Normative theories of argumentation tend to assume that logical and dialectical rules suffice to ensure the rationality of argumentative discourse. Yet, in everyday debates people use arguments that seem valid in light of such rules but nonetheless biased and tendentious. This article seeks to show that the rationality of argumentation can only be fully promoted if we take into account its ethical dimension. To substantiate this claim, I review some of the empirical evidence indicating that people’s inferential reasoning is systematically (...) affected by a variety of biases and heuristics. Insofar as these cognitive illusions are typically unintentional, it appears that arguers may be biased despite their well-intended efforts to follow the rules of critical argumentation. Nevertheless, I argue that people remain responsible for the rationality of their arguments, given that there are a number of measures that they can (and ought to) take to avoid such distortions. I highlight the importance of argumentational virtues and critical thinking to rational debates, and describe a set of indirect strategies of “argumentative self-control”. (shrink)

In this article I argue that most biases in argumentation and decision-making can and should be counteracted. Although biases can prove beneficial in certain contexts, I contend that they are generally maladaptive and need correction. Yet critical thinking alone seems insufficient to mitigate biases in everyday contexts. I develop a contextualist approach, according to which cognitive debiasing strategies need to be supplemented by extra-psychic devices that rely on social and environmental constraints in order to promote rational reasoning. Finally, I examine (...) several examples of contextual debiasing strategies and show how they can contribute to enhance critical thinking at a cognitive level. (shrink)

In this article I argue that most biases in argumentation and decision-making can and should be counteracted. Although biases can prove beneficial in certain contexts, I contend that they are generally maladaptive and need correction. Yet critical thinking alone seems insufficient to mitigate biases in everyday contexts. I develop a contextualist approach, according to which cognitive debiasing strategies need to be supplemented by extra-psychic devices that rely on social and environmental constraints in order to promote rational reasoning. Finally, I examine (...) several examples of contextual debiasing strategies and show how they can contribute to enhance critical thinking at a cognitive level. (shrink)

In this paper, I argue that ordinary cases of self-deception and akrasia derive from the phenomenon of motivated irrationality. According to the ‘motivational’ account, self-deception is typically induced by the influence that desires and emotions exert upon our cognitive faculties, and thereby upon the process of belief formation. Crucially, I show that this hypothesis is consistent with the empirical research carried out by social psychologists, and that it avoids a number of paradoxes that undermine the ‘intentionalist’ account. But motivated irrationality (...) also seems to account for most cases of akrasia, insofar as desires are equally liable to affect the evaluative judgments through which we assess feasible options. This analysis thus set the premises for a unified account of irrationality. (shrink)

This monograph is a detailed study, and systematic defence, of the Growing Block Theory of time (GBT), first conceived by C.D. Broad. The book offers a coherent, logically perspicuous and ideologically lean formulation of GBT, defends it against the most notorious objections to be found in the extant philosophical literature, and shows how it can be derived from a more general theory, consistent with relativistic spacetime, on the pre-relativistic assumption of an absolute and total temporal order. -/- The authors devise (...) axiomatizations of GBT and its competitors which, against the backdrop of a shared quantified tense logic, significantly improves the prospects of their comparative assessment. Importantly, neither of these axiomatizations involves commitment to properties of presentness, pastness or futurity. The authors proceed to address, and defuse, a number of objections that have been marshaled against GBT, including the so-called epistemic objection according to which the theory invites skepticism about our temporal location. The challenge posed by relativistic physics is met head-on, by replacing claims about temporal variation by claims about variation across spacetime. -/- The book aims to achieve the greatest possible rigor. The background logic is set out in detail, as are the principles governing the notions of precedence and temporal location. The authors likewise devise a novel spacetime logic suited for the articulation, and comparative assessment, of relativistic theories of time. The book comes with three technical appendices which include soundness and completeness proofs for the systems corresponding to GBT and its competitors, in both their pre-relativistic and relativistic forms. -/- The book is primarily directed at researchers and graduate students working on the philosophy of time or temporal logic, but is of interest to metaphysicians and philosophical logicians more generally. (shrink)

