A critical analysis of Kelsen’s theory leads to a broad concept of custom, which covers diverse types of customary norms, where the always required conviction of legal bindingness depends on different types of factual and normative reasons. In it we should include a strict concept of custom or legal usage, derogating custom, custom of general international law, custom that establishes an unwritten constitution, custom that establishes a new written constitution, judicial custom which creates a rule of precedent and custom newly (...) expressed in the judicial application of customary rules. The basic norm could be formulated as a constitutive norm: ‘If the norms created through the first historical constitution are effective, then the first historical constitution are valid.’ It is thus a customary constitutive rule that recognizes the first historical constitution as valid law. Norms which establish sources of law are constitutive rules, they can be customary norms or legislated norms, but if they are legislated, they have their validity recognized by, directly or indirectly, a constitutive customary norm. By using a broad concept of custom as a conventional practice, Hart implies that general recognition of a customary rule, together with the practice that accompanies it, are sufficient conditions of validity. A doctrine of recognition that is arrived at by means of criticism and a rational reconstruction of the doctrines of Kelsen and Hart regains the essential theses of the traditional recognition theory of Bierling and Engisch. (shrink)

A critical analysis of Kelsen’s theory leads to a broad concept of custom, which covers diverse types of customary norms, where the always required conviction of legal bindingness depends on different types of factual and normative reasons. In it we should include a strict concept of custom or legal usage, derogating custom, custom of general international law, custom that establishes an unwritten constitution, custom that establishes a new written constitution, judicial custom which creates a rule of precedent and custom newly (...) expressed in the judicial application of customary rules. The basic norm could be formulated as a constitutive norm: ‘If the norms created through the first historical constitution are effective, then the first historical constitution are valid.’ It is thus a customary constitutive rule that recognizes the first historical constitution as valid law. Norms which establish sources of law are constitutive rules, they can be customary norms or legislated norms, but if they are legislated, they have their validity recognized by, directly or indirectly, a constitutive customary norm. By using a broad concept of custom as a conventional practice, Hart implies that general recognition of a customary rule, together with the practice that accompanies it, are sufficient conditions of validity. A doctrine of recognition that is arrived at by means of criticism and a rational reconstruction of the doctrines of Kelsen and Hart regains the essential theses of the traditional recognition theory of Bierling and Engisch. (shrink)

Este trabajo analiza los intentos llevados a cabo por Jeremy Bentham y John Stuart Mill para hacer converger algunos de los principales modelos de fundamentación moral: las éticas de la felicidad, como la aristotélica, o la propia ética utilitarista, las éticas del deber de raíz kantiana y las éticas de los derechos.Si conseguimos “reducir”, en primer lugar, las éticas de los derechos al modelo de la ética del deber, podremos simplificar mucho la cuestión y limitarnos a contrastar este último modelo (...) con las éticas de la felicidad, que a su vez deberían converger en la propia ética de la utilidad. No obstante, y aun reconociendo su gran interés, una convergencia completa entre modelos alternativos se revela como imposible. A pesar de los esfuerzos, sobre todo de John Stuart Mill, no es posible una unificación completa de los planteamientos utilitaristas con los de Aristóteles y Kant. La continuación de la empresa utilitarista de lucha por la unificación teórica en el ámbito del problema de la fundamentación moral encuentra un buen ejemplo actual en la obra de Esperanza Guisán. (shrink)

Ivan Domingues é professor do Departamento de Filosofia da Universi­dade Federal de Minas Gerais. Seu livro, “Filosofia no Brasil: legados e perspectivas” foi publicado pela Editora UNESP, ele traz em sua obra um forte e pertinente problema que muitos estudiosos se debruçam afim de entender e esclarecer pontos sobre a filosofia no Brasil, e todo contexto histórico envolto dela.

