In 1996, W. Veldman and F. Waaldijk present a constructive (intuitionistic) proof for the homogeneity of the ordered structure of the Cauchy real numbers, and so this result holds in any topos with natural number object. However, it is well known that the real numbers objects obtained by the traditional constructions of Cauchy sequences and Dedekind cuts are not necessarily isomorphic in an arbitrary topos with natural numbers object. Consequently, Veldman and Waaldijk's result does not apply to the ordered (...) structure of Dedekind real numbers in toposes. The main result to be proved in the present paper is that the ordered structure of the Dedekind real numbers object is homogeneous, in any topos with natural numbers object. This result is obtained within the framework of local set theory. (shrink)

In Zermelo-Fraenkel set theory with the axiom of choice every set has the same cardinal number as some ordinal. Von Rimscha has weakened this condition to “Every set has the same cardinal number as some transitive set”. In set theory without the axiom of choice, we study the deductive strength of this and similar statements introduced by von Rimscha.

La critica che Ludwig Wittgenstein muove ai presupposti filosofici del dibattito sui fondamenti della matematica si estende oltre le tematiche specifiche di tale dibattito ed investe un’intera tradizione di pensiero. Dietro alle argomentazioni di Frege e Russell, alle dimostrazioni di Cantor e di Dedekind, al programma di Hilbert e al teorema di Gödel, c’è uno sfondo filosofico che le acute osservazioni del filosofo ci permette di smascherare. Questa ricerca, articolata in quattro studi, intende presentare alcuni momenti fondamentali del dibattito (...) sui fondamenti e la relativa critica di Wittgenstein. Si prenderà in considerazione la definizione di limite di Cantor, la sezione di Dedekind, la definizione logicista di numero naturale ed infine il problema della scoperta in matematica. In conclusione si cercherà di interpretare il cosiddetto anti-platonismo di Wittgenstein. (shrink)

avec de nombreux textes inédits Pierre Dugac. APPENDICE XVII Wilhelm WEBER : Brie)'e an Richard Dedekind (Cod. Ms. Richard Dedekind 14, II; Niedersàchsische Staats- und Universitàts- bibliothek Gôttingen) Gôttingen 10. Aug.

There can be no doubt about the value of Frege's contributions to the philosophy of mathematics. First, he invented quantification theory and this was the first step toward making precise the notion of a purely logical deduction. Secondly, he was the first to publish a logical analysis of the ancestral R* of a relation R, which yields a definition of R* in second-order logic.1 Only a narrow and arid conception of philosophy would exclude these two achievements. Thirdly and very importantly, (...) the discussion in §§58-60 of the G r u n d l a g e n defends a conception of mathematical existence, to be found in Cantor (1883) and later in the writings of Dedekind and Hilbert, by basing it upon considerations about meaning which have general application, outside mathematics.2.. (shrink)

By the middle of the nineteenth century, it had become clear to mathematicians that the study of finite field extensions of the rational numbers is indispensable to number theory, even if one’s ultimate goal is to understand properties of diophantine expressions and equations in the ordinary integers. It can happen, however, that the “integers” in such extensions fail to satisfy unique factorization, a property that is central to reasoning about the ordinary integers. In 1844, Ernst Kummer observed that unique factorization (...) fails for the cyclotomic integers with exponent 23, i.e. the ring Z[ζ] of integers of the field Q(ζ), where ζ is a primitive twenty-third root of unity. In 1847, he published his theory of “ideal divisors” for cyclotomic integers with prime exponent. This was to remedy the situation by introducing, for each such ring of integers, an enlarged domain of divisors, and showing that each integer factors uniquely as a product of these. He did not actually construct these integers, but, rather, showed how one could characterize their behavior qua divisibility in terms of ordinary operations on the associated ring of integers. (shrink)

