In this paper we will discuss the active part played by certain diagonal arguments in the genesis of computability theory. 1?In some cases it is enough to assume the enumerability of Y while in others the effective enumerability is a substantial demand. These enigmatical words by Kleene were our point of departure: When Church proposed this thesis, I sat down to disprove it by diagonalizing out of the class of the ??definable functions. But, quickly realizing that the diagonalization cannot be (...) done effectively, I became overnight a supporter of the thesis. (1981, p. 59) The title of our paper alludes to this very work, a task on which Kleene claims to have set out after hearing such a remarkable statement from Church, who was his teacher at the time. There are quite a few points made in this extract that may be surprising. First, it talks about a proof by diagonalization in order to test?in fact to try to falsify?a hypothesis that is not strictly formal. Second, it states that such a proof or diagonal construction fails. Third, it seems to use the failure as a support for the thesis. Finally, the episode we have just described took place at a time, autumn 1933, in which many of the results that characterize Computability Theory had not yet materialized. The aim of this paper is to show that Church and Kleene discovered a way to block a very particular instance of a diagonal construction: one that is closely related to the content of Church's thesis. We will start by analysing the logical structure of a diagonal construction. Then we will introduce the historical context in order to analyse the reasons that might have led Kleene to think that the failure of this very specific diagonal proof could support the thesis. This is a joint paper. We have both attempted to add a small piece to an amazing historical jigsaw puzzle at a juncture we feel to be appropiate. In the paper by Manzano 1997 the aforementioned words by Kleene were quoted, and since then several logicians, Enrique Alonso first and foremost, have questioned her on this issue. Here we both submit our reply. (1999, pp. 249--273). (shrink)
Shared agency is of central importance in our lives in many ways. We enjoy engaging in certain joint activities with others. We also engage in joint activities to achieve complex goals. Current approaches propose that we understand shared agency in terms of the more basic phenomenon of shared intention. However, they have presented two antagonistic views about the nature of this phenomenon. Some have argued that shared intention should be understood as being primarily a structure of attitudes of individual participants (...) and their interrelations (Bratman, Searle, Tuomela and Miller). Others have claimed that shared intention should be regarded as being primarily a normative transaction which gives rise to interpersonal obligations (Gilbert). In contrast to these approaches, I propose a compromise view. I argue that shared intention involves a complex socio-psychological structure which ensures, in the absence of special circumstances, the existence of relevant moral obligations. My argument involves two main steps. First, I show that shared intention includes important relations of mutual reliance between the participants. Then, I argue that the existence of these relations of mutual reliance in shared intention helps us explain why, failing special circumstances, shared intention generates those obligations. This provides, in my view, a solution to the vexed question of the relation between shared intention and interpersonal obligations. (shrink)
Este trabajo constituye una revisión de los contenidos, orientación y objetivos de una parte significativa de los manuales de lógica elemental de las décadas de 1960 y 1970 redactados por autores españoles. En concreto, analizamos los prólogos, los rudimentos prerios, y la presentación de los distintos cálculos gue aparecen en tales obras. EI estudio de la semántica, los contenidos metatcóricos o las extensiones de Ia lógica elemental quedan para una segunda etapa de esta investigacion.This work is a critical examination of (...) contents, orientation, and goals of a significative portion of elementary spanish logic textbooks in the 60’s and 70’s. It is centered on an analysis ofprefaces, preliminaries and the different kinds of calculi appearing in these books. Topics, like semantics, metatheory or extensiones of elementary logic, are left for futrher analysis. (shrink)