Rawls says that public reason is the reason of the citizens of a democratic state and takes the Supreme Court in the USA as the exemplar of public reason. It differs from non public reason, which is used e.g., in universities and academic institutions. Rawls contrasts with Kant, which opposes the public reason of the scholar—or the philosopher—, who speaks before the world, to the private reason of state or church officials. The later, once they accept an authority, cannot think (...) by themselves (selbst denken). A closer examination shows that Rawls is not so far from Kant as it seems, because he takes the constitutional judges not as they are, but as they should be. However Rawls still apparently refuses Kant’s unity of reason. Further investigation of the relations between ethical reason, democratic reason and legal reason is needed. Democratic reason is tantamount both to public reason and to legal reason in a modern constitutional state. It is a requirement of ethics but still not identical with ethical reason, since it is possible to accept democratic reason and to argue against it from an ethical point of view. There is just one good way of reasoning, in spite of the constraints that the sources of law and the rules of procedure impose on legal reasoning, compared with ethics. Such constraints are based on the democratic principle, which is again based on ethical reason, which at last both grounds and limits the constraints that law imposes on reason. (shrink)

Does Duncan Kennedy successfully cannibalize jurisprudence? He attempts to do it by demonstrating the inexistence of rightness in legal argumentation. If there is no right legal argument, then there is no right answer in adjudication, adjudication is not a rational enterprise and legal doctrine cannot be said to be a science. It can be shown that skepticism is self-defeating. Duncan Kennedy can avoid self defeat only because he actually believes in a lot of legal arguments. His thesis that judges decide (...) questions of policy without any methodology that distinguishes them from legislators does not hold. Judicial reasoning is subject to constraints that do not affect legislators. It must be based on the sources of law and is limited by rules of procedure. Even when the judges have ‘interstitial’ legislative powers they are, unlike the legislator, bound to fit the system and their decisions are considered in procedure from the perspective of the right answer doctrine. The only work that can convincingly refute the skeptic argument against legal science is the reconstruction of jurisprudence as a scientific enterprise. Such work is beyond the scope of any single paper. The article aims to give some inspirations for such a task. (shrink)

A pesquisa analisou a liberdade de expressão e a censura judicial no contexto inserido pela internet. Por meio do estudo bibliográfico e jurisprudencial, buscou-se definir o conteúdo do direito à liberdade de expressão e o seu exercício através da internet. Em seguida, passou-se a examinar o polêmico Inquérito das “fake news” (4.781 DF), do qual emanaram-se decisões colidentes com as garantias conferidas à liberdade de expressão. Por fim, após a discussão dos resultados, buscou-se evidenciar os perigos da censura judicial nas (...) plataformas virtuais. (shrink)

ObjectiveThis study aims to analyze sociohistorically how the normative patterns of hegemonic masculinity produced impacts on men’s health/mental health in the context of the COVID-19 pandemic.MethodsA qualitative study from a socio-historical perspective was conducted with 50 men based on an online survey. A semistructured form was applied. The data were analyzed by the Collective Subject Discourse method, interpreted in the light of the context of epidemic disease and hegemonic masculinity.ResultsThe experience of the pandemic exposed the normative patterns of masculinities from (...) the consummation of acts representative of the pandemic context, which incited men to deny the existence of COVID-19 disease and to delay the understanding and adoption of measures to protect and control COVID-19. As a repercussion, men presented conflicts in the regulation of emotions; presented emotional suppression; were more reactive; felt threatened regarding the loss of the role of family provider, virility; and revealed a sense of invulnerability, added to the weakening of self-care.ConclusionThe discourse revealed that the men’s behaviors are consistent with the characteristics of hegemonic masculinity, but express signs of recognition that this behavior causes harm to themselves and their health. (shrink)

The scientific community has debated the importance of “return” activities after ethnobiological studies. This issue has provoked debate because it touches on the ethics of research and the relationships with the people involved in these studies. This case study aimed to investigate community perception of an ethnobotany research project that was carried out in the semi-arid region of northeastern Brazil. Furthermore, we reported how the residents of this rural community felt about participating in the activities of “return” that arose from (...) the projects. Our findings demonstrate that “return” activities should be planned from the design phase of the research until its closure as a lifelong process that allows the communities involved to gradually take ownership of the information and actions that are being generated. Similarly, we argue that such activities must be negotiated with the people of the community so that they have decision-making power and autonomy to decide what is most relevant to their lives. (shrink)

Este artigo propõe-se a discutir, sob o paradigma do Estado Democrático de Direito, em que medida a aplicação da cota de gênero contribui para fomentar a representatividade feminina na política. Utilizam-se a pesquisa bibliográfica e o método jurídico-dedutivo. Os resultados sinalizam que não há uma correlação necessária entre o preenchimento da cota de gênero e o incremento do número de candidatas eleitas. Os resultados apontam que a superação dessa desigualdade requer a discussão de outras possibilidades, tais como reserva de vagas (...) no Legislativo, combate às candidaturas femininas fictícias e aplicação obrigatória de recursos nas campanhas femininas. (shrink)

