The purpose of the present paper is to reply to a misleading paper by M. Sachs entitled “Einstein's later view of the Twin Paradox” (TP) (Found. Phys. 15, 977 (1985)). There, by selecting some passages from Einstein's papers, he tried to convince the reader that Einstein changed his mind regarding the asymmetric aging of the twins on different motions. Also Sachs insinuates that he presented several years ago “convincing mathematical arguments” proving that the theory of relativity does not predict asymmetrical (...) aging in the TP. Here we give a definitive treatment to the clocks problem showing that Sachs' “convincing mathematical arguments” are non sequitur. Also, by properly quoting Einstein, we show that his later view of the TP coincides with the one derived from the rigorous theory of time developed in this paper. (shrink)
In his thesis Para uma Teoria Geral dos Homomorfismos (1944), the Portuguese mathematician José Sebastião e Silva constructed an abstract or generalized Galois theory, that is intimately linked to F. Klein’s Erlangen Program and that foreshadows some notions and results of today’s model theory; an analogous theory was independently worked out by M. Krasner in 1938. In this paper, we present a version of the theory making use of tools which were not at Silva’s disposal. At the same time, we (...) tried to keep in mind, so much as possible, the gist of his standpoint. (shrink)
This article focuses on maternal-fetal surgery (MFS) and on the concept of clinical equipoise that is a widely accepted requirement for conducting randomized controlled trials (RCT). There are at least three reasons why equipoise is unsuitable for MFS. First, the concept is based on a misconception about the nature of clinical research and the status of research subjects. Second, given that it is not clear who the research subject/s in MFS is/are, if clinical equipoise is to be used as a (...) criterion to test the ethical appropriateness of RCT, its meaning should be unambiguous. Third, because of the multidisciplinary character of MFS, it is not clear who should be in equipoise. As a result, we lack an adequate criterion for the ethical review of MFS protocols. In our account, which is based on Chervenak and McCullough's seminal work in the field of obstetric ethics, equipoise is abandoned. and RCT involving MFS can be ethically initiated when a multidisciplinary ethics review board (ERB), having an evidence-based assessment of the risks involved, is convinced that the value of answering the research hypothesis, for the sake of the health interests of future pregnant women carrying fetuses with certain congenital birth defects, justifies the actual risks research participants might suffer within a set limit of low/manageable. (shrink)
Delusion is one of the most intriguing psychopathological phenomena and its conceptualization remains the subject of genuine debate. Claims that it is ill-defined, however, are typically grounded on essentialist expectations that a given definition should capture the core of every instance acknowledged as delusion in the clinical setting.
Chervenak and McCullough, authors of the most acknowledged ethical framework for maternal–fetal surgery, rely on the ‘ethical–obstetrical’ concept of the fetus as a patient in order to determine what is morally owed to fetuses by both physicians and the women who gestate them in the context of prenatal surgery. In this article, we reconstruct the argumentative structure of their framework and present an internal criticism. First, we analyse the justificatory arguments put forward by the authors regarding the moral status of (...) the fetus qua patient. Second, we discuss the internal coherence and consistency of the moral obligations those authors derive from that concept. We claim that some of the dilemmas their approach is purported to avoid, such as the debate about the independent moral status of the fetus, and the foundation of the moral obligations of pregnant women (towards the fetuses they gestate) are not, all things considered, avoided. Chervenak and McCullough construct the obligations of physicians as obligations towards entities with equal moral status. But, at the same time, they assume that the woman has an independent moral status while the moral status of the fetus is dependent on the decision of the woman to present it to a physician for care. According to the logic of their own argumentation, Chervenak and McCullough implicitly admit a different moral status of the woman and the fetus, which will lead to different ascription of duties of the physician than those they ascribed. (shrink)
This paper responds briefly to the criticism of Rodrigues and Rosa on my earlier analysis of the twin paradox. The main point that I have emphasized (and that the authors have not refuted, either logically or mathematically) is the error in directly identifying anabstract measure relative to a reference frame [and its transformations to all other possible reference frames in which the laws of nature are to be compared (such as temporal and spatial measures)], with aphysical extension and (...) duration of a material body. (shrink)
