This text is an outgrowth of notes prepared by J. Y. Girard for a course at the University of Paris VII. It deals with the mathematical background of the application to computer science of aspects of logic (namely the correspondence between proposition & types). Combined with the conceptual perspectives of Girard's ideas, this sheds light on both the traditional logic material & its prospective applications to computer science. The book covers a very active & exciting research area, & it will (...) be essential reading for all those working in logic & computer science. (shrink)

This is a collection of new investigations and discoveries on the theory of opposition (square, hexagon, octagon, polyhedra of opposition) by the best specialists from all over the world. The papers range from historical considerations to new mathematical developments of the theory of opposition including applications to theology, theory of argumentation and metalogic.

The hexagon of opposition is an improvement of the square of opposition due to Robert Blanché. After a short presentation of the square and its various interpretations, we discuss two important problems related with the square: the problem of the I-corner and the problem of the O-corner. The meaning of the notion described by the I-corner does not correspond to the name used for it. In the case of the O-corner, the problem is not a wrong-name problem but a no-name (...) problem and it is not clear what is the intuitive notion corresponding to it. We explain then that the triangle of contrariety proposed by different people such as Vasiliev and Jespersen solves these problems, but that we don’t need to reject the square. It can be reconstructed from this triangle of contrariety, by considering a dual triangle of subcontrariety. This is the main idea of Blanché’s hexagon. We then give different examples of hexagons to show how this framework can be useful to conceptual analysis in many different fields such as economy, music, semiotics, identity theory, philosophy, metalogic and the metatheory of the hexagon itself. We finish by discussing the abstract structure of the hexagon and by showing how we can swing from sense to non-sense thinking with the hexagon. (shrink)

Using methods of abstract logic and the theory of valuation, we prove that there is no paraconsistent negation obeying the law of double negation and such that $\neg(a\wedge\neg a)$ is a theorem which can be algebraized by a technique similar to the Tarski-Lindenbaum technique.

qui y recense ses nombreuses victoires. Une brève histoire des choraules et de leur participation aux concours peut ainsi être esquissée : malgré sa popularité, surtout en Occident, la discipline n'a été acceptée que tardivement dans les concours, et aux Pythia sans doute seulement à la fin du Ier siècle. Un premier appendice évoque rapidement les catalogues du personnel cultuel conservés à Olym- pie ; un second établit le texte d'une inscription de Nîmes (IG XIV 2499), où l'on doit reconnaître (...) un acte de l'association universelle des artistes dionysiaques. (shrink)

Rarely is the problem of the diversity of languages taken into account whenever population groups are formed into States. When the problem does come up, it is later, in a primarily political context which tries to find political solutions, such as we may presently see them in Canada or in Belgium for instance. These solutions are few and they deal with situations that may contain a host of nuances.Certain countries have chosen a vehicular language while keeping their local languages: the (...) common language in the USSR is the language of one of its republics. In Senegal it is French, which is of a totally foreign origin but has the advantage of avoiding the rivalry existing among the native languages, and it also has a place within the international community. Other countries have accepted as official languages the different languages spoken within its borders. Thus Switzerland is officially tri-lingual (French, German, Italian), giving legal status to what somewhere else may simply be an accepted fact. Many Alsatians speak three languages (Alsatian, French, German). As far as it concerns countries with a strong linguistic heterogeneity, whether it be their history or their size making for a centralizing policy, they have adopted, with the resulting neglect of all others, the language or the idiom of the region which was politically or culturally the dominant one at the time of their unification. Pekinese has been extended to all of China, Florentine to Italy, Hindi to India. Some original combinations can be found: in Israel Jewish immigrants who came from more than seventy different countries, have again taken up the nation's old cultural and religious language, which had been out of use for two thousand years, and have placed it on equal footing with Arabic spoken by the local population, while English is being used for international relations. (shrink)

t.l. Introduction à une anthropologie philosophique.

