The purpose of this paper is to present a paraconsistent formal system and a corresponding intended interpretation according to which true contradictions are not tolerated. Contradictions are, instead, epistemically understood as conflicting evidence, where evidence for a proposition A is understood as reasons for believing that A is true. The paper defines a paraconsistent and paracomplete natural deduction system, called the Basic Logic of Evidence, and extends it to the Logic of Evidence and Truth. The latter is a logic of (...) formal inconsistency and undeterminedness that is able to express not only preservation of evidence but also preservation of truth. LETj is anti-dialetheist in the sense that, according to the intuitive interpretation proposed here, its consequence relation is trivial in the presence of any true contradiction. Adequate semantics and a decision method are presented for both BLE and LETj, as well as some technical results that fit the intended interpretation. (shrink)

In this paper we present a philosophical motivation for the logics of formal inconsistency, a family of paraconsistent logics whose distinctive feature is that of having resources for expressing the notion of consistency within the object language in such a way that consistency may be logically independent of non-contradiction. We defend the view according to which logics of formal inconsistency may be interpreted as theories of logical consequence of an epistemological character. We also argue that in order to philosophically justify (...) paraconsistency there is no need to endorse dialetheism, the thesis that there are true contradictions. Furthermore, we show that mbC, a logic of formal inconsistency based on classical logic, may be enhanced in order to express the basic ideas of an intuitive interpretation of contradictions as conflicting evidence. (shrink)

From the technical point of view, philosophically neutral, the duality between a paraconsistent and a paracomplete logic lies in the fact that explosion does not hold in the former and excluded middle does not hold in the latter. From the point of view of the motivations for rejecting explosion and excluded middle, this duality can be interpreted either ontologically or epistemically. An ontological interpretation of intuitionistic logic is Brouwer’s idealism; of paraconsistency is dialetheism. The epistemic interpretation of intuitionistic logic is (...) in terms of preservation of constructive proof; of paraconsistency is in terms of preservation of evidence. In this paper, we explain and defend the epistemic approach to paraconsistency. We argue that it is more plausible than dialetheism and allows a peaceful and fruitful coexistence with classical logic. (shrink)

This paper introduces the logic of evidence and truth \ as an extension of the Belnap–Dunn four-valued logic \. \ is a slightly modified version of the logic \, presented in Carnielli and Rodrigues. While \ is equipped only with a classicality operator \, \ is equipped with a non-classicality operator \ as well, dual to \. Both \ and \ are logics of formal inconsistency and undeterminedness in which the operator \ recovers classical logic for propositions in its (...) scope. Evidence is a notion weaker than truth in the sense that there may be evidence for a proposition \ even if \ is not true. As well as \, \ is able to express preservation of evidence and preservation of truth. The primary aim of this paper is to propose a probabilistic semantics for \ where statements \\) and \\) express, respectively, the amount of evidence available for \ and the degree to which the evidence for \ is expected to behave classically—or non-classically for \ \). A probabilistic scenario is paracomplete when \ + P 1\), and in both cases, \ < 1\). If \ = 1\), or \ = 0\), classical probability is recovered for \. The proposition \, a theorem of \, partitions what we call the information space, and thus allows us to obtain some new versions of known results of standard probability theory. (shrink)

The aim of this text is to reply to criticisms of the logics of evidence and truth and the epistemic approach to paraconsistency advanced by Barrio [2018], and Lo Guercio and Szmuc [2018]. We also clarify the notion of evidence that underlies the intended interpretation of these logics and is a central point of Barrio’s and Lo Guercio & Szmuc’s criticisms.

The main aim of this paper is to introduce first-order versions of logics of evidence and truth, together with corresponding sound and complete Kripke semantics with variable and constant domains. According to the intuitive interpretation proposed here, these logics intend to represent possibly inconsistent and incomplete information bases over time. The paper also discusses the connections between Belnap-Dunn’s and da Costa’s approaches to paraconsistency, and argues that the logics of evidence and truth combine them in a very natural way.