The Abolition of Man, C. S. Lewis's masterpiece in ethics and the philosophy of science,warns of the danger of combining modern moral skepticism with the technological pursuit of human desires. The end result is the final destruction of human nature. From Brave New World to Star Trek, from Steampunk to starships, science fiction film has considered from nearly every conceivable angle the same nexus of morality, technology, and humanity of which C. S. Lewis wrote. As a result,science fiction film has (...) unintentionally given us stunning depictions of Lewis's terrifying vision of the future. In Science Fiction and the Abolition of Man: Finding C. S. Lewis in Sci-Fi Film and Television, scholars of religion, philosophy, literature, and film explore the connections between sci-fi film and the three parts of Lewis's book:how sci-fi portrays "Men Without Chests" incapable of responding properly to moral good, how it teaches the Tao or "The Way," and how it portrays "The Abolition of Man.". (shrink)
Learning programming is thought to be troublesome. One doable reason why students don’t do well in programming is expounded to the very fact that traditional way of learning within the lecture hall adds more stress on students in understanding the Material rather than applying the Material to a true application. For a few students, this teaching model might not catch their interest. As a result, they'll not offer their best effort to grasp the Material given. Seeing however the information is (...) applied to real issues will increase student interest in learning. As a consequence, this may increase their effort to be taught. In the current paper, we try to help students learn C# programming language using Intelligent Tutoring System. This ITS was developed using ITSB authoring tool to be able to help the student learn programming efficiently and make the learning procedure very pleasing. A knowledge base using ITSB authoring tool style was used to represent the student's work and to give customized feedback and support to students. (shrink)
El artículo propone una interpretación de la obra literaria "Las Crónicas de Narnia" del autor ingles C. S Lewis. Tal interpretación posibilita considerar la alegoría religiosa que esta obra literaria realiza sobre la experiencia de la divinidad a través de la figura del León.
For each natural number n, let C (n) be the closed and unbounded proper class of ordinals α such that V α is a Σ n elementary substructure of V. We say that κ is a C (n) -cardinal if it is the critical point of an elementary embedding j : V → M, M transitive, with j(κ) in C (n). By analyzing the notion of C (n)-cardinal at various levels of the usual hierarchy of large cardinal principles we show (...) that, starting at the level of superstrong cardinals and up to the level of rank-into-rank embeddings, C (n)-cardinals form a much finer hierarchy. The naturalness of the notion of C (n)-cardinal is exemplified by showing that the existence of C (n)-extendible cardinals is equivalent to simple reflection principles for classes of structures, which generalize the notions of supercompact and extendible cardinals. Moreover, building on results of Bagaria et al. (2010), we give new characterizations of Vopeňka’s Principle in terms of C (n)-extendible cardinals. (shrink)
Recent work in the history of philosophy of science details the Kantianism of philosophers often thought opposed to one another, e.g., Hans Reichenbach, C.I. Lewis, Rudolf Carnap, and Thomas Kuhn. Historians of philosophy of science in the last two decades have been particularly interested in the Kantianism of Reichenbach, Carnap, and Kuhn, and more recently, of Lewis. While recent historical work focuses on recovering the threatened-to-be-forgotten Kantian themes of early twentieth-century philosophy of science, we should not elide the differences between (...) the Kantian strands running throughout this work. In this paper, I disentangle a few of these strands in the work of Reichenbach and Lewis focusing especially on their theories of relativized, constitutive a priori principles in empirical knowledge. In particular, I highlight three related differences between Reichenbach and Lewis concerning their motivations in analyzing scientific knowledge and scientific practice, their differing conceptions of constitutivity, and their relativization of constitutive a priori principles. In light of these differences, I argue Lewis’s Kantianism is more similar to Kuhn’s Kantianism than Reichenbach’s, and so might be of more contemporary relevance to social and practice-based approaches to the philosophy of science. (shrink)
