Konrad Zdanowski

Lundi 17 novembre de 14h00 à 16h00 dans la grande salle de l'IHPST, Philform accueille Konrad Zdanowski (Polish Academy of Sciences / Université Paris 7) :
"On the second order intuitionistic propositional logic without a universal quantifier".

Télécharger l'article ici.

Michael von Boguslawski

Prochaine séance du séminaire Philform :
lundi 03 novembre de 14h00 à 16h00 dans la grande salle de l'IHPST
Michael von Boguslawski (université d'Helsinki): "Ketonen's logical discovery".

Abstract :
In this talk I will describe Oiva Ketonen's work on logic, in particular his discovery of a sequent calculus with invertible rules. Additionally I will give a brief overview of how logic arrived in Finland. Ketonen being the only student of Gerhard Gentzen - the father of sequent calculus - some recent research on the latter will also be presented.

Allen Mann

Prochaine séance du séminaire Philform :
lundi 27 octobre, grande salle de l'IHPST, 14h-16h.
Allen Mann : IF logic and Kleene algebras

Abstract:
It is well known that the Principle of Bivalance fails in IF logic--there are sentences that are neither true nor false. We will use the techniques of algebraic logic to show that the Principle of Trivalence holds--every sentence has one of exactly three possible truth-values. We will further show that IF logic can be viewed an a first-order extension of Kleene's strong three-valued logic.

Michael Freund

Lundi 13 octobre de 14h à 16h dans la grande salle de l'IHPST, le séminaire Philform reçoit Michael Freund (Paris IV):
'Une théorie de la catégorisation pour les concepts constructibles'.


Résumé: Les concepts constructibles sont ceux que l'on peut définir à l'aide de concepts plus simples dans un processus similaire à celui de l'apprentissage. Pour cette classe de concepts, les notions de base de la théorie de la categorisation et de la théorie du prototype peuvent être simplement modélisées par des relations qualitatives. On obtient ainsi un formalisme qui permet de mieux cerner les problèmes classiques liés à l'appartenance, la typicité relative et la ressemblance. En particulier, le modèle proposé est cohérent avec l'opération de compositionalité, et rend fidèlement compte de phénomènes expérimentaux peu ou mal expliqués par les théories antérieures. La réinterprétation, enfin, de la notions de trait essentiel et de trait typique en termes de relation d'inférence conduit à traitement intéressant dans le cadre de la logique non monotone des notions d'induction catégorielle.

Thibault Gajdos

Lundi 9 juin (14h-16h), le séminaire Philform (IHPST) reçoit Thibault Gajdos(CNRS-Paris 1):

"The Ignorant Observer"

Most prominent models of economic justice (and especially those proposed by Harsanyi and Rawls) are based on the assumption that impartiality is required for making moral decisions. However, although Harsanyi and Rawls agree on that and furthermore agree on the notion that impartiality can be obtained under appropriate conditions of ignorance, they strongly disagree on the consequences of these assumptions. According to Harsanyi, they provide a justification for the utilitarian doctrine, whereas Rawls considers that they imply egalitarianism. We propose here an extension of Harsanyi's Impartial Observer Theorem, that is based on the representation of ignorance as the set of all possible probability distributions over individuals. We obtain a characterization of the observer's preferences that, under our most restrictive conditions, is a convex combination of Harsanyi's and Rawls' criteria. Furthermore, this representation is ethically meaningful, in the sense that individuals' utilities are cardinally measurable and fully comparable. This allows us to conclude that the impartiality requirement cannot be used to decide between Rawls' and Harsanyi's positions. Finally, we defend the view that a (strict) combination of Harsanyi's and Rawls' criteria provides a reasonable rule for social decisions.

Lucie Menager

lundi prochain 26 mai de 14h à 16h dans la grande salle de l'IHPST, Philform reçoit Lucie Ménager (Paris II): "La connaissance interactive en économie et en théorie des jeux"

Albert J.J. Angelberger

Albert J.J. Angelberger (Salzburg) est l'invité du séminaire Philform ce lundi 19 mai 2008 : "Dynamic Deontic Logic".

V. Hendricks

Philform reçoit Vincent Hendricks (Roskilde University, Denmark) le lundi 22 octobre de 14h à 16h dans la grande salle de l'IHPST.

Limiting Skepticism

Abstract/ Modal operator epistemology is a formal epistemological paradigm obtained by mixng modal, tense and epistemic logic with rudimentary elements from formal learning theory. The paradigm was developed in The Convergence of Scientific Knowledge (Springer: 2001) and used there and elsewhere to study the validity of limiting convergent knowledge(Mainstream and Formal Epistemology (Cambridge UniversityPress, 2006)).Studying knowledge is also studying skepticism. Skepticism is usually considered to being a short-run strategy. Using modal operator epistemology this paper scrutinizes what happens to skepticism in the long run: Can skepticism outstrip knowledge in the limit?

