead us to a strong consequence: that the presence of this term in a prescriptive ambit it’s in fact a misuse of it (and we will also understand why this improper practice is nevertheless so widely spread).

Attention : les horaires du GdT ont changé (voir le message ci-dessous).

Dates et Horaire des séances à venir

Changement de semestre et d'emplois du temps obligent, les séances du Groupe de Travail auront désormais lieu à des horaires différents.

Les séances auront lieu de 11 heures à 13 heures les jeudis suivants :

2 février, 16 février.

8 mars, 22 mars.

5 avril, 12 avril.

10 mai, 24 mai.

7 juin, 28 juin.

Séance du 12 décembre

Lundi 12 décembre, 14h-16h

Salle Corbin

The gap in the proof

Nicolas Clerbout

Abstract:

In my last talk I mentionned a result which holds in propositional and first-order dialogical games, namely that the Proponent has a winning strategy in D(F) if and only if he has one in D1(F), where F is a sentence of the relevant language and D1(F) is the subgame of D(F) where the Opponent chooses rank 1.
I also mentionned that there is currently a gap in the proof of the righ-to-left direction. Briefly, the point is that in order to prove this direction we need to prove that if the Opponent cannot win by chosing rank 1 then she cannot win at all.

The aim of this talk is to discuss and hopefully give the proof of that last claim.

Séance du 5 décembre

Lundi 5 décembre, 14 h - 16h,

Salle Corbin

Formalism towards strategical behaviours

Pierre Cardascia

Résumé :

In my last talk I criticized some hypotheses of our approach calling them "meta", and expressed the desire to wipe them out. I had some arguments, but no formal arguments, so my intervention looked like a moment of poetry in a terrible world. I worked a lot, and today I can implement some important notions I spoke about last time. At the end of this talk the strategical reflexion won't be a black box anymore, but will be defined properly as a function from the rules and a project to the strategical behaviour. Then, maybe I will be able to present the notion of orthogonality of behaviours, then show that all the hypotheses I criticize can be reduced into one result of biorthogonality.
After showing that, you will see that I'm a big cheater, because though I can define the "strategical reflexion", it is very nominative, and then, it will be the next problem I have to solve.