This paper is concerned with formal aspects of the logic of theory change, and in particular with the process of shrinking or contracting a theory to eliminate a proposition. It continues work in the area by the authors and Peter Gärdenfors. The paper defines a notion of safe contraction of a set of propositions, shows that it satisfies the Gärdenfors postulates for contraction and thus can be represented as a partial meet contraction, and studies its properties both in general and (...) under various natural constraints. (shrink)

Investigates the resolution of contradictions and ambiguous derogations in a code, by means of the imposition of partial orderings.

In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose (...) of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open. (shrink)

The main purpose of this paper is to explore the role played by logic in the legal domain. In the traditional conception which underlies the movement of codification, judges are able to find in the legal system (the Master System) a unique answer for every legal problem. This entails its completeness, consistency and the possibility of deriving from it the contents of all judicial decisions. Although the ideal model of this conception is supported by important theoretical and political ideals, it (...) has significant shortcomings. The elements of normative systems (Master Systems) are “norms” and not mere “norm-formulations.” A “norm” is the meaning attributed to normative linguistic expressions. The set of all normative expressions, such as statutes, codes, etc. forms what is called the Master Book. One of the main problems for the ideal model is the identification of a normative system behind the Master Book. Interpretative arguments are the tools designed to solve these problems. Although the requirements of the model are not totally fulfilled in actual practice, it remains as an effective ideal rational goal behind legal activities linked to adjudication and most theoretical approaches to law. (shrink)

Este artigo pretende expor a teoria cartesiana da criação encontrada nas Meditações, da qual decorre coerentemente a teoria da livre criação das verdades eternas desenvolvida por Descartes nas Cartas, entre os anos de 1630 e 1649. Fazendo isso, tenta-se refutar interpretações segundo as quais a teoria da livre criação seria marginal ou incompatível com o sistema cartesiano. Para tanto, apresentaremos a concepção tomasiana da criação e a gradativa refutação cartesiana da mesma, donde emerge uma moderna teoria da criação, fundamento sine (...) qua non da teoria da livre criação das verdades eternas. (shrink)

Davidson’s treatment of akrasia resorts to the introduction of a type of operator, the prima facie connector. This operator should yield conditional judgments in which the affirmation of the antecedent does not admit to obtain the consequent as a separate conclusion; and it must allow to separate ..

A study in the logic of theory change, examining the properties of maxichoice contraction and revision operations.

Standardly, the usual approach to rationality is based on the notion of ‘being a reason for’. Honouring the traditional distinction between practical and theoretical philosophy, reasons are classified as justificative and explicative. In both cases, a reason-statement has the form ‘’. For reasons of type , ‘A’ is a factual statement and ‘B’ is a statement which describes an action of the agent. The reason-statement has a prescriptive sense because ‘A is a reason for doing B’ means ‘A is a (...) reason an agent ought to do B’. So, it is advisable to schematize that kind of statements as ‘’, where ‘OB’ is a deontic statement prescribing the duty to do B. Reasons of type have a descriptive sense and do not require the above-mentioned constraint. But ‘being a reason for’ has different senses according to context, even when the distinction between justificative and explicative reasons is drawn. Accordingly, it is important to distinguish two basic types of reasons: sufficient and necessary, and two subordinate types of reasons: contributing and substitutive . A lot of attention has been paid, lately, to a sense of contributive reasons: prima facie reasons . The paper will deal with that kind of reasons. Its main thesis are: 1) prima facie reason-statements are defeasible conditionals ‘’ pointing out that A is a contributing condition of B, 2) a defeasible conditional has the properties of ‘’, where ‘ =>’ is a strict implication and ‘f’’ a revision-operator satisfying the conditions set up by the theory AGM on the rational change of theories. (shrink)

1. EI dilema de Jørgensen. 2. La salución propuesta. 3. Breve historia de un prejudicio filosófico. 4. Normas sin lógica. 4.1. Imperativos sin lógica. 4.2. Normas y proposicienesnormativas. 4.3. Proposiciones normativas y normas verdaderas. 4.4. Mundos posibles. 4.5. Validez e invalidez. 4.6. La racionalidad del legislador. 5. La noción abstracta, sintáctica y semántica de consecuencia. 5.1. La noción abstracta de consecuencia. 5.2. La noción sintáctica de consecuencia. 5.3. La noción semántica de consecuencia. 5.4. EI sentido dado por las reglas de (...) uso en un contexto. 5.5. Qué operadores para la lógica. 5.6. Solo en un contexto la parte cobra sentido. 6. La lógica deóntica. 7. De donde la solución del dilema interesa a toda la lógica. 8. Consecuendas para la informática. (shrink)

Teniendo como punto de partida el importante intercambio crítico entre John Rawls y Jürgen Habermas desplegado en The Journal of Philosohy en marzo de 1995, el presente escrito tiene por objetivo explorar el lugar que ocupa el consenso en la fundamentación del pensamiento político de ambos autores. De modo tal que pueda ponerse en evidencia el carácter intersubjetivo que subyace tanto en los planteos de la teoría de la justicia de Rawls como en la ética del discurso habermasiana. Lo anterior, (...) en efecto, implica un ejercicio conceptual que decanta en el esclarecimiento de dos sendas argumentativas, ambas herederas de una interpretación de Kant, encauzadas a dar solución a la fundamentación de principios morales en las sociedades plurales contemporáneas. (shrink)

The purpose of the paper is to present a logical framework that allow to formalize a kind of prima facie duties, defeasible conditional duties, indefeasible conditional duties and actual (indefeasible) duties, as well as to show their logical interconnections.

