An overview is provided of how the concept of the thought experiment has developed and changed for the natural sciences in the course of the 20th century. First, we discuss the existing definitions of the term 'thought experiment' and the origin of the thought experimentation method, identifying it in Greek Presocratics epoch. Second, only in the end of the 19th century showed up the first systematic enquiry on thought experiments by Ernst Mach's work. After the Mach's work, a negative attitude (...) towards thought experiments came in the beginning of the 20th century, which went on until the Thomas Kuhn's and Karl Popper's work on thought experiments. Only from the mid-1980s did thought experiments begin to be considered relevant to scientific enterprise. Finally, we show the existing empirical and 'functional' theories which have developed about the nature and purpose of thought experiments. (shrink)

Previous studies have offered indications that the way pre-adolescents structure their perceptions of their teacher’s interaction in terms of Agency and Communion differs from adolescents. The purpose of this study was to delineate previous findings by thoroughly examining the structure of pre-adolescents’ perceptions of their teacher’s interpersonal behaviour, and by investigating the extent to which this structure relates to pre-adolescents’ learning outcomes. A mixed methods research design was implemented including a qualitative instrument adaptation procedure followed by a quantitative large-scale administration. (...) Participants for the latter were a random sample of 504 pre-adolescents and 36 teachers. Results showed that participants placed significantly more emphasis on their teachers’ Communion behavioural dimension and this emphasis was illustrated on the association of perceived teacher interaction and students’ learning outcomes. Implications for theory, research and practice are discussed. (shrink)

This is the second paper of an essay in two parts. The first paper (Part I) is a critical discussion of Mark Risjord's conception of nursing knowledge where I argued against the conception of nursing knowledge as a kind of nursing science. The aim of the present paper (Part II) is to explicate and substantiate the thesis of nursing as a kind of concrete philosophy. My strategy is to elaborate upon certain themes from Wittgenstein's Tractatus in order to canvass a (...) general scheme of philosophy based on a distinction between reality and the world. This distinction will be employed in the appropriation of certain significant features of nursing and nursing knowledge. By elaborating on the contrast between the abstract and the concrete, I will suggest that nursing may be seen as a kind of concrete philosophy, being primarily concerned with reality (and secondarily with the world). This thesis, I will argue, implies that philosophy is the kind of theory that is essential to nursing (which is not so much a theory than a certain kind of activity). (shrink)

This essay addresses the problem of the essentiality of nursing knowledge and what kind of theory, if any, is essential to nursing practice. The overarching aim of the essay was to argue for the thesis that nursing may be described as a kind of philosophical activity, and, consequently, that philosophy is the kind of “theory” that is essential to nursing practice and to the nursing discipline at large. The essay consists of two papers. The present paper, Part I, is a (...) critical examination of Mark Risjord's discussion of the problem of the theory‐practice gap in his Nursing Knowledge: Practice, Science, Philosophy, from 2010. According to Risjord, the cause of the theory‐practice gap originates in an erroneous conception of science (logical positivism) which had a decisive influence upon the way nursing scholars appropriated theoretical frameworks for the nursing discipline. This philosophical influence is considered in effect to have generated the theory–practice gap. In order to bridge the gap, Risjord suggests, the nursing discipline needs to adopt a standpoint epistemology conjoined with a postpositivist conception of scientific theory. In this way, a legitimate brand of nursing science may be developed and the theory–practice gap overcome. I will argue that neither Risjord's diagnosis of the problem, nor his recommended cure, may succeed in rescuing the nursing discipline from the theory–practice gap. Rather, the real cause of the theory–practice gap, I will claim, derives from an erroneous conception of nursing (not of science), namely the conception of nursing as a kind of science (roughly speaking). On my view, to overcome the gap, the nursing discipline needs to make salient the inherently philosophical character of nursing. In the second paper (Part II), I will continue the discussion of nursing knowledge and delineate the thesis of nursing as a kind of concrete philosophy. (shrink)