In a previous work, we have shown that the null result of the Michelson–Morley experiment in vacuum is deeply connected with the notion of time. The same is true for the postulate of constancy of the two-way speed of light in vacuum in all frames independently of the state of motion of the emitting body. The argumentation formerly given is very general and has to be true not only within Special Relativity and its “equivalence” of all inertial frames, but as (...) well as in Lorentz-Poincaré scenario of a preferred reference frame. This paper is the second of a trilogy intending to revisit the foundations of Special Relativity, and addresses the question of the constancy of the one-way speed of light and of the differences and similarities between both scenarios. Although they manifestly differ in philosophy, it is debated why and how the assumption of a “special system of reference experimentally inaccessible” is indeed compatible with Einstein’s Special Relativity, as beautifully outlined and discussed by Bell [Speakable and Unspeakable in Quantum Mechanics (Cambridge University Press, Cambridge, 1988)]. This rather trivial statement is still astonishing nowadays to a big majority of scientists. The purpose of this work is to bring such assertion into perspective, widening the somewhat narrow view of Special Relativity often presented in textbooks and scientific papers. (shrink)

The COVID-19 outbreak has ravaged all societal domains, including education. Home confinement, school closures, and distance learning impacted students, teachers, and parents’ lives worldwide. In this study, we aimed to examine the impact of COVID-19-related restrictions on Italian and Portuguese students’ academic motivation as well as investigate the possible buffering role of extracurricular activities. Following a retrospective pretest–posttest design, 567 parents reported on their children’s academic motivation and participation in extracurricular activities. We used a multi-group latent change score model to (...) compare Italian and Portuguese students’: pre-COVID mean motivation scores; rate of change in motivation; individual variation in the rate of change in motivation; and dependence of the rate of change on initial motivation scores. Estimates of latent change score models showed a decrease in students’ motivation both in Italy and in Portugal, although more pronounced in Italian students. Results also indicated that the decrease in students’ participation in extracurricular activities was associated with changes in academic motivation. Furthermore, students’ age was significantly associated with changes in motivation. No significant associations were found for students’ gender nor for parents’ education. This study provides an important contribution to the study of students’ academic motivation during home confinement, school closures, and distance learning as restrictive measures adopted to contain a worldwide health emergency. We contend that teachers need to adopt motivation-enhancing practices as means to prevent the decline in academic motivation during exceptional situations. (shrink)

O foco deste trabalho repousa sobre um certo caminho histórico percorrido pela ciência, como um todo, no sentido desta se despir de qualquer revestimento metafísico e que teve como marco incontornável a criação, em 1929, do Círculo de Viena. Abordamos algumas tendências e limitações desse movimento e argumentamos que o metafísico terá sempre um espaço no seio mais íntimo da reflexão científica. Este trabalho foi realizado no âmbito da disciplina de Filosofia das Ciências I, parte do curso de Filosofia da (...) Faculdade de Letras da Universidade do Porto, Portugal. (shrink)

Neste trabalho abordamos a obra de Francis Bacon e as suas contribuições para a Filosofia da Ciência, incluindo a sua proposta de método científico e o seu posicionamento crítico face à anterior versão aristotélica e a influência que o pensamento baconiano exerceu na promoção de um novo quadro filosófico para o desenvolvimento científico na modernidade. Este trabalho foi realizado no âmbito da disciplina de Filosofia das Ciências I, parte do curso de Filosofia da Faculdade de Letras da Universidade do Porto, (...) Portugal. (shrink)

We systematically study the completion of choice problems in the Weihrauch lattice. Choice problems play a pivotal rôle in Weihrauch complexity. For one, they can be used as landmarks that characterize important equivalences classes in the Weihrauch lattice. On the other hand, choice problems also characterize several natural classes of computable problems, such as finite mind change computable problems, non-deterministically computable problems, Las Vegas computable problems and effectively Borel measurable functions. The closure operator of completion generates the concept of total (...) Weihrauch reducibility, which is a variant of Weihrauch reducibility with total realizers. Logically speaking, the completion of a problem is a version of the problem that is independent of its premise. Hence, studying the completion of choice problems allows us to study simultaneously choice problems in the total Weihrauch lattice, as well as the question which choice problems can be made independent of their premises in the usual Weihrauch lattice. The outcome shows that many important choice problems that are related to compact spaces are complete, whereas choice problems for unbounded spaces or closed sets of positive measure are typically not complete. (shrink)

