The paper deals with the contributions of Jacques Herbrand to logic and philosophy in historical context.

Logic and psychology overlap in judgment, inference and proof. The problems raised by this commonality are notoriously difficult, both from a historical and from a philosophical point of view. Sundholm has for a long time addressed these issues. His beautiful piece of work [A Century of Inference: 1837-1936] begins by summarizing the main difficulty in the usual provocative manner of the author: one can start, he says, by the act of knowledge to go to the object, as the Idealist does; (...) one can also start by the object to go to the act, in the Realist mood; never the two shall meet. He is himself inclined to accept the first perspective as the right one and he has eventually developed an original version of antirealism which starts, not from considerations about the publicity of meaning, in the manner of Dummett, but from an epistemic standpoint, trying to search in a non-Fregean tradition of analysis of judgement and cognate notions a way of founding constructivist semantics. The present paper ploughes the same field. We concentrate on the significance, for Sundholm’s program, of the perspective that has been opened by Twardowski in his important essay on acts and products (1912. (shrink)

Bolzano was the first to establish an explicit distinction between the deductive methods that allow us to recognise the certainty of a given truth and those that provide its objective ground. His conception of the relation between what we, in this paper, call "subjective consequence", i.e., the relation from epistemic reason to consequence and "objective consequence", i.e., grounding however allows for an interpretation according to which Bolzano advocates an "explicativist" conception of proof: proofs par excellence are those that reflect the (...) objective order of grounding. In this paper, we expose the problems involved by such a conception and argue in favour of a more rigorous demarcation between the ontological and the epistemological concern in the elaboration of a theory of demonstration. (shrink)

Beth has tried to vindicate the kantian doctrine of mathematical intuition in the frame of contemporary logic. The paper proposes a critical evaluation of this attempt. The theory of mathematical intuition that is exposed in the Critic of Pure Reason is twofold: on one hand, the intuition of the "first principles", as it is analyzed in the Aesthetics, on the other hand, the intuition which is involved in the proofs, as it is analyzed in the Methodology. Contrasting with most defenders (...) of Kant, who try to show that the first kind of intuition remains, in some way, compatible with the non-euclidean geometries, Beth wants to defend the second kind of intuition, by suggesting that it is nothing else than the "instanciation" method, well-known in the predicate calculus. I show that this strategy of defending Kant is unsuccessful. (shrink)

Les sciences cognitives poursuivent un objectif fort ancien, qui consiste, sommairement dit, à décrire et à expliquer les comportements intelligents. Elles appliquent à cet effet des principes méthodologiques moins traditionnels, dont l'adoption définit ce qu'il est convenu d'appeler le "tournant cognitif". Je me propose ici d'exposer brièvement ces principes, de les illustrer par des exemples appropriés et d’en discuter la signification philosophique. Pour l’essentiel, j’ai mis en avant un domaine qui me semble particulièrement pertinent pour les philosophes: l'analyse de la (...) catégorisation, c'est-à-dire du processus par lequel un ensemble d'entités (stimuli sonores ou visuels, objets concrets ou abstraits) en vient à être classifié en catégories séparées, qui peuvent être de type perceptif (phonèmes, couleurs) ou conceptuel (espèces naturelles, types d'événements, catégories esthétiques et morales). (shrink)

Standard epistemic logic actually formalizes folk-psychology. The problem of logical omniscience shows that this logic is not adequate in a cognitivist setting. In order to describe realistic information-processing believers, we need both an ontology of particulars and a hyper-intensional taxonomy of representations. From this point of view, sub-structural logics, which do not overlook the syntaxic details of the processing of information, are an interesting alternative to possible worlds semantics.

