Search

L’élevage pastoral au Sahel est extrêmement dépendant des irrégularités climatiques, et particulièrement de la qualité de la saison des pluies qui conditionne la repousse des pâturages et le remplissage des points d’eau. Les éleveurs nomades et transhumants adaptent leurs stratégies de déplacement à l’état et à la disponibilité de ces ressources. Les outils de suivi de la sécurité alimentaire de ces territoires pastoraux doivent donc intégrer, en plus des données spatialisées sur la biomasse, des informations sur ces mouvements pastoraux et sur les facteurs qui les conditionnent. Pour accompagner les systèmes d’alerte locaux au Sahel, l’organisation non gouvernementale Action contre la Faim propose un modèle de vulnérabilité pastorale basé sur des données satellitaires acquises en temps réel et sur la connaissance des pratiques pastorales. Ce modèle permet d’alimenter en informations un système d’alerte précoce en identifiant les zones d’intérêt pastoral déficitaires en ressources plusieurs mois avant la période de soudure potentiellement problématique. La confrontation avec l’information concomitante collectée sur le terrain par des relais sentinelles permet une surveillance de la situation pastorale, contribuant au développement des infrastructures ou au déploiement de l’aide humanitaire.

Quine is the foremost representative of naturalism in the second half of the twentieth century. His naturalism consists of an insistence upon a close connection or alliance between philosophical views and those of the natural sciences. Philosophy so construed is an activity within nature wherein nature examines itself. This contrasts with views which distinguish philosophy from science and place philosophy in a special transcendent position for gaining special knowledge. The methods of science are empirical; so Quine, who operates within a scientific perspective, is an empiricist, but with a difference. Traditional empiricism, as in Locke, Berkeley, Hume and some twentieth-century forms, takes impressions, ideas or sense-data as the basic units of thought. Quine’s empiricism, by contrast, takes account of the theoretical as well as the observational facets of science. The unit of empirical significance is not simple impressions (ideas) or even isolated individual observation sentences, but systems of beliefs. The broad theoretical constraints for choice between theories, such as explanatory power, parsimony, precision and so on, are foremost in this empiricism. He is a fallibilist, since he holds that each individual belief in a system is in principle revisable. Quine proposes a new conception of observation sentences, a naturalized account of our knowledge of the external world, including a rejection of a priori knowledge, and he extends the same empiricist and fallibilist account to our knowledge of logic and mathematics. Quine confines logic to first-order logic and clearly demarcates it from set theory and mathematics. These are all empirical subjects when empiricism is understood in its Quinian form. They are internal to our system of beliefs that make up the natural sciences. The language of first-order logic serves as a canonical notation in which to express our ontological commitments. The slogan ‘To be is to be the value of a variable’ ([1953] 1961: 15) encapsulates this project. Deciding which ontology to accept is also carried out within the naturalistic constraints of empirical science – our ontological commitments should be to those objects to which the best scientific theories commit us. On this basis Quine’s own commitments are to physical objects and sets. Quine is a physicalist and a Platonist, since the best sciences require physical objects and the mathematics involved in the sciences requires abstract objects, namely, sets. The theory of reference (which includes notions such as reference, truth and logical truth) is sharply demarcated from the theory of meaning (which includes notions such as meaning, synonymy, the analytic–synthetic distinction and necessity). Quine is the leading critic of notions from the theory of meaning, arguing that attempts to make the distinction between merely linguistic (analytic) truths and more substantive (synthetic) truths has failed. They do not meet the standards of precision which scientific and philosophical theories adhere to and which are adhered to in the theory of reference. He explores the limits of an empirical theory of language and offers a thesis of the indeterminacy of translation as further criticism of the theory of meaning.

Geach's account of the Aristotelian logic of categorical sentences supplemented the views shared by Frege, Russell, Quine and others. I argue that this particular predicate logic approach and Geach's points apply to only one variety of natural language categorical sentences. For example, it takes the universal categorical as a universal conditional “If anything is a man, then it is mortal”. A different natural language form can and should be invoked: “Every man is a mortal.” Employing special restricted quantifiers in a version of predicate logic, we justify a full square of opposition and the rules of quality and quantity that Geach rejected.1

This paper presents an anti-realist account of fictional objects. Arguing for the involvement of non-veridical prepositional attitude ascriptions in the understanding of fiction, I maintain that there is no need to invoke Meinongian objects, possibilia or abstract objects for this purpose. In addition I argue against object dependent views (if there is no object, e.g., Sherlock Holmes, then there is no proposition expressed by “Sherlock Holmes lived in London”). I make a case for empty names playing a more significant role than that accorded on direct reference accounts of names. I close by noting points of similarity and of difference with Amie Thomasson and with Kendall Walton.