Neste breve ensaio, exploramos alguns caminhos de uma controvérsia milenar em torno do estatuto dos entes matemáticos e apresentamos alguns argumentos a favor de uma posição platonista, aproximadamente clássica, sobre o tema. Este trabalho foi realizado no âmbito da disciplina de Filosofia das Ciências II, parte do curso de Filosofia da Faculdade de Letras da Universidade do Porto, Portugal.

Background Ethical conflict is a problem with negative consequences, which can compromise the quality and ethical standards of the nursing profession and it is a source of stress for health care practitioners’, especially for nurses. Objectives The main aim of this study was to analyze Spanish critical care nurses’ level of exposure to ethical conflict and its association with sociodemographic, occupational, and COVID-19–related variables. Research Design, Participants, and Research context: This was a quantitative cross-sectional descriptive study conducted among 117 nurses (...) working in critical care units. Data collection tools were sociodemographic, occupational, and COVID-19–related questionnaires and previously validated Spanish version of Ethical Conflict in Nursing Questionnaire-Critical Care Version. Ethical Considerations We obtained permission from the Ethics Committee and participants' informed consent. Findings Data indicates a moderate level of exposure to ethical conflicts. The most frequent ethical conflicts were related to situations about "treatment and clinical procedures." The most intensity of ethical conflicts was related to situations about "treatment and clinical procedures" and "dynamics of the service and working environment." No statistical significance was identified between the socio-demographic variables and level of exposure to ethical conflicts. However, for critical care nurses working in ICU, nurses with perceived worked stress had a higher level of exposure to ethical conflicts. Likewise, critical care nurses whose family/friends were infected with COVID-19 had a higher level of exposure. Conclusions Critical care nurses experience a moderate level of exposure to ethical conflicts which is consistent with the results of previous studies. A deeper understanding of ethical conflicts in conflictive situations allows recognition of the situations that occur in everyday clinical practice, identification of the ethical conflicts, and facilitation of the nurses working in the challenging clinical situation. (shrink)

: This article aims to show that although the apostle Paul did not call himself a prophet, still makes his presentation in his letters in the same way that the Old Testament prophets. The article points out the many similarities between Paul and the prophets. It seeks to analyze and interact with Scripture and literature concerning the matter.We conclude that the Apostle founded the authority of his call, highlighting the prophetic aspect of his apostolate. It is evident that the Apostle (...) had a awareness of the prophetic character of his person, mission and message. It is called and sent directly by God, records the Scripture inspired by the Spirit and has a fruitful ministry of preaching and teaching. Este artigo tem como objetivo mostrar que embora o apóstolo Paulo não chame a si mesmo de profeta, ainda assim faz sua apresentação em suas cartas nos mesmos moldes que os profetas do Antigo Testamento. O artigo aponta as várias semelhanças entre Paulo e os profetas. Procura-se fazer uma análise e interação com a Escritura bem como literatura pertinente ao tema. Conclui-se que o Apóstolo fundamenta a autoridade de seu chamado, destacando o aspecto profético de seu apostolado. Evidencia-se que o Apóstolo possuía uma consciência do caráter profético de sua pessoa, missão e mensagem. É chamado e enviado diretamente por Deus, registra a Escritura de maneira inspirada pelo Espírito e tem um profícuo ministério de pregação e ensino. (shrink)

Neste trabalho abordamos as contribuições de Larry Laudan para a questão do progresso científico. O modelo proposto, baseado na eficácia das teorias na resolução de problemas, serve de ponto de partida para uma breve reflexão sobre a influência contemporânea que as dificuldades de visão do mundo exercem sobre o desenvolvimento das ciências. Este trabalho foi realizado no âmbito da disciplina de Filosofia das Ciências II, parte do curso de Filosofia da Faculdade de Letras da Universidade do Porto, Portugal.