This essay addresses the problem of the essentiality of nursing knowledge and what kind of theory, if any, is essential to nursing practice. The overarching aim of the essay was to argue for the thesis that nursing may be described as a kind of philosophical activity, and, consequently, that philosophy is the kind of “theory” that is essential to nursing practice and to the nursing discipline at large. The essay consists of two papers. The present paper, Part I, is a (...) critical examination of Mark Risjord's discussion of the problem of the theory‐practice gap in his Nursing Knowledge: Practice, Science, Philosophy, from 2010. According to Risjord, the cause of the theory‐practice gap originates in an erroneous conception of science (logical positivism) which had a decisive influence upon the way nursing scholars appropriated theoretical frameworks for the nursing discipline. This philosophical influence is considered in effect to have generated the theory–practice gap. In order to bridge the gap, Risjord suggests, the nursing discipline needs to adopt a standpoint epistemology conjoined with a postpositivist conception of scientific theory. In this way, a legitimate brand of nursing science may be developed and the theory–practice gap overcome. I will argue that neither Risjord's diagnosis of the problem, nor his recommended cure, may succeed in rescuing the nursing discipline from the theory–practice gap. Rather, the real cause of the theory–practice gap, I will claim, derives from an erroneous conception of nursing (not of science), namely the conception of nursing as a kind of science (roughly speaking). On my view, to overcome the gap, the nursing discipline needs to make salient the inherently philosophical character of nursing. In the second paper (Part II), I will continue the discussion of nursing knowledge and delineate the thesis of nursing as a kind of concrete philosophy. (shrink)

I undertake a metaphysical investigation of Saul Kripke's modern classic, Naming and Necessity . The general problem of my study may be expressed as follows: What is the metaphysical justification of the validity and existence of the pertinent classes of truths, the necessary a posteriori and the contingent a priori, according to the Kripke Paradigm? My approach is meant to disclose the logical and ontological principles underlying Kripke's arguments for the necessary a posteriori and the contingent a priori respectively. The (...) results of my study are to a certain extent negative: They attempt to show that the classes of the necessary a posteriori and the contingent a priori statements cannot possibly be valid. If the general argument of this thesis is sound, then, on this ground, the realist conception of metaphysical essentialism is rejected. The positive thesis of this study is the articulation of certain ways to frame the necessary a posteriori and the contingent a priori which avoid the problems of realistic essentialism and which suggest a certain transcendental reading of modality. According to the Kripke Paradigm, any de dicto modal status derives ultimately from the de re modality inherent in the object designated, as the object is characterised by contingent and necessary properties on the ontological level. Thus, the Kripke Paradigm is primarily a thesis in de re realist essentialism. The final verdict in this study is that the Kripke Paradigm cannot sustain the realistic conception of de re metaphysical essentialism. If we should adopt a transcendental reading of modality, then certain portions of the Kripke Paradigm are valid. I do not delineate or possess the details of a comprehensive doctrine of transcendental metaphysic. Nevertheless, the observations I make should suffice to bring about the rough orientation of how I conceive the notion of transcendental modality. (shrink)

It is shown that in ZF Martin's $ \aleph_{0}^{}$-axiom together with the axiom of countable choice for finite sets imply that arbitrary powers 2X of a 2-point discrete space are Baire; and that the latter property implies the following: the axiom of countable choice for finite sets, power sets of infinite sets are Dedekind-infinite, there are no amorphous sets, and weak forms of the Kinna-Wagner principle.

We show that none of the following statements is provable in Zermelo-Fraenkel set theory (ZF) answering the corresponding open questions from Brunner in ``The axiom of choice in topology'':(i) For every T2 topological space (X, T) if X is well-ordered, then X has a well-ordered base,(ii) For every T2 topological space (X, T), if X is well-ordered, then there exists a function f : X × W T such that W is a well-ordered set and f ({x} × W) is (...) a neighborhood base at x for each x X,(iii) For every T2 topological space (X, T), if X has a well-ordered dense subset, then there exists a function f : X × W T such that W is a well-ordered set and {x} = f ({x} × W) for each x X. (shrink)