Background: how mind functions is subject to continuing scientific discussion. A simplistic approach says that, since no convincing way has been found to model subjective experience, mind cannot exist. A second holds that, since mind cannot be described by classical physics, it must be described by quantum physics. Another perspective concerns mind's hypothesized ability to interact with the world of quanta: it should be responsible for reduction of quantum wave packets; physics producing 'Objective Reduction' is postulated to form the basis (...) for mind-matter interactions. This presentation describes results derived from a new approach to these problems. It is based on well-established biology involving physics not previously applied to the fields of mind, or consciousness studies, that of critical feedback instability. -/- Methods: 'self-organized criticality' in complexity biology places system loci of control at critical instabilities, physical properties of which, including information properties, are presented. Their elucidation shows that they can model hitherto unexplained properties of experience. -/- Results: All results depend on physical properties of critical instabilities. First, at least one feed-back or feed-forward loop must have feedback gain, g = 1: information flows round the loop impress perfect images of system states back on themselves: they represent processes of perfect self-observation. This annihilates system quanta: system excitations are instability fluctuations, which cannot be quantized. Major results follow: -/- 1. Information vectors representing criticality states must include at least one attached information loop denoting self-observation. -/- 2. Such loop structures are attributed a function, 'registering the state's own existence', explaining -/- a. Subjective 'awareness of one's own presence' -/- b. How content-free states of awareness can be remembered (Jon Shear) -/- c. Subjective experience of time duration (Immanuel Kant) -/- d. The 'witness' property of experience – often mentioned by athletes 'in the zone' -/- e. The natural association between consciousness and intelligence -/- This novel, physically and biologically sound approach seems to satisfactorily model subjectivity. -/- Further significant results follow: -/- 1. Registration of external information in excited states of systems at criticality reduces external wave-packets: the new model exhibits 'Objective Reduction' of wave packets. -/- 2. High internal coherence (postulated by Domash & Penrose) leading to a. Non-separable information vector bundles. b. Non-reductive states (Chalmers's criterion for experience). -/- 3. Information that is: a. encoded in coherence negentropy; b. non-digitizable, and therefore c. computationally without digital equivalent (posited by Penrose). -/- Discussion and Conclusions: instability physics implies anharmonic motion, preventing excitation quantization, and totally different from the quantum physics of simple harmonic motion at stability. Instability excitations are different from anything hitherto conceived in information science. They can model aspects of mind never previously treated, including genuine subjectivity, objective reduction of wave-packets, and inter alia all properties given above. (shrink)
This paper advances a version of physicalism which reconciles the “a priori entailment thesis” (APET) with the analytic independence of our phenomenal and physical vocabularies. The APET is the claim that, if physicalism is true, the complete truths of physics imply every other truth a priori. If so, “cosmic hermeneutics” is possible: a demon having only complete knowledge of physics could deduce every truth about the world. Analytic independence is a popular physicalist explanation for the apparent “epistemic gaps” between phenomenal (...) and physical truths. The two are generally seen as incompatible, since the demon’s deductions seem to presuppose analytic connections between physical and phenomenal terms. I begin by arguing, in support of the APET, that implications from the complete truths of physics to phenomenal truths cannot be a posteriori. Such implications are (according to the physicalist) necessarily true. But they cannot be Kripke-style a posteriori necessities, since (according to the physicalist) the complete truths of physics fix any relevant a posteriori facts about the reference of terms. I then show how the physicalist can turn the tables: the demon can exploit the physical fixing of reference to bridge the gap between the vocabularies, by deducing when phenomenal and physical terms co-refer. This opens the way for a “type-C” physicalism, which accepts in-principle deducibility while still appealing to analytic independence to explain why we (who are not demons) find it impossible to see phenomenal-physical connections a priori. (shrink)
The C (n)-cardinals were introduced recently by Bagaria and are strong forms of the usual large cardinals. For a wide range of large cardinal notions, Bagaria has shown that the consistency of the corresponding C (n)-versions follows from the existence of rank-into-rank elementary embeddings. In this article, we further study the C (n)-hierarchies of tall, strong, superstrong, supercompact, and extendible cardinals, giving some improved consistency bounds while, at the same time, addressing questions which had been left open. In addition, we (...) consider two cases which were not dealt with by Bagaria; namely, C (n)-Woodin and C (n)-strongly compact cardinals, for which we provide characterizations in terms of their ordinary counterparts. Finally, we give a brief account on the interaction of C (n)-cardinals with the forcing machinery. (shrink)