Ranging from Alan Turing’s seminal 1936 paper to the latest work on Kolmogorov complexity and linear logic, this comprehensive new work clarifies the relationship between computability on the one hand and constructivity on the other. The authors argue that even though constructivists have largely shed Brouwer’s solipsistic attitude to logic, there remain points of disagreement to this day. Focusing on the growing pains computability experienced as it was forced to address the demands of rapidly expanding applications, the content maps the (...) developments following Turing’s ground-breaking linkage of computation and the machine, the resulting birth of complexity theory, the innovations of Kolmogorov complexity and resolving the dissonances between proof theoretical semantics and canonical proof feasibility. Finally, it explores one of the most fundamental questions concerning the interface between constructivity and computability: whether the theory of recursive functions is needed for a rigorous development of constructive mathematics. This volume contributes to the unity of science by overcoming disunities rather than offering an overarching framework. It posits that computability’s adoption of a classical, ontological point of view kept these imperatives separated. In studying the relationship between the two, it is a vital step forward in overcoming the disagreements and misunderstandings which stand in the way of a unifying view of logic. (shrink)

Philosophy of Probability provides a comprehensive introduction to theoretical issues that occupy a central position in disciplines ranging from philosophy of ...

The paper is a defense of a strict form of anti-realism, competing the "in principle" form defended by Michael Dummett. It proposes to ground anti-realism on the basis of two principles ("immanence" and "implicitness") and to develop the consequences of these principles in the light of sub-structural logics.

According to the realist, the meaning of a declarative, non-indexical sentence is the condition under which it is true and the truth-condition of an undecidable sentence can obtain or fail to obtain independently of our capacity, even in principle, to recognize that it obtains or that fails to do so.1 In a series of papers, beginning with “Truth” in 1959, Michael Dummett challenged the position that the classical notion of truth-condition occupied as the central notion of a theory of meaning, (...) and proposed that it should be replaced by the anti-realist (and intuitionistic) notion of assertability-condition. Taken together with normalization results obtained by Dag Prawitz, Dummett’s work truly opened up the anti-realist challenge at the level of proof-theoretical semantics.2 There has been since numerous rejoinders from partisans of classical logic, which were at times met with by attempts at watering down the anti-realist challenge, e.g., by arguing that anti-realism does not necessarily entail the adoption of intuitionistic logic. Only a few anti-realists, such as Crispin Wright and Neil Tennant, tried to look instead in the other direction, towards a more radical version of anti-realism which would entail deeper revisions of classical logic than those recommended by intuitionists.3 In this paper, which is largely programmatic, we shall also argue in favour of a radical anti-realism which would be a genuine alternative to the traditional anti-realism of Dummett and Prawitz. The debate about anti-realism has by now more or less run out of breath and we wish to provide it with a new lease on life, by taking into account the profound changes that took place in proof theory during the intervening years. We have in mind in particular the considerable development within Gentzen-style proof theory of non-classical, substructural logics other than intuitionistic logic, which seriously opens up the possibility that anti-realism, when properly understood, might end up justifying another logic, and the development of closer links between proof theory and computational complexity theory that has renewed interest in a radical form of anti-realism, namely strict finitism. (shrink)