The main aim of this paper is to introduce the logics of evidence and truth $$LET_{K}^+$$ and $$LET_{F}^+$$ together with sound, complete, and decidable six-valued deterministic semantics for them. These logics extend the logics $$LET_{K}$$ and $$LET_{F}^-$$ with rules of propagation of classicality, which are inferences that express how the classicality operator $${\circ }$$ is transmitted from less complex to more complex sentences, and vice-versa. The six-valued semantics here proposed extends the 4 values of Belnap-Dunn logic with 2 more values (...) that intend to represent (positive and negative) reliable information. A six-valued non-deterministic semantics for $$LET_{K}$$ is obtained by means of Nmatrices based on swap structures, and the six-valued semantics for $$LET_{K}^+$$ is then obtained by imposing restrictions on the semantics of $$LET_{K}$$. These restrictions correspond exactly to the rules of propagation of classicality that extend $$LET_{K}$$. The logic $$LET_{F}^+$$ is obtained as the implication-free fragment of $$LET_{K}^+$$. We also show that the 6 values of $$LET_{K}^+$$ and $$LET_{F}^+$$ define a lattice structure that extends the lattice L4 defined by the Belnap-Dunn four-valued logic with the 2 additional values mentioned above, intuitively interpreted as positive and negative reliable information. Finally, we also show that $$LET_{K}^+$$ is Blok-Pigozzi algebraizable and that its implication-free fragment $$LET_{F}^+$$ coincides with the degree-preserving logic of the involutive Stone algebras. (shrink)

Proof-theoretic semantics provides meanings to the connectives of intuitionistic logic without the need for a semantics in the standard sense of an attribution of semantic values to formulas. Meanings are given by the inference rules that, in this case, do not express preservation of truth but rather preservation of availability of a constructive proof. Elsewhere we presented two paraconsistent systems of natural deduction: the Basic Logic of Evidence and the Logic of Evidence and Truth. The rules of BLE have been (...) conceived to preserve a notion weaker than truth, namely, evidence, understood as reasons for believing in or accepting a given proposition. \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$LET_{J}$$\end{document}, on the other hand, is a logic of formal inconsistency and undeterminedness that extends \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$BLE$$\end{document} by adding resources to recover classical logic for formulas taken as true, or false. We extend the idea of proof-theoretic semantics to these logics and argue that the meanings of the connectives in BLE are given by the fact that its rules are concerned with preservation of the availability of evidence. An analogous idea also applies to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$LET_{J}$$\end{document}. (shrink)

In this paper we present a philosophical motivation for the logics of formal inconsistency, a family of paraconsistent logics whose distinctive feature is that of having resources for expressing the notion of consistency within the object language in such a way that consistency may be logically independent of non- contradiction. We defend the view according to which logics of formal inconsistency may be interpreted as theories of logical consequence of an epistemological character. We also argue that in order to philosophically (...) justify paraconsistency there is no need to endorse dialetheism, the thesis that there are true contradictions. Furthermore, we argue that an intuitive reading of the bivalued semantics for the logic mbC, a logic of formal inconsistency based on classical logic, fits in well with the basic ideas of an intuitive interpretation of contradictions. On this interpretation, the acceptance of a pair of propositions A and ¬A does not mean that A is simultaneously true and false, but rather that there is conflicting evidence about the truth value of A. (shrink)

The book Paraconsistent Logic: Consistency, Contradiction and Negation by Walter Carnielli and Marcelo Coniglio is the most thorough study of Logics of Formal Inconsistency...

Foreword : Consistency, Contradiction, and Consequence.

In this paper, we propose Kripke-style models for the logics of evidence and truth LETJ and LETF. These logics extend, respectively, Nelson’s logic N4 and the logic of first-degree entailment with a classicality operator ∘ that recovers classical logic for formulas in its scope. According to the intended interpretation here proposed, these models represent a database that receives information as time passes, and such information can be positive, negative, non-reliable, or reliable, while a formula ∘A means that the information about (...) A, either positive or negative, is reliable. This proposal is in line with the interpretation of N4 and FDE as information-based logics, but adds to the four scenarios expressed by them two new scenarios: reliable information for the truth and for the falsity of a given proposition. (shrink)

