We look at two fundamental logical processes, often intertwined in planning and problem solving: inference and update. Inference is an internal process with which we uncover what is implicit in the information we already have. Update, on the other hand, is produced by external communication, usually in the form of announcements and in general in the form of observations, giving us information that might not have been available (even implicitly) before. Both processes have received attention from the logic community, usually (...) separately. In this work, we develop a logical language that allows us to describe them together. We present syntax, semantics and a complete axiom system; we discuss similarities and differences with other approaches and mention how the work can be extended. (shrink)

Classical epistemic logic describes implicit knowledge of agents about facts and knowledge of other agents based on semantic information. The latter is produced by acts of observation or communication that are described well by dynamic epistemic logics. What these logics do not describe, however, is how significant information is also produced by acts of inference— and key axioms of the system merely postulate "deductive closure". In this paper, we take the view that all information is produced by acts, and hence (...) we also need a dynamic logic of inference steps showing what effort on the part of the agent makes a conclusion explicit knowledge. Strong omniscience properties of agents should be seen not as static idealizations, but as the result of dynamic processes that agents engage in. This raises two questions: (a) how to define suitable information states of agents and matching notions of explicit knowledge, (b) how to define natural processes over these states that generate new explicit knowledge. To this end, we use a static base from the existing awareness literature, extending it into a dynamic system that includes traditional acts of observation, but also adding and dropping formulas from the current ' awareness' set. We give a completeness theorem, and we show how this dynamics updates explicit knowledge. Then we extend our approach to multi-agent scenarios where awareness changes may happen privately. Finally, we mention further directions and related approaches. Our contribution can be seen as a ' dynamification' of existing awareness logics. (shrink)

Epistemic logic with its possible worlds semantic model is a powerful framework that allows us to represent an agent’s information not only about propositional facts, but also about her own information. Nevertheless, agents represented in this framework are logically omniscient: their information is closed under logical consequence. This property, useful in some applications, is an unrealistic idealisation in some others. Many proposals to solve this problem focus on weakening the properties of the agent’s information, but some authors have argued that (...) solutions of this kind are not completely adequate because they do not look at the heart of the matter: the actions that allow the agent to reach such omniscient state. Recent works have explored how acts of observation, inference, consideration and forgetting affect an agent’s implicit and explicit knowledge; the present work focuses on acts that affect an agent’s implicit and explicit beliefs. It starts by proposing a framework in which these two notions can be represented, and then it looks into their dynamics, first by reviewing the existing notion of belief revision, and then by introducing a rich framework for representing diverse forms of inference that involve both knowledge and beliefs. (shrink)

Classical epistemic logic describes implicit knowledge of agents about facts and knowledge of other agents based on semantic information. The latter is produced by acts of observation or communication that are described well by dynamic epistemic logics. What these logics do not describe, however, is how significant information is also produced by acts of inference—and key axioms of the system merely postulate “deductive closure”. In this paper, we take the view that all information is produced by acts, and hence we (...) also need a dynamic logic of inference steps showing what effort on the part of the agent makes a conclusion explicit knowledge. Strong omniscience properties of agents should be seen not as static idealizations, but as the result of dynamic processes that agents engage in. This raises two questions: (a) how to define suitable information states of agents and matching notions of explicit knowledge, (b) how to define natural processes over these states that generate new explicit knowledge. To this end, we use a static base from the existing awareness literature, extending it into a dynamic system that includes traditional acts of observation, but also adding and dropping formulas from the current ‘awareness’ set. We give a completeness theorem, and we show how this dynamics updates explicit knowledge. Then we extend our approach to multi-agent scenarios where awareness changes may happen privately. Finally, we mention further directions and related approaches. Our contribution can be seen as a ‘dynamification’ of existing awareness logics. (shrink)

This work proposes an understanding of deductive, default and abductive reasoning as different instances of the same phenomenon: epistemic dynamics. It discusses the main intuitions behind each one of these reasoning processes, and suggest how they can be understood as different epistemic actions that modify an agent’s knowledge and/or beliefs in a different way, making formal the discussion with the use of the dynamic epistemic logic framework. The ideas in this paper put the studied processes under the same umbrella, thus (...) highlighting their relationship and allowing a better understanding of how they interact together. (shrink)

