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)

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)

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)

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)

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)

El presente documento intenta colocar diversas discusiones sobre la realidad latinoamericana, particularmente en la forma como diversos escenarios nacionales han asumido críticos periodos de violencia política en décadas recientes. Ello teniendo en cuenta que hay toda una serie de variantes y contextos políticos en la región, en donde se imponen por un lado, diferentes regímenes de gobierno y por otro, distintos posicionamientos políticos de los movimientos sociales. En ambos casos, estos se despliegan acorde al momento socioeconómico experimentado en una determinada (...) nación. El énfasis de esta propuesta, acentúa en abrir un debate respecto a cómo cada sociedad instaurada dentro de los marcos nacionales, ha enfrentado posterior o simultáneamente, críticos periodos de violación de los Derechos Humanos ocurridos en periodos de aguda confrontación política y social. Han sido momentos históricos donde se concentran las contradicciones sociales, ya sea bajo la forma de dictaduras o bajo la imposición de gobiernos autoritarios encubiertos en un sistema democrático. Son etapas pasadas y presentes que aún hoy dejan una huella profunda en la conciencia y vida de muchos activistas, de académicos, de organizaciones sociales y de víctimas del terrorismo de Estado. (shrink)

En el campo de la intervención clínica en psicología existen diversos modelos psicoterapéuticos, cada uno de los cuales está apoyado de manera particular en una cosmovisión y en una concepción antropológica del hombre. La concepción antropológica influye directamente en la manera como se realiza la invención terapéutica. En el caso de la Logoterapia considerada como uno de los modelos más representativos de la psicoterapia existencial, es posible identificar claramente que tanto su concepción antropológica como su intervención clínica se fundamentan en (...) principios éticos ampliamente reconocidos y sostenidos por la bioética, como son: el respeto por la vida y la dignidad de la persona, la importancia de la dimensión espiritual en el hombre o el sentido trascendente de la existencia humana, entre otros. (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)

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 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)

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)

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)

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)

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)

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)

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.

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)

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)

Abstract The article addresses three aspects of the humanitarian intervention doctrine. It argues, first, that the value of sovereignty rests on the justified social processes of the target state ? the horizontal contract. Foreign interventions, even when otherwise justified, must respect the horizontal contract. In contrast, morally objectionable social processes (such as the subjection of women) are not protected by sovereignty (intervention, of course, may be banned for other reasons). In addition, tyrants have no moral protection against interventions directed at (...) them. Second, the article addresses the internal legitimacy of humanitarian intervention. It concludes that the liberal state may only use voluntary soldiers (either the voluntary army or mercenaries) to conduct humanitarian intervention. Conscription for that purpose is not permissible. The article shows that the long-standing criticism of mercenaries stems from a romantic prejudice and is thus unfair. Third, the article makes a distinction between intention (the determination to perform an action) and motive (a further goal that the agent seeks with that action) and shows that only intention is relevant for humanitarian intervention. A justified humanitarian intervention requires the intention to liberate the victims, but not necessarily a good further motive. It shows how mainstream doctrine has impermissibly confused the two concepts. (shrink)

In Frege’s logicism, numbers are logical objects in the sense that they are extensions of certain concepts. Frege’s logical system is inconsistent, but Richard Heck showed that its restriction to predicative quantification is consistent. This predicative fragment is, nevertheless, too weak to develop arithmetic. In this paper, I will consider an extension of Heck’s system with impredicative quantifiers. In this extended system, both predicative and impredicative quantifiers co-exist but it is only permissible to take extensions of concepts formulated in the (...) predicative fragment of the language. This system is consistent. Moreover, it proves the principle of reducibility applied to concepts true of only finitely many objects. With the aid of this form of reducibility, it is possible to develop arithmetic in a thoroughly Fregean way. (shrink)

It is possible today to observe in hindsight the epistemological landscape of the twentieth century, and the work of Albert Lautman in mathematical philosophy appears as a profound turning point, opening to a true under- standing of creativity in mathematics and its relation with the real. Little understood in its time or even today, Lautman’s work explores the difficult but exciting intersection where modern mathematics, advanced mathe- matical invention, the structural or unitary relations of mathematical knowledge and, finally, the metaphysical (...) and dialectical tensions underly- ing mathematical activity converge. Well beyond other better-known names in philosophy of mathematics – who are focused above all on ques- tions concerning the logical problem of foundations, important but frag- mentary studies in the vast panorama of modern mathematics – Lautman broaches the emergence of inventiveness in the very broad spectrum of the development of the mathematical real. Group theory, differential geome- try, algebraic topology, differential equations, functional analysis, functions of complex variables and number fields are some of the domains of his preferred examples. He detects in them methods of construction, structu- ration and unification of modern mathematics that he connects to a precise Platonic interpretation in which powerful pairs of ideas serve to organize the edifice of effective mathematics. (shrink)

We introduce the work of Mariano Picón Salas, who tries to enlarge the Hispanoamerican tradition —historically focused on the web of transits/obstructions between Europe and Latin America— via a larger triangulation that includes the presence of the culture of the United States. His essays from the period 1930-1950 show how pragmatism —understood in Peircean terms as a web of topological transfers of knowledge between the borders of culture— can help to provide a vision that encompasses America as a whole.

"If being a humanitarian imperialist means advocating that the hegemon use its might to advance freedom, human rights, and democracy, then I am a humanitarian imperialist.".

This essay examines the many problems with public and private development aid and argues that global liberalization of trade and immigration would have a greater direct effect in reducing global poverty. It also examines and rejects the view that people in rich countries have a strong moral obligation to give to the global poor. Such an obligation is in tension with an ethic that prizes personal projects. A political morality of equal respect and concern is congenial not with foreign aid, (...) but with recognizing the agency of the global poor by lifting the many obstacles they currently face to participating in the market as producers and consumers. (shrink)