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)

Theory of Mind (ToM), the cognitive capacity to attribute internal mental states to oneself and others, is a crucial component of social skills. Its formal study has become important, witness recent research on reasoning and information update by intelligent agents, and some proposals for its formal modelling have put forward settings based on Epistemic Logic (EL). Still, due to intrinsic idealisations, it is questionable whether EL can be used to model the high-order cognition of ‘real’ agents. This manuscript proposes a (...) framework that takes visibility, memory, perspective and communication as the main factors underpinning mental attributions. This is more in-line with findings in cognitive science and allows us to model well-known False-Belief Tasks that are typically used in testing people's ToM. We discuss some of the framework's technical features, arguing why it does justice to empirical observations. (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)

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)

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)

Belief revision is concerned with belief change fired by incoming information. Despite the variety of frameworks representing it, most revision policies share one crucial feature: incoming information outweighs current information and hence, in case of conflict, incoming information will prevail. However, if one is interested in representing the way actual humans revise their beliefs, one might not always want for the agent to blindly believe everything they are told. This manuscript presents a semantic approach to non-prioritized belief revision. It uses (...) plausibility models for depicting an agent’s beliefs, and model operations for displaying the way beliefs change. The first proposal, semantically-based screened revision, compares the current model with the one the revision would yield, accepting or rejecting the incoming information depending on whether the ‘differences’ between these models go beyond a given threshold. The second proposal, semantically-based gradual revision, turns the binary decision of acceptance or rejection into a more general setting in which a revision always occurs, with the threshold used rather to choose ‘the right revision’ for the given input and model. (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)

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)

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 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)

Theory of Mind (ToM), the cognitive capacity to attribute internal mental states to oneself and others, is a crucial component of social skills. Its formal study has become important, witness recent research on reasoning and information update by intelligent agents, and some proposals for its formal modelling have put forward settings based on Epistemic Logic (EL). Still, due to intrinsic idealisations, it is questionable whether EL can be used to model the high-order cognition of ‘real’ agents. This manuscript proposes a (...) framework that takes visibility, memory, perspective and communication as the main factors underpinning mental attributions. This is more in-line with findings in cognitive science and allows us to model well-known False-Belief Tasks that are typically used in testing people's ToM. We discuss some of the framework's technical features, arguing why it does justice to empirical observations. (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)

The paper proposes a logical framework representing the notion of explicit knowledge as the combination of awareness of and awareness that. The setting, semantically combining neighbourhood models with ideas from awareness logic, separates the mere fact of entertaining some information (being aware of $\varphi$) from the acknowledgement that the information is indeed the case (being aware that $\varphi$ holds). The text discusses not only the main properties these concepts obtain under the given representation, but also several of the epistemic actions (...) that can be defined, and the way they affect the agent’s awareness (and thus her knowledge). (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)

Communication within groups of agents has been lately the focus of research in dynamic epistemic logic. This paper studies a recently introduced form of partial (more precisely, topic-based) communication. This type of communication allows for modelling scenarios of multi-agent collaboration and negotiation, and it is particularly well-suited for situations in which sharing all information is not feasible/advisable. The paper can be divided into two parts. In the first part, we present results on invariance and complexity of model checking. Moreover, we (...) compare partial communication with the public announcement and arrow update settings in terms of both language-expressivity and update-expressivity. Regarding the former, the three settings are equivalent, their languages being equally expressive. Regarding the latter, all three modes of communication are incomparable in terms of update-expressivity. In the second part, we shift our attention to strategic topic-based communication. We do so by extending the language with a modality that quantifies over the topics the agents can ‘talk about’, thus allowing a form of arbitrary partial communication. For this new framework, we provide a complete axiomatisation, showing also that the new language’s model checking problem is PSPACE-complete. Finally, we argue that, in terms of expressivity, this new language of arbitrary partial communication is incomparable to that of arbitrary public announcements and also to that of arbitrary arrow updates. (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)

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)

This special issue on Formal Models of Awareness contains five papers that concentrate on different approaches to the notion of awareness. They include syntactic and semantic approaches to modelling awareness and an alternative view from the multi-agent systems perspective where awareness is identified as the ability to perceive and understand actions of other agents.Velázquez-Quesada studies a logic of plausibility acknowledgement models used to interpret the notions of implicit and explicit beliefs. The models use the notion of a formula (...) being acknowledged as true that is similar to syntactic awareness in that the set of formulas acknowledged as true by an agent is not assumed to be closed under logical consequence. However it has a different meaning . A dynamic epistemic logic over such models is cons .. (shrink)