W ciągu 30 lat dokonała się głęboka przemiana w relacji między Internetem a aktywnością naukową. Nastąpiło przesunięcie funkcji Internetu, który przestał być jedynie instrumentem współpracy akademickiej, a stał się również narzędziem używanym przez media społecznościowe, zezwalające na maksymalną dyfuzję irracjonalizmu i starego faktualizmu. Aby zrozumieć tę przemianę, należy ponownie zbadać mechanizmy zbieżności opinii. Wynika ona z istnienia wspólnego świata, który ukazuje nam te same fakty i determinuje nieustanną rewizję przekonań każdej osoby. W tym procesie asymptotycznej zbieżności opinii nie wymaga się (...) żadnej komunikacji między jednostkami. Oczywiście, jeśli fakty znane przez jednych są komunikowane innym, konwergencja znacznie przyspiesza, i to tak bardzo, że wiedzę musimy ująć jako rezultat zbiorowej aktywności, w której wymiana informacji jest jednym z jej istotnych źródeł. Z jednej strony takie poznawcze współdziałanie wydaje się naturalne i łatwe do implementacji. Biorąc pod uwagę właściwości informacji, które przechowujemy, nawet jeśli je udostępniamy, to dzielenie się informacją przestaje być przedmiotem zwykłych trudności związanych ze współpracą. Z drugiej strony takie współdziałanie jest produktywne z samej natury: współpraca między kimś, kto zna φ, i kimś, kto wie, że φ implikuje ψ u obydwu jako mających wiedzę ψ, której żaden z nich nie posiadał przed wymianą informacji. Wczesny Internet pozwolił na ekstremalną intensywność tej informacyjnej współpracy. Obecnie mamy do czynienia z odmienną sytuacją. Poszczególne wyznaczniki rosnącej porowatości między naukowcami a opinią publiczną wzmocniły rolę wymiany. Nie jest to już wymiana informacji, lecz wymiana opinii. Stronniczość tkwiąca w naturze ludzkiej, a szczególnie potwierdzenie tej stronniczości, prowadzi do odwrócenia relacji między faktami a opiniami. Szukamy faktów potwierdzających podzielane przez nas opinie, wątpiąc w te, które ich nie określają, i tworzymy fakty do potwierdzenia tego, o czym jesteśmy przekonani. Dlatego przechodzimy od współdziałania do przynależności, dzieląc Internet na homogeniczne grupy wyznawców. (shrink)

Résumé. En trente ans, le rapport d’Internet à l’entreprise scientifique a changé. Nous sommes passés d’un instrument de collaboration scientifique à un dispositif de réseaux sociaux qui assure la plus large diffusion à l’irrationalisme et à l’alt-factualisme. Pour comprendre ce changement, il convient de réexaminer les mécanismes de la convergence des opinions. La première source de cette convergence est l’existence d’un monde commun, qui nous expose aux mêmes faits et qui détermine par révision successive des croyances de chacun, sans que (...) la moindre communication soit requise, une convergence asymptotique des opinions, et ce quelles que soient les croyances de départ. Naturellement, si les faits connus par les uns sont communiqués aux autres, cette convergence s’accélère considérablement, si bien que nous devons considérer la connaissance comme le résultat d’une activité collective, et l’échange d’informations comme l’une de ses sources nécessaires. D’une part, cette coopération épistémique est naturelle et facilement implémentable : en vertu des propriétés caractéristiques de l’information, qui est un bien que nous conservons lorsque nous le donnons, le partage informationnel est exempt des difficultés qui affectent généralement la coopération. D’autre part, cette coopération est intrinsèquement productive : la collaboration entre celui qui sait que φ et celui qui sait que φ implique ψ met chacun des deux agents en possession de la connaissance de ψ, qui n’était pourtant détenue par personne avant l’échange. L’internet des débuts donne à cette coopération informationnelle une ampleur inégalée. La situation actuelle est différente. Un certain nombre de facteurs, dont la porosité croissante entre les scientifiques et le large public, ont mis au premier plan l’échange, non des informations factuelles, mais celui des opinions. Les biais notoires de la psychologie humaine, au premier rang desquels le biais de confirmation, tendent à inverser le rapport entre les faits et les opinions. On cherche les faits confirmant les opinions entretenues, on met en doute les faits récalcitrants et l’on crée des faits corroborants. En bref, on passe d’une problématique de la coopération à une logique de l’affiliation, segmentant l’internet en groupes doxastiques homogènes. (shrink)

This paper can be read as an attempt at providing philosophical foundations to linear logic. The only plausible form of philosophical antirealism deals with practical feasibility rather than with effectivity in principle. The very notion of recognizability is ambiguous, audit has to be considered from a stricter perspective than currently done. The intuitionistic assertability conditions are to be reinforced. This change requires a move towards a frame in which the circumstances of the application of a logical rule can be specified. (...) Gentzen's sequential calculi provide such a frame, when some structural rules have been removed or limited. (shrink)

According to foundationalism, mathematical propositions form a complex objective structure we have to discover and in which each proposition depends for its truth on the propositions that precede and ground it. Proofs that only establish the truth of their conclusions are contrasted with proofs that give also the objective reason of that truth. Foundationalism claims that the cognitive resources required by these proofs are universally available. This paper tries to undermine that claim and to show that foundationalism is a dead (...) end. (shrink)

