O objetivo deste trabalho é apresentar a versão carrolliana de dois paradoxos clássicos e um original, acompanhadas da reconstrução e exame do tratamento lógico oferecido por Carroll e de como tais paradoxos foram tratados por outros autores.

Most, perhaps all, non-classical logics are a blend of classical logic with extralogical elements. Possibly this thesis has no general proof, and only a casuistic argument can be provided. I discuss a case of paraconsistency that results of applying a “filter” to two syllogistics. These syllogistics incorporate two ideas of Nikolai Vasiliev: the idea of a complete system of contrary judgements, and the idea of double judgements. I also show how these results can be extended to propositional logic, with the (...) aid of the conjunctive and disjunctive normal forms. Despite the non-classical appearance, it is used, without exception, the classical notion of deductive validity: a conclusion cannot carry more information, but may carry less information than the information carried by the collection of the premisses. (shrink)

I provide a proof method for First Order Monadic Predicate Logic. This method uses the Normal Form of Herbrand and the Disjunctive and Conjunctive Normal Forms for Propositional Logic. The validity is determined by mere inspection of the presence and arrangement of formulas that act as informational atoms. The exact relationship between First Order Monadic Predicate Logic and the extended syllogistic developed during the nineteenth century is established by the Normal Form of Herbrand.

A maioria, talvez todas, as lógicas não-clássicas são um amálgama da lógica clássica com elementos extralógicos. Possivelmente esta tese nao possui uma prova geral, mas somente um argumento caso a caso possa ser fomecido. Discuto um caso de paraconsistência que resulta da aplicação de urn "filtro" a duas silogísticas. Essas silogísticas incorporam duas idéias de Nikolai Vasiliev: a idéia de um sistema completo de juízos contrários, e a idéia de juízos duplos. Tarnbém mostro como esses resultados podem ser estendidos à (...) lógica proposicional, com a ajuda das formas nornais conjuntiva e disjuntiva. Apesar da aparencia não-clássica, utilize-se, sem exceção, a noção clássica de validade dedutiva: uma conclusão não pode veicular mais inforrnação, mas pode veicular menos inforrnação, do que a informação veiculada pelo conjunto das premissas. (shrink)

O Método de Gardner – um método por dígrafos para a Silogística – implementa a concepção de proposições categóricas como expressões de subordinação e de não-subordinação entre pares de conceitos; nele, a representação das proposições universais é mais complexa do que a representação das proposições particulares. Neste trabalho desenvolverei uma implementação da Silogística na qual as proposições categóricas são expressões de instanciação e de não-instanciação de pares de conceitos. Adaptarei o Sistema Beta dos Grafos Existenciais de Peirce ao Método de (...) Gardner. Essa adaptação tem o mérito de igualar a complexidade da representação das proposições categóricas, mas introduz outros inconvenientes. (shrink)

As Redes Dialéticas visam a representação dos elementos de uma disputa: as asserções do Proponente e do Oponente, e as ações de ataque e de defesa. Proponho uma representação diagramática – o Diagrama Dialético – e uma representação algébrica – o Grafo Dialético – das Redes Dialéticas. Este trabalho está limitado aos aspectos estático-estruturais das Redes Dialéticas.

Anthony Shiver (2013) desenvolveu dois jogos de cartas lógicas para a prática da derivação no contexto da Lógica Proposicional Clássica. Embora ele tenha apresentado os contornos gerais desses jogos, muitos detalhes do desenho deles estão faltando. Neste artigo proponho uma metodologia para o desenho detalhado do primeiro dos jogos de Shiver. Esta metodologia utiliza uma abordagem informacional para a seleção das cartas do baralho, que conforma-se a critérios de alcançabilidade de cada carta e de balanço entre elas.

Hume's Law, according to which an ought cannot result from an is, and its reciprocal, according to which an is cannot result from an ought, occupy salient positions in discussions on metaethics. In this paper I will show logical relations between distinct formulations of Hume's Law and of its reciprocal. I will show, also, how these formulations are related to theses sustained by important thinkers such as Poincaré, Nelson, Jörgensen and Hare.A Lei de Hume, pela qual um dever ser não (...) pode resultar de um ser, e a sua recíproca, pela qual um ser não pode resultar de um dever ser, ocupam posições proeminentes nas discussões de metaética. Neste trabalho mostrarei relações lógicas entre distintas formulações da Lei de Hume e da sua recíproca. Também mostrarei como essas formulações estão relacionadas a teses sustentadas por importantes pensadores como Poincaré, Nelson, Jörgensen e Hare. (shrink)

: I give two interpretations of the supreme rules of all syllogisms provided by Kant in his pre-critical essay “The False Subtlety of the Four Syllogistic Figures”. One interpretation understands literally, i.e., grammatically, the expressions ‘positive syllogism’ and ‘negative syllogism’; the other interprets them non-literally, i.e., it interprets them logically.