Among the non-monotonic reasoning processes, abduction is one of the most important. Usually described as the process of looking for explanations, it has been recognized as one of the most commonly used in our daily activities. Still, the traditional definitions of an abductive problem and an abductive solution mention only theories and formulas, leaving agency out of the picture. Our work proposes a study of abductive reasoning from an epistemic and dynamic perspective. In the first part we explore syntactic definitions (...) of both an abductive problem in terms of an agent’s information and an abductive solution in terms of the actions that modify the agent’s information. We look at diverse kinds of agents, including not only omniscient ones but also those whose information is not closed under logical consequence and those whose reasoning abilities are not complete. In the second part, we look at an existing logical framework whose semantic model allows us to interpret the previously stated formulas, and we define two actions that represent forms of abductive reasoning. (shrink)

This paper introduces and studies a notion of cautious distributed belief. Different from the standard distributed belief, the cautious distributed belief of a group is inconsistent only when all group members are individually inconsistent. The paper presents basic results about cautious distributed belief, investigates whether it preserves properties of individual belief, and compares it with standard distributed belief. Although both notions are equivalent in the class of reflexive models, this is not the case in general. While we argue that an (...) understanding of the concept of cautious distributed belief from first principles is important, cautious distributed belief can be expressed using standard distrbuted belief and we show that the propositional language extended only with cautious distributed belief is in fact strictly less expressive than the propositional language extended only with standard distributed belief. We, finally, identify a small extension of the language making the former as expressive as the latter. (shrink)

The paper develops an interface between syntax-based logical models of awareness and dynamic epistemic logic. The framework is shown to be able to accommodate a variety of notions of awareness and knowledge, as well as their dynamics. This, it is argued, offers a natural formal environment for the analysis of epistemic phenomena typical of multi-agent information exchange, such as how agents become aware of relevant details, how they perform inferences and how they share their information within a group. Technically, the (...) logics presented are all simple refinements of the logic of public announcements. (shrink)

As a new type of epistemic logics, the logics of knowing how capture the high-level epistemic reasoning about the knowledge of various plans to achieve certain goals. Existing work on these logics focuses on axiomatizations; this paper makes the first study of their model theoretical properties. It does so by introducing suitable notions of bisimulation for a family of five knowing how logics based on different notions of plans. As an application, we study and compare the expressive power of these (...) logics. (shrink)

In this paper, we explore the relation between an agent’s doxastic attitude and her arguments in support of a given claim. Our main contribution is the design of a logical setting that allows us reason about binary arguments which are either in favour or against a certain claim. This is a setting in which arguments and propositions are the basic building blocks so that the concept of argument-based belief emerges in a straightforward way. We work against the background of Dung’s (...) abstract argumentation framework, extending it to a new setting in which we can study the formal properties of binary arguments as well as the larger structures they establish. This paper introduces a formal ‘two-dimensional’ language to talk about propositions and arguments, for which a sound and complete axiom system is provided. (shrink)

The paper focuses on a recent challenge brought forward against the interventionist approach to the meaning of counterfactual conditionals. According to this objection, interventionism cannot account for the interpretation of right-nested counterfactuals, the problem being its strict interventionism. We will report on the results of an empirical study supporting the objection. Furthermore, we will extend the well-known logic of intervention with a new operator expressing an alternative notion of intervention that does away with strict interventionism. This new notion of intervention (...) operates on the valuation of the variables in a causal model, and not on their functional dependencies. (shrink)

This manuscript presents a topological argumentation framework for modelling notions of evidence-based (i.e., justified) belief. Our framework relies on so-called topological evidence models to represent the pieces of evidence that an agent has at her disposal, and it uses abstract argumentation theory to select the pieces of evidence that the agent will use to define her beliefs. The tools from abstract argumentation theory allow us to model agents who make decisions in the presence of contradictory information. Thanks to this, it (...) is possible to define two new notions of beliefs, grounded beliefs and fully grounded beliefs. These notions are discussed in this paper, analysed and compared with the existing notion of topological justified belief. This comparison revolves around three main issues: closure under conjunction introduction, the level of consistency and their logical strength. (shrink)

This paper is part of an on-going programme on the study of the logical aspects of social network formation. It recalls the so-called social network model, discussing the properties of a notion of closeness between agents ; then introduces an extended social network model in which different agents might assign different values to different traits, discussing the properties of the notion of weighted closeness that arises. These notions are used to define social network creation operations by means of a threshold (...) strategy. The paper studies the properties of the social networks the updates create, providing sound and complete axiom systems for formal languages describing these updates’ effects. (shrink)

We investigate dynamic operations acting over a knowing how logic. Our approach makes use of a recently introduced semantics for the knowing how operator, based on an indistinguishability relation between plans. This semantics is arguably closer to the standard presentation of knowing that modalities in classic epistemic logic. Here, we discuss how the semantics enables us to define dynamic modalities representing different ways in which an agent can learn how to achieve a goal. In this regard, we study two types (...) of updates: ontic updates (for which we provide axiomatizations over a particular class of models), and epistemic updates (for which we investigate some semantic properties). (shrink)

Abductive problems and their solutions are presented by means of justification logic. We introduce additional meta-constructions in order to generate and compare different solutions to the same abductive problem. Our approach has three advantages: (i) it makes structurally explicit the solution to an abductive problem (as it has a syntactic nature); (ii) it gives a precise meaning to the notion of evidence; (iii) it provides clear definitions and procedures for the comparison of solutions that can be adapted to different needs.