The scientific community has debated the importance of “return” activities after ethnobiological studies. This issue has provoked debate because it touches on the ethics of research and the relationships with the people involved in these studies. This case study aimed to investigate community perception of an ethnobotany research project that was carried out in the semi-arid region of northeastern Brazil. Furthermore, we reported how the residents of this rural community felt about participating in the activities of “return” that arose from (...) the projects. Our findings demonstrate that “return” activities should be planned from the design phase of the research until its closure as a lifelong process that allows the communities involved to gradually take ownership of the information and actions that are being generated. Similarly, we argue that such activities must be negotiated with the people of the community so that they have decision-making power and autonomy to decide what is most relevant to their lives. (shrink)

Inicialmente, o texto indaga sobre o significado do exercício do filósofo social; pretende também localizar as origens do debate moderno sobre ‘subjetividade’ no pensamento filosófico e social. As idéias norteadoras de Kant, se situam na confluência e na disjunção entre razão (conhecimento) e subjetividade (moral). A partir dessa referência, o debate entre alguns pensadores considerados como pós-modernos (Badiou e Zizek), por um lado, e por outro Castoriadis que recusa esta nomenclatura, vão derivando idéias novas sobre ‘sujeito’ e ‘verdade’. Esse debate (...) não é sem conseqüências para a teoria sociológica que assume para si o desafio de introduzir a categoria de ‘sujeito’ em seus cânones (Touraine). As reflexões de Stengers servem também para questionar e aproximar as práticas da produção do conhecimento e dos discursos científicos. Finalmente, restam desafios para se pensar teorias e práticas sócio-ambientais à luz desses conceitos apresentados ao longo do texto. (shrink)

Existen dos corrientes de la filosofía analítica en la historiografía: el neopositivismo de Hempel y la filosofía analítica de la historia de Gardiner y Danto. Para el primero, el modelo de la historiografía debe ser similar al de todo conocimiento científico, a saber, el modelo nomotético de las ciencias físicas y naturales. Para Gardiner y Danto, en cambio, este modelo debe desprenderse del propósito particular de los historiadores y del lenguaje acorde a dichos propósitos. Sus conclusiones abrieron la posibilidad de (...) una nueva perspectiva de análisis, el texto historiográfico, lo que impulsó la reflexión hacia la filosofía del lenguaje y la hermenéutica. There are two historiographic prospects of analytical philosophy: Hempel’s neo-positivism and Gardiner and Danto’s analytical philosophy of history. According to Hempel, the model of historiography should be the same as all scientific knowledge, namely, the nomothetic model of the physical and natural sciences. According to Gardiner and Danto, however, this model must arise from the purpose of historians and language consistent with those purposes. Gardiner and Danto’s conclusions opened the possibility of a new analytical perspective, the historiographic text, prompting the debate toward the philosophy of language and hermeneutics. (shrink)

La decouverte de plus en plus profonde de la signification du christianisme a transforme la pensee de Fichte. Reciproquement, Fichte s'engage dans la voie d'une transformation du christianisme, au sens d'une metamorphose de la croyance en vision; il saisit la foi comme un stade imparfait de la science et souligne que seule cette derniere est a meme de supprimer l'exteriorite de l'Absolu. Le present ouvrage allie les points de vue genetique et systematique. De ses cinq parties, les quatre premieres exposent, (...) en suivant l'ordre chronologique, l'evolution de la theorie fichteenne du christianisme, depuis les textes prekantiens jusqu'a la Doctrine de l'Etat de 1813. La longue cinquieme partie, structuree thematiquement plutot que chronologiquement, est reservee non seulement a la reprise synthetique, mais aussi a la confrontation critique. Elle examine les differents aspects de la conception fichteenne du christianisme, notamment sa position a l'egard du Nouveau Testament, de la dogmatique, de la morale et de la mystique chretiennes. (shrink)

