Proofs from assumptions are amongst the most fundamental reasoning techniques. Yet the precise nature of assumptions is still an open topic. One of the most prominent conceptions is the placeholder view of assumptions generally associated with natural deduction for intuitionistic propositional logic. It views assumptions essentially as holes in proofs, either to be filled with closed proofs of the corresponding propositions via substitution or withdrawn as a side effect of some rule, thus in effect making them an auxiliary notion subservient (...) to proper propositions. The Curry–Howard correspondence is typically viewed as a formal counterpart of this conception. I will argue against this position and show that even though the Curry–Howard correspondence typically accommodates the placeholder view of assumptions, it is rather a matter of choice, not a necessity, and that another more assumption-friendly view can be adopted. (shrink)

In Transparent Intensional Logic we can recognize two distinct notions of computation that loosely correspond to term rewriting and term interpretation as known from lambda calculus. Our goal will be to further explore these two notions and examine some of their properties.

In this paper we examine two approaches to the formal treatment of the notion of problem in the paradigm of algorithmic semantics. Namely, we will explore an approach based on Martin-Löf’s Constructive Type Theory, which can be seen as a direct continuation of Kolmogorov’s original calculus of problems, and an approach utilizing Tichý’s Transparent Intensional Logic, which can be viewed as a non-constructive attempt of interpreting Kolmogorov’s logic of problems. In the last section we propose Kolmogorov and CTT-inspired modifications to (...) TIL-based approach. The focus will be on non-empirical problems only. (shrink)

La théologie morale est en recherche continue de son interlocuteur philosophique et scientifique : elle se distingue par l'ouverture de son esprit. L'interdisciplinarité se présente sous la forme d'un programme de pensée. Il s'agit d'établir grâce à elle un dialogue constructif avec les sciences médicales. C'est l'interdisciplinarité qui assume une forme concrète dans les situations clefs de l'humaine existence. Confronté aux données de la biologie moléculaire et de la médecine, le théologien se doit de différencier, de moderniser et de développer (...) ses définitions habituelles voire ses modèles de pensée. L'A. se propose de contribuer par cet article à cet objectif. (shrink)

L'article est consacré à la procréation médicalement assistée et aux techniques médicales qui la concernent: les concepts bioéthiques, l'option anthropologique, le dialogue interdisciplinaire et la philosophie de la nature impliqués sont étudiés. Les problèmes concrets du diagnostic préimplantatoire, de la sélection de l'embryon, du clônage, et de la compétence du médecin en matière de conseil sont analysés par l'A.

Ecumenical dialogue in the field of Theological Ethics needs a reflection upon the underlying »Denkforrn«. The present article tries to shed light on recent developments in Catholic Moral Theology insofar as naturallaw and scriptural argument are concerned. Its proper purpose is to show that both foundations of moral judgment are undergirded by theological presuppositions like as christological anthropology and theology of justification.

The main objective of this paper is to sketch unifying conceptual and formal framework for inference that is able to explain various proof techniques without implicitly changing the underlying notion of inference rules. We base this framework upon the so-called two-dimensional, i.e., deduction to deduction, account of inference introduced by Tichý in his seminal work The Foundation’s of Frege’s Logic (1988). Consequently, it will be argued that sequent calculus provides suitable basis for such general concept of inference and therefore should (...) not be seen just as technical tool, but philosophically well-founded system that can rival natural deduction in terms of its “naturalness”. (shrink)

The designation of Diego Maradona’s ‘handball’ goal, that it was an intervention by God himself, brings the phenomena of sport and religion into an interrelationship. The basic thesis of this paper is that, despite many of their phenomenal similarities, explicit religion is not, and cannot be, substantially related to sport, as the two manifest themselves in different ways of being. This thesis is supported by arguments from three philosophical areas: 1. The ontological dimension of the manifestation of the sacred in (...) the profane through the process of hierophany in sport does not refer to a specific deity or God, and is therefore not a presentation but an indirect representation of the sacred; 2. The epistemological perspective of the intentional relation of consciousness to religious ritual justifies the necessity of situating them in an overall horizon of references and meanings to the horizon of the lifeworld; 3. The existential and experiential aspects of transformative sport experiences transform the horizon of meanings of empirical reality, but lack the sacramental perspective. Implicit religion as a possibility of transition on a continuum of complementary existential states is a suitable explicative framework for analyzing the phenomenal similarities and essential differences of religion and sport. (shrink)