La Teoría de la Computación es un campo especialmente rico para la indagación filosófica. EI debate sobre el mecanicismo y la discusión en torno a los fundamentos de la matemática son tópicos que estan directamente asociados a la Teoria de la Computación desde su misma creación como disciplina independiente. La Tesis de Turing-Church constituye uno de los resultados mas característicos en este campo estando, además, lleno de consecuencias filosóficas. En este ensayo se ofrece una guía de referencia útil a aquellos (...) que desean prestar alguna atención a estos asuntos y carecen de la base técnica o histórica que se precisa. En primer lugar se ofrece un resurnen de los principales problemas relacionados con la Tesis de Turing-Church para ofrecer a continuación información sobre sus aspectos más controvertidos. Se proponen algunos problemas no resueltos y se analiza su relevancia filosófica.Computer Science is a field specially rich for philosophical inquiry. Mechanism and the discussion around foundations of mathematics are topics directly asociated to Computer Science for its very constitution as an independent discipline. Church-Turing Thesis is one of the most characteristic results in this field and is plenty of philosophical consequences. In this article I offer a referenee guide useful for those who are willing to pay some attention to these matters and ignore the technical and historical basis needed for this task. I resume the main topics related to Church-Turing Thesis and give some informationabout the most controversial aspects of this subject. Some open questions are settled for further investigation paying special attention to their philosophical importance. (shrink)
Neste artigo defendo que a Teoria da Informação Fortemente Semântica de Floridi (2004) – TIFS – está correta ao assumir a Tese da Veracidade, que por sua vez orienta a definição de informação semântica como “p é informação se e somente se p é constituído por dados bem-formados, com significado e verdadeiros”. Argumento que a teoria não é arbitrária, pois dá conta do desembaraço de conundrums filosóficos importantes, principalmente por evitar o paradoxo de Bar-Hillel e Carnap (1953), que é gerado (...) a partir da teoria clássica da informação semântica. Primeiro é discutido um dos principais resultados da teoria clássica, o de produzir “sentenças muito informativas para serem verdadeiras”. Depois são resumidas as motivações para a elaboração de uma “lógica de estar informado” e é mostrado como o sistema KTB-IL é montado e modelado mantendo-se entre os seus axiomas o da veracidade – K ou A4. Finalmente, a TIFS é examinada e defendida ao mostrar que ela restringe aleticamente a extensão do conceito clássico de informação para evitar problemas com tautologias e contradições. A TIFS oferece uma solução original ao capturar nossas intuições modais a respeito da informatividade como noção básica. (shrink)
El Estado es un concepto clave en la filosofía jurídico-política de José Ortega y Gasset (Madrid, 1883-1955). Sin embargo, resulta sorprendente que, pese a la importancia que para este autor tenía dicha noción, no haya sido estudiada con la misma profundidad e interés que otras vertientes de su pensamiento. A este respecto, basta repasar las monografías y los artículos publicados hasta la fecha sobre la figura y la obra de Ortega para constatar que, en términos cuantitativos, las investigaciones dedicadas a (...) la idea orteguiana del Estado han sido apenas testimoniales, y desde luego no son tan significativas como las que se han podido dedicar a otros temas o tópicos más conocidos de su pensamiento. Así pues, el presente libro pretende abordar el estudio de la realidad problemática del Estado en su triple dimensión histórica, sociológica y política. De acuerdo con tal propósito, esta monografía se divide en tres partes: en la primera de ellas, se estudian las instituciones políticas de Roma entendidas por Ortega como precedentes ineludibles para la formación histórica del Estado. La segunda parte de la obra versa sobre el Estado concebido como culminación de lo social, es decir, como órgano diferenciado para el ejercicio del poder público, lo cual conduce indefectiblemente hasta la Teoría de los usos sociales. Por último, la tercera parte se centra en el concepto orteguiano de Estado como forma de organización política, explica la relación que mantienen el Estado y nación en su obra, y expone las líneas principales del programa político pensado por Ortega para modernizar, regenerar y europeizar a España. (shrink)
La presente exposición es una reflexión sobre los conceptos de “sociedad de control” y “revolución” con el fin de responder una pregunta básica: ¿Cómo resistir al control? Es ante todo una reflexión ética sobre la sociedad y las posibilidades prácticas, micropolíticas, de nuestra acción en ella. Se describe, en un primer momento, qué es una sociedad de control y sus dispositivos de seguridad a nivel político y económico; luego se reflexiona en torno a los procesos sociales revolucionarios, dando un concepto (...) de revolución; y se finaliza mostrando, en líneas generales, lo que constituiría una ética de la resistencia. Los autores que servirán de base teórica de la misma serán Foucault, Deleuze y Guattari. (shrink)