Tras la llegada de los conquistadores españoles y durante los dos siglos del reinado de su monopolio, no se permitió el ingreso de extranjeros y la población permaneció distribuida en las regiones, en proporciones casi inversas a las actuales. Con la caída del régimen español y los avances del monopolio inglés, comenzó a desplazarse el centro territorial argentino desde el Noroeste hacia el Litoral y a producirse variaciones en la dinámica demográfica. El establecimiento del modelo agroexportador produjo una afluencia excepcional (...) de inmigrantes de ultramar, que generaron cambios vertiginosos en la estructura de la población. Asimismo, el fin del modelo agroexportador que provocó la abrupta interrupción del flujo inmigratorio de ultramar, generó nuevamente otro intenso cambio demográfico que incidió en la estructura poblacional hasta la actualidad. Este artículo se centra en el movimiento migratorio que produjo el modelo agroexportador, con el objetivo de analizar sus efectos en el ritmo de crecimiento de la población, en la distribución de las variables demográficas básicas —sexo y edad—, y en los cambios en la distribución espacial, siendo su fuente principal los censos nacionales de población realizados hasta la actualidad. (shrink)

La presente obra reúne los temas imprescindibles de un curso de filosofía política, dirigido tanto a estudiantes como a lectores interesados en la historia, los fundamentos y las implicaciones actuales de esta disciplina. La primera parte trata de la tradición liberal, los socialismos, las dimensiones del nacionalismo, el feminismo como proyecto filosófico-político y la institución de la democracia. La segunda parte aborda en profundidad un amplio abanico de cuestiones, desde la globalización o los problemas de legitimación del poder, pasando por (...) las relaciones entre Estado y nación, los derechos humanos como legado de la Modernidad o la actualidad y perspectivas de la ciudadanía, hasta la multiculturalidad y la inmigración, los movimientos sociales, la ecología o la justicia social. (shrink)

This chapter contains sections titled: Acosta, José de (1539–1600) Alberdi, Juan Bautista (1810–84) Bello, Andrés (1781–1865) Bilbao, Francisco (1823–65) Bolkvar, Simón (1783–1830) Casas, Bartolomé de las (1484–1566) Caso, Antonio (1883–1946) Cruz, Sor Juana Inés de la (1651–95) da Costa, Newton Carneiro Affonso (b. 1929) Dussel, Enrique (b. 1934) Frondizi, Risieri (1910–83) Gaos, José (1900–69) González Prada, Manuel (1848–1918) Gracia, Jorge J. E. (b. 1942) Haya de la Torre, Victor Raúl (1895–1979) Hostos, Eugenio Marka de (1839–1903) Ingenieros, José (1877–1925) Korn, Alejandro (...) (1860–1936) Lastarria, José Victorino (1817–88) Lemos, Miguel (1854–1917) Mariátegui, José Carlos (1895–1930) Martk, José (1853–95) Méndez Sierra, Justo (1848–1912) Mora, José Maria Luis (1794–1850) Miró Quesada, Francisco (b. 1918) Rabossi, Eduardo (1930–2005) Ramos, Samuel (1897–1959) Rodó, José Enrique (1872–1917) Romero, Francisco (1891–1962) Sahagún, Fray Bernardino de (1499–1590) Salazar Bondy, Augusto (1925–74) Sarmiento, Domingo Faustino (1811–88) Ofelia Schutte (b. 1945) Sepslveda, Juan Ginés de (ca. 1494–1573) Torretti, Roberto (b. 1930) Vasconcelos, José (1882–1959) Vaz Ferreira, Carlos (1872–1958) Villoro, Luis (b. 1922) Vitoria, Francisco de (ca. 1483–1546) Zea Aguilar, Leopoldo (1912–2004) Acknowledgment Further Reading. (shrink)