From the early 1930s to the early 1960s many scholars, whether liberal-minded or socialist ideologues, Marxist or scientific positivists, classical scholars or political theorists and historians, have shown a widespread consensus in discrediting and assailing the man and political philosopher Plato. Such an extensive assault led the 'Platonic Legend' to an unprecedented crisis. Philosophically, it was a reaction to the undisguised Platonolatry coming from Oxford and the school of the British Idealists. Ideologically, the appropriation of Plato by Nazi apologists fostered (...) further this vehement indictment. But a lot of other causes worked to the same effect. The general anguish and humanistic anxiety on the eve of World War II and the postwar traumas led scholars to reconsider the meaning of history and historicism, the psychology of the masses and the ethical responsibility of the citizen, the role of propaganda and state education. Such complementary elements converged in sustained anti-Platonic polemics, which in turn provoked a vigorous defence. Here an attempt is made to offer a preliminary survey of this complex debate and to provide a general intellectual framework in terms of which that controversy can be further explored. (shrink)

From the early 1930s to the early 1960s many scholars, whether liberalminded or socialist ideologues, Marxist or scientific positivists, classical scholars or political theorists and historians, have shown a widespread consensus in discrediting and assailing the man and political philosopher Plato. Such an extensive assault led the ‘Platonic Legend’ to an unprecedented crisis. Philosophically, it was a reaction to the undisguised Platonolatry coming from Oxford and the school of the British Idealists. Ideologically, the appropriation of Plato by Nazi apologists fostered (...) further this vehement indictment. But a lot of other causes worked to the same effect. The general anguish and humanistic anxiety on the eve ofWorldWar II and the postwar traumas led scholars to reconsider the meaning of history and historicism, the psychology of the masses and the ethical responsibility of the citizen, the role of propaganda and state education. Such complementary elements converged in sustained anti-Platonic polemics, which in turn provoked a vigorous defence. Here an attempt is made to offer a preliminary survey of this complex debate and to provide a general intellectual framework in terms of which that controversy can be further explored. (shrink)

From the early 1930s to the early 1960s many scholars, whether liberalminded or socialist ideologues, Marxist or scientific positivists, classical scholars or political theorists and historians, have shown a widespread consensus in discrediting and assailing the man and political philosopher Plato. Such an extensive assault led the ‘Platonic Legend’ to an unprecedented crisis. Philosophically, it was a reaction to the undisguised Platonolatry coming from Oxford and the school of the British Idealists. Ideologically, the appropriation of Plato by Nazi apologists fostered (...) further this vehement indictment. But a lot of other causes worked to the same effect. The general anguish and humanistic anxiety on the eve ofWorldWar II and the postwar traumas led scholars to reconsider the meaning of history and historicism, the psychology of the masses and the ethical responsibility of the citizen, the role of propaganda and state education. Such complementary elements converged in sustained anti-Platonic polemics, which in turn provoked a vigorous defence. Here an attempt is made to offer a preliminary survey of this complex debate and to provide a general intellectual framework in terms of which that controversy can be further explored. (shrink)

The riddle of the Cleitophon is a creature of nineteenth-century German scholarship which premised that Plato had developed a profound philosophical system. Thus, having no intrinsic purpose to serve in the context of the development of Plato's philosophy, Cleitophon was disallowed as spurious. Documenting the reception of this minor dialogue provides insights into the pluralism and the perplexities of modern Platonic exegesis. The more recent idea of a genre of literary fiction helps to restore cleitophon to its place in the (...) Platonic corpus. S.R. Slings's edition of this dialogue, with introduction, translation and commentary reconsiders both Plato's dialogical engagements and intellectual commitments, utilizes a two-dimensional approach to the text that avoids exaggerated conjectures, and effectively defends the authenticity of Cleitophon. (shrink)

Let X be an infinite set and let and denote the propositions “every filter on X can be extended to an ultrafilter” and “X has a free ultrafilter”, respectively. We denote by the Stone space of the Boolean algebra of all subsets of X. We show: For every well‐ordered cardinal number ℵ, (ℵ) iff (2ℵ). iff “ is a continuous image of ” iff “ has a free open ultrafilter ” iff “every countably infinite subset of has a limit point”. (...) implies “every open filter on extends to an open ultrafilter” implies “has an open ultrafilter” implies It is relatively consistent with that (ω) holds, whereas (ω) fails. In particular, none of the statements given in (2) implies (ω). (shrink)