Between the two horns of Jørgensen's dilemma, the authors opt for that according to which logic deals not only with truth and falsity but also with those concepts not possessing this semantic reference. Notwithstanding the “descriptive” prejudice, deontic logic has gained validity among modal logics. The technical foundation proposed consists in an abstract characterization of logical consequence. By identifying in the abstract notion of consequence the primitive from which to begin, it is possible to define the connectives - even those (...) of obligation - by means of the rules of introduction or elimination in a context of derivation. (shrink)

Este artículo hace una presentación de un tema que ha sido pasado por alto en la filosofía, la filosofía de la ciencia y las ciencias de la complejidad, a saber: la importancia de las ciencias sociales y el modo como pueden beneficiarse con las matemáticas de los sistemas dinámicos. Por tanto, el ar..

La filosofía de la nada fue la respuesta ofrecida por Kitaro Nishida a la necesidad de asentar las bases de un diálogo filosófico con Occidente. Se propone en este trabajo que ese diálogo que todavía prosigue en la Escuela de Kyoto tenga entre uno de sus referentes occidentales a la filosofía del límite de Eugenio Trías. Para ello, y tras un repaso de los conceptos principales de cada propuesta filosófica, se considerará la adecuación del método categorial de análisis histórico propuesto (...) por Trías y se estudiarán los conceptos fundantes de «nada» y «límite», que a su vez son la base para una ética humanista capaz de entablar un diálogo entre las dos culturas. (shrink)

Mucopolysaccharidosis type I (MPS I) is a rare lysosomal storage disorder treated with bone marrow transplantation or enzyme replacement therapy with laronidase, a high-cost orphan drug. Laronidase was approved by the US Food and Drug Administration and the European Medicines Agency in 2003 and by the Brazilian National Health Surveillance Agency in 2005. Many Brazilian MPS I patients have been receiving laronidase despite the absence of a governmental policy regulating access to the drug. Epidemiological and treatment data concerning MPS I (...) are scarce. This study aims to present a demographic profile of Brazilian patients with MPS I, describe the routes of access to laronidase in Brazil, and discuss associated ethical issues relating to public funding of orphan drugs. (shrink)

Over recent years, the research community has been increasingly using preprint servers to share manuscripts that are not yet peer-reviewed. Even if it enables quick dissemination of research findings, this practice raises several challenges in publication ethics and integrity. In particular, preprints have become an important source of information for stakeholders interested in COVID19 research developments, including traditional media, social media, and policy makers. Despite caveats about their nature, many users can still confuse pre-prints with peer-reviewed manuscripts. If unconfirmed but (...) already widely shared first-draft results later prove wrong or misinterpreted, it can be very difficult to “unlearn” what we thought was true. Complexity further increases if unconfirmed findings have been used to inform guidelines. To help achieve a balance between early access to research findings and its negative consequences, we formulated five recommendations: (a) consensus should be sought on a term clearer than ‘pre-print’, such as ‘Unrefereed manuscript’, “Manuscript awaiting peer review” or ‘’Non-reviewed manuscript”; (b) Caveats about unrefereed manuscripts should be prominent on their first page, and each page should include a red watermark stating ‘Caution—Not Peer Reviewed’; (c) pre-print authors should certify that their manuscript will be submitted to a peer-review journal, and should regularly update the manuscript status; (d) high level consultations should be convened, to formulate clear principles and policies for the publication and dissemination of non-peer reviewed research results; (e) in the longer term, an international initiative to certify servers that comply with good practices could be envisaged. (shrink)

El presente trabajo investiga las tesis sobre el poder civil de Alonso de la Veracruz que buscan incorporar en la comunidad política española a los habitantes autóctonos del Nuevo Mundo, tesis que suelen relacionarse con F. de Vitoria y el tomismo español, y que últimamente son consideradas parte del republicanismo novohispano elaborado desde la periferia americana. Se busca demostrar que su propósito era aplicar una teoría de derechos naturales, sin que ello implique participación política de los indios americanos. Se analiza (...) la postura del fraile frente a la diversidad cultural y la guerra contra los indios. The paper explores Alonso de la Veracruz's theses on civil power, which sought to integrate the native inhabitants of the New World into the Spanish political community. These theses, which have usually been associated with F. de Vitoria and Spanish Thomism, have recently come to be considered part of a Novohispanic republicanism developed in the American periphery. The article seeks to show that the purpose of such theses was to apply a theory of natural rights that did not entail the political participation of the indigenous population, as well as to analyze Veracruz's position regarding cultural diversity and the war against the indigenous peoples. (shrink)