In the present paper, I raise some questions referring to Chateaubriand’s discussion of the nature of language, its origin, its development and its functions in human live. These questions arise when his view is compared with the partly similar views defended by Gödel and Jørgensen, among others.No presente trabalho levanto algumas questões referentes à discussão de Chateaubriand sobre a natureza da linguagem, sua origem, seu desenvolvimento e suas funções na vida humana. Essas questões surgem quando seu ponto de vista é (...) comparado aos pontos de vista parcialmente similares defendidos por Gödel e Jorgensen, entre outros. (shrink)

Analisarei estruturas resultantes da utilização coordenada de múltiplos silogismos, e investigarei o problema de normalização de tais estruturas.

Formulações da validade dedutiva clássica costumam recorrer explicitamente a modalidades: por exemplo, um argumento é classicamente dedutivamente válido se, e somente se, necessariamente se as premissas forem verdadeiras, a conclusão também é verdadeira. Não é possível abolir completamente esse apelo ao discurso modal, porque a lógica clássica é o domínio das possibilidades. Não obstante, pode-se, por intermédio de uma semântica informacional, evitar que o usuário da lógica clássica tenha de manipular modalidades, ainda que elas estejam, de algum modo, imbricadas nos (...) infons – unidades mínimas de informação. A partir do trabalho pioneiro de Carnap e de Bar-Hillel, apresentarei duas semânticas informacionais: uma delas diretamente relacionada a mundos possíveis, e a outra relacionada aos duais de mundos possíveis. (shrink)

A formalização de noções pré-teóricas não é uma ciência, mas uma arte. Isso se evidencia quando temos de decidir o que é indispensável e o que é prescindível na passagem do intuitivo para o formal. Exemplifico esse tipo de dificuldade com a formalização de uma noção intuitiva de coleção finita de objetos. A observância de maior fidelidade à noção pré-teórica, mesmo que desnecessária da perspectiva formal, resultou em duas novas definições de conjunto finito.

A Lei de Hume, pela qual um dever ser não pode resultar de um ser, e a sua recíproca, pela qual um ser não pode resultar de um dever ser, ocupam posições proeminentes nas discussões de metaética. Neste trabalho mostrarei relações lógicas entre distintas formulações da Lei de Hume e da sua recíproca. Também mostrarei como essas formulações estão relacionadas a teses sustentadas por importantes pensadores como Poincaré, Nelson, Jörgensen e Hare.

O livro reúne textos apresentados no II Workshop de Filosofia e Ensino, realizado na UFRGS em 2015, com a temática "Epistemologia e Currículo" -/- .

Frank Sautter’s questions are directed at the precise senses of the words ‘invention’ and ‘creation’ used in my remarks on the origin of language, and at the connection between Jørgensen’s and my views on the development of language. In my response I clarify my use of the words ‘invention’ and ‘creation’ vis-à-vis Frank’s suggested interpretations, and examine Jørgensen’s distinction of stages in the development of language in relation to imperatives and the “directive use of language”.As perguntas de Frank (...) class='Hi'>Sautter estão direcionadas ao sentido mais preciso das palavras ‘invenção’ e ‘criação’ utilizadas em minhas observações sobre a origem da linguagem, e à relação de meu ponto de vista sobre o desenvolvimento da linguagem ao de Jørgensen. Em minha réplica esclareço meu uso das palavras ‘invenção’ e ‘criação’ comparativamente às diversas interpretações sugeridas por Frank, e examino a distinção de estágios no desenvolvimento da linguagem proposta por Jørgensen em relação aos imperativos e ao “uso direcionado da linguagem”. (shrink)

This paper presents, assesses, and compares six diagrammatic methods for Categorical Syllogistic. Venn’s Method is widely used in logic textbooks; Carroll’s Method is a topologically indistinguishable version of Venn’s Method; and the four remaining methods are my own: the Dual of Carroll’s Method, Gardner’s Method, Gardner–Peirce’s Method, and Ladd’s Method. These methods are divided into two groups of three and the reasons for switching from a method to another within each group are discussed. Finally, a comparison between the Dual of (...) Carroll’s Method and Ladd’s Method supports the main result of the paper, which is an approximation of the two groups of methods. (shrink)

I present the realist conception of logic supported by Oswaldo Chateaubriand which integrates ontological and epistemological aspects, opposing it to mathematical and linguistic conceptions. I give special attention to the peculiarities of his hierarchy of types in which some properties accumulate and others have a multiple degree. I explain such deviations of the traditional conception, showing the underlying purpose in each of these peculiarities. I compare the ideas of Chateaubriand to the similar ideas of Frege, Tarski and Gödel. I suggest (...) a view of the logical properties in terms of the Aristotelian notion of focal meaning and I give a formal expression to the type of the entities in the hierarchy proposed by Chateaubriand. (shrink)

