Church's Thesis (CT) was first published by Alonzo Church in 1935. CT is a proposition that identifies two notions: an intuitive notion of an effectively computable function defined in natural numbers with the notion of a recursive function. Despite the many efforts of prominent scientists, Church's Thesis has never been disproven. There exists a vast literature concerning the thesis. The aim of this book is to provide a one volume summary of the state of research on Church's Thesis. These include (...) the following: different formulations of CT, CT and intuitionism, CT and intensional mathematics, CT and physics, the epistemic status of CT, CT and philosophy of mind, provability of CT and CT and functional programming. Adam Olszewski, is assistant professor of the philosophy of mathematics and mathematical logic at the Department of Philosophy of Pontifical Academy of Theology, Cracow (Poland). Jan Wolenski is professor of philosophy, Institute of Philosphy, Jagiellonian University, Cracow (Poland). He is one of the most distinguished logicians in Poland. Robert Janusz is assistant professor in the Department of Philosophy of Ignatius College, Cracow (Poland). (shrink)

The paper consists of two parts. In the first one I present some general remarks regarding the history of negation and attempt to answer the philosophical question concerning the essence of negation. In the second part I resume the theological teaching on the degrees of certainty and point to five forms of negation – known from other areas of research -- as applied in the framework of theological investigations.

The starting point of this paper is the empirically determined ability to reason in natural language by employing probable sentences. A sentence is understood to be logically probable if its schema, expressed as a formula in the language of classical propositional calculus, takes the logical value of truth for the majority of Boolean valuations, i.e., as a logically probable formula. Then, the formal system P is developed to encode the set of these logically probable formulas. Based on natural semantics, a (...) strong completeness theorem for P is proved. Alternative notions of consequence for logically probable sentences are also considered. (shrink)

The article analyses the role of Church’s Thesis (hereinafter CT) in the context of the development of hypercomputation research. The text begins by presenting various views on the essence of computer science and the limitations of its methods. Then CT and its importance in determining the limits of methods used by computer science is presented. Basing on the above explanations, the work goes on to characterize various proposals of hypercomputation showing their relative power in relation to the arithmetic hierarchy. The (...) general theme of the article is the analysis of mutual relations between the content of CT and the theories of hypercomputation. In the main part of the paper the arguments for abolition of CT caused by the introduction of hypercomputable methods in computer science are presented and critique of these views is presented. The role of the efficiency condition contained in the formulation of CT is stressed. The discussion ends with a summary defending the current status of Church’s thesis within the framework of philosophy and computer science as an important point of reference for determining what the notion of effective calculability really is. The considerations included in this article seem to be quite up-to-date relative to the current state of affairs in computer science.1. (shrink)

The title question of the paper has its empirical origin in the form of an individual’s existential experience arising from the personal use of a computer, which we attempt to describe in the first section. The rest of the entire paper can be understood as a philosophical essay answering the question posed. First the connection between the main problem of the article and its “premonition” by mankind, which was expressed in the form of ancient myths and legends, is briefly suggested. (...) After shortly discussing the problems that early considerations of AI focused on, i.e. whether machines can think at all, we move on to reformulate our title question, about the possibility of outsmarting AI. This outsmarting will be understood by us in a rather limited way as to prevent a machine from completing its implemented task. To achieve this objective, after softly clarifying the basic terms, an analogy is built between the “outsmarting” of a machine by a human (the target domain) and the playing of a mathematical game between two players (the base domain), where this outsmarting is assigned a “winning strategy” in the certain game. This mathematical model is formed by games similar to Banach-Mazur games. The strict theorems of such games are then proved and applied to the target of the analogy. We then draw conclusions and look for counter-examples to our findings. The answer to the title question posed is negative, and it is not clear how far it should be taken seriously. (shrink)

This work is interdisciplinary as it lies at the crossroads of three disciplines: philosophy, theology, and logic. The article attempts to discuss the way in which sentences (judgements) are accepted and rejected within theology. First, the role of the argument of authority in theology is discussed. Subsequently, the most important types of theorems with certain degrees of theological certainty were identified. Finally, censorship was presented as a means of rejecting theorems in theology. Finally, censorship was indicated as a model for (...) philosophical-logical research on denial. (shrink)

In the introduction to the volume on negation, first the source ways of understanding it from antiquity to modern times are presented, as well as the basic points of contention connected with it. Subsequently, the works contained in this volume are briefly presented in the order in which they appeared.

The aim of the paper is to evaluate the usefulness of W.V.O. Quine's criterion for establishing the ontological commitments of a theory. At the outset, Quine's conception is reconstructed. It is argued that Quine does not provide a particularly clear exposition of the procedure of establishing ontological commitments. It is further maintained that - on a persuasive interpretation - one should distinguish several concepts associated with Quine's conception. