Our objective in this paper is to clearly highlight the linguistic status of the copulative verb, especially with regard to the copula verb to be, with an eye on tracingthe influences of Logic on its approach as a syntactic entity and also on emphasizing the details that led to an eclectic definition. This epistemological approach aims at placing an emphasis on the subject of the diachronic and interdisciplinary copulative verb, in order to observe the way in which the conclusions from the level of the logical approach were transferred to the one of the linguistic approach and also to avoid the misuse of a series of concepts that were established either in a different domain or in the same domain, but at a different level. The main emphasis falls on defining the linguistic predicate through the grammatical tense.

Due to the failure of the classical principles of bivalence and verifunctionality, the logic of experimental propositions relative to quantum systemscannot be interpreted in Boolean algebras. However, we cannot say neither that this logic is captured by orthomodular lattices, as claimed by many authors along the line of Birkhoff‘s and von Neumann‘s standard approach. For the alleged violation of distributivity is based on the possibility of combining statements relative to complementary contexts, which does not refer to any experience and, consequently, has no meaning. Indeed, quantum logic should be interpreted in partial, transitive Boolean algebras whose compatibility relation limits the application of the connectives within each of its Boolean sub-algebras, which refer to partial, classical descriptions. Moreover, this approach of quantum logic makes it possible to deal with composite systems, which was not possible to do within the standard approach, and then to deal with the fundamental notion of quantum entanglement. The latter notion can be represented by a series of axioms of the object language that restrict the set of experimental statements bearing on a composite system, while its close link to the notion of complementarity can be expressed in the metalanguage.

Cherchant à refonder l’édifice euclidien, Leibniz a formulé une Caractéristique géométrique qui annonce les concepts géneraux de la théorie des ensembles. Dans ce cadre, il a pu en particulier formaliser sa conception du continu. L’intérêt du Pacidius Philalethi (1676) est de montrer qu’en choisissant la conception intensionnelle du continu -position qu’il ne dementira jamais- il sélectionne parmi les images duales celle dont se déduit le changement qualitatif, base d’une philosophie naturelle qui soutiendra encore la dynamique ultérieure. Une tâche se dessine maintenant, soit déduire la nécessité d’un mouvement universei et infiniment varié à partir de ses conditions topologiques.We know that Leibniz intended to bring new foundations to the euclidean geometry and he has according to this view formulate a Characteristica geometrica which announces few general concepts of set theory. Parlicularly he tried to formalise his conception of continuity. Before the main interest of the Pacidius Philalethi (1676) is here: showing us that Leibniz when he chooses an intensional conception of continuity he chooses in the same time the dual image from which be can deduce the qualitative variation. We reckon again these conception at the grounds of his later philosophy of nature. But now we have to follow Leibniz demostrating how universal and infinite variations flow from its topological conditions.

Trois sortes de définitions sont présentées et discutées: les définitions nominales, les définitions contextuelles et les définitions amplificatrices. On insiste sur le fait que I’elimination des definitions n’est pas forcement un procede automatique en particulier dans le cas de la logique paraconsistante. Finalement on s’int’resse à la théorie des objets de Meinong et l’on montre comment elle peut êrre considéréecomme une théorie des descripteurs.Three kinds of definitions are presented and discussed: nominal definitions, contextual definitions, amplifying definitions. It is emphasized that the elimination of definitions is not necessarily straightforward in particular in the case of paraconsistent logic. Finally we have a look at Meinong’s theory objects and we show how it can be considered as a theory of descriptors.

A dix ans d’intervalle deux déontciens de premier plan, G.H. von Wright et H.N. Castañeda, ont abordé -indépendamment l’un de l’autre- le probleme du fondement des normes et des énoncés normatifs. Leurs solutions respectives méritent d’être attentivement examinées. Ne prêtent-elles pas a discussion? Pour qu’une norme juridique soit fondée, suffit-il qu’elle soit édictée par un législateur compétent conformément a la procédure législative en vigueur? Un énoncé nornlatif est-il fondé du moment que l’ordre en faisant partie est légitimé au sens conféré a ce terme par l’auteur de Thinking and doing? Et tout d’abord peut-on admettre que les ordres fassent partie des énoncés nomlatifs? L’article qui suit essaie de répondre à ces questions et aux questions connexes.

In this paper everyday reasoning is examined fromm the standpoint of natural logic. In natural logic there is the supposition of the concept of schematisation, i.e. the discursive representation of a situation that a speaker A constructs for a listener B and that B must reconstruct for himself.Under these circumstances, in order to prove that a statement s is true A must present it in such a way that B does not call it into question, that he considers it a fact. For this it is necessary to have proofs. Moreover, a fact is never isolated and it may therefore appear inconsistent with other facts. A is thus led to provide reasons in order to substantiate his statements.Some mechanisms of proofs and of reasons are investigated.