Multialgebras have been much studied in mathematics and in computer science. In 2016 Carnielli and Coniglio introduced a class of multialgebras called swap structures, as a semantic framework for dealing with several Logics of Formal Inconsistency that cannot be semantically characterized by a single finite matrix. In particular, these LFIs are not algebraizable by the standard tools of abstract algebraic logic. In this paper, the first steps towards a theory of non-deterministic algebraization of logics by swap structures are given. Specifically, (...) a formal study of swap structures for LFIs is developed, by adapting concepts of universal algebra to multialgebras in a suitable way. A decomposition theorem similar to Birkhoff’s representation theorem is obtained for each class of swap structures. Moreover, when applied to the 3-valued algebraizable logics J3 and Ciore, their classes of algebraic models are retrieved, and the swap structures semantics become twist structures semantics. This fact, together with the existence of a functor from the category of Boolean algebras to the category of swap structures for each LFI, suggests that swap structures can be seen as non-deterministic twist structures. This opens new avenues for dealing with non-algebraizable logics by the more general methodology of multialgebraic semantics. (shrink)

À quoi bon la pensée? Pour de nombreux chercheurs, inspirés par les théories évolutionnistes, la pensée réfléchie est utile à notre espèce. Elle lui confère des avantages importants et contribue à son succès reproductif. Pourtant ses avantages ne sont pas si évidents. La pensée ne figure ni dans les mécanismes de l'évolution qui ont façonné la vie, ni parmi les procédés dont se servent la plupart des organismes pour s'y maintenir. Dans Évolution et rationalité, Ronald de Sousa montre que, (...) pour comprendre les avantages de la pensée réfléchie, il faut changer nos présupposés relatifs à la rationalité et reconnaître la multiplicité de ses dimensions. La rationalité ne nous sert pas seulement à avoir des croyances vraies et à agir de manière efficace dans un environnement changeant. Elle nous aide à gérer nos plaisirs et nos peines dans le temps et nous permet d'envisager des situations qui n'existent pas. En général, le statut de la rationalité comme ensemble de capacités ayant évolué dans le cours de l'histoire naturelle de notre espèce, passant des tropismes aux désirs et de la détection à la représentation, n'a pas été pris suffisamment au sérieux. Suivre ce processus d'évolution de la rationalité permet de comprendre comment elle est devenue une norme, mais aussi pourquoi il lui arrive aussi souvent d'échouer. Ronald de Sousa a profondément modifié nos façons de concevoir les émotions. Avec Évolution et rationalité, il pourrait avoir une influence aussi décisive sur nos façons de concevoir la rationalité. (shrink)

Despite being fairly powerful, finite non-deterministic matrices are unable to characterize some logics of formal inconsistency, such as those found between mbCcl and Cila. In order to overcome this limitation, we propose here restricted non-deterministic matrices (in short, RNmatrices), which are non-deterministic algebras together with a subset of the set of valuations. This allows us to characterize not only mbCcl and Cila (which is equivalent, up to language, to da Costa's logic C_1) but the whole hierarchy of da Costa's calculi (...) C_n. This produces a novel decision procedure for these logics. Moreover, we show that the RNmatrix semantics proposed here induces naturally a labelled tableau system for each C_n, which constitutes another decision procedure for these logics. This new semantics allows us to conceive da Costa's hierarchy of C-systems as a family of (non deterministically) (n+2)-valued logics, where n is the number of "inconsistently true" truth-values and 2 is the number of "classical" or "consistent" truth-values, for every C_n. (shrink)

ResumenLa investigación social cualitativa ha prescindido de la utilización de referentes empíricos accesibles y compartidos a partir de los cuales acordar la producción y el análisis del habla. A partir de este criticable déficit, lo que hace este trabajo es analizar el problema del habla utilizada como material empírico para observación desde el punto de vista de la labor científica. Con esta finalidad se argumenta la importancia de la comunicabilidad de las observaciones producidas y de su análisis a partir de (...) los problemas que plantea la función deíctica del habla observada en la investigación. La conclusión del trabajo plantea la necesidad acordar e introducir un referente objetual en la situación de observación experimental con el fin de garantizar la comunicabilidad de las acciones investigadoras, así como la recepción y circulación del habla observada entre las distintas comunidades de hablantes y sistemas discursivos.Palabras clave: discurso social; validez; investigación cualitativa; función deíctica; comunicación. (shrink)

Introduction -- Function and destiny -- What's the good of thinking? -- Rationality, individual and collective -- Irrationality.