A Lógica Contemporânea dá pouca ou, mesmo, nenhuma atenção à construção de argumentos para uma conclusão dada, diferentemente do que ocorre nos Analíticos Anteriores, de Aristóteles. O procedimento de Aristóteles foi, posteriormente, compilado sob a forma de um diagrama lógico conhecido como “Ponte de Asnos” (Pons Asinorum). Neste trabalho proponho um procedimento para a construção de argumentos para uma dada conclusão, no âmbito da Lógica Proposicional Clássica, abstraído do procedimento de Aristóteles. Utilizo a noção de informação semântica como fio de (...) Ariadne para a obtenção do procedimento. (shrink)

After haring presented statistical data, an ethical framework for analysing the poverty-problem is discussed, using this framework the roots of the poverty-problem are analyzed: poverty causing rules of allocation and of distribution, deficient transfer systems. Basing on this analysis the elements of an anti-poverty strategy are shown.

I will apply a technique employed by Giovanni Girolamo Saccheri in Logica demonstrative to concisely prove the invalidity of moods of the First Figure of the Theory of the Assertoric Syllogism without appealing to facts outside logic.

In this paper Chateaubriand’s approach to solve some problems related to the nature of logic is confronted with the traditional approaches. It is shown that his hierarchy of logical types opens up new possibilities to characterize logical properties and logical truths and that it also sheds some new light on the foundations of mathematics.

Autor (2020) desenvolveu duas semânticas informacionais para a Lógica Sentencial Clássica, decorrentes da utilização de formais normais. A abordagem informacional em questão utiliza unidades mínimas de informação (infons) para realizar o trabalho lógico. Neste artigo, expandiremos a aplicação da abordagem informacional às lógicas sentenciais polivalentes finitas mediante um procedimento dedicado à extração de unidades mínimas de informação (infons). Tal procedimento decorre do trabalho com tablôs semânticos para Lógicas Sentenciais Polivalentes Finitas desenvolvido por Carnielli (1982).

The article deals with the crisis of the German welfare system. Protestant churches are challenged by this crisis. Six challenges are discussed: Recognize facts. One fact is, that the economies of countfies like Germany cannot be separated from the trend of economic globalization. It is every country's position in global economic competition which determines the possible Ievel of its national welfare. A secend fact is, that the present old-age insurance system cannot be maintained. The third fact mentioned is the inconsistency (...) of the system of social security. Becoming open for economic thinking: Solidarity is not possible against but only in conformity with economic rationality. Understand the worldwide dimension of solidarity: lt is exactly economic globalization which promotes worldwide solidarity. Promote selfresponsibility: Those who are able to help themselves should do so more than before so that assistance for the helpless can be maintained. Stimulate innovations in the field of social policy: An example is the negative income tax. Protect the needy: This is indispensable, and it corresponds not only to christian convictions but also to the enlightened self-interest of a secular society. (shrink)

In recent years, there has been heightened concern regarding the marketing of potentially harmful products (PHPs) to disadvantaged markets. Three issues which commonly dominate discussions in this controversy are: (1) the potential for exploitation of vulnerable markets, (2) the tradeoff between protection of disadvantaged consumers and their rights to make informed choices and (3) the appropriateness of using the commercial speech doctrine to settle the issue of targeting minority markets with PHPs. This paper examines the arguments raised in this debate (...) so that interested parties will better appreciate the ethical complexity of marketing PHPs to minority segments. (shrink)

The moral doctrine of Hobbes, in many ways the most interesting of our major British philosophers, is, I think, commonly seen in a false perspective which has seriously obscured its real affinities. This is, no doubt, largely due to the fact that most modern readers begin and end their study of Hobbes's ethics with the Leviathan , a rhetorical and, in many ways, a popular Streitschrift published in the very culmination of what looked at the time to be a permanent (...) revolution, and do not pay such attention to the more calmly argued statements of the same doctrine contained in the Elements of Law , circulated before the outbreak of the Civil War, or the De Cive. (shrink)