We prove that, in any fine structural extender model with Jensen’s λ-indexing, there is a \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\square(\kappa^{+})}$$\end{document} -sequence if and only if there is a pair of stationary subsets of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\kappa^{+} \cap {\rm {cof}}( < \kappa)}$$\end{document} without common reflection point of cofinality \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${ < \kappa}$$\end{document} which, in turn, is equivalent to the existence of a (...) family of size \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${ < \kappa}$$\end{document} of stationary subsets of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\kappa^{+} \cap {\rm {cof}}( < \kappa)}$$\end{document} without common reflection point of cofinality \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${ < \kappa}$$\end{document}. By a result of Burke/jensen, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\square_\kappa}$$\end{document} fails whenever \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\kappa}$$\end{document} is a subcompact cardinal. Our result shows that in extender models, it is still possible to construct a canonical \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\square(\kappa^{+})}$$\end{document} -sequence where \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\kappa}$$\end{document} is the first subcompact. (shrink)

The present article proceeds from the mainstream view that the conceptual framework underpinning adversarial systems of criminal adjudication, i.e. a mixture of common-sense philosophy and probabilistic analysis, is unsustainable. In order to provide fact-finders with an operable structure of justification, we need to turn to epistemology once again. The article proceeds in three parts. First, I examine the structural features of justification and how various theories have attempted to overcome Agrippa’s trilemma. Second, I put Inferential Contextualism to the test and (...) show that a defeasible structure of justification allocating epistemic rights and duties to all participants of an inquiry manages to dissolve the problem of scepticism. Third, I show that our epistemic practice already embodies a contextualist mechanism. Our problem was not that our Standard of Proof is inoperable but that it was not adequately conceptualized. Contextualism provides the framework to articulate the abovementioned practice and to treat ‘reasonable doubts’ as a mechanism which we can now describe in detail. The seemingly insurmountable problem with our efforts to define the concept “reasonable doubts” was the fact that we have been conflating the surface features of this mechanism and its internal structure, i.e. the rules for its use. (shrink)

The present article proceeds from the mainstream view that the conceptual framework underpinning adversarial systems of criminal adjudication, i.e. a mixture of common-sense philosophy and probabilistic analysis, is unsustainable. In order to provide fact-finders with an operable structure of justification, we need to turn to epistemology once again. The article proceeds in three parts. First, I examine the structural features of justification and how various theories have attempted to overcome Agrippa’s trilemma. Second, I put Inferential Contextualism to the test and (...) show that a defeasible structure of justification allocating epistemic rights and duties to all participants of an inquiry manages to dissolve the problem of scepticism. Third, I show that our epistemic practice already embodies a contextualist mechanism. Our problem was not that our Standard of Proof is inoperable but that it was not adequately conceptualized. Contextualism provides the framework to articulate the abovementioned practice and to treat ‘reasonable doubts’ as a mechanism which we can now describe in detail. The seemingly insurmountable problem with our efforts to define the concept “reasonable doubts” was the fact that we have been conflating the surface features of this mechanism and its internal structure, i.e. the rules for its use. (shrink)

The present article proceeds from the mainstream view that the conceptual framework underpinning adversarial systems of criminal adjudication, i.e. a mixture of common-sense philosophy and probabilistic analysis, is unsustainable. In order to provide fact-finders with an operable structure of justification, we need to turn to epistemology once again. The article proceeds in three parts. First, I examine the structural features of justification and how various theories have attempted to overcome Agrippa’s trilemma. Second, I put Inferential Contextualism to the test and (...) show that a defeasible structure of justification allocating epistemic rights and duties to all participants of an inquiry manages to dissolve the problem of scepticism. Third, I show that our epistemic practice already embodies a contextualist mechanism. Our problem was not that our Standard of Proof is inoperable but that it was not adequately conceptualized. Contextualism provides the framework to articulate the abovementioned practice and to treat ‘reasonable doubts’ as a mechanism which we can now describe in detail. The seemingly insurmountable problem with our efforts to define the concept “reasonable doubts” was the fact that we have been conflating the surface features of this mechanism and its internal structure, i.e. the rules for its use. (shrink)