The logics of formal inconsistency (LFIs, for short) are paraconsistent logics (that is, logics containing contradictory but non-trivial theories) having a consistency connective which allows to recover the ex falso quodlibet principle in a controlled way. The aim of this paper is considering a novel semantical approach to first-order LFIs based on Tarskian structures defined over swap structures, a special class of multialgebras. The proposed semantical framework generalizes previous aproaches to quantified LFIs presented in the literature. The case of QmbC, (...) the simpler quantified LFI expanding classical logic, will be analyzed in detail. An axiomatic extension of QmbC called QLFI1o is also studied, which is equivalent to the quantified version of da Costa and D'Ottaviano 3-valued logic J3. The semantical structures for this logic turn out to be Tarkian structures based on twist structures. The expansion of QmbC and QLFI1o with a standard equality predicate is also considered. (shrink)

O presente trabalho procura se debruçar sobre a dimensão ontológica do homem animal-político-social em Aristóteles. Logo, desde já nos cabe ressaltar que a verificação do homem enquanto animal político-social abarcará um caráter metafísico para a efetivação no e do físico-material-natural, ou seja, o ser biopsicossocial. Refletindo, construindo e interligando o ser físico e “espiritual”. Portanto, o objeto principal será o que diz respeito ao homem como um animal político-social, no sentido ontológico do ser sensível em Aristóteles. Para tanto, a proposta (...) abarcará a Teoria das Quatro Causas de Aristóteles. Isso para demonstrar certa ontologia de uma suposta essência da ou na substancia no e do ser humano. Ou seja, quem é o “homem-ser-ente” coberto por sua estrutura física e sensível no sentido ontológico no corporal? São os seres humanos animais essencialmente políticos? E se forem são seres políticos do e ou no “espiritual”, “almático” e metafísico ou no físico-corporal? (shrink)

In 1986, Mikenberg et al. introduced the semantic notion of quasi-truth defined by means of partial structures. In such structures, the predicates are seen as triples of pairwise disjoint sets: the set of tuples which satisfies, does not satisfy and can satisfy or not the predicate, respectively. The syntactical counterpart of the logic of partial truth is a rather complicated first-order modal logic. In the present article, the notion of predicates as triples is recursively extended, in a natural way, to (...) any complex formula of the first-order object language. From this, a new definition of quasi-truth is obtained. The proof-theoretic counterpart of the new semantics is a first-order paraconsistent logic whose propositional base is a 3-valued logic belonging to hierarchy of paraconsistent logics known as Logics of Formal Inconsistency, which was proposed by Carnielli and Marcos in 2002. (shrink)

In 1988, J. Ivlev proposed some (non-normal) modal systems which are semantically characterized by four-valued non-deterministic matrices in the sense of A. Avron and I. Lev. Swap structures are multialgebras (a.k.a. hyperalgebras) of a special kind, which were introduced in 2016 by W. Carnielli and M. Coniglio in order to give a non-deterministic semantical account for several paraconsistent logics known as logics of formal inconsistency, which are not algebraizable by means of the standard techniques. Each swap structure induces naturally a (...) non-deterministic matrix. The aim of this paper is to obtain a swap structures semantics for some Ivlev-like modal systems proposed in 2015 by M. Coniglio, L. Fariñas del Cerro and N. Peron. Completeness results will be stated by means of the notion of Lindenbaum–Tarski swap structures, which constitute a natural generalization to multialgebras of the concept of Lindenbaum–Tarski algebras. (shrink)

In this paper we report a study conducted in Mongolia on the scope of morality, that is, the extent to which people moralize different social domains. Following Turiel’s moral-conventional task, we characterized moral transgressions (in contrast to conventional transgressions) in terms of two dimensions: authority independence and generality of scope. Different moral domains are then defined by grouping such moral transgressions in terms of their content (following Haidt’s classification of morally relevant domains). There are four main results of the study. (...) First, since all five Haidtian domains were moralized by the Mongolian participants, the study provides evidence in favour of pluralism about moral domains. However, the study also suggests that the domain of harm can be reduced to the fairness domain. Furthermore, although the strong claim about reduction of all moral domains to the domain of fairness does not seem to hold a significant number of participants did indicate considerations of fairness across domains. Finally, a significant amount of participants moralized conventional transgressions a la Turiel, but it did not reach a statistical significance. (shrink)