There are two foundational, but not fully developed, ideas in paraconsistency, namely, the duality between paraconsistent and intuitionistic paradigms, and the introduction of logical operators that express metalogical notions in the object language. The aim of this paper is to show how these two ideas can be adequately accomplished by the logics of formal inconsistency and by the logics of formal undeterminedness. LFIs recover the validity of the principle of explosion in a paraconsistent scenario, while LFUs recover the validity of (...) the principle of excluded middle in a paracomplete scenario. We introduce definitions of duality between inference rules and connectives that allow comparing rules and connectives that belong to different logics. Two formal systems are studied, the logics mbC and mbD, that display the duality between paraconsistency and paracompleteness as a duality between inference rules added to a common core—in the case studied here, this common core is classical positive propositional logic. The logics mbC and mbD are equipped with recovery operators that restore classical logic for, respectively, consistent and determined propositions. These two logics are then combined obtaining a pair of LFI and undeterminedness, namely, mbCD and mbCDE. The logic mbCDE exhibits some nice duality properties. Besides, it is simultaneously paraconsistent and paracomplete, and able to recover the principles of excluded middle and explosion one at a time. The last sections offer an algebraic account for such logics by adapting the swap structures semantics framework of the LFIs the LFUs. This semantics highlights some subtle aspects of these logics, and allows us to prove decidability by means of finite nondeterministic matrices. (shrink)

The book Paraconsistent Logic: Consistency, Contradiction and Negation by Walter Carnielli and Marcelo Coniglio is the most thorough study of Logics of Formal Inconsistency...

This paper reviews the central points and presents some recent developments of the epistemic approach to paraconsistency in terms of the preservation of evidence. Two formal systems are surveyed, the basic logic of evidence (BLE) and the logic of evidence and truth (LET J ), designed to deal, respectively, with evidence and with evidence and truth. While BLE is equivalent to Nelson’s logic N4, it has been conceived for a different purpose. Adequate valuation semantics that provide decidability are given for (...) both BLE and LET J . The meanings of the connectives of BLE and LET J , from the point of view of preservation of evidence, is explained with the aid of an inferential semantics. A formalization of the notion of evidence for BLE as proposed by M. Fitting is also reviewed here. As a novel result, the paper shows that LET J is semantically characterized through the so-called Fidel structures. Some opportunities for further research are also discussed. (shrink)

This papers’ goal is to present a survey of the contemporary discussions regarding truthmakers. The emphasis will be on the characterization of the truthmaking relation and on the problems involved in universal propositions and negations.

The aim of this paper is to present and analyze the truthmaker monism , a result according to which any truthmaker makes true any true proposition. Truthmaker monism depends on the characterization of the truthmaking relation in terms of strict implication, the principle of excluded middle and the so called disjunction thesis. I will restrict the discussion to a theory of truthmakers of empirical truths and I will argue that, in the scope of such a theory, the problem does not (...) lie in the use of strict implication neither in the excluded middle but, rather, in the disjunction thesis, that must be rejected. (shrink)

We present a philosophical motivation for the logics of formal inconsistency, a family of paraconsistent logics whose distinctive feature is that of having resources for expressing the notion of consistency within the object language. We shall defend the view according to which logics of formal inconsistency are theories of logical consequence of normative and epistemic character. This approach not only allows us to make inferences in the presence of contradictions, but offers a philosophically acceptable account of paraconsistency.

There are two foundational, but not fully developed, ideas in paraconsistency, namely, the duality between paraconsistent and intuitionistic paradigms, and the introduction of logical operators that express meta-logical notions in the object language. The aim of this paper is to show how these two ideas can be adequately accomplished by the Logics of Formal Inconsistency (LFIs) and by the Logics of Formal Undeterminedness (LFUs). LFIs recover the validity of the principle of explosion in a paraconsistent scenario, while LFUs recover the (...) validity of the principle of excluded middle in a paracomplete scenario. We introduce definitions of duality between inference rules and connectives that allow comparing rules and connectives that belong to different logics. Two formal systems are studied, the logics mbC and mbD, that display the duality between paraconsistency and paracompleteness as a duality between inference rules added to a common core– in the case studied here, this common core is classical positive propositional logic (CPL + ). The logics mbC and mbD are equipped with recovery operators that restore classical logic for, respectively, consistent and determined propositions. These two logics are then combined obtaining a pair of logics of formal inconsistency and undeterminedness (LFIUs), namely, mbCD and mbCDE. The logic mbCDE exhibits some nice duality properties. Besides, it is simultaneously paraconsistent and paracomplete, and able to recover the principles of excluded middle and explosion at once. The last sections offer an algebraic account for such logics by adapting the swap-structures semantics framework of the LFIs the LFUs. This semantics highlights some subtle aspects of these logics, and allows us to prove decidability by means of finite non-deterministic matrices. (shrink)