The present article proceeds from the mainstream view that the conceptual framework underpinning adversarial systems of criminal adjudication, i.e. a mixture of common-sense philosophy and probabilistic analysis, is unsustainable. In order to provide fact-finders with an operable structure of justification, we need to turn to epistemology once again. The article proceeds in three parts. First, I examine the structural features of justification and how various theories have attempted to overcome Agrippa’s trilemma. Second, I put Inferential Contextualism to the test and (...) show that a defeasible structure of justification allocating epistemic rights and duties to all participants of an inquiry manages to dissolve the problem of scepticism. Third, I show that our epistemic practice already embodies a contextualist mechanism. Our problem was not that our Standard of Proof is inoperable but that it was not adequately conceptualized. Contextualism provides the framework to articulate the abovementioned practice and to treat ‘reasonable doubts’ as a mechanism which we can now describe in detail. The seemingly insurmountable problem with our efforts to define the concept “reasonable doubts” was the fact that we have been conflating the surface features of this mechanism and its internal structure, i.e. the rules for its use. (shrink)

We formulate an abstract version of the finite injury method in the form of the Baire category theorem. The theorem has the following corollaries: The Friedberg-Muchnik pair of recursively enumerable degrees, the Sacks splitting theorem, the existence of a minimal degree below 0′ and the Shoenfield jump theorem.

We establish the following results: 1. In ZF (i.e., Zermelo-Fraenkel set theory minus the Axiom of Choice AC), for every set I and for every ordinal number α ≥ ω, the following statements are equivalent: (a) The Tychonoff product of| α| many non-empty finite discrete subsets of I is compact. (b) The union of| α| many non-empty finite subsets of I is well orderable. 2. The statement: For every infinite set I, every closed subset of the Tychonoff product [0, 1] (...) I which consists of functions with finite support is compact, is not provable in ZF set theory. 3. The statement: For every set I, the principle of dependent choices relativised to I implies the Tychonoff product of countably many non-empty finite discrete subsets of I is compact, is not provable in ZF⁰ (i.e., ZF minus the Axiom of Regularity). 4. The statement: For every set I, every ℵ₀-sized family of non-empty finite subsets of I has a choice function implies the Tychonoff product of ℵ₀ many non-empty finite discrete subsets of I is compact, is not provable in ZF⁰. (shrink)

In \(\textbf{ZF}\), the well-known Fichtenholz–Kantorovich–Hausdorff theorem concerning the existence of independent families of _X_ of size \(|{\mathcal {P}} (X)|\) is equivalent to the following portion of the equally well-known Hewitt–Marczewski–Pondiczery theorem concerning the density of product spaces: “The product \({\textbf{2}}^{{\mathcal {P}}(X)}\) has a dense subset of size |_X_|”. However, the latter statement turns out to be strictly weaker than \(\textbf{AC}\) while the full Hewitt–Marczewski–Pondiczery theorem is equivalent to \(\textbf{AC}\). We study the relative strengths in \(\textbf{ZF}\) between the statement “_X_ has (...) no independent family of size \(|{\mathcal {P}}(X)|\) ” and some of the definitions of “_X_ is finite” studied in Levy’s classic paper, observing that the former statement implies one such definition, is implied by another, and incomparable with some others. (shrink)

We show that the axiom of choice AC is equivalent to the Vector Space Kinna-Wagner Principle, i.e., the assertion: “For every family [MATHEMATICAL SCRIPT CAPITAL V]= {Vi : i ∈ k} of non trivial vector spaces there is a family ℱ = {Fi : i ∈ k} such that for each i ∈ k, Fiis a non empty independent subset of Vi”. We also show that the statement “every vector space over ℚ has a basis” implies that every infinite well (...) ordered set of pairs has an infinite subset with a choice set, a fact which is known not to be a consequence of the axiom of multiple choice MC. (shrink)