We present a single sequent calculus common to classical, intuitionistic and linear logics. The main novelty is that classical, intuitionistic and linear logics appear as fragments, i.e. as particular classes of formulas and sequents. For instance, a proof of an intuitionistic formula A may use classical or linear lemmas without any restriction: but after cut-elimination the proof of A is wholly intuitionistic, what is superficially achieved by the subformula property and more deeply by a very careful treatment of structural rules. (...) This approach is radically different from the one that consists in “changing the rule of the game” when we want to change logic, e.g. pass from one style of sequent to another: here, there is only one logic, which—depending on its use—may appear classical, intuitionistic or linear. (shrink)

In his Brouillon Project on conic sections, Girard Desargues studies the notion of traversale, which generalizes that of diameter introduced by Apollonius. One often reads that it is equivalent to the notion of polar, a concept that emerged in the beginning of 19th century. In this article we shall study in great detail the developments around that notion in the middle part of the Brouillon project. We shall in particular show, using the notes added by Desargues after the first draft (...) was written, how here arises a new theory, that of the polarity associated to a conic section. We shall show that besides a natural correspondance between points and lines, Desargues has understood that a conic induces on every line in its plane an involution, and how he progressively handles the considerable conceptual difficulties he has to deal with when trying to explain clearly his novative ideas. (shrink)

This paper aims to shed new light on Hegel’s rather problematic statements about Asian thinking and Chinese philosophy by disclosing the Orientalist antecedents found in Kant’s anthropological works. First, the notion of Orientalism will be defined with reference to Orientalism and “Orientalism Reconsidered” by Edward Said. Second, an exploration of Kant’s anthropological research will show that this constituted the turning point in the Western Orientalist perception of China which had a strong influence on Hegel Finally, it will be claimed that (...) Hegel’s Orientalist perception of China rests on a definition of culture as the expression of the “spirit of a people” that has recently been revised by contemporary post-colonial anthropologists. (shrink)

Le but de cet article est, à travers l’histoire des relations entre science et philosophie du temps, de retracer l’archéologie épistémologique du temps pensé comme progrès linéaire. Nous voudrions montrer : 1. que la pensée du « temps » évolue avec le temps, 2. que cette évolution peut se lire en même temps en science et en philosophie sans qu’il soit nécessaire d opposer l’une à l’autre, 3. qu’elle n’est pas réductible à une opposition entre réversibilité ou irréversibilité ; 4. (...) qu’elle s’exprime à travers trois « métaphores épistémiques » distinctes : cercle, ligne ou réseau — à l’intérieur desquels l’antinomie entre conception « idéaliste » ou « réaliste » de la temporalité ne cesse de se rejouer ; 5. qu’il est possible de dépasser cette antinomie par l’idée régulatrice d’une fonction cosmologique de la temporalité définie comme la forme de l’interaction entre événements physiques et lois naturelles. (shrink)

Le but de cet article est, à travers l’histoire des relations entre science et philosophie du temps, de retracer l’archéologie épistémologique du temps pensé comme progrès linéaire. Nous voudrions montrer : 1. que la pensée du « temps » évolue avec le temps, 2. que cette évolution peut se lire en même temps en science et en philosophie sans qu’il soit nécessaire d opposer l’une à l’autre, 3. qu’elle n’est pas réductible à une opposition entre réversibilité ou irréversibilité ; 4. (...) qu’elle s’exprime à travers trois « métaphores épistémiques » distinctes : cercle, ligne ou réseau — à l’intérieur desquels l’antinomie entre conception « idéaliste » ou « réaliste » de la temporalité ne cesse de se rejouer ; 5. qu’il est possible de dépasser cette antinomie par l’idée régulatrice d’une fonction cosmologique de la temporalité définie comme la forme de l’interaction entre événements physiques et lois naturelles. (shrink)

Jean-Yves Strasser The Olympia of Alexandria and the Pancratiast M. Aur. Asklepiades p.421-468 The Alexandrian Olympia are known thanks to inscriptions and especially papyri. The latter mention the olympionikoi, who may have been victors not in the great competition at Pisa, but in the Olympia of the Egyptian city. These competitions, created under Marcus Aurelius, became eiselastikoi under Gallien; they were first celebrated in 268. Like the majority of the great competitions in Egypt, they took place in the (...) winter of even years divisible by four. That was the case already in the 2nd century AD: the first Olympia were organised in 180. In 200, at the time of the sixth celebration, the periodonikes M. Aur. Asklepiades won the Olympia pancration in the presence of Septimius Severus and Caracalla. An inscription at Coptus (I. Portes 88) mentions a hellanodikes of Alexandria: he could have been serving at the time of the seventeenth Olympiad in 244; in 246-247 he had a statue of Sarapis Polieus erected under the prefect of Egypt Valerius Firmus. (shrink)

We present a paraconsistent logic, called Z, based on an intuitive possible worlds semantics, in which the replacement theorem holds. We show how to axiomatize this logic and prove the completeness theorem.