Bolzano fut le premier philosophe à établir une distinction explicite entre les procédés déductifs qui nous permettent de parvenir à la certitude d’une vérité et ceux qui fournissent son fondement objectif. La conception que Bolzano se fait du rapport entre ce que nous appelons ici, d’une part, « conséquence subjective », à savoir la relation de raison à conséquence épistémique et, d’autre part, la « conséquence objective », c’est-à-dire la fondation , suggère toutefois que Bolzano défendait une conception « explicativiste (...) » de la preuve : les preuves par excellence sont celles qui reflètent l’ordre de la fondation objective. Dans cet article nous faisons état des problèmes liés à une telle conception et argumentons en faveur d’une démarcation plus stricte entre la préoccupation ontologique et la préoccupation épistémologique dans l’élaboration d’une théorie de la preuve.Bolzano was the first to establish an explicit distinction between the deductive methods that allow us to recognise the certainty of a given truth and those that provide its objective ground. His conception of the relation between what we, in this paper, call “subjective consequence”, i.e. the relation from epistemic reason to consequence and “objective consequence”, i.e. grounding however suggests that Bolzano advocated an “explicativist” conception of proof : proofs par excellence are those that reflect the objective order of grounding. In this paper, we expose the problems involved by such a conception and argue in favour of a more rigorous demarcation between the ontological and the epistemological concern in the elaboration of a theory of proof. (shrink)

RésuméSelon K. Gödel, les restrictions méthodologiques des constructivistes sont aberrantes, et le point de vue réaliste est beaucoup plus fécond: il est hi‐même parvenu à ses résultats logiques fondarnentaux en donnant une place à la notion de vérite, qui n'est pas de type combinatoire. Le premier théorème d'incomplétude est hi‐même un argument décisif en faveur du réalisme, si l'on accepte le principe d'«accessibilité» en vertu duquel nous pouvons décider de toutes les propriétés de nos constructions intellectuelles. Par ailleurs, il existe (...) un large spectre d'arguments permettant de statuer sur un énoncé indécidable dans un système formel. La thèse mécaniste, selon laquelle l'intelligence humaine peut être pensée sans distorsion significative sur le modèle d'une machine de Turing, est donc inacceptable.SummaryAccording to K. Gödel, the methodological restrictions of the constructivists are aberrant, and the realist point of view is much more fruitful. He reached these fundamental logical results himself by making place for a non‐cornbinatorial notion of truth. The first incompletness theorem is itself a decisive argument in favor of realism, provided that the principle of «accessibility» is accepted, by virtue of which we are capable of determining all the properties of our intellectual constructions. Moreover, there are numerous arguments that permit the evaluation of an undecidable statement in a formal system. The mechanistic thesis, according to which the functioning of the human mind, without significant distorsion, can be compared to a Turing machine, is now unacceptable.ZusammenfassungNach Gödel sind die methodologischen Einschränkungen der Konstruktivisten irrig, und er hält den realistischen Standpuukt für viel fruchtbarer. Er selbst erreichte seine grundlegenden logischen Ergebnisse dadurch, dass er Platz machte für einen nichtkombinatorischen Begriff der Wahrheit. Das erste Unvollständigkeitstheorem ist selbst ein entscheidendes Argument zugunsten des Realismus, sofern das «Zugänglichkeitsprinzip» akzeptiert wird, wonach wir fähig sind, alle Eigenschaften unserer intellektuellen Konstruktionen zu bestinmen. Zudem gibt es zahlreiche Argumente, die die Beurteilung einer unentscheidbaren Aussage in einem formalen System erlauben. Die mechanistische These, nach welcher das Funktionieren des menschlichen Geistes ohne wesentliche Verzerrung mit einer Turingmaschine verglichen werden kann, ist heute nicht mehr annehmbar. (shrink)