The most influential philosopher in the analytic tradition of his time, Willard Van Orman Quine (1908–2000) changed the way we think about language and its relation to the world. His rejection of the analytic/synthetic distinction, his scepticism about modal logic and essentialism, his celebrated theme of the indeterminacy of translation, and his advocacy of naturalism have challenged key assumptions of the prevailing orthodoxy and helped shape the development of much of recent philosophy. This introduction to Quine's philosophical ideas provides philosophers, students and generalists with an authoritative analysis of his lasting contributions to philosophy. Quine's ideas throughout are contrasted with more traditional views, as well as with contemporaries such as Frege, Russell, Carnap, Davidson, Field, Kripke and Chomsky, enabling the reader to grasp a clear sense of the place of Quine's views in twentieth-century philosophy and the important criticisms of them.

Shouldn’t we expect a proper account of existence sentences to do justice to claims involving empty names, especially those denying the existence of objects such as Pegasus and Vulcan? Pegasus is a product of ancient mythology and Vulcan an unnecessary and discarded posit of nineteenth century astronomy. A test of such accounts is how they deal with the problem Quine named ‘Plato’s Beard’. I begin by posing the Plato’s Beard problem as it appears in Quine and then as involving identity.’ David Wiggins extended the scope of this problem. Quine’s version concerned objects that do not exist. Wiggins extended it to objects that exist but might not have done so. I discuss Wiggins’ solution and one of two conceptions of “free logic”. I then suggest a solution along the lines of a second conception of free logic that has its roots in an older Aristotelian tradition.

Once upon a time there was a thesis, an antithesis, and a synthesis. The dialectic of this particular Hegelian story is the relation of natural language to logical theory. The thesis was provided by that early stage in analytic philosophy wherein when logical theory clashed with natural language, it was natural language that suffered. An epidemic of charges of meaninglessness occured. Among those charged as linguistic deviants were such purported perversions of use as singular existentials, strings with vacuous singular terms, and the improper mating of objects or expressions of the wrong type. The title of Ryle’s famous essay “Systematically Misleading Expressions” captures the ethos of that period. That essay documented purported cases of natural language, usage which were perceived to be at odds with certain logical forms provided at the time, and predictably for that period, the fault was located in natural language, not in the logical forms suggested by Principia Mathematica. The antithesis in this dialectic was supplied by ordinary-language philosophy, where such clashes lead to downplaying the role of logical theory and upgrading natural-language considerations. A favored practice of the period consisted of dissolving philosophical problems by illustrating that they had their roots in the misuse of ordinary language. The problem would disappear upon abandoning some theoretical infringement on natural language and by carefully sticking to ordinary language. The synthesis (the hero in Hegelian fictions) is the present period, and especially the position taken by the author of the fiction. Here natural language considerations and those of logic go hand in hand. This is due to a number of factors: a growth in logical theory, a more flexible attitude towards logical forms (competing theories of logical form are tolerated) and the growth of linguistics as a theoretical and somewhat formal theory of natural languages.

It is common to find philosophers claiming that it is possible to free the quantifiers — especially the particular (or so-called existential) quantifier — from questions of reference, existence, and ontology, by having recourse to what is now referred to as the substitutional interpretation of the quantifiers. Although there may be ontologically neutral uses of the substitutional interpretation, it is one of the goals of this paper to point out where this feature has been misconceived and to give equal due to uses of the substitutional account that have ontological import. I will examine the relation of the substitutional treatment of the quantifiers to the most important nonsubstitutional one, that of Tarski, with reference to recent claims that the difference between the two kinds is that the former lacks ontological significance.

A Symmetric Approach to Axiomatizing Quantifiers and Modalities.- The Knowing Mathematician.- "Conservative" Kripke Closures.- Frege, Le?niewski, and Information Semantics on the Resolution of Antinomies.- De Finetti's Probabilism.- Probability Functions and Their Assumption Sets - The Binary Case.- Logic and Reasoning.- Paradoxes.- Referential and Nonreferential Substitutional Quantifiers.- Foundations for Analysis and Proof Theory.- Chameleonic Languages.- Relational Model Systems: The Craft of Logic.- Realizability and Intuitionistic Logic.

When we mention an expression, do we use it? It depends on how we mention the expression in question. We can mention an expression A by using another expression B which names it. In such a case we are not using A, but its name (“heterony-mous mention”). But we can also use A itself in “suppositio materialis”, that is, autonymously. That is what is ordinarily called “mention” as opposed to “use”. This traditional contrast between use and (autonymous) mention should not make us forget that in autonymous mention, the mentioned word itself is used, though deviantly.