Suszko's Thesis maintains that many-valued logics do not exist at all. In order to support it, R. Suszko offered a method for providing any structural abstract logic with a complete set of bivaluations. G. Malinowski challenged Suszko's Thesis by constructing a new class of logics (called q-logics by him) for which Suszko's method fails. He argued that the key for logical two-valuedness was the "bivalent" partition of the Lindenbaum bundle associated with all structural abstract logics, while his q-logics were generated (...) by "trivalent" matrices. This paper will show that contrary to these intuitions, logical two-valuedness has more to do with the geometrical properties of the deduction relation of a logical structure than with the algebraic properties embedded on it. (shrink)

The article went deeper into Richard Rorty’s texts that address the self as “a set of beliefs and desires.” In an imbrication of philosophy with psychoanalysis, Rorty’s hermeneutics accompanies the critique of psychoanalysis regarding the self-centralization from Metaphysical tradition, one of the strategies of self-redescription. The other strategy is aesthetic redescription. This redescription is based on understanding the psychic world as an encounter of “beliefs and desires” as “quasi-people.” The thread of our argument is the articulation of psychoanalysis with the (...) concept of “hegemony.” This reflexive line occurs due to the agonist and conflicting context of internal alterity from the “interpersonal” relationship between conscious and unconscious, rediscovering the self. (shrink)

Trying to overcome Dugundji’s result on uncharacterisability of modal logics by finite logical matrices, Kearns and Ivlev proposed, independently, a characterisation of some modal systems by means of four-valued multivalued truth-functions , as an alternative to Kripke semantics. This constitutes an antecedent of the non-deterministic matrices introduced by Avron and Lev . In this paper we propose a reconstruction of Kearns’s and Ivlev’s results in a uniform way, obtaining an extension to another modal systems. The first part of the paper (...) is devoted to four-valued Nmatrices, including Kearns’s and Ivlev’s. Besides proving with full details Kearns’s results for T, S4 and S5, we also obtain a characterisation of the system B by four-valued Nmatrices with level valuations. Concerning Ivlev’s results, two new modal systems are introduced and char.. (shrink)

Trata-se de um artigo de viés ensaístico que tenta apontar a impressão de que a instituição escolar habita uma densa crise existencial. A suposição que norteia essa reflexão visa à crise na educação escolar como uma aparência que costuma continuar velada na maior parte dos discursos críticos acerca da escolarização atual: o afastamento do sentido humano ontológico-social e do significado da experiência que relacionam professor-estudante. A investigação nesta atividade será realizada a partir de conceito recentemente desenvolvido, o absurdar-se, em uma (...) tentativa de aplicação desse conceito nas nossas experiências em escolas, nas quais atuamos como psicólogo da educação. (shrink)

RESENHA: COMBLIN, José. O Espírito Santo e a tradição de Jesus . São Paulo: Nhanduti, 2012.

This sentence: «Infinita è la violenza delle convinzioni acquisite», which appears in this text for the first time, could be the most faithful motto of Mario Martelli’s critical production, always characterized by his hard and consistent struggle against the «convizioni acquisite» of critical literature, historiography and philosophy, all of which have so severely mislead our view of Niccolò Machiavelli’s work and thought.

This sentence: «Infinita è la violenza delle convinzioni acquisite», which appears in this text for the first time, could be the most faithful motto of Mario Martelli’s critical production, always characterized by his hard and consistent struggle against the «convizioni acquisite» of critical literature, historiography and philosophy, all of which have so severely mislead our view of Niccolò Machiavelli’s work and thought.

Resenha do livro The Ethics of Environmentally Responsible Health Care.

The Logics of Deontic (In)Consistency (LDI's) can be considered as the deontic counterpart of the paraconsistent logics known as Logics of Formal (In)Consistency. This paper introduces and studies new LDI's and other paraconsistent deontic logics with different properties: systems tolerant to contradictory obligations; systems in which contradictory obligations trivialize; and a bimodal paraconsistent deontic logic combining the features of previous systems. These logics are used to analyze the well-known Chisholm's paradox, taking profit of the fact that, besides contradictory obligations do (...) not trivialize in LDI's, several logical dependencies of classical logic are blocked in the context of LDI's, allowing to dissolve the paradox. (shrink)

We analyze the variety of A. Monteiro’s tetravalent modal algebras under the perspective of two logic systems naturally associated to it. Taking profit of the contrapositive implication introduced by A. Figallo and P. Landini, sound and complete Hilbert-style calculi for these logics are presented.