As regards cognitive capacities, the point of view of classical Artificial Intelligence has been much challenged by the so-called emergentist point of view. This paper attempts to outline,on the basis of logical considerations dealing with practical feasibility, a general theory of incompressible unfolding that is consonant with an old Leibnizian stance rather with the contemporary theory of complexity. I defend a variant of emergentism according to which any process that leads to endow a system with cognitive capacities is such an (...) incompressible unfolding. (shrink)

Financing innovative and costly treatments in various therapeutic fields entails a number of problems in countries where costs are covered by public services. Providing these drugs is forcing actors to define the maximum sums of money society is willing to spend for given health improvements. This raises the question of whether maximum financing should vary according individuals’ circumstances, such as the rareness of a disease, lifestyles, social inequalities experienced over a life time, etc. This article examines a particular priority, namely (...) that given to the youngest patients, such prioritising usually refers to the “fair innings argument”. We question what could justify such a prioritization criterion. Three arguments are considered. At first we consider that FIA could be justified by the objective of equalizing the opportunities of well-being. Next, we proposed justifying the fair innings argument with the aim of equalizing the time provided to individuals to achieve their plan of life, in accordance with Rawls’s theory of justice as fairness. Finally, we proposed considering the FIA as being justified because of the goal of equalizing the time provided to individuals to accept death. These three arguments, of course, have many limitations, some of which we have highlighted. This article doesn’t aim to convince about the superiority of one argument over the other ones. We seek to contribute to the discussions which could happen on prioritization criteria regarding health care, by making explicit what could justify one specific criterion: the age criterion. (shrink)

Le corpus de littéracie avancée réunit des écrits universitaires et professionnels produits par des étudiants du niveau Licence 1 au Master 2. Il contient actuellement 338 textes (+ d’1 million de mots) et est mis à disposition au format xml, assorti de métadonnées (niveau, discipline, genre, consigne d’écriture etc.). Il est à la fois un aboutissement et un point de départ dans le champ de la littéracie avancée : parce que l’enjeu n’est pas tant de constituer des corpus que de (...) les savoir utilisés et de nourrir les recherches actuelles et futures, il est pensé comme un construit évolutif. L’article expose d’abord les objectifs du corpus : le premier, d’ordre descriptif est de cerner les compétences rédactionnelles et les besoins de formation à un niveau avancé ; le second, d’ordre didactique, est qu’il sert de ressource pour la formation, notamment pour des activités d’observation et de manipulation par les apprenants. Sont ensuite présentées les métadonnées, conçues en phase avec les recommandations de la TEI et dans la perspective d’un outillage des linguistes et des didacticiens dans le champ de la littéracie avancée. Enfin, l’article met en évidence les potentialités du corpus : intégrer des données sur les processus d’écriture et des textes annotés par des relecteurs-correcteurs, élaborer des dispositifs didactiques à l’échelle textuelle. à terme, le corpus gagnera à être associé à des outils de requête et à s’enrichir d’annotations diverses, selon les besoins des chercheurs et des formateurs. (shrink)

Compact set valued iterations generalize classical point iterations quite naturally by replacing the function f with a tube f in the discrete iterations equation. In Section 3, some bifurcation results about logistic tube iterations are given. In Section 4, an analogous dynamical behaviour for the phase response tube involved in the entrainment of the respiratory rhythm is studied.

Formal semantics - the scientific study of meaning in natural language - is one of the most fundamental and long-established areas of linguistics. This Handbook offers a comprehensive, yet compact guide to the field, bringing together research from a wide range of world-leading experts. Chapters include coverage of the historical context and foundation of contemporary formal semantics, a survey of the variety of formal/logical approaches to linguistic meaning and an overview of the major areas of research within current semantic theory, (...) broadly conceived. The Handbook also explores the interfaces between semantics and neighbouring disciplines, including research in cognition and computation. This work will be essential reading for students and researchers working in linguistics, philosophy, psychology and computer science. (shrink)