SIRAkabayashi et al1 presented us with an account of the difficulties when attempting to respect the patient's autonomy while we do not know the patient's own understanding regarding the autonomy we are attempting to respect. Most times we, as doctors, face difficult decisions, we do not have previous, reliable knowledge of the patients' views on the issue which we are finding difficult to resolve. Even previous discussions which happened far from the turmoil of cancer disclosure or similar events, can only (...) be relied upon to a limited extent. We have all seen patients changing their minds in the face of catastrophe, in ways not only unpredictable to their doctor, but also to themselves. Transcultural study of the meanings and practice of individual autonomy provides a very useful way of extending our understanding of these issues, enlarging our horizons, as it does, beyond the anglo-saxon view.The main point, however, is to construe a definition of autonomy which will encompass the cultural and individual variations of whatever autonomy stands for. Here I can only offer my view that autonomy …. (shrink)

In this paper we study a new approach to classify mathematical theorems according to their computational content. Basically, we are asking the question which theorems can be continuously or computably transferred into each other? For this purpose theorems are considered via their realizers which are operations with certain input and output data. The technical tool to express continuous or computable relations between such operations is Weihrauch reducibility and the partially ordered degree structure induced by it. We have identified certain choice (...) principles such as co-finite choice, discrete choice, interval choice, compact choice and closed choice, which are cornerstones among Weihrauch degrees and it turns out that certain core theorems in analysis can be classified naturally in this structure. In particular, we study theorems such as the Intermediate Value Theorem, the Baire Category Theorem, the Banach Inverse Mapping Theorem, the Closed Graph Theorem and the Uniform Boundedness Theorem. We also explore how existing classifications of the Hahn—Banach Theorem and Weak Kőnig's Lemma fit into this picture. Well-known omniscience principles from constructive mathematics such as LPO and LLPO can also naturally be considered as Weihrauch degrees and they play an important role in our classification. Based on this we compare the results of our classification with existing classifications in constructive and reverse mathematics and we claim that in a certain sense our classification is finer and sheds some new light on the computational content of the respective theorems. Our classification scheme does not require any particular logical framework or axiomatic setting, but it can be carried out in the framework of classical mathematics using tools of topology, computability theory and computable analysis. We develop a number of separation techniques based on a new parallelization principle, on certain invariance properties of Weihrauch reducibility, on the Low Basis Theorem of Jockusch and Soare and based on the Baire Category Theorem. Finally, we present a number of metatheorems that allow to derive upper bounds for the classification of the Weihrauch degree of many theorems and we discuss the Brouwer Fixed Point Theorem as an example. (shrink)

In this paper we study a reducibility that has been introduced by Klaus Weihrauch or, more precisely, a natural extension for multi-valued functions on represented spaces. We call the corresponding equivalence classes Weihrauch degrees and we show that the corresponding partial order induces a lower semi-lattice. It turns out that parallelization is a closure operator for this semi-lattice and that the parallelized Weihrauch degrees even form a lattice into which the Medvedev lattice and the Turing degrees can be embedded. The (...) importance of Weihrauch degrees is based on the fact that multi-valued functions on represented spaces can be considered as realizers of mathematical theorems in a very natural way and studying the Weihrauch reductions between theorems in this sense means to ask which theorems can be transformed continuously or computably into each other. As crucial corner points of this classification scheme the limited principle of omniscience LPO, the lesser limited principle of omniscience LLPO and their parallelizations are studied. It is proved that parallelized LLPO is equivalent to Weak Kőnig's Lemma and hence to the Hahn—Banach Theorem in this new and very strong sense. We call a multi-valued function weakly computable if it is reducible to the Weihrauch degree of parallelized LLPO and we present a new proof, based on a computational version of Kleene's ternary logic, that the class of weakly computable operations is closed under composition. Moreover, weakly computable operations on computable metric spaces are characterized as operations that admit upper semi-computable compact-valued selectors and it is proved that any single-valued weakly computable operation is already computable in the ordinary sense. (shrink)