This pioneering book presents a reconstitution of Charles Sanders Peirce philosophical system as a coherent architecture of concepts that form a unified theory of reality. Historically, the majority of Peircean scholars adopted a thematic approach to study isolated topics such as semiotics and pragmatism without taking into account the author’s broader philosophical framework, which led to a poor and fragmented understanding of Peirce’s work. In this volume, professor Ivo Assad Ibri, past president of The Charles Sanders Peirce Society and a (...) leading figure in the Brazilian community of Peircean scholars, adopts a systemic approach to Peirce’s thought and presents Peirce’s scientific metaphysics as a deep ontological architecture based on a semiotic logic and on pragmatism as criteria of meaning. Originally published in Portuguese, this book became a classic among Brazilian Peircean scholars by presenting a conceptual matrix capable of providing a clear reference system to ground the thematic studies into the broader Peircean system. Now translated to English, this reviewed, amplified and updated edition aims to make this contributions available to the international community of Peircean scholars and to serve as a tool to understand Peirce’s work in a more systemic way by integrating concepts such as experience, phenomenon, existence and reality, as well as theories such as Chance, Continuity, Objective Idealism, Cosmology and Pragmatism, in a coherent system that reveals Peirce’s complex metaphysical architecture. "As the philosophical reputation of Charles S. Peirce continues to rise to first-tier prominence in the history of American philosophy, Ivo Ibri’s Kósmos Noetós assumes a unique status in both a pioneering and a magisterial work of transcontinental Peirce scholarship. This original work of this internationally renowned scholar and editor, and Professor of Philosophy at the Pontifical Catholic University of San Paulo, penetrates to the heart of Peirce’s architectonic system of phenomenological, metaphysical, and semiotic categories which heuristically characterize our world as “a universe perfused with signs.” Ibri’s own synergistic commentary on the radiating registers of Peirce’s cosmogonically and pragmatistically conceived “one intelligible theory of the universe” also instructively contributes to the illumination of significant nodes of interface with a range of relevant theoretical trends in the contemporary academy; as well, it places Peirce in the company of such thinkers as Plato, Aristotle, Plotinus, Kant, and Schelling who preceded Peirce in providing a legacy of first-tier reasoning on our intelligibly developing world. Kosmos Noetos impresses as Ibri’s pure, lucid, passionately thought-loving, philosophical articulation of his own and as the indispensable prolegomena to all future Peirce studies." David Dilworth, State University of New York at Stone Brook – USA "Ivo Ibri has offered us in this exquisite work a framing of the inner logic of Charles S. Peirce's core metaphysical vision and its existential implications. It is a deep and nuanced exploration of the internal dynamics of Peirce’s central metaphysical categories, developed through rigorous and detailed attention to the evolution of Peirce’s thought on the ‘vitally important topics’ of the appearing, the reality, and the intelligibility of the world. The two-leveled format of the book, an intricate weaving of Peirce’s texts and discursive elaboration and linkage by Ibri, gives it a distinctive feel and is the bedrock of its value. The book is a remarkable combination of presentation and analysis. It is informed by Ibri’s deep philosophical culture and is a gentle and convincing argument for the centrality of metaphysics in understanding Peirce’s thought. It offers in a new way indispensable suggestions for our own attempts to think about our places in an evolving universe with the aid of Peirce and offers threads of thought to be followed up by others." Robert E. Innis, University of Massachusetts Lowell – USA. (shrink)

Contact relations have been studied in the context of qualitative geometry and physics since the early 1920s, and have recently received attention in qualitative spatial reasoning. In this paper, we present a sound and complete proof system in the style of Rasiowa and Sikorski (1963) for relation algebras generated by a contact relation.

Before examining de Moivre's contributions to the science of mathematics, this article reviews the source materials, consisting of the printed works and the correspondence of de Moivre, and constructs his biography from them. The analytical part examines de Moivre's contributions and achievements in the study of equations, series, and the calculus of probability. De Moivre contributed to the continuing development from Viète to Abel and Galois of the theory of solving equations by means of constructing particular equations, the roots of (...) which can be written in the form $$\sqrt[n]{{a + \sqrt b }} + \sqrt[n]{{a - \sqrt b }}$$. He also discovered the reciprocal equations. In the course of this work de Moivre discovered an expression equivalent to (cos α+i sin α) n =cos n α+i sin n α and, following Cotes, he succeeded in expressing the nth roots of unity in trigonometric form. In the theory of series, de Moivre developed a polynomial theorem encom-passing Newton's binomial theorem and, in particular, a theorem of recurrent series useful in the calculus of probability. The demands of the calculus of probability led de Moivre to an approximation for the binomial coefficients $$\left( {_m^n } \right)$$ for large values of n. The interaction between de Moivre and James Stirling, particularly in regard to the asymptotic series for log (n!), is treated at length. This work supplied the foundation for de Moivre's limit theorem for the binomial distribution. The calculus of probability, which occupied him from 1708 onward, became in time ever more the center of de Moivre's inquiries. Proceeding from contemporary collections of gambling exercises, de Moivre, by introducing an explicit measure of probability for the so-called Laplace experiments, found the beginnings of a theory of probability. De Moivre expanded the classic application of probability calculus to games of chance by addressing himself to the problem of annuities and by adopting Halley's work with its conception of “Probability of life”. De Moivre was the first to publish a mathematically formulated law for the decrements of life derived from mortality tables. (shrink)

In this paper, we investigate the possibility of translating a fragment of natural deduction system (NDS) for natural language semantics into modern type theory (MTT), originally suggested by Luo (2014). Our main goal will be to examine and translate the basic rules of NDS (namely, meta-rules, structural rules, identity rules, noun rules and rules for intersective and subsective adjectives) to MTT. Additionally, we will also consider some of their general features.