Joe Salerno

Joe Salerno has given a talk at Philform seminar yesterday, on "Counterpossible Conditionals"

ABSTRACT: Subjunctive conditionals with impossible antecedents (or counterpossibles) are standardly treated as vacuously true---the classical lore being that if an impossibility were to obtain, then anything would be the case. We'll discuss and develop a non-vacuous reading for (some) counterpossibles. The account provides resources for capturing some illusive philosophical notions---including the intuitive difference between essence and necessity, and an intuitive account of epistemic possibility.

Eric Martin

Le séminaire Philform reprend (lieu et horaire habituels). Lundi 24 septembre de 14h à 16h Eric Martin (Department of Artificial Intelligence School of Computer Science and Engineering University of New South Wales)parlera présentera un exposé intitulé : "Logique déductive et logique inductive, une généralisation".

Alexandre Costa-Leite

Lundi 4 juin, 14h-16h, Philform reçoit Alexandre Costa-Leite : Combining knowledge and contingency.

Delia Graff

jeu. 24 mai 16:00 -18:00, Philform reçoit Delia Graff : " Adjectives and Contingent Identities" [abstract]
(IHPST, 13 rue du Four, 75006 Paris)

Benedikt Loewe

Mercredi 9 mai de 14h à 16h, Philform reçoit Benedikt Loewe : "Empirical Philosophy of Mathematics".

Abstract: Traditional philosophy of mathematics (as traditional philosophy of language) often bases statements about the community of mathematicians (native speakers) on personal introspection or anecdotal evidence. A naturalistic philosophy of mathematics that takes actual mathematical practice seriously will have to base at least some of its basic concepts on empirical truths about the practice of mathematicians. In this talk, we describe the general enterprise of "empirical philosophy of mathematics" and will see two case studies, one on knowledge attributions in mathematics, and a second one on attitudes towards various fragments of the axiom of choice.

Gillman Payette

Lundi 30 Avril de 14h à 16h, Philform reçoit Gillman Payette (Dalhousie University, Halifax) : "Schotch-Jennings forcing and structural properties of logics".

Richard Bradley

Le Professeur Richard BRADLEY (LSE, Département de Philosophie), spécialiste de la théorie des conditionnels, sera l'invité du séminaire PHILFORM à l'IHPST le vendredi 27 avril 2007, de 14h à 16h, et donnera une conférence sur le thème:
"Reconciling Adams' Thesis with Truth-Conditional Semantics?"

Abstract: I argue that the various triviality results for Adams' Thesis - the hypothesis that the probability of a conditional equals the conditional probability of its consequent given its antecedent - fail to disprove it. On the contrary, since it is possible to construct a triviality result for any 'orthodox' theory of conditionals satisfying a much weaker 'Preservation' condition, we should consider abandoning elements of the orthodoxy. I consider a number of possibilities and especially the route taken by McGee, who allows the semantic contents of conditionals to be determined (in part) by agents' subjective probabilities.

[La séance aura lieu en liaison avec le cours donné à l'ENS par M. Cozic et P. Egré sur les conditionnels, et se tiendra dans la grande salle de l'IHPST de 14h à 16h.]

Scott Soames (2)

Rappel : Philform reçoit Scott Soames lundi 23 avril à l'IHPST (14h-16h) : " Actually: The Epistemology and Metaphysics of Actuality and Possibility, plus the semantics and pragmatics of our talk about them"

Yael Sharvit

Lundi 2 avril de 14h à 16h dans la grande salle de l'IHPST, le séminaire Philform reçoit Yael Sharvit (University of Connecticut, linguistic departement). L'exposé est intitulé : "Presuppositions and quantificational variability".

Sonja Smets

La prochaine séance de Philform aura lieu lundi 12 mars de 14h à 16h à l'IHPST (salle spéciale). L'invité est Sonja Smets (Vrije Universiteit, Bruxelles) qui exposera ses travaux sur: "Quantum Dynamic Propositional Logic"

F. Lepage

François Lepage est à Paris, et il sera l'invité du séminaire Philform à l'IHPST lundi 12 février de 16h à 18h (notez l'horaire). Il nous parlera de logique partielle (abstract ici).

Davide Grossi

Lundi 29 janvier 2007, de 15h30 à 17h30 (notez l'horaire), Philform reçoit Davide Grossi (Utrecht) sur le thème suivant: On the Logic of constitutive Norms.