Despite its wealth and economic performances, Western Europe is anxious about its future and unable to solve its main problem: unemployment. Its great project is the building or Europe. But many questions have no real answers: how can we avoid social fractures? is globalisation and internationalisation a risk or chance? how should we fight corruption? Europe should be the best answer to those questions. But it depends on the answers to new questions: what are the social values on which we (...) want to build the European society of the next century. Eastern Europe is still poor. But the questions are the same and people are confronted with the same problems. Our common challenge is to build a society for the future. And for the first time of our long history, we have no model. We have to invent it. Firms and managers from Hungary and Eastern Europe have to bring their contribution and promote values and virtues as a major factor of the building of our common Europe. (shrink)

Jean-Yves Béziau Abstract In this paper I relate the story about the new rising of the square of opposition: how I got in touch with it and started to develop new ideas and to organize world congresses on the topic with subsequent publications.

Nous tentons dans cet article de proposer une thèse cohérente concernant la formation de la notion d’involution dans le Brouillon Project de Desargues. Pour cela, nous donnons une analyse détaillée des dix premières pages dudit Brouillon, comprenant les développements de cas particuliers qui aident à comprendre l’intention de Desargues. Nous mettons cette analyse en regard de la lecture qu’en fait Jean de Beaugrand et que l’on trouve dans les Advis Charitables.

The paper extends a result in Dutta and Ray's (1989) theory of constrained egalitarianism initiated by relying on the concept of proportionate rather than absolute equality. We apply this framework to redistributive systems in which what the individuals get depends on what they receive or pay qua members of generally overlapping groups. We solve the constrained equalization problem for this class of models. The paper ends up comparing our solution with the alternative solution based on the Shapley value, which has (...) been recommended in some distributive applications. (shrink)

Résumé Le but de cet article est de montrer que la manière dont à été posée la question de la scolarisation du créole trahit une sorte d’aveuglement sur ce que peut signifier le fait de parler créole - quelque chose comme l’oubli d’une de ses dimensions. Je dis qu’en réfléchissant à ce que pourrait être une institution (comme l’école ou autre chose) tirée de la vie créole étudiée dans sa manière de dire les choses, on pourrait porter remède à cet (...) oubli. (shrink)

In this article, I attempt to draw as many possible consequences from this fact : in the Mascareignes islands, the use of the word « Creole » is regulated by criteria that limit its application to subgroups of the Creole world. The use of this word is not “cognitive”, it does not refer to the inhabitant of the islands, the “native” : it marks that from which one must separate oneself within the Creole language itself, possibly through the evocation of (...) back-languages, of customs, beliefs and attitudes inherited from somewhere else. A crucial defining feature of Creole life thus appears to consist in a distance between forms of experience that coexist but that strive to be as separated and watertight as possible. Sensitivities are deeply trained in measuring this distance, which leads hybridization to be conceived as subtractions to the norms inherited from colonial times. Distance and hybridization are the main terms through which I have attempted to describe the Creole world in the Mascareignes ; but I tried to do so “from a distance”, in the spirit with which Derek Walcott described fragments of epics in the Caribbean. (shrink)

Jean-Jacques Rousseau est l'auteur de l'entrée "économie politique" dans l'Encyclopédie en 1755. A ce titre, il aurait pu être l'un des fondateurs de cette discipline. Pourtant, la définition qu'il en donne est à l'encontre de la pensée libérale des physiocrates, puis des classiques, et constitue une véritable "anti-économique". En hypertrophiant le rôle de l'Etat et en niant l'intérêt personnel, Rousseau est au contraire l'un des pères du socialsme. En niant la liberté humaine, il nie aussi l'existence de choix éthiques.

New commentary on Hadrian’s second letter to Dionysiac artists. A thorough study of the text structure and vocabulary reveals that the emperor has not always altered the schedule of Greek games. His main concern is to insert the competitions he himself has created and to avoid conflicts between the cities. He certainly didn’t offend the susceptibilities of the Greeks, but he probably also resisted numerous requests. He has favoured considerably Athens. The understanding of the end of the text can be (...) improved. The dates provided by Hadrian in the solar Julian calendar must be reinterpreted in light of a lunar calendar. (shrink)