© The Author [2017]. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: [email protected] Dedekind was a contemporary of Bernhard Riemann, Georg Cantor, and Gottlob Frege, among others. Together, they revolutionized mathematics and logic in the second half of the nineteenth century. Dedekind had an especially strong influence on David Hilbert, Ernst Zermelo, Emmy Noether, and Nicolas Bourbaki, who completed that revolution in the twentieth century. With respect to mainstream mathematics, he is best known for (...) his contributions to algebra and number theory. With respect to logic and the foundations of mathematics, many of his technical results — his conceptualization of the natural and real numbers, his analysis of proofs by mathematical induction and definitions by recursion (extended to the transfinite by Zermelo, John von... (shrink)

1. If A is strongly amorphous , then its power set P is dually Dedekind infinite, i. e., every function from P onto P is injective. 2. The class of “inexhaustible” sets is not closed under supersets unless AC holds.

Axioms for the continuum, or smooth real line R. These include the usual axioms for a commutative ring with unit expressed in terms of two operations + and i , and two distinguished elements 0 ≠ 1. In addition we stipulate that R is a local ring, i.e., the following axiom: ∃y x i y = 1 ∨ ∃y (1 – x) i y = 1. Axioms for the strict order relation < on R. These are: 1. a < b (...) and b < c implies a < c. 2. ¬(a < a) 3. a < b implies a + c < b + c for any c. ≤ 4. a < b and 0 < c implies acbc.. (shrink)

In Hájek et al. (J Symb Logic 65(2):669–682, 2000) the authors introduce the concept of supersound logic, proving that first-order Gödel logic enjoys this property, whilst first-order Łukasiewicz and product logics do not; in Hájek and Shepherdson (Ann Pure Appl Logic 109(1–2):65–69, 2001) this result is improved showing that, among the logics given by continuous t-norms, Gödel logic is the only one that is supersound. In this paper we will generalize the previous results. Two conditions will be presented: the first (...) one implies the supersoundness and the second one non-supersoundness. To develop these results we will use, between the other machineries, the techniques of completions of MTL-chains developed in Labuschagne and van Alten (Proceedings of the ninth international conference on intelligent technologies, 2008) and van Alten (2009). We list some of the main results. The first-order versions of MTL, SMTL, IMTL, WNM, NM, RDP are supersound; the first-order version of an axiomatic extension of BL is supersound if and only it is n-potent (i.e. it proves the formula ${\varphi^{n}\,\to\,\varphi^{n\,{+}\,1}}$ for some ${n\,\in\,\mathbb{N}^+}$ ). Concerning the negative results, we have that the first-order versions of ΠMTL, WCMTL and of each non-n-potent axiomatic extension of BL are not supersound. (shrink)

Durkheim écrit ce livre avec un but double : d'abord il voulait expliquer ce qui crée une société, ce qui la tient ensemble ; ensuite il voulait éclaircir l'influence qu'a la société sur la pensée logique. Pour Durkheim, la religion est la clé utilisée pour déverrouiller ces deux problématiques.Dans ce livre, Durkheim argumente que les représentations religieuses sont en fait des représentations collectives : l'essence du religieux ne peut être que le sacré. Il est une caractéristique qui se trouve universellement (...) dans toutes les religions. Le sacré, être collectif et impersonnel, représente ainsi la société elle-même. Ensuite il argumente que la société a un impact majeur dans la genèse de la pensée logique. C'est la société qui fournit à l'individu les catégories (le temps, l'espace, le nombre etc.) et les concepts nécessaires pour la pensée logique. (shrink)

When we perceive an object, we perceive the object from a perspective. As a consequence of the perspectival nature of perception, when we perceive, say, a circular coin from different angles, there is a respect in which the coin looks circular throughout, but also a respect in which the coin's appearance changes. More generally, perception of shape and size properties has both a constant aspect—an aspect that remains stable across changes in perspective—and a perspectival aspect—an aspect that changes depending on (...) one's perspective on the object. How should we account for the perspectival aspect of spatial perception? We present a framework within which to discuss the perspectival aspect of perception and put forward three desiderata that any account of the perspectival aspect of perception should satisfy. We discuss views on which the perspectival aspect of perception is analyzed in terms of constitutively mind-dependent appearance properties as well as views on which the perspectival aspect of perception is analyzed in terms of representations of mind-independent perspectival properties. (shrink)

With special emphasis on Foucault's many recently published lecture series this book provides an updated, comprehensive presentation of his most important diagnoses, his many ground-breaking analytical concepts as well as a systematic account of his unique conception of philosophy.