As pervasive as the use of the Internet has become in the United States, a huge percentage of the world’s population has yet to ever use a telephone. It seems ironic, then, that there is a concerted effort on the part of industrialized nations to first hook up their traditionally disadvantaged citizens to the Internet and second, to hook up citizens of developing nations. This paper addresses the universal access phenomenon by considering the growth of the Internet in terms of (...) Leaver and Taker users—idioms usually associated with a culture’s interactions with its environment. Leaver cultures interact with their environment in a sustainable manner while Taker cultures produce more than they need and impose their ways upon others. The Internet is explored as a community of users, which in its current state is dominated by Takers. However, realizing the need for a more heterogeneous Internet community, this paper explores incentives for Leaver cultures to assimilate online and methods of improving interface designs to be more intuitive to Leaver communities. It is hoped that a tragedy of the commons of Internet resources can be avoided as more Leavers participate in the sustainment of the Internet as a valuable tool for all communities. (shrink)

We investigate the join semilattice of modal operators on a Boolean algebra B. Furthermore, we consider pairs ⟨f,g⟩\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\langle f,g \rangle $$\end{document} of modal operators whose supremum is the unary discriminator on B, and study the associated bi-modal algebras.

Nemonotónní logika vznikla za účelem systematicky zachytit tzv. zrušitelné uvažování, tj. typ každodenního uvažování, které vede jen k provizorně platným argumentům, jenž mohou být následně staženy s příchodem nových informací. Tím se ovšem nemonotónní logika dostává do ostrého kontrastu s klasickou logikou, která je monotónní, tj. žádné dodatečné premisy nemohou zrušit jednou již platné argumenty. To bylo pro mnohé dostatečným důvodem k tomu, aby nemonotónní logice upřeli status logiky. V tomto textu si ukážeme, že takový závěr je příliš unáhlený a (...) že nemonotónní logika má právo se nazývat logikou. (shrink)

Svoboda, V. a kol. Logika a přirozený jazyk. Praha: Filosofia, 2010, 300 stran.

We consider the results of adding to a basic modal system T0the axioms G1.CLpp;Pn.CLnpLn+1p; Bn.CpLnMp, where n ≧ 11, in all combinations. The method of Meredith's [7] will be extended to get models of these systems in lower predicate calculus (LPC) with a constant binary relation,U. Most of the results were already obtained in [1]–[6], though systems as in (i) and (ii) below were not investigated, except that S40in (ii) was mentioned in [1]. However some repetition may be excused in (...) view of the simplicity with which the results are obtained by the present method. (shrink)

Jeder weiss, dass er sterben muss. Er weiss nur nicht wann. Wüsste er es, er könnte den Tod nicht mehr aus seinem Leben verdrängen. Dieses Buch geht von einer utopischen Situation aus: Durch eine gentechnische Analyse wird bei jedem Menschen gleich nach seiner Geburt festgestellt, wann sein "Endtag", also sein Todestag, sein wird. Frühere Todesfälle gibt es nur bei Unfall oder Mord, spätere nie. Das Wissen um den Endtag verändert das Leben jedes Einzelnen, die Familien, die Gesellschaft, Ausbildung, Beziehungen und (...) Lebensplanung, Laufbahnen im Beruf, das Rentensystem u.v.m. Was für die einen ein "Horrorszenario" sein kann, entpuppt sich für die anderen als ein Segen: Alle können ihren Lebensabend planen und zur rechten Zeit bewusst Abschied nehmen. Und an diesem Punkt wird das Szenario von Ivo W. Greiter zum Plädoyer: Versucht euch täglich bewusst zu sein und zu akzeptieren, dass Ihr nicht ewig leben werdet. Rechnet mit dem Tod, redet über das Sterben, räumt eure Sachen auf. Und: Der Tod kann seinen Schrecken verlieren, wenn er am Leben teilhaben darf. "Und immer wieder stellte ich mir die Frage: Wenn ich weiss, was ich ändern würde, wenn ich in vier Monaten sterben würde, warum ändere ich es dann nicht gleich?" DR. GREITER, geb. 1940, ist Rechtsanwalt in Innsbruck; er ist vielfach in Berufsverbänden und ehrenamtlich engagiert, so als österreichischer Vorsitzender der internationalen Juristenorganisation World Jurist Association, Washington, als Vizepräsident des Österreichischen Juristentages und des österreichischen Anwaltsvereins u. a.; von 1983 bis 1989 war Dr. Greiter Mitglied des Gemeinderates von Innsbruck und von 1993 bis 2010 französischer Honorarkonsul in Innsbruck. Er befasst sich unter anderem mit Rechtsfragen für Menschen über 66; zahlreiche sonstige fachbezogene Veröffentlichungen. (shrink)