The investigation of computational properties of discontinuous functions is an important concern in computable analysis. One method to deal with this subject is to consider effective variants of Borel measurable functions. We introduce such a notion of Borel computability for single-valued as well as for multi-valued functions by a direct effectivization of the classical definition. On Baire space the finite levels of the resulting hierarchy of functions can be characterized using a notion of reducibility for functions and corresponding complete functions. (...) We use this classification and an effective version of a Selection Theorem of Bhattacharya-Srivastava in order to prove a generalization of the Representation Theorem of Kreitz-Weihrauch for Borel measurable functions on computable metric spaces: such functions are Borel measurable on a certain finite level, if and only if they admit a realizer on Baire space of the same quality. This Representation Theorem enables us to introduce a realizer reducibility for functions on metric spaces and we can extend the completeness result to this reducibility. Besides being very useful by itself, this reducibility leads to a new and effective proof of the Banach-Hausdorff-Lebesgue Theorem which connects Borel measurable functions with the Baire functions. Hence, for certain metric spaces the class of Borel computable functions on a certain level is exactly the class of functions which can be expressed as a limit of a pointwise convergent and computable sequence of functions of the next lower level. (shrink)

Standard possible world semantics for propositional modal languages ignore truth-value gaps. However, simple considerations suggest that it should not be so. In Section 1, I identify what I take to be a correct truth-clause for necessity under the assumption that some possible worlds are incomplete (i.e., "at" which some propositions lack a truth-value). In Section 2, I build a world semantics, the semantics of TV-models, for standard modal propositional languages, which agrees with the truth-clause for necessity previously identified. Sections 3–5 (...) are devoted to systematic concerns. In particular, in Section 4, Prior’s system Q (propositional version) is given a TV-models semantics and proved adequate (i.e., sound and complete) with respect to it. (shrink)

Studies of multiple paternity in mammals and other animal species generally report proportion of multiple paternity among litters, mean litter sizes, and mean number of sires per litter. It is shown how these variables can be used to produce an estimate of the probability of reproductive success for a male that has mated with a female. This estimate of male success is more informative about the mating system that alternative measures, like the proportion of litters with multiple paternity or the (...) mean number of sires per litter. The probability of success for a mated male can be measured both theoretically and empirically, and gives an estimate of the intensity of sperm competition and of a male's “confidence of paternity” upon mating. The probability of success for mated males for ten “exemplar” species of mammals is estimated and they are compared for insights into the functioning of their mating systems. (shrink)

In this article, we propose to question the accuracy of Jean Wahl’s definition of Vladimir Jankélévitch’s Philosophie Première (1953) as one of the “ultimate efflorescences of negative theology.” In fact, we maintain that—although conceiving the apophatic discourse as a necessary (but insufficient) stepping-stone to the absolute—the aforementioned work constitutes, if anything, an effort to overcome it by means of what we shall call a tesiphatic philosophy, i.e., one that identifies the first principle, not as the absolute negation of being, but (...) as the absolute position of being. To defend our thesis, we shall start by discussing the meaning of the five divine names that Jankélévitch bestows upon his absolute, namely, (1) the “totally-other-order,” (2) the “super-truth,” (3) “the itself,” (4) the “I-know-not-what,” and (5) the “almost-nothing.” In this section of our paper, we will try to show how Jankélévitch’s discourse is, in fact, shaped by the whole negative theology tradition (from Plotinus to Nicholas of Cusa). Finally, in the last part of our paper, we will strive to reflect upon Jankélévitch’s interpretation of the limits of a apophatic metaphysical discourse, questioning whether his Philosophie Première effectively overcomes negative theology’s conception of the absolute. (shrink)