Firms engage in corporate social responsibility (CSR) because they consider that some kind of competitive advantage accrues to them. We contend that resource-based perspectives (RBP) are useful to understand why firms engage in CSR activities and disclosure. From a resource-based perspective CSR is seen as providing internal or external benefits, or both. Investments in socially responsible activities may have internal benefits by helping a firm to develop new resources and capabilities which are related namely to know-how and corporate culture. In (...) effect, investing in social responsibility activities and disclosure has important consequences on the creation or depletion of fundamental intangible resources, namely those associated with employees. The external benefits of CSR are related to its effect on corporate reputation. Corporate reputation can be understood as a fundamental intangible resource which can be created or depleted as a consequence of the decisions to engage or not in social responsibility activities and disclosure. Firms with good social responsibility reputation may improve relations with external actors. They may also attract better employees or increase current employees’ motivation, morale, commitment and loyalty to the firm. This article contributes to the understanding of why CSR may be seen as having strategic value for firms and how RBP can be used in such endeavour. (shrink)

After satisfying their quantitative and qualitative needs as regards nutrition, consumers in developed countries are becoming more involved in the ethical aspects of food production, especially when it relates to animal products. Social demands for respecting animal welfare in housing systems are increasing rapidly, as is social awareness of human responsibility towards farm animals. Many studies have been conducted on animal welfare measurement in different production systems, but the available information for small ruminants remains insufficient. In this study, a 75 (...) criteria-evaluation tool has been set up on the basis of the five freedoms concept. Animal welfare considerations have been analyzed in 25 documents, including labeling schemes, regulations, and recommendations from different European countries. The results show many differences between regular and organic small ruminant farming standards. Emergency measures are generally lacking. A weak representation of psychological aspects of animal welfare, especially by the current European legislation, is highlighted. (shrink)

Philosophy Compass, Volume 17, Issue 8, August 2022.

The aim of this paper is to investigate the relationship between information and abductive reasoning in the context of problem-solving, focusing on non-human animals. Two questions guide our investigation: What is the relation between information and abductive reasoning in the context of human and non-human animals? Do non-human animals perform discovery based on inferential processes such as abductive reasoning? In order to answer these questions, we discuss the semiotic concept of information in relation to the concept of abductive reasoning and, (...) more specifically, to the notion of manipulative abduction proposed by Magnani. Finally, we investigate a case study of corvids’ intelligence, namely, their capacity of causal cognition. (shrink)

Bioethics, Volume 36, Issue 3, Page 243-251, March 2022.

Delusion is one of the most intriguing psychopathological phenomena and its conceptualization remains the subject of genuine debate. Claims that it is ill-defined, however, are typically grounded on essentialist expectations that a given definition should capture the core of every instance acknowledged as delusion in the clinical setting.

This edited volume addresses the morality of war from a comparative perspective to develop a cross-cultural and cross-ideological quorum on when it is justifiable to initiate or enter into war and what methods of violence are acceptable once engaged in such a conflict.

A ficção corresponde a um estilo de escrita que sustenta a construção de narrativas capazes de arrancar o escritor de si mesmo em um sentido de, por meio do experimento da própria linguagem, constituir-se esteticamente. Quando observamos as obras de Nietzsche, percebemos que há uma pluralidade de estilos literários, compostos, frequentemente, por aforismos que demandam outro performático: a escrita hiperbólica. Por meio da escrita artística, Nietzsche cria um mundo compreendido como vontade de poder em que dá a si mesmo como (...) personagem dentre outros tipos psicológicos. Já na filosofia de Foucault o traço marcante de suas obras é o tom histórico com o qual aborda seus temas. Porém, como o próprio afirma em algumas entrevistas, não escreve outra coisa que não sejam ficções, seleciona e organiza enunciados históricos criando diversos cenários, sujeitos e objetos de seu discurso. Este estilo presente em ambos entra em contato com o exterior provocando um reposicionamento do leitor, que é afetado promovendo, como efeito de subjetivação, um reposicionamento político de insubmissão de não querer mais ser governado dessa forma. (shrink)

Utopía, la posibilidad de la imposibilidad: una lectura desde Thomas More, es un trabajo que muestra, por un lado, la vitalidad de la utopía; por otro lado se destaca su grado de necesidad en la sociedad contemporánea. La Utopía de Thomas More se presenta como un paradigma del pensamiento utópico, y del influjo que éste ejerce en las diferentes sociedades. Además, ésta se yergue como el epítome de toda posibilidad de visualizar un mejor mundo, es la máxima expresión de la (...) simbología del Renacimiento y es la obra cumbre del humanismo de aquel período histórico. La utopía no es la simple imposibilidad que sugiere su construcción semántica. Utopía es la posibilidad de construir el mejor mundo posible, de volver a ubicar en su perspectiva correcta la esperanza y toda la capacidad simbólica del género humano. (shrink)