We report three experimental studies of reasoning with double conditionals, i.e. problems based on premises of the form: If A then B. If B then C. where A, B, and C, describe everyday events. We manipulated both the logical structure of the problems, using all four possible arrangements (or ''figures" of their constituents, A, B, and C, and the believability of the two salient conditional conclusions that might follow from them, i.e. If A then C , or If C then (...) A . The experiments showed that with figures for which there was a valid conclusion, the participants more often, and more rapidly, drew the valid conclusion when it was believable than when it was unbelievable. With figures for which there were no valid conclusions, the participants tended to draw whichever of the two conclusions was believable. These results were predicted by the theory that reasoning depends on constructing mental models of the premises. (shrink)

O texto tem como objetivo discutir acerca de uma estratégia metodológica para análise de dados em estudos de pesquisa-ação fundamentada na teoria de Jürgen Habermas, denominada por Círculos Argumentativos. Concebe-se a pesquisa-ação para além de uma abordagem metodológica, que tem como pressupostos centrais a relação entre pesquisador e participante, e da ação para a mudança. Assim, a pesquisa-ação, em virtude de sua processualidade, necessita de um método de análise capaz de explorar, em conjunto com os autores-pesquisadores, os distintos movimentos do (...) fazer a pesquisa, tendo a ação como condutora desse processo. Dessa forma, a ação comunicativa de Habermas apresenta fundamentos teóricos que permitem essa construção, considerando os conceitos de pretensões de validade, argumento, entendimento mútuo e a busca por consensos provisórios. Assim os Círculos Argumentativos, concebidos como espaço de debate para que os enunciados do mundo social na pesquisa educacional sejam problematizados e as pretensões de validade sejam desafiadas, se organizam enquanto espaços de retomada dos momentos para escuta do outro, buscando o diálogo com os autores-pesquisadores seja por meio de argumentos escritos ou pelos argumentos ditos. As contribuições deste estudo apontam que os Círculos Argumentativos não apenas permitem uma análise crítica dos dados, como também, promovem a autorreflexão dos autores e atores envolvidos. Portanto, o processo comunicativo, centrado na racionalidade comunicativa, oferece uma via metodológica robusta para superar as limitações da racionalidade instrumental predominante na pesquisa científica, especialmente em áreas como a educação. (shrink)

Fornece um panorama sobre os avanços biotecnológicos, dando ênfase aos aspectos jurídicos e éticos do impacto destes na área genética sobre o homem e o meio ambiente.

Neste artigo partimos da hipótese de que a afinidade que atrai evangélicos e conservadorismo está muito mais ligada às condições discursivas que engendram os sujeitos e suas subjetividades, do que as características intrínsecas à teologia cristã ou, especificamente, evangélica pentecostal. Com isso não queremos dizer que conformações teológicas específicas não ensejaram discursos religiosos regressivos, que a maioria de nós classificaria como conservador. Assim, chamamos a atenção, tanto para o caráter relacional, posicional das identidades evangélicas, que engendram o discurso conservador, quanto (...) para a base material deste discurso, ligando, portanto, sujeitos e formas de sujeição e subjetivação. Interessam-nos, as formas políticas em que se precipitarão os antagonismos articulados a partir dos grupos de identidade evangélica, bem como os deslocamentos na base material destes sujeitos, que possibilitam o engendramento de subjetividades atomizadas e refratárias a solidariedades coletivas exógenas a sua comunidade. Defenderemos que, embora evangélicos tenham ganhado relevo no espaço público por pautas reativas à ampliação de direitos de minorias, tais ações não se devem unicamente a aspectos intrínsecos à teologia pentecostal, ou ao seu caráter alienante ou irracional, mas, principalmente a forma como se posicionam no jogo político nacional, ou melhor, como se publicizaram, bem como a forma como o discurso de fundo conservador é acionado como estratégia de sobrevivência nas grandes cidades. (shrink)

This commentary is a critical appraisal of Gil-Pérez et al.'s (2002) conceptualization of constructivism. It is argued that the following aspects of their presentation are problematic: (a) Although the role of controversy is recognized, the authors implicitly subscribe to a Kuhnian perspective of `normal' science; (b) Authors fail to recognize the importance of von Glasersfeld's contribution to the understanding of constructivism in science education; (c) The fact that it is not possible to implement a constructivist pedagogy without a constructivist epistemology (...) has been ignored; and (d) Failure to recognize that the metaphor of the `student as a developing scientist' facilitates teaching strategies as students are confronted with alternative/rival/conflicting ideas. Finally, we have shown that constructivism in science education is going through a process of continual critical appraisals. (shrink)

En este texto se discuten los principales desarrollos de Alain Badiou en cuanto a las aportaciones de las matemáticas a una ontología materialista de lo múltiple, desde una perspectiva platónica; a través de éstas Badiou pretende enfrentar el reto que implica la antifilosofía de Jacques Lacan. Posteriormente, con base en la crítica que Slavoj Žižek realiza a las nociones de presentación y representación de Badiou, se juzgan los límites y las posibilidades de su propuesta ontológica.