Sont réexaminées plusieurs inscriptions agonistiques d’Athènes. 1. Le texte IG II3 4, 624 pour un héraut périodonique doit certainement être attribué à Valerius Eklektos de Sinope, déjà connu par un long texte d’Athènes, une base à Olympie et un piédestal retrouvé à Delphes resté inédit et publié ici. L’ensemble permet de reconstituer le parcours d’un artiste hors norme connu par quatre textes gravés à des moments différents de sa carrière. 2. Les fragments IG II3 4, 616 et 617 appartiennent au (...) même palmarès du second tiers du IIIe s. et peuvent vraisemblablement être reliés l’un à l’autre. Si IG II3 4, 618 ne provient pas du même monument, il pourrait lui être en revanche contemporain. 3. La base SEG 58, 185 honore non un agonothète mais un épistate, dont sont vantés les succès lors d’une longue carrière. 4. IG II² 2772 est une dédicace funéraire faite par un boxeur et xystarque pour un parent ou un ami. (shrink)

Le pancratiaste périodonique Markos Aurèlios Dèmostratos Damas de Sardes est connu par de nombreux témoignages trouvés dans sa patrie, à Rome, à Éphèse, à Delphes et en Egypte. Leur réexamen permet de reconstruire avec précision la carrière du champion, comme d'éclairer certains points de l'histoire des concours qu'il a remportés. Deux inscriptions d'Éphèse qui lui ont été rapportées ne doivent sans doute pas l'être. On peut proposer de nouveaux suppléments aux palmarès de Sardes et de Delphes ; un autre texte (...) delphique est identifié comme une nouvelle liste chronologique des victoires de Dèmostratos Damas. Le pancratiaste, dont le floruit se situe sous le règne de Marc Aurèle, a brillé en fin de carrière dans la boxe. Les statues dont on a retrouvé les bases ont été érigées essentiellement après sa carrière sportive, lorsqu'il exerce, sous Septime Sévère, les plus hautes charges au sein de l'association des athlètes. (shrink)

In some situations, a decision is best represented by an incompletely analyzed act: conditionally on a given event A, the consequences of the decision on sub-events are perfectly known and uncertainty becomes probabilizable, whereas the plausibility of this event itself remains vague and the decision outcome on the complementary event ${\bar{A}}$ is imprecisely known. In this framework, we study an axiomatic decision model and prove a representation theorem. Resulting decision criteria aggregate partial evaluations consisting of (i) the conditional expected utility (...) associated with the analyzed part of the decision, and (ii) the best and worst consequences of its non-analyzed part. The representation theorem is consistent with a wide variety of decision criteria, which allows for expressing various degrees of knowledge on ( ${A, \bar{A}}$ ) and various types of attitude toward ambiguity and uncertainty. This diversity is taken into account by specific models already existing in the literature. We exploit this fact and propose some particular forms of our model incorporating these models as sub-models and moreover expressing various types of beliefs concerning the relative plausibility of the analyzed and the non-analyzed events ranging from probabilities to complete ignorance that include capacities. (shrink)

These lectures on logic, more specifically proof theory, are basically intended for postgraduate students and researchers in logic. The question at stake is the nature of mathematical knowledge and the difference between a question and an answer, i.e., the implicit and the explicit. The problem is delicate mathematically and philosophically as well: the relation between a question and its answer is a sort of equality where one side is ``more equal than the other'': one thus discovers essentialist blind spots. Starting (...) with Godel's paradox --so to speak, the incompleteness of answers with respect to questions--the book proceeds with paradigms inherited from Gentzen's cut-elimination. Various settings are studied: sequent calculus, natural deduction, lambda calculi, category-theoretic composition, up to geometry of interaction, all devoted to explicitation, which eventually amounts to inverting an operator in a von Neumann algebra. Mathematical language is usually described as referring to a preexisting reality. Logical operations can be given an alternative procedural meaning: typically, the operators involved in GoI are invertible, not because they are constructed according to the book, but because logical rules are those ensuring invertibility. Similarly, the durability of truth should not be taken for granted: one should distinguish between imperfect and perfect modes. The procedural explanation of the infinite thus identifies it with the unfinished, i.e., the perennial. But is perenniality perennial? This questioning yields a possible logical explanation for algorithmic complexity. This highly original course on logic by one of the world's leading proof theorists challenges mathematicians, computer scientists, physicists, and philosophers to rethink their views and concepts on the nature of mathematical knowledge in an exceptionally profound way. (shrink)

This paper introduces the special issue on Logic and Religion of the journal Logica Universalis (Springer). The issue contains the following articles: Logic and Religion, by Jean-Yves Beziau and Ricardo Silvestre; Thinking Negation in Early Hinduism and Classical Indian Philosophy, by Purushottama Bilimoria; Karma Theory, Determinism, Fatalism and Freedom of Will, by Ricardo Sousa Silvestre; From Logic in Islam to Islamic Logic, by Musa Akrami; Leibniz’s Ontological Proof of the Existence of God and the Problem of Impossible Objects, (...) by Wolfgang Lenzen; A Logical Analysis of the Anselm’s Unum Argumentum (from Proslogion), by Jean-Pierre Desclés; Monotonic and Non-monotonic Embeddings of Anselm’s Proof, by Jacob Archambault; Computer-Assisted Analysis of the Anderson–Hájek Ontological Controversy, by C. Benzmüller, L. Weber and B. Woltzenlogel Paleo. (shrink)