It is often argued that the great quantity of evil in our world makes God’s existence less likely than a lesser quantity would, and this, presumably, because the probability that some evils are gratuitous increases as the overall quantity of evil increases. Often, an additive approach to quantifying evil is employed in such arguments. In this paper, we examine C. S. Lewis’ objection to the additive approach, arguing that although he is correct to reject this approach, there is a sense (...) in which he underestimates the quantity of pain. However, the quantity of pain in that sense does not significantly increase the probability that some pain is gratuitous. Therefore, the quantitative argument likely fails. (shrink)
Section 1 of this essay distinguishes between four interpretations of Socratic intellectualism, which are, very roughly: a version in which on any given occasion desire, and then action, is determined by what we think will turn out best for us, that being what we all, always, really desire; a version in which on any given occasion action is determined by what we think will best satisfy our permanent desire for what is really best for us; a version formed by the (...) assimilation of to, labelled the ‘standard’ version’ by Thomas C. Brickhouse and Nicholas D. Smith, and treated by them as a single alternative to their own interpretation; and Brickhouse and Smith’s own version. Section 2 considers, in particular, Brickhouse and Smith’s handling of the ‘appetites and passions’, which is the most distinctive feature of interpretation. Section 3 discusses Brickhouse and Smith’s defence of ‘Socratic studies’ in its historical context, and assesses the contribution made by their distinctive interpretation of ‘the philosophy of Socrates’. One question raised in this section, and one that is clearly fundamental to the existence of ‘Socratic studies’, is how different Brickhouse and Smith’s Socrates turns out to be from Plato himself, i.e., the Plato of the post-‘Socratic’ dialogues; to which the answer offered is that on Brickhouse and Smith’s interpretation Socratic moral psychology becomes rather less distinguishable from its ‘Platonic’ counterpart—as that is currently understood—than it is on the interpretation they oppose. (shrink)
The strong weak truth table (sw) reducibility was suggested by Downey, Hirschfeldt, and LaForte as a measure of relative randomness, alternative to the Solovay reducibility. It also occurs naturally in proofs in classical computability theory as well as in the recent work of Soare, Nabutovsky, and Weinberger on applications of computability to differential geometry. We study the sw-degrees of c.e. reals and construct a c.e. real which has no random c.e. real (i.e., Ω number) sw-above it.
In his thesis 'Para uma Teoria Geral dos Homomorfismos' (1944) the Portuguese mathematician José Sebastião e Silva constructed an abstract or generalized Galois theory, that is intimately linked to F. Klein’s Erlangen Program and that foreshadows some notions and results of today’s model theory; an analogous theory was independently worked out by M. Krasner in 1938. In this paper, we present a version of the theory making use of tools which were not at Silva’s disposal. At the same time, we (...) tried to keep in mind, so much as possible, the gist of his standpoint. (shrink)
C.S. Peirce defended a pragmatist view of assertion in terms of its normative effect. This paper has two goals. First, to reconstruct and assess Peirce’s argument for the thesis that to assert a proposition is to make oneself responsible for its truth. Second, to argue that Peirce interpreted “responsibility for truth” as the acquisition of a dialogical commitment, namely, the duty to defend the proposition asserted by giving reasons upon challenge.
This thesis introduces and defends a ‘C theory’ of time. The metaphysics of time literature is primarily concerned with the distinction between the A and B theories of time, with the disagreement concerning whether the passage of time is an objective feature of reality. I argue that the distinction between the B and C theories—in terms of whether time has a ‘privileged’ direction—is of more obvious relevance to the philosophy of physics than is the distinction between the A and B (...) theories. The thesis has three main contentions. (1) In order to maintain a substantial metaphysical dispute between the different theories of time, they must be defined in terms of structural properties, and the naturalistic metaphysics of time direction involves the assessment of these structures in light of contemporary physics. (2) The A theory of time requires a model with two temporal dimensions, and although such a model provides a resolution to a number of problems faced by standard A theories, it is not motivated by physical theory. (3) The dispute between the B and C theories of time is of direct relevance to the philosophy of physics: the B theorist’s assumption of the existence of a privileged temporal direction is of explanatory relevance to physics; and a comparison between unidirectional and adirectional explanations in physics can in principle shed light on whether time is B- or C-theoretic. (shrink)