# Théorie du droit et logique

**Programme**

**Mardi 12 Mars**

8h30 – Accueil / 8h45 – Ouverture

9h – *Michel Crubellier, *Université Lille3 STL – UMR 8163 : "Al-Fârâbî on Greek Logic and Islamic Legal Reasoning"

9h45 – *Karlheinz Hülser, *Konstanz Universität : "Proculus on the meanings of OR and types of disjunction"

10h30 – Pause

11h – *Bettine Jankowski*, Konstanz Universität : "The Rhetoric's Dilemma - Leibniz' take on an ancient case"

11h45 – Déjeuner

13h30 – *Juliele Maria Sievers, *Université Lille3 STL – UMR 8163 : "Jørgensen’s Dilemma Revisited"

14h15 – *Giuliano Bacigalupo,* Konstanz Universität : "What is Fictional about the Fiction Theory of Juridical Persons?"

15h – *Juliana de Albuquerque Katz*, Konstanz Universität : "Contradictions and Hegel's Philosophy of Right"

15h45 – Pause

16h15 – *Patrice Canivez, *Université Lille3 STL – UMR 8163 : "Compromise Making and

Democratic Institutions"

17h – *Gildas Nzokou*, Libreville Université – CERP : "De la typologie du conflit des arguments usant de proverbes"

18h – City tour

19h30 – Dîner : "L'origan"

**Mercredi 13 Mars**

8h30 – Accueil

9h – *Sandrine Chassagnard-Pinet*, Université Lille2 – Centre René Demogue : "La contractualisation, un mode consensuel et participatif de régulation de la société ?"

9h45 – *Juliette Sénéchal*, Université Lille2 – Centre René Demogue : "La classification et la typologie au service des notions juridiques de droits réels et de contrats"

10h30 – Pause

11h – *Matthias Armgardt*, Konstanz Universität : "Conditionals and Object of Litigation"

11h45 – Déjeuner

13h30 – *Sébastien Magnier*, Université Lille3 STL – UMR 8163 : "The burden of proof in Law: A (dia)logical investigation"

14h15 – *Rainhard Bengez*, Munich Universität* *: "A Note on Conceptual Change” *Cancelled*

15h – *Shahid Rahman,* Université Lille3 STL – UMR 8163, "Some considerations on evidence, content and object-language"

15h45 – Pause

16h15 – Bilan / discussion

18h – Visite à l’Opéra de Lille

19h30 – Dîner : "Brasserie de la Paix"

**Abstracts**

*Karlheinz Hülser *: "Proculus on the meanings of OR and types of disjunction"

Proculus, a Roman lawyer, belonging to the sphere of Nero, flourished around the middle of the 1st century AD. With respect to logic, he distinguished three meanings of *OR*, that despite of their deviating names look very much like the contravalence, the disjunction, and the exclusion of the modern propositional calculus; the resp. truth values are 0110, 1110 and 0111. Though the explanations given by Proculus himself belong to the tradition of Stoic logic, they are by far the eldest document we have, where a clear definition of the non-exclusive disjunction(s) is to be found. But in four respects Proculus' text also differs from the received Stoic logic. The most important difference is the way how Proculus, in order to define the *OR*s, refers to ›conflicts‹ between the ›or‹-connected elements. Touching on those ›conflicts‹ in this way, avoided a lot of logical difficulties and allowed for the clear differentiation of the various *OR*s. Hence, Proculus’ argument could be seen as the real beginning of truth-functional logic.

*Bettine Jankowski,* "The Rhetoric's Dilemma - Leibniz' take on an ancient case"

A well-known paradox (supposedly) dating back to ancient Greece is Protagoras court case against his pupil Euathlus. If and how this case can be solved has been in discussion for 1800 years. This presentation focuses on the approach taken by Leibniz and contrasts it with modern ways of solving the issue.

*Juliele Sievers, "*Jorgensen's Dilemma Revisited"

Jorgensen’s Dilemma, as pointed out by the legal philosopher Alf Ross, deals with the question whether if imperatives can be a part of a logical inference, as one of the premises or as a conclusion. If a first reaction points to a negative answer (since norms cannot be true or false), most of us will have to agree that inferences involving norms make part of our daily lives and that the evidence of their validity seems to be out of question. This difficulty in understanding the role of imperatives in our reasoning about norms intrigued also Hans Kelsen, who severely criticized the answers previously given. Our aim is to show how Kelsen’s approach is capable of enlighten a new understanding of the dilemma.