The aim of this study is to assess the knowledge, attitudes and experiences of Spanish nurses in relation to euthanasia and physician-assisted suicide. In an online questionnaire completed by 390 nurses from Andalusia, 59.1% adequately identified a euthanasia situation and 64.1% a situation involving physician-assisted suicide. Around 69% were aware that both practices were illegal in Spain, while 21.4% had received requests for euthanasia and a further 7.8% for assisted suicide. A total of 22.6% believed that cases of euthanasia had (...) occurred in Spain and 11.4% believed the same for assisted suicide. There was greater support (70%) for legalisation of euthanasia than for assisted suicide (65%), combined with a greater predisposition towards carrying out euthanasia (54%), if it were to be legalised, than participating in assisted suicide (47.3%). Nurses in Andalusia should be offered more education about issues pertaining to the end of life, and extensive research into this area should be undertaken. (shrink)

Este trabalho analisa a influência tributária na definição do modelo constitucional de atribuição dos resultados econômicos da exploração do petróleo offshore, no Brasil. Além da abordagem constitucional do tema, destaca-se a participação dos entes federativos estaduais nas rendas da produção de petróleo, sua federalização e, em decorrência, a redução das rendas dos entes federativos subnacionais, implicando num movimento compensatório pela via da utilização de elementos de natureza tributária, tais como o extinto Imposto Único sobre Minerais e o regime constitucional especial (...) de cobrança na origem do ICMS devido nas operações de combustíveis e derivados de petróleo. (shrink)

Este libro ofrece una imprescindible riqueza de perspectivas sobre el aspecto más problemático -que coincide con el menos tratado por los investigadores. de la obra de F. Nietzsche (1844-1990): la cuestión política. Nuestro reto de cara al Centenario de su muerte fue encarar lo que suele escamotearse. Y, al menos en este país, así ha sido por regla general. bien porque Nietzsche era "apolítico", otra forma más, como en el caso de otros pensadores, de situarlo universitariamente a la derecha, ángulo (...) desde el que se le importaba, ya porque, consigna progresista y transición filosófica, había que poner esta última interpretación en su sitio y demostrarle al mundo que Nietzsche había sido "utilizado erróneamente" por el totalitarismo nazi, el caso es que ya porque nos repugnaba moralmente aquella lectura, ya porque de tanto estar en favor de Nietzsche tampoco lo leíamos, cuestiones fundamentales de su obra y, por qué no decirlo, irritantes tanto para la derecho como para la izquierda, quedaron piadosamente salvadas. Y ahora ¿qué?... Los trabajos aquí presentados, nacionales e internacionales, han sido rigurosamente seleccionados. (shrink)

Realiza una lectura "nietzscheana" de El mundo como voluntad y representación, al igualmente que de El nacimiento de la tragedia para unificar sus tres aspectos: metafísico-gnoseológico, estético y político. Finalmente se analiza la esencia de la "intempestividad" en relación a la metafísica platónico-cristiana, así como frente a la historia lineal-progresista, al Estado y al nacionalismo.

This paper explores two persistent questions in the literature on presumptions: the place and the nature of presumptions in law and legal argumentation. These questions were originally raised by James Bradley Thayer, one of the masters of the Law of Evidence and the author of the classic chapter devoted this subject in A preliminary treatise on Evidence. Like Thayer, I believe that these questions deserve attention. First the paper shows that the connection between presumptions and argumentation is a constant feature (...) in the literature on presumptions, since its foundation in the Middle Ages to modern times. James Bradley Thayer was probably the last jurist who clearly saw that presumptions belong to argumentation. Second, the paper examines two sources of controversy in the language of presumptions. First, “presumption” is an ambiguous word in the legal discourse. As a result, it is almost impossible to provide a clear and succinct answer to the question “What is a presumption?”. Second, there are at least four reconstructions of the concept of presumption whose merits and shortcomings are relevant to explore. The analysis presented here may be of interest for legal and non-legal scholars and, hopefully, it may help to shed light on the possibilities and limits of an interdisciplinary dialogue about presumptions. (shrink)

The confinement of the population into their homes as a result of COVID-19 has entailed a notable increase in the consumption of diverse media. This exploratory study aimed to examine how the increase in media consumption was related to subjective happiness and psychological well-being. For this purpose, a questionnaire was administered to a sample of Spanish adults to assess their consumption of different media before and during confinement. Moreover, participants were evaluated for hedonic, eudaimonic, social, and experienced happiness by using (...) the Pemberton Happiness Index. The results underlined the great increase in the consumption of TV for entertainment and social networking sites during confinement. Furthermore, it was found that higher consumption was negatively correlated with the level of happiness, so that, people who reported greater well-being, both subjective and psychological, spent less time watching TV and using SNS. In contrast, no association was found between the level of happiness and the consumption of news and radio. Therefore, it seems that far from cultivating greater happiness, those who engaged in heavy consumption of TV entertainment and SNS during confinement were less happy than those who did so more moderately and spent more time using other media or performing other activities. (shrink)