The title of our session today is “Virtue Ethics from a Global Perspective.” In my remarks, I would like to sketch out an account of what a global perspective on virtue ethics would look like. Here’s how I’ll proceed. First, I would like to explore some of the reasons why we need a global perspective on virtue ethics. This leads naturally to the second issue, which is a clarification of what we mean by a global perspective on virtue ethics. I (...) shall suggest a three part framework—consisting of the object of the virtue, the virtue itself, and the actions through which that virtue is expressed—for a global perspective on virtue ethics. This framework is a pluralistic one, striking a middle ground between absolutism and relativism. Along the way, especially in part two, I will look at several specific virtues, especially respect and courage, to see how this tripartite framework can be applied. The final result, I hope, will be an outline of what a global perspective on virtue ethics would look like. (shrink)
In this work we study the behavior of a time discrete multiregional stochastic model for a population structured in age classes and spread out in different spatial patches between which individuals can migrate. The dynamics of the population is controlled both by reproduction-survival and by migration. These processes take place at different time scales in the sense of the latter being much faster than the former. We incorporate the effect of demographic stochasticity into the population, which results in both dynamics (...) being modelled by multitype Bienaymé–Galton–Watson branching processes. We present a multitype global model that incorporates the effect of both processes and, making use of the existence of different time scales for demography and migration, build a reduced model in which the variables correspond to the total population in each age class. We extend previous results that relate the behavior of the original and the reduced model showing that, given a large enough separation of time scales between demography and migration, we can obtain information about the behavior of the multitype global model through the study of the simpler reduced model. We concentrate on the case where the two systems are supercritical and therefore the expected number of individuals grows to infinity, and show that we can approximate the asymptotic structure of the population vector and the asymptotic population size of the original system through the study of the reduced model. (shrink)
Introducción -- Pedro Hispano y la lógica mexicana de la Colonia -- Nebrija como antecesor de la lingüística en la Nueva España: las Institutiones de Nebrija como libro de texto y otros influjos -- La teoría del significado semántico en Alonso de la Vera Cruz -- La teoría del significado semántico en Tomás de Mercado -- Lenguaje y lógica en Antonio Rubio -- Lenguaje y lógica en el siglo XVIII -- Los tropos en la retórica de Vallarta y Palma (...) (s. XVIII) -- El uso de la analogía por fray Diego Durán, O.P.: semiótica y antropología -- Conclusiones. (shrink)
Traditional causation posits that the past alone influences the present. In principle, however, the basic laws of physics permit the future an equal measure of influence: retrocausation. This symposium explores theoretical developments and experimental evidence for retrocausation. It is unique in stressing recent experiments in this exciting and potentially important new field.
The natural interpretation of counterfactuals with disjunctive antecedents involves selecting from each of the disjuncts the worlds that come closest to the world of evaluation. It has been long noticed that capturing this interpretation poses a problem for a minimal change semantics for counterfactuals, because selecting the closest worlds from each disjunct requires accessing the denotation of the disjuncts from the denotation of the disjunctive antecedent, which the standard boolean analysis of or does not allow (Creary and Hill, Philosophy of (...) Science 43:341–344, 1975; Nute, Journal of Philosophy 72:773–778, 1975; Fine, Mind 84(335):451–458, 1975; Ellis et al. Journal of Philosophical Logic 6:335–357, 1977). This paper argues that the failure to capture the natural interpretation of disjunctive counterfactuals provides no reason to abandon a minimal change semantics. It shows that the natural interpretation of disjunctive counterfactuals is expected once we refine our assumptions about the semantics of or and the logical form of conditionals, and (i) we assume that disjunctions introduce propositional alternatives in the semantic derivation, in line with independently motivated proposals about the semantics of or (Aloni, 2003a; Simons, Natural Language Semantics 13:271–316, 2005; Alonso-Ovalle, Disjunction in Alternative Semantics. PhD thesis, 2006); and (ii) we treat conditionals as correlative constructions, as advocated in von Fintel (1994), Izvorski (Proceedings of NELS 26, 1996), Bhatt and Pancheva (2006), and Schlenker (2004). (shrink)