The latest news from our planet is threatening: climate change, pollution, forest loss, species extinctions. All these words are frightening and there is no sign of improvement. Simple logic leads to the conclusion that humanity has to react, for its own survival. But at the scale of a human being, it is less obvious. Organizing one’s daily life in order to preserve the environment implies self-questioning, changing habits, sacrificing some comfort. In one word, it is an effort. Then, what justifies (...) such an effort? The personal choice to act in order to preserve our environment is often made by simple altruism. This choice is based on our love for other human beings: our love for the others grounds our effort. Our moral values, our ethical reflections and our religious beliefs are the deep core of these choices. “This is my commandment, that you love one another as I have loved you.” (John 15.12 NRSV). This Charter shows the moral and religious values that can help us react regarding the current environmental crisis and it should empower us to transcend the ideas of effort and sacrifice in order to consider the respect of the shared house, in a prophetic fulfillment of the being. (shrink)

Today’s students are accustomed to a world where information is available on-demand, anywhere and anytime. They bring this expectation to their academic world where they want to work cooperatively and flexibly, using the modern information processing tools and access with which they are familiar. New hardware platforms such as e-Readers and tablet computers have made substantial inroads in the consumer market. E-Readers are becoming more prevalent in universities – replacing the need for physical textbooks, lecturing notes and other academic documents. (...) Many universities are now running pilot programs, while some are already using e-Readers. Tablet computers, apart from their ability to read, edit or create various types of information documents, also offer additional features such as collaborative and social networking services. This empirical research project investigated student perspectives on the educational use of e-Readers and tablets within the University of Cape Town. A questionnaire was distributed to a significant portion of the student population and stratified according to seniority and faculty. Quantitative data was gathered and analysed on themes ranging from awareness to preferences to facilitating conditions around e-Readers within the academic environment. The students sent a clear signal: that they are keen to embrace these new technologies and the advantages they offer. E-Books can be updated automatically and downloaded to e-Readers instantly from almost anywhere in the world. Students feel they would benefit greatly through the use of e-Readers and many believe they are set to replace books completely. Having access to a portable library of information in their backpacks would benefit both students and the environment. However, there are a number of barriers to the comprehensive introduction of these technologies, including the cost of the devices; cost, rights and file format of e-books; the need for a critical mass of textbooks available in digital format and device characteristics such as battery life, and ubiquitous Wi-Fi access. (shrink)

Formal semantics - the scientific study of meaning in natural language - is one of the most fundamental and long-established areas of linguistics. This Handbook offers a comprehensive, yet compact guide to the field, bringing together research from a wide range of world-leading experts. Chapters include coverage of the historical context and foundation of contemporary formal semantics, a survey of the variety of formal/logical approaches to linguistic meaning and an overview of the major areas of research within current semantic theory, (...) broadly conceived. The Handbook also explores the interfaces between semantics and neighbouring disciplines, including research in cognition and computation. This work will be essential reading for students and researchers working in linguistics, philosophy, psychology and computer science. (shrink)

The way people at the receiving end of humanitarian assistance perceive this intervention may provide invaluable bottom-up feedback to improve the quality of the intervention. We analyzed and mapped Haitians’ views regarding international humanitarian aid in cases of natural disaster. Two hundred fifty participants–137 women and 113 men aged 18-67–who had suffered from the consequences of the earthquake in 2010 were presented with a series of vignettes depicting a humanitarian team's action and were asked to what extent these actions corresponded (...) to what ought to be expected from an international aid mission. Four factors were considered in the vignettes whether the team worked in close association with local institutions, whether it was composed of competent people who were prepared for their mission, whether they treated people as a function of immediate needs, and whether they behaved in a respectful way. Through cluster analysis, five qualitatively different positions were found: Complete hostility to any kind of humanitarian aid ; Strong hostility to humanitarian aid in the case of disrespectful attitudes or behaviors ; Technical competence is the only factor that matters ; Both manifestation of respect for the population and technical competence matter and Undetermined. Most Haitians expect humanitarian teams to be technically competent, but even very competent aid is not considered adequate if provided in an arrogant and disrespectful manner. (shrink)