*Giuliano Bacigalupo,* "What is Fictional about the Fiction Theory of Juridical Persons?"

The presentation focuses on Friedrich Carl von Savigny´s fiction theory of juridical persons. My aim consists in a clarification of what is fictional about Savigny´s theory, i.e. which notion of fiction is at stake and which entities are allegedly fictional. In doing so, I take advantage of some philosophical and logical tools: David Lewis´ fiction-operator, the analysis of “as if”-statements by Hans Vaihinger and second-order modal logic.

*Gildas Nzokou,* "De la typologie du conflit des arguments usant de proverbes"

Dans des travaux antérieurs nous avons longuement abordé la question des formes abstraites de l’argumentation dans les traditions orales africaines. Nous y avions clairement exposé le caractère non monotonique de la relation d’inférence qui y a cours. Par ailleurs, nous avions reformulé ce modèle argumentatif dans le cadre théorique de la logique dialogique que nous avions réaménagé au passage, afin que ledit cadre dialogique accueille de nouveaux opérateurs logiques (ceux de la dynamique épistémique : révision et contraction).

Dans le présent essai, nous voulons aborder la question portant sur les types de conflits possibles entre arguments usant respectivement de proverbes comme de prémisses stratégiques. Et, de notre point de vue, il apparaît que l’attaque par affaiblissement d’une règle d’inférence caractérise au mieux le type de conflit considéré ici.

De fait, nous allons précisément montrer que les proverbes, en tant que propositions générales et principes de raisonnement, sont les éléments de l’ensemble des prémisses qu’un contre argument doit neutraliser afin de déduire raisonnablement une contre-conclusion recherchée. Ce qui nous met chaque fois en présence d’une attaque par ce que John Pollock nommait «*undercutting*».

La question va alors se poser de savoir si, en dehors de l'undercutting, il n’y aurait pas d’autre types de conflit entre arguments faisant un usage stratégique des prémisses proverbiales.

*Sébastien Magnier, "*The burden of proof in Law: A (dia)logical investigation"

The notion of proof is crucial in law but is also a wide area. In this presentation we focus on Legal proof in the French Civil Law. This kind of proof binds the power of the judge, so only the two parties involved in the trial have to deal with the proof. Following the Article 1315 of the French Civil Code, the burden of proof is generally bore by the claiming party. Nevertheless there exist some exceptions. These exceptions come from presumptions which allow a shift of the burden of proof. In such case the defending party must prove the evidence to the contrary. Since dialogical logic also involves a trail between two parties, we would like to take advantage of this particular setting in order to investigate the problem of the burden of proof from a (dia)logical point of view.

*Shahid Rahman*, "Some considerations on evidence, content and object-language"

Evidence is a fundamental in legal reasoning and legal proceedings. More precisely in Law, the notion of evidence is implemented by the means of series of rules and principles that determine the ways the proof of a fact must be carried in a legal proceeding and which of these ways are accepted or not and what weight or importance these proofs should be ascribed. These rules and principles concern the quantum or amount; the quality and the type of proofs specific to a given litigation.

Accordingly we might expect that a theory of legal reasoning can contribute to the elucidationof this issue. The challenge for a logical approach or reconstruction is that the notion involved; despite being formal, in the sense that it follows general norms that regulate the form to carry the proof it is about content after all.

The main aim of the presentation is to suggest that logical approaches to the notion of evidence should distinguish between the fact expressed correspondent to a proposition and the grounds the support that fact at the object language level: the ground that supports a proposition is of a different type as the one of the proposition itself. Furthermore the idea is to, following the constructive type theory, consider a proposition as the set of all its possible groundings (or proof-objects). The corresponding sets follow precise rules determining: canonical (or direct) proof-objects, those that are not canonical (indirect proof objects) but can be shown to be grounded on canonical ones and those that do not constitute elements of the set at all.

A striking example; to my limited knowledge of theory of law, is the case of hearsay evidence. I will mainly focus on quality and type of evidence, however I do think that an extension to quantum considerations is straightforward. I will also explore the possibilities that offer this frame to develop an alternative perspective to the notion of conditional right as a special case.