As palavras que se seguem constituem uma tentativa de explorar os diversos sentidos que revestem a figura do «com» [mit], tal como surge configurada ao longo dos §§ 25–27 de Sein und Zeit 2 . Escutaremos atentamente aquilo que Heidegger tem a dizer a respeito da necessária determinação do ser-no-mundo [in-der-Welt-sein] como ser-com [Mitsein] e veremos, depois, em que medida a sua analítica existencial faz (ou não) depender a constituição do ser-si-mesmo [Selbstsein] da figura do outro. Por último, e em (...) jeito de conclusão, tentaremos mostrar como Heidegger articula a interrogação pela ipseidade ou pelo «quem?» [Wer?] do ser-aí quotidiano [alltägliche Dasein], com uma breve reflexão acerca da inautenticidade [Uneigentlichkeit] fáctica em que o mesmo muitas vezes parece soçobrar. Será então, estamos em crer, o momento apropriado para debatermos o significado da controversa noção heideggeriana de «eles» [das Man], aproveitando também o ensejo para lançarmos a questão relativa à responsabilidade (ética?) do Dasein. Metodologicamente, contornaremos (sempre que possível) os tradicionais comentários a respeito das infinitas modalidades alternativas de tradução do jargão filosófico heideggeriano. (shrink)

Signalling games are popular models for studying the evolution of meaning, but typical approaches do not incorporate vagueness as a feature of successful signalling. Complementing recent like-minded models, we describe an aggregate population-level dynamic that describes a process of imitation of successful behaviour under imprecise perception and realization of similar stimuli. Applying this new dynamic to a generalization of Lewis’s signalling games, we show that stochastic imprecision leads to vague, yet by-and-large efficient signal use, and, moreover, that it unifies evolutionary (...) outcomes and helps avoid sub-optimal categorization. The upshot of this is that we see ‘as-if’-generalization at an aggregate level, without agents actually generalizing. _1_ Introduction _2_ Background _2.1_ Sim-max games and conceptual spaces _2.2_ Vagueness in sim-max games and conceptual spaces _2.3_ Vagueness, functional pressure, and transmission biases _3_ Imprecise Imitation _3.1_ Replicator dynamic in behavioural strategies _3.2_ Noise-perturbed conditional imitation _4_ Exploring Imprecise Imitation _4.1_ Setting the stage _4.2_ Simulation set-up _4.3_ Measures of interest _4.4_ Results _5_ Discussion _5.1_ Levels of vagueness _5.2_ Evolutionary benefits of imprecision _5.3_ Related work _6_ Conclusion Appendix. (shrink)

We prove that the Weihrauch lattice can be transformed into a Brouwer algebra by the consecutive application of two closure operators in the appropriate order: first completion and then parallelization. The closure operator of completion is a new closure operator that we introduce. It transforms any problem into a total problem on the completion of the respective types, where we allow any value outside of the original domain of the problem. This closure operator is of interest by itself, as it (...) generates a total version of Weihrauch reducibility that is defined like the usual version of Weihrauch reducibility, but in terms of total realizers. From a logical perspective completion can be seen as a way to make problems independent of their premises. Alongside with the completion operator and total Weihrauch reducibility we need to study precomplete representations that are required to describe these concepts. In order to show that the parallelized total Weihrauch lattice forms a Brouwer algebra, we introduce a new multiplicative version of an implication. While the parallelized total Weihrauch lattice forms a Brouwer algebra with this implication, the total Weihrauch lattice fails to be a model of intuitionistic linear logic in two different ways. In order to pinpoint the algebraic reasons for this failure, we introduce the concept of a Weihrauch algebra that allows us to formulate the failure in precise and neat terms. Finally, we show that the Medvedev Brouwer algebra can be embedded into our Brouwer algebra, which also implies that the theory of our Brouwer algebra is Jankov logic. (shrink)

Nosso objetivo neste trabalho é tentar esclarecer o mal-estar causado por algumas leituras que muitas vezes despacham a influência e a presença constante de Hegel na obra de Adorno de forma muito breve e fácil, seja a partir da perspectiva antissistêmica da filosofia adorniana, ou então, desde a perspectiva negativa que a dialética assume em seu pensamento. Nesse sentido, pretendemos expor alguns pontos fundamentais da filosofia hegeliana, em relação aos quais Adorno se coloca claramente como herdeiro. Pretendemos mostrar que o (...) filósofo de Frankfurt pensa não somente sobre estes pontos, mas também a partir deles, i.e., superando-os. (shrink)

This paper presents a restructured set of axioms for categorical logic. In virtue of it, the syllogistic with indefinite terms is deduced and proved, within the categorical logic boundaries. As a result, the number of all the conclusive syllogisms is deduced through a simple and axiomatic methodology. Moreover, the distinction between immediate and mediate inferences disappears, which reinstitutes the unity of Aristotelian logic.