Let {: i ∈I } be a family of compact spaces and let X be their Tychonoff product. [MATHEMATICAL SCRIPT CAPITAL C] denotes the family of all basic non-trivial closed subsets of X and [MATHEMATICAL SCRIPT CAPITAL C]R denotes the family of all closed subsets H = V × Πmath imageXi of X, where V is a non-trivial closed subset of Πmath imageXi and QH is a finite non-empty subset of I. We show: Every filterbase ℋ ⊂ [MATHEMATICAL SCRIPT CAPITAL (...) C]R extends to a [MATHEMATICAL SCRIPT CAPITAL C]R-ultrafilter ℱ if and only if every family H ⊂ [MATHEMATICAL SCRIPT CAPITAL C] with the finite intersection property extends to a maximal [MATHEMATICAL SCRIPT CAPITAL C] family F with the fip. The proposition “if every filterbase ℋ ⊂ [MATHEMATICAL SCRIPT CAPITAL C]R extends to a [MATHEMATICAL SCRIPT CAPITAL C]R-ultrafilter ℱ, then X is compact” is not provable in ZF. The statement “for every family {: i ∈ I } of compact spaces, every filterbase ℋ ⊂ [MATHEMATICAL SCRIPT CAPITAL C]R, Y = Πi ∈IYi, extends to a [MATHEMATICAL SCRIPT CAPITAL C]R-ultrafilter ℱ” is equivalent to Tychonoff's compactness theorem. The statement “for every family {: i ∈ ω } of compact spaces, every countable filterbase ℋ ⊂ [MATHEMATICAL SCRIPT CAPITAL C]R, X = Πi ∈ωXi, extends to a [MATHEMATICAL SCRIPT CAPITAL C]R-ultrafilter ℱ” is equivalent to Tychonoff's compactness theorem restricted to countable families. The countable Axiom of Choice is equivalent to the proposition “for every family {: i ∈ ω } of compact topological spaces, every countable family ℋ ⊂ [MATHEMATICAL SCRIPT CAPITAL C] with the fip extends to a maximal [MATHEMATICAL SCRIPT CAPITAL C] family ℱ with the fip”. (shrink)

In the realm of Lindelöf metric spaces the following results are obtained in : (i) If is a Lindelöf metric space then it is both densely Lindelöf and almost Lindelöf. In addition, under the countable axiom of choice, the three notions coincide. (ii) The statement “every separable metric space is almost Lindelöf” implies that every infinite subset of has a countably infinite subset). (iii) The statement “every almost Lindelöf metric space is quasi totally bounded implies. (iv) The proposition “every quasi (...) totally bounded metric space is separable” lies, in the deductive hierarchy of choice principles, strictly between the countable union theorem and. Likewise, the statement “every pre‐Lindelöf (or Lindelöf) metric space is separable” lies strictly between and. (shrink)

PREFACE Strange or inappropriate as it may appear, we propose to start this little book by stating as flatly and unrhetorically as possible a fundamental ...

Nearly 20 years after the Shonubi case and an extended discussion in the Anglophone world on the admissibility and probative force of statistical evidence, the labour courts of Germany seem not to have learned a simple lesson: aleatory probabilities are not informative for the individual in question. In this paper I argue that innumeracy (that is the lack of ability to understand and apply simple numerical concepts) is underestimated – if not ignored – both within the German jurisprudence and legal (...) theory. In this paper the pseudo-scientific methods of analyzing the evidence in the recent GEMA case by the labor courts of Berlin-Brandenburg and the Federal Labor Court are examined and it is shown that the persistence on applying reference class evidence to an individual-case ends up being not only theoretically unacceptable but also socially harmful. (shrink)

We show: iff every countable product of sequential metric spaces (sequentially closed subsets are closed) is a sequential metric space iff every complete metric space is Cantor complete. Every infinite subset X of has a countably infinite subset iff every infinite sequentially closed subset of includes an infinite closed subset. The statement “ is sequential” is equivalent to each one of the following propositions: Every sequentially closed subset A of includes a countable cofinal subset C, for every sequentially closed subset (...) A of, is a meager subset of, for every sequentially closed subset A of,, every sequentially closed subset of is separable, every sequentially closed subset of is Cantor complete, every complete subspace of is Cantor complete. (shrink)

It is shown that in ZF Martin's -axiom together with the axiom of countable choice for finite sets imply that arbitrary powers 2X of a 2-point discrete space are Baire; and that the latter property implies the following: (a) the axiom of countable choice for finite sets, (b) power sets of infinite sets are Dedekind-infinite, (c) there are no amorphous sets, and (d) weak forms of the Kinna-Wagner principle.

We show that for every we ordered cardinal number m the Tychonoff product 2m is a compact space without the use of any choice but in Cohen's Second Mode 2ℝ is not compact.