De Vries' mutation theory has not stood the test of time. The supposed mutations of Oenothera were in reality complex recombination phenomena, ultimately explicable in Mendelian terms, while instances of large-scale mutations were found wanting in other species. By 1915 the mutation theory had begun to lose its grip on the biological community; by de Vries' death in 1935 it was almost completely abandoned. Yet, as we have seen, during the first decade of the present century it achieved an enormous (...) popularity. As this paper has tried to suggest, one of the principal reasons for this was that de Vries' theory served as a banner around which a whole crowd of disaffected Darwinians or anti-Darwinians could rally. However, not all of those who favored de Vries did so for quite the same reasons. Underlying the multitude of views ran several common threads: a dissatisfaction with current Darwinian theory born out of misunderstanding natural selection, a general misunderstanding of the nature of species, and a prejudice against speculative, nontestable theories in biology.Supporters of de Vries were not the only opponents of Darwinism, nor was the mutation theory the only alternative to natural selection. In the early twentieth century a number of theories had been proposed to explain away the problems which Darwin had left unsolved. There was the idea of orthogenesis, championed by the American paleontologists Cope, Osborn and others; organic selection (or orthoplasy) was championed by M. M. Baldwin and C. Lloyd Morgan; there were the concepts of convergent evolution proposed by Hermann Friedmann, the theory of physiological selection by John George Romanes, and the concepts of reproductive divergence by H. M. Vernon. Virtually none of these men either accepted or were strong supporters of the de Vriesian theory, for each had his own particular ‘ism” to advocate as the major factor in evolution. The existence of a large number of such theories, each purporting to be the explanation, was characteristic of evolutionary theory at the turn of the century. It is to a large extent the emphasis on such fragmentary concepts that retarded development of the comprehensive theory of evolution which emerged in the 1920's and 1930's. For the historian, however, a study of these alternative theories is instructive in trying to understand the inherent difficulties which Dawwinian theory posed to biologists at the time. De Vries' mutation theory serves historically as a mirror to reflect the critical mood of a generation hostile to the theory of natural selection.It has often been claimed that it was impossible to understand the mechanism of natural selection until it could be placed in genetic and mathematical terms. It is certainly true that great strides have been made in population genetics and the treatment of evolutionary concepts with mathematical tools in the last forty years. But the very people who developed the genetical and mathematical approach to evolution were already convinced of the essential correctness of Darwinian theory before they started. Advances in an understanding of Mendelian heredity aided greatly in solving one important issue for evolutionists: the origin of variations. And the rigor with which selection acted could best be studied by observing changes in gene frequencies (calculated mathematically) over a number of generations. But as this paper has shown, two of the basic problems which biologists faced in evaluating Darwinian theory at the turn of the century-the nature of species, and the criteria of what constituted an acceptable explanation in biological science-could not be answered directly by mathematics. What mathematical and genetical theory did do was to help convince the skeptics of the validity of the Darwinian proposition.The change in explanatory criteria which many hailed as de Vries' most important contribution to evolutionary theory seems to have been part of a general emergence of twentieth-century biology from the domination of theorizers in the nineteenth. It also marked the emergence of America from the domination of biological, and particularly evolutionary, influence of Europeans. The change occurred in three areas: in the kinds of questions asked: testable versus non-testable; in the kind of data sought: quantitative versus qualitative; and in the kinds of theories proposed: analytical and reductive—the attempt to see complex processes in terms of simpler components-as opposed to synthetic and speculative. Although ultimately wrong in his idea, de Vries and his theories rode high on the wave of “experimentalism” which was the harbinger of a new era in evolutionary theory. (shrink)

Ethics teaching in engineering can be problematic because of student perceptions of its subjective, ambiguous and philosophical content. The use of discipline-specific case studies has helped to address such perceptions, as has practical decision making and problem solving approaches based on some ethical frameworks. However, a need exists for a wider range of creative methods in ethics education to help complement the variety of activities and learning experiences within the engineering curriculum. In this work, a novel approach is presented in (...) which first-year undergraduate students are responsible for proposing ethics education activities of relevance to their peers and discipline area. The students are prepared for the task through a short introduction on engineering ethics, whereby generic frameworks for moral and professional conduct are discussed, and discipline and student-relevance contexts provided. The approach has been used in four departments of engineering at Imperial College London, and has led to the generation of many creative ideas for wider student engagement in ethics awareness, reflection and understanding. The paper presents information on the premise of the introductory sessions for supporting the design task, and an evaluation of the student experience of the course and task work. Examples of proposals are given to demonstrate the value of such an approach to teachers, and ultimately to the learning experiences of the students themselves. (shrink)

The purpose of this study was to determine the opinions and expectations of patients and nurses about privacy during a hospital admission for surgery. The study explored what enables and maintains privacy from the perspective of Turkish surgical patients and nurses. The study included 102 adult patients having surgery and 47 nurses caring for them. Data were collected via semistructured questionnaire by face-to-face interviews. The results showed that patients were mostly satisfied by the respect shown to their privacy by the (...) nurses but were less confident of the confidentiality of their personal data. It was found that patients have expectations regarding nursing approaches and attitudes about acknowledging and respecting patient autonomy and confidentiality. It is remarkable that while nurses focused on the physical dimension of privacy, patients focused on informational and psychosocial dimensions of privacy, as well as its physical dimension. (shrink)