Written over the course of two months in early 2008, Art as "Night" is a series of essays in part inspired by a January 2007 visit to the Velázquez exhibition at the National Gallery of Art, London, with subsequent forays into related themes and art-historical judgments for and against theories of meta-painting. Art as "Night" proposes a type of a-historical dark knowledge (a-theology and theology, at once) crossing painting since Velázquez, but reaching back to the Renaissance, especially Titian and Caravaggio. (...) As a form of formalism, this "night" is also closely allied with forms of intellection that come to reside in art as pure visual agency or material knowledge while invoking moral agency, a function of art more or less bracketed in modern art for ethical and/or political agency. Not a theory of meta-painting, Art as "Night" restores coordinates arguably lost in painting since the separation of natural and moral philosophy in the Baroque era. It is with Velázquez that we see a turning point, an emphasis on the specific resources of painting as a form of speculative intellect, while it is with contemporary works by Gerhard Richter and Anselm Kiefer that we see the return of the same after the collapse of modernism, and after subsequent postmodern maneuvers to make art discursive yet without the austerities of the formal means present in Art as Art. Art as "Night" argues for a nondiscursive form of intellection fully embodied in the work of art – and, foremost, painting. A synoptic and intentionally elusive and allusive survey of painting, through the collapse of the art market in late 2007, Art as "Night" suggests by way of this critique of an elective "night" crossing painting that the art world is an endlessly deferred version of pleroma (Hegel’s Absolute Knowledge), a fully synthetic world given to an exploration and appropriation of the given through classical mimesis and epistemology and its complete incorporation and transfiguration in a theory of knowledge and art as pure speculative agency. In effect, Art as "Night" is an incarnational theory of art as absolute knowledge. (shrink)
Wednesday, October 10th in Research Alonso-Ovalle, Luis. 2007. Alternatives in the Disjunctive Antecedents Problem. Proceedings of the 26th West Coast Conference on Formal Linguistics. University of California, Berkeley.
The purpose of this paper is twofold: to discuss some challenging issues concerning Sextus’ works and outlook, and to offer an overview of the influence exerted by Sextan Pyrrhonism on both early modern and contemporary philosophy.
Kentridge and Heywood (this issue) extend the concept of metacognition to include unconscious processes. We acknowledge the possible contribution of unconscious processes, but favor a central role of awareness in metacognition. We welcome Shimamura's (this issue) extension of the concept of metacognitive regulation to include aspects of working memory, and its relation to executive attention.
Understanding the intrinsic/extrinsic distinction Content Type Journal Article Pages 1-4 DOI 10.1007/s11016-011-9549-x Authors Robert Francescotti, Department of Philosophy, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-6044, USA Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796.
cal basis of consciousness. We continue by discussing the relation between spatiotem- One of the outstanding problems in the cog- poral patterns of brain activity and con- nitive sciences is to understand how ongo- sciousness, with particular attention to pro- ing conscious experience is related to the cesses in the gamma frequency band. We workings of the brain and nervous system. then adopt a critical perspective and high-.
Metacognition refers to any knowledge or cognitive process that monitors or controls cognition. We highlight similarities between metacognitive and executive control functions, and ask how these processes might be implemented in the human brain. A review of brain imaging studies reveals a circuitry of attentional networks involved in these control processes, with its source located in midfrontal areas. These areas are active during conflict resolution, error correction, and emotional regulation. A developmental approach to the organization of the anatomy involved in (...) executive control provides an added perspective on how these mechanisms are influenced by maturation and learning, and how they relate to metacognitive activity. (shrink)
Scientiﬁc concepts are deﬁned by metaphors. These metaphors determine what atten- tion is and what count as adequate explanations of the phenomenon. The authors analyze these metaphors within 3 types of attention theories: (a) --cause-- theories, in which attention is presumed to modulate information processing (e.g., attention as a spotlight; attention as a limited resource); (b) --effect-- theories, in which attention is considered to be a by-product of information processing (e.g., the competition meta- phor); and (c) hybrid theories that combine (...) cause and effect aspects (e.g., biased- competition models). The present analysis reveals the crucial role of metaphors in cognitive psychology, neuroscience, and the efforts of scientists to ﬁnd a resolution to the classic problem of cause versus effect interpretations. (shrink)