A Hausdorff space is called effectively Hausdorff if there exists a function F—called a Hausdorff operator—such that, for every with,, where U and V are disjoint open neighborhoods of x and y, respectively. Among other results, we establish the following in, i.e., in Zermelo–Fraenkel set theory without the Axiom of Choice (): is equivalent to “For every set X, the Cantor cube is effectively Hausdorff”. This enhances the result of Howard, Keremedis, Rubin and Rubin [13] that is equivalent to “Hausdorff (...) spaces are effectively Hausdorff” in. The Boolean Prime Ideal Theorem and the statement “For every infinite set X, the Stone space of the Boolean algebra is effectively Hausdorff” are mutually independent. In particular, the latter statement is not provable in. The Axiom of Choice for non‐empty subsets of () is equivalent to each of “Separable Hausdorff spaces are effectively Hausdorff” and “The Cantor cube is effectively Hausdorff”. The Principle of Dependent Choices in conjunction with the Axiom of Choice for continuum sized families of non‐empty subsets of does not imply the axiom of choice for partitions of. The latter independence result fills the gap in information in Howard and Rubin's book “Consequences of the Axiom of Choice”. The axiom of countable choice for non‐empty subsets of is equivalent to each of “Denumerable Hausdorff spaces are effectively Hausdorff”, “Denumerable T3 spaces are completely normal” and “Denumerable Tychonoff spaces are Urysohn”. (shrink)

We show that the both assertions “in every vector space B over a finite element field every subspace V ⊆ B has a complementary subspace S” and “for every family [MATHEMATICAL SCRIPT CAPITAL A] of disjoint odd sized sets there exists a subfamily ℱ={Fj:j ϵω} with a choice function” together imply the axiom of choice AC. We also show that AC is equivalent to the statement “in every vector space over ℚ every generating set includes a basis”.

We find a characterization of the covering number $cov({\mathbb R})$ , of the real line in terms of trees. We also show that the cofinality of $cov({\mathbb R})$ is greater than or equal to ${\mathfrak n}_\lambda$ for every $\lambda \in cov({\mathbb R}),$ where $\mathfrak n_\lambda \geq add({\mathcal L})$ ( $add( {\mathcal L})$ is the additivity number of the ideal of all Lebesgue measure zero sets) is the least cardinal number k for which the statement: $(\exists{\mathcal G}\in [^\omega \omega ]^{\leq \lambda (...) })(\forall{\mathcal F}\in [^\omega \omega ]^{\leq k})(\exists g\in{\mathcal G})(\exists h\in ^\omega \omega )(\forall f\in{\mathcal F})(\forall ^\infty n)(\exists u\in [g(n),g(n+1))(f(u)=h(u))$ fails. (shrink)

We study within the framework of Zermelo-Fraenkel set theory ZF the role that the axiom of choice plays in the theory of Lindelöf metric spaces. We show that in ZF the weak choice principles: Every Lindelöf metric space is separable and Every Lindelöf metric space is second countable are equivalent. We also prove that a Lindelöf metric space is hereditarily separable iff it is hereditarily Lindelöf iff it hold as well the axiom of choice restricted to countable sets and to (...) topologies of Lindelöf metric spaces as the countable union theorem restricted to Lindelöf metric spaces. (shrink)

We show that (i) it is consistent with that there are infinite sets X on which every metric is discrete; (ii) the notion of real infinite is strictly stronger than that of metrically infinite; (iii) a set X is metrically infinite if and only if it is weakly Dedekind‐infinite if and only if the cardinality of the set of all metrically finite subsets of X is strictly less than the size of ; and (iv) an infinite set X is weakly (...) Dedekind‐infinite if and only if has infinite towers if and only if X has countable partitions. (shrink)

We show that the countable axiom of choice CAC strictly implies the statements “Lindelöf metric spaces are second countable” “Lindelöf metric spaces are separable”. We also show that CAC is equivalent to the statement: “If is a Lindelöf topological space with respect to the base ℬ, then is Lindelöf”.

We show that the statement “separable, countably compact, regular spaces are Baire” is deducible from a strictly weaker form than AC, namely, CAC . We also find some characterizations of the axiom of dependent choices.

We find some characterizations of the Axiom of Choice in terms of certain families of open sets in T1 spaces.