Carrying out research on brains is important for medical advances in various diseases. However, such research ought not be carried out on human brains because the benefits do not outweigh the potential risks. A possible alternative is the use of brain surrogates. Nevertheless, some scholars who uphold a threshold account of moral status suggest the possibility that, with technological advances in the near future, more advanced brain surrogates will have very similar features to humans. This may suffice for these having (...) the same moral status as humans, and as a result, the situation may have implications for brain research, indeed, leading to the implication that this ought also not to be carried out upon brain surrogates. In this article, we present a relational approach to moral status which upholds that brain surrogates do not have the same moral status as human beings. Hence, brain research ought not be rejected on the grounds of equality of moral status between humans and brain surrogates. (shrink)

ABSTRACT In this article, I will carry out an epistemic and interpretative project, drawing out the implications of African values for the morality of war. More precisely, I wish to interpret the African value system and tease out some conclusions as to what this value system entails in terms of the following: the morality of when to enter war, how to act in war, and what to do after war. I carry out this inquiry by articulating the African value of (...) Ubuntu in light of the actions and speeches of two prominent African leaders, Nelson Mandela and Amilcar Cabral. (shrink)

The Portuguese animal rights movement has been extremely active in campaigning against bullfighting. Indeed, from 2002 to 2014, this was their main priority in terms of campaigns. In this article, I assess how these campaigns have been carried out, arguing that the animal rights movement in Portugal has been othering supporters and practitioners of bullfights in their campaigns. In other words, their campaigns have consisted of drawing a sharp contrast between bullfight supporters and practitioners and the rest of the population. (...) I argue that a consequence of this is that the speciesist practices of the majority of Portuguese have become normalised; consequently, leading to the reinforcement of some speciesist norms. (shrink)

This paper introduces the logic _Q__L__E__T_ _F_, a quantified extension of the logic of evidence and truth _L__E__T_ _F_, together with a corresponding sound and complete first-order non-deterministic valuation semantics. _L__E__T_ _F_ is a paraconsistent and paracomplete sentential logic that extends the logic of first-degree entailment (_FDE_) with a classicality operator ∘ and a non-classicality operator ∙, dual to each other: while ∘_A_ entails that _A_ behaves classically, ∙_A_ follows from _A_’s violating some classically valid inferences. The semantics of _Q__L__E__T_ (...) _F_ combines structures that interpret negated predicates in terms of anti-extensions with first-order non-deterministic valuations, and completeness is obtained through a generalization of Henkin’s method. By providing sound and complete semantics for first-order extensions of _FDE_, _K3_, and _LP_, we show how these tools, which we call here the method of _anti-extensions + valuations_, can be naturally applied to a number of non-classical logics. (shrink)

The production of vaccines for COVID-19 has been far from ideal in terms of meeting world demand, thereby mitigating the infections and deaths caused by the pandemic. Part of the reason production has been inefficient is that those pharmaceutical companies that own the vaccine do not have sufficient productive capacity to meet demand. Resultantly, many have advocated for waiving patent rights to the vaccine so it can be massively produced worldwide. Pharmaceutical companies and their advocates have opposed this waiving of (...) patent rights. In this article, I respond to the arguments that oppose waiving patents and contend that there is a case for temporarily waiving them. Mainly, I present a negative argumentative strategy that upholds the view that patents ought to be waived. However, in light of my arguments, the absence of positive reasons to withhold the patents implies that there are positive views for temporarily waiving them. (shrink)

Ce travail s’insère dans un projet intitulé « Le discours aux frontières du social », qui vise à analyser, dans des films documentaires, l’entrecroisement des différents matériaux en jeu dans ces productions. Pour comprendre comment se formule la critique sociale, j’ai choisi d’analyser deux documentaires ayant pour thème des conflits sociaux : Tereza (« Thérèse », qui met en scène la vie des détenus dans une prison de Campinas) et Boca de Lixo (« Décharge publique », qui présente la vie (...) de personnes qui habitent et travaillent dans les dépôts d’ordures). (shrink)