We study the uniform computational content of different versions of the Baire category theorem in the Weihrauch lattice. The Baire category theorem can be seen as a pigeonhole principle that states that a complete metric space cannot be decomposed into countably many nowhere dense pieces. The Baire category theorem is an illuminating example of a theorem that can be used to demonstrate that one classical theorem can have several different computational interpretations. For one, we distinguish two different logical versions of (...) the theorem, where one can be seen as the contrapositive form of the other one. The first version aims to find an uncovered point in the space, given a sequence of nowhere dense closed sets. The second version aims to find the index of a closed set that is somewhere dense, given a sequence of closed sets that cover the space. Even though the two statements behind these versions are equivalent to each other in classical logic, they are not equivalent in intuitionistic logic, and likewise, they exhibit different computational behavior in the Weihrauch lattice. Besides this logical distinction, we also consider different ways in which the sequence of closed sets is “given.” Essentially, we can distinguish between positive and negative information on closed sets. We discuss all four resulting versions of the Baire category theorem. Somewhat surprisingly, it turns out that the difference in providing the input information can also be expressed with the jump operation. Finally, we also relate the Baire category theorem to notions of genericity and computably comeager sets. (shrink)

SIRThere are some important flaws in Michael Ardagh's reasoning.11. Cardiopulmonary resuscitation is a “blanket term” for different interventions. Curative and supportive treatments have different ethical contexts and cannot be discussed at the same level. It is imperative to ascribe curative interventions within CPR the same status as any other curative intervention, such as antibiotics for infections or surgery for appendicitis. Then we will be able to discuss the ethical context of purely supportive measures such as chest compressions. To address the (...) “ethics of CPR” is a dangerous misnomer.The preferences of emergency personnel2 suggest the willingness to undergo curative interventions early during CPR, but not protracted supportive interventions. Conversely, withholding curative interventions during CPR should only be considered when any curative treatments would also be withheld.2. Cardiopulmonary resuscitation is performed to offer the patient a benefit. However, CPR as a whole is only marginally effective. …. (shrink)

The classical Hahn–Banach Theorem states that any linear bounded functional defined on a linear subspace of a normed space admits a norm-preserving linear bounded extension to the whole space. The constructive and computational content of this theorem has been studied by Bishop, Bridges, Metakides, Nerode, Shore, Kalantari Downey, Ishihara and others and it is known that the theorem does not admit a general computable version. We prove a new computable version of this theorem without unrolling the classical proof of the (...) theorem itself. More precisely, we study computability properties of the uniform extension operator which maps each functional and subspace to the set of corresponding extensions. It turns out that this operator is upper semi-computable in a well-defined sense. By applying a computable version of the Banach–Alaoglu Theorem we can show that computing a Hahn–Banach extension cannot be harder than finding a zero in a compact metric space. This allows us to conclude that the Hahn–Banach extension operator is ${\bf {\Sigma^{0}_{2}}}$ -computable while it is easy to see that it is not lower semi-computable in general. Moreover, we can derive computable versions of the Hahn–Banach Theorem for those functionals and subspaces which admit unique extensions. (shrink)

In the third of his Logical Investigations, Husserl draws an important distinction between two kinds of parts: the dependent parts like the redness of a visual datum or the squareness of a given picture, and the independent parts like the head of a horse or a brick in a wall. On his view, the distinction is to be understood in terms of a more fundamental notion, the notion of foundation. This paper is an attempt at clarifying that notion. Such attempts (...) have already been undertaken by Peter Simons and Kit Fine, and the paper also contains elements of comparison of our three sets of views. (shrink)

Social influence and persuasion are not synonyms. This paper traces back the different approaches and distinctions constituting the two concepts and argues that the two research traditions focused respectively on social influence in group processes and on individual attitude change through persuasive communication, could be re-examined from a different vantage point, casting a new light on the continuities between them.