This paper seeks to establish whether the categories of MacIntyrean virtue ethics as applied to business organizations are meaningful in a non-western business context. It does so by building on research reported in Moore : 363–387, 2012) in which the application of virtue ethics to business organizations was investigated empirically in the UK, based on a conceptual framework drawn from MacIntyre’s work. Comparing these results with an equivalent study in Sri Lanka, the paper finds that the categories are meaningful but (...) that there are both similarities to and considerable differences in the content of these categories from the UK study. The paper draws on aspects of institutional theory to explore and explain these findings. Overall, there is supportive evidence that the categories of MacIntyrean virtue ethics are generalizable, and so can be used to characterize problems of organizational virtue and vice around the world, while providing evidence that there may be polities which are more conducive to the ‘practice-like conduct of production’ : 77–91, 2008). (shrink)

We present a new functional interpretation, based on a novel assignment of formulas. In contrast with Gödel’s functional “Dialectica” interpretation, the new interpretation does not care for precise witnesses of existential statements, but only for bounds for them. New principles are supported by our interpretation, including the FAN theorem, weak König’s lemma and the lesser limited principle of omniscience. Conspicuous among these principles are also refutations of some laws of classical logic. Notwithstanding, we end up discussing some applications of the (...) new interpretation to theories of classical arithmetic and analysis. (shrink)

En el terreno de la moral, el contraste entre lo ¿que el filósofo Wilfrid Sellars denominó «la ¿imagen manifiesta» y la «imagen científica» es enorme y tiene unas consecuencias prácticas ineludibles. Este libro reduce la distancia entre esa imagen manifiesta y la imagen científica, dotando al lector de referencias fundamentales, enfoques diversos y un amplio abanico de temáticas a partir de investigaciones experimentales sobre nuestra conducta moral.

English translates ‘genos’ as kind and ‘eidos’ as form, which differ in meaning as much as ‘herd’ and ‘brand’ do. But there are hard passages where ‘genos’ and ‘eidos’ have appeared to be synonyms, usually given the new meaning class. We show that, although ‘genos’ and ‘eidos’ are never synonyms and continue to mean kind and form, the word ‘eidos’ can be used figuratively, as a metonym, for a genos.

Fernando Pessoa, a par de diatribes ao regímen republicano implantado em Portugal a 5 de Outubro de 1910, enuncia como e porquê o verdadeiro regímen político português: «república nova», promoverá liberdade e humanismo autênticos sob a organização de um escol de eleitos indispensáveis ao «Império de Cultura» capaz de colocar Portugal de novo como grande potência europeia constituindo uma «Confederação Ibérica», assim cultive a virtude da nação germânica.

Se realizó una propuesta metodológica en el Hospital Militar Clínico Quirúrgico Docente Doctor Octavio de la Concepción y la Pedraja de Camagüey durante el año 2014 con el objetivo de argumentar el valor ético que tiene para el estudiante de Medicina ser insertado al sistema de garantía de la calidad hospitalaria. Se emplearon métodos de nivel teórico como análisis y síntesis, histórico-lógico, inducción-deducción. La vinculación del estudiante universitario al sistema de garantía de calidad en un centro asistencial docente permite elevar (...) la utilización correcta del método clínico y provee al discente de conocimiento para que al egresar desempeñe un servicio de excelencia y alcance a reducir los errores e insatisfacciones de la población y con ello los costos innecesarios. In order to increase the ethical value integrating medical students into a hospital quality guarantee system has, a methodological proposal was put forward in the Doctor Octavio de la Concepcion y la Pedraja Teaching Clinical-Surgical Military Hospital of Camaguey during 2014. Theoretical methods such as analysis and synthesis, historical-logical methods and induction-deduction were used. Linking college students to the quality guarantee system allows increasing the proper use of the clinician and it provides the learner with the knowledge he needs to carry out an excellent service and to reduce errors making and people dissatisfactions, therefore cutting on unnecessary costs. (shrink)

We construct a weak second-order theory of arithmetic which includes Weak König's Lemma (WKL) for trees defined by bounded formulae. The provably total functions (with Σ b 1 -graphs) of this theory are the polynomial time computable functions. It is shown that the first-order strength of this version of WKL is exactly that of the scheme of collection for bounded formulae.

A dilemma has stymied interpretations of the Stranger’s method of dividing kinds into subkinds in Plato’sSophistandStatesman. The dilemma assumes that the kinds are either extensions or intensions. Now kinds divide like extensions, not intensions. But extensions cannot explain the distinct identities of kinds that possess the very same members. We propose understanding a kind as like an animal body—the Stranger’s simile for division—possessing both an extension and an intension. We find textual support in the Stranger’s paradigmatic four steps for collecting (...) a subkind. (shrink)