It is tempting to consider Girard Desagues’ mathematical work, more precisely his Brouillon project on conics, as a work of mathematics applied to perspective. We would like to show in this text that it is probably more pertinent to consider that Desargues does mathematics as a practitionner of the art of perspective. We shall analyse a few extracts of Desargues’ work with this point of view in mind so as to shed light on his innovative ideas that could be hard (...) to understand in his sometimes obscure style. We shall show how this way of doing geometry can be also be found in the works Philippe de la Hire and Jacques-Francois le Poîvre, leading them to consider a transformation of the plane into itself as an explicited mathematical object. (shrink)

In the middle part of his Brouillon Project on conics, Girard Desargues develops the theory of the traversale, a notion that generalizes the Apollonian diameter and allows to give a unified treatment of the three kinds of conics. We showed elsewhere that it leads Desargues to a complete theory of projective polarity for conics. The present article, which shall close our study of the Brouillon Project, is devoted to the last part of the text, in which Desargues puts his theory (...) of the traversal into practice by giving a very elegant tratment of the classical theory of parameters and foci. This will lead us to show that Desargues’ proofs can only be understood if one accepts that he reasons in a resolutely projective framework, completely assimilating elements at infinity to those at finite distance in his proofs. (shrink)

The relations of Frederic Bastiat with Faith are complex. He often speaks of God in his works, but his conversion, or rather his return, to the Catholicism was progressive and ended at the time of his death in 1850 in Rome. According to Bastiat, there is no opposition between science and Faith and, above all, economic and social harmonies express and reflect the wisdom of God.Moreover, Bastiat was to join the Catholics of his time, especially in the struggles for the (...) freedom of eductaion, and he was to propose some reforms that the French Catholics adopted only later, such as the separation of the Church and the State; in this way, when he disagreed with the nineteenth century’s Catholics, he anticipated in fact the positions of the twentieth century’s Catholics, being in this instance, as in economic thought, ahead of his time.Les rapports de Frédéric Bastiat et de la foi sont complexes. Il parle souvent de Dieu dans ses oeuvres, mais sa conversion, ou plutôt son retour, au catholicisme a été lente et ne s’est achevée qu’au moment de sa mort à Rome en 1850. Pour Bastiat, il n’y a pas d’opposition entre science et Foi et, surtout, les harmonies sociales expriment et reflètent la sagesse de Dieu.Par ailleurs, Bastiat rejoindra les catholiques de son époque, en particulier dans les combats en faveur de la liberté de l’enseignement, et il proposera des réformes que les catholiques français n’accepteront que plus tard, comme la séparation de l’Eglise et de l’Etat ; en ce sens, lorsqu’il est en désaccord avec les catholiques du XIXème siècle, il anticipe en fait sur les positions des catholiques du XXème siècle, étant là aussi, comme en économie, en avance sur son temps. (shrink)

Le terme de catallaxie a été forgé par F. Hayek pour exprimer l’ordre spontané du marché. Hayek a créé ce terme à partir du mot catallactique, ressorti peu avant de l’oubli par L. Mises, mot venu du verbe grec signifiant « échanger », pour éviter les ambigüités du mot « économie ». Ce papier a pour objet de rechercher la généalogie du terme « catallactique », depuis Richard Whately, qui a été le premier auteur, en 1831, à vouloir rebaptiser « (...) l’économie politique » en « catallactique ». Ce terme était connu et utilisé tout au long du XIX° siècle et on le trouve encore au début du XX° siècle dans divers manuels. L’utilisation de ce terme par Mises, puis Hayek, est donc la reprise d’une tradition remontant à Richard Whately. C’est l’occasion aussi de se pencher sur la vie de Richard Whately, professeur d’économie politique à Oxford jusqu’en 1831, puis archevêque anglican de Dublin. Il a notamment joué un grand rôle dans l’enseignement de cette discipline, en créant 4 000 cours d’économie politique. Un personnage intéressant, un peu trop ignoré aujourd’hui, qui a joué un rôle non négligeable dans la pensée économique. (shrink)