As scholars commonly maintain, the coming of modernity raised the stakes regarding the pursuit of objective truth and inaugurated the critique of error, unfounded beliefs, prejudice, and ideological interest. In our times, postmodernism has turned the weapons of critique against modernity itself and promoted the wholesale rejection of reason; in the aftermath, without any appraisal criteria left, ideological ‘opinions’ keep growing in numbers, get decentralized and multifaceted , and are considered as equivalent voices expressing the different experiences of individuals and (...) local groups. But is this inward and self-destructive turn of critique warranted? Unpacking the relevant arguments one finds many contradictions inside postmodernism, derivative of its peculiar antinomial relations to modernity/modernism. A discussion of the various meanings and forms of the notion of ‘meta-narrative’ demonstrates the weaknesses of both the absolutist (modernist) and radical relativist (postmodernist) positions and points the way toward a moderate, critico-pragmatic understanding of the relationships between, on the one hand, knowledge and critique and, on the other, ideology. (shrink)

We study statements about countable and well-ordered unions and their relation to each other and to countable and well-ordered forms of the axiom of choice. Using WO as an abbreviation for “well-orderable”, here are two typical results: The assertion that every WO family of countable sets has a WO union does not imply that every countable family of WO sets has a WO union; the axiom of choice for WO families of WO sets does not imply that the countable union (...) of countable sets is WO. (shrink)

The evolution of the understanding of evidence-based proof and decision processes in the law, especially criminal law, and standards of proof in this area, has a long-standing and controversial history. Competing accounts cause the legal scholarship to engage in critical and thoughtful exchanges. Some of the divergent views reflect different methodological perspectives similarly recognized in other fields, such as applied psychology and economy, and the broader interdisciplinary research fields of judgment and decision-making, system analysis and decision science. One such methodological (...) perspective asserts that accounts of juridical proof should provide a description and explanation of how the legal system actually works as a whole. Other—more mathematical and analytical accounts—concentrate on how, ideally, legal decision-making under uncertainty ought to be made in order be considered sensible. This paper focuses on the relative plausibility account advocated by Professors Allen and Pardo as an example of the former perspective. Its logical structure and argumentative implications are analysed using elements of decision theory, which is the prime representative of the latter, more mathematical approach to legal proof. Using formal diagrammatic schemes to depict the structural relationships between the core elements of the two accounts, it is demonstrated in what sense they can be considered logically related and congruent. The demonstration shows that the principal disagreements among the proponents of the two examined theories derive from differences in the criteria used to judge the adequacy of competing accounts of legal decision-making, and the level of formalization of the bases of decisions in each candidate account. This structural analysis supports the view that adherence to one or the other of the examined perspectives does not imply a contradiction, but reflects the coverage of different aspects of the same overall decision architecture. Using decision-theoretic notions, our analyses also provide a way to explain RP decisions through an explicit criterion, thus providing a reply to the recurrent critique that RP theory lacks specific means to justify its decisional framework. (shrink)

We study conditions for a topological space to be metrizable, properties of metrizable spaces, and the role the axiom of choice plays in these matters.

This is a continuation of [2]. We study the Tychonoff Compactness Theorem for various definitions of compactness and for various types of spaces . We also study well ordered Tychonoff products and the effect that the multiple choice axiom has on such products.

According to public health data, the US Hispanic population is far healthier than would be expected for a population with low socioeconomic status. Ever since Kyriakos Markides and Jeannine Coreil highlighted this in a seminal 1986 article, public health researchers have sought to explain the so-called “Hispanic paradox.” Several candidate explanations have been offered over the years, but the debate goes on. This article offers a philosophical analysis that clarifies how two sets of obstacles make it particularly difficult to (...) explain the Hispanic paradox. First, different research projects define the Hispanic paradox phenomenon in substantially different ways. Moreover, using Bas van Fraassen’s pragmatic theory of explanation and Sean Valles’s extension of it with the concept of “phenomenon choice,” it also becomes clear that there are also multiple ways of explaining each individual definition of the phenomenon. A second set of philosophical and methodological challenges arises during any attempt to study “Hispanic” phenomena, with one key challenge being that the “Hispanic” panethnic concept was intentionally made vague as it was developed and popularized during the 1960s–1970s. After comparing this case with similar cases in the philosophical literature, the article concludes with observations on what makes this problem unique, particularly its ethical features. (shrink)