We argue that the trend toward providing users with feasible and actionable explanations of AI decisions—known as recourse explanations—comes with ethical downsides. Specifically, we argue that recourse explanations face several conceptual pitfalls and can lead to problematic explanation hacking, which undermines their ethical status. As an alternative, we advocate that explanations of AI decisions should aim at understanding.

A dialogue between a foreign philosopher and a powerful statesman outline Plato's reflections on the family, the status of women, property rights, and criminal law.

The Anthropocene is heralded as a new epoch distinguishing itself from all foregoing eons in the history of the Earth. It is characterized by the overarching importance of the human species in a number of respects, but also by the recognition of human dependence and precariousness. A critical human turn affecting the human condition is still in the process of arriving in the wake of an initial Copernican Revolution and Kant's ensuing second Copernican Counter-revolution. Within this landscape, issues concerning the (...) human - its finitude, responsiveness, responsibility, maturity, auto-affection and relationship to itself - appear rephrased and re-accentuated as decisive probing questions. In this book Sverre Raffnsøe explores how the change has ramifications for the kinds of knowledge that can be acquired concerning human beings and for the human sciences as a study of human existential beings in the world. (shrink)

Neste livro Gombrich discute as idéias e as posturas específicas que tiveram influência decisiva na prática da arte renascentista. Todos os estudos aqui reunidos tratam de algo a que se pode chamar clima renascentista de opiniões sobre a arte, além da influência desse clima sobre a prática e a crítica da arte.

Criticism on Bhagavadgītā, Hindu sacred work.

What makes us human is our special motivation to share with others how we feel, what we believe, and what we want to happen in the future. We want to share with others what is real about the world. Shared reality is crucial to what we believe--sharing is believing. It is central to our sense of self, what we strive for and how we strive. It is basic to how we get along with others. It brings us together in fellowship (...) and companionship, but it also tears us apart by creating in-group "bubbles" that conflict with one another. Our shared realities are the best of us, and the worst of us. (shrink)

Etienne Gilson Reason and Revelation in the Middle Ages, first delivered as the Richard Lectures in 1937, was published in 1938 and became an immediate success. Not only does it contribute to a major question of debate in Christian, Jewish, and Islamic philosophy and religion in the medieval period but it also insists on the validity of truth obtainable through reason as well as revelation, on rational argument alongside religious faith. This message is as important in the twenty-first century as (...) it was in the fourth century of the young Augustine, the thirteenth of St Thomas Aquinas, and the twentieth of the mature Gilson. (shrink)

A collection of Essays over the last 20 years, exploring different dimensions of the philosophical debate on "subjecthood" and "subjectivity" in Modernity, as it was framed by the "Controversy on the subject" from the 1960's, and showing how it is now continued in a "controversy on the Universal.".

This article critically reflects on the research portfolio by the ecological economist Clive Spash who has helped pinpoint specific and systemic blindspots in a political-economic system that prioritises myopic development trajectories divorced from ecological reality. Drawing on his published work and collaborations it seeks to make sense of the slow, or absent, progress in averting global warming and ecological destruction. Three strands of key concern and influence are identified and discussed with reference to their orientation and explicit expression regarding Ontology, (...) Epistemology and Axiology. Some complementary points about indeterminacy and holism are presented to further strengthen the arguments for a transition towards a social-ecological economic system that puts values and principles back into focus. While Clive Spash's work has made a strong case within the economic community and appealing to ecology professionals, the value-myopia or value-vacuum has to be tackled across all disciplines, politics and society for a meaningful and urgently required transformation in decision making. Hence, the article finishes with some suggestions for the (higher) education system, and highlights the importance of simplicity and sufficiency, as well as strong sustainability-driven citizen and community action as necessary catalysts of change in this social-ecological transformation. (shrink)