This paper first provides a brief survey of a possibilistic handling of default rules. A set of default rules of the form, "generally, from α deduce β", is viewed as the family of possibility distributions satisfying constraints expressing that the situation where α and β is true has a greater plausibility than the one where α and ⇁β is true. When considering only the subset of linear possibility distributions, the well-known System P of postulates proposed by Kraus, Lehmann and Magidor, (...) has been obtained. We also present two rational extensions: one based on the minimum specificity principle and the other is based on the lexicographic ordering. The second part of the paper presents an empirical study of three desirable properties for a consequence relation that capture default reasoning: Rationality, Property Inheritance and Ambiguity Preservation. An experiment is conducted to investigate 13 patterns of inference for the test of these properties. Our experimental apparatus confirms previous results on the relevance of System P, and enforces the psychological relevance of the studied properties. (shrink)

This article tests human inference rationality when dealing with default rules. To study human rationality, psychologists currently use classical models of logic or probability theory as normative models for evaluating human ability to reason rationally. Our position is that this approach is convincing, but only manages to capture a specific case of inferential ability with little regard to conditions of everyday reasoning. We propose that the most general case to be considered is inference with imperfect knowledge - in the present (...) case restricted to uncertain knowledge - and that a natural framework for testing the rationality of plausible reasoning is System P. This system provides rational postulates for nonmonotonic inference. The semantic of the nonmonotonic inference is given by a possibilistic constraint introduced by Dubois and Prade (1991). This constraint states that a rule p ( q is a plausible rule if "the degree to which p ( q is possible" is greater than "the degree to which p ( (q is possible". Given the choice of this constraint, we study two supplementary postulates of rationality. Eighty-eight subjects participated in an experiment whose results confirm - provided that reflexivity and left logical equivalence would be tested in a further experiment - the rationality of human nonmonotonic inference according to the rational postulates of System P. (shrink)

ABSTRACT In the current debate between scientific realism and empiricism, both sides seem to embrace some sort of structuralism as an important component of their descriptions of science. The structural realism is generally presented in two versions: one ontic and the other epistemic. It has been argued that that epistemic structural realism is close, if not identical, to a Kantian approach. We aim to show that this is not the case, since ESR, being fundamentally a realist position, cannot be fully (...) consistent with a transcendental approach. Such a position is better called transcendental structuralism, an alternative that we believe is worth being investigated on its own. In this paper, we will take Henry Allison's interpretation of transcendental idealism as a starting point to establish the distinctions between ESR and TS.RESUMO No debate atual entre realismo científico e empirismo, ambos os lados parecem abraçar algum tipo de estruturalismo como um componente importante de suas descrições sobre a ciência. O realismo estrutural é geralmente apresentado em duas versões: uma ôntica e outra epistêmica. Tem-se argumentado que o realismo estrutural epistêmico, por sua vez, é próximo, se não idêntico, a uma abordagem kantiana. Nosso objetivo neste artigo é mostrar que esse não é o caso. Sendo o ESR fundamentalmente uma posição realista, queremos defender que ele não pode ser totalmente compatível com uma abordagem transcendental. Uma posição kantiana mais coerente é aqui defendida sob o nome de estruturalismo transcendental. Neste artigo, partiremos da interpretação de Henry Allison do idealismo transcendental para estabelecer as devidas distinções entre ESR e TS. (shrink)

Preference queries from databases aim to retrieve the best answers w.r.t. user's requirements. The integration of preferences in database queries has known many advances in the last decade. Most of works however are based on comparative preference statements obeying more or less strong semantics. Representing and reasoning about comparative preference statements has also been widely investigated in Artificial Intelligence. In this paper, we bridge the two frameworks and develop a simple and unified framework to reason about preferences in database queries. (...) Our framework is based on insights from non-monotonic reasoning. (shrink)

This article starts with a historical questioning of postmodernity religious phenomenon, revisiting the "Masters of Suspicion", trying to detect the "perversions" of religion. The article presents the spirituality as something different from religion. Spirituality as the expression of the ancient spiritual traditions and religion as their historical formulations. It is argued that a Holistic Spirituality would seek convergences between all spiritual traditions. From that point we examine some of the major contemporary challenges, namely neoliberalism, postmodernity, as well as matters relating (...) to Justice, Peace and Ecology. The holism is indicated as output to a new paradigm. Finally, we intend to combine the holistic paradigm to the paradigm of liberation theology. Thus, the article concludes with practical issues: the problem of mediations of God's Kingdom, for example: a) the Christian churches today would be mediating the Kingdom? What about the religious life); b) some urgent issues of justice, peace, ecological respect, option for the poor and oppressed, looking for a non-capitalist economic model and more direct democracy, the need for active non-violence, the presence of grace in the midst of strategic and tactics mediations, as well as practice Spirituality following the Master of Galilee. (shrink)

A publicação de Signos (1897), de Nestor Victor, é um marco na expansão conceitual do Simbolismo no Brasil e nas reflexões acerca dos problemas da civilização no fim de século. Verifica-se nos seus contos a presença do heterodiscurso, sendo fundamental a voz de Arthur Schopenhauer, tendo como referência a sua obra Metafísica do Amor. Por outro lado, o narrador desenvolverá uma voz que se oporá ao maquinismo do amor, a essa determinação dos sentimentos pelo dever biológico. No universo de Signos, (...) levando-se em conta a grande verdade sobre a natureza, revelada pelo filósofo, os casais não mais se encontrarão, uma vez que a paixão se esgota no tédio por causa da violência do instinto. (shrink)

Papers presented at the 6th BRICS Academic Forum held in Rio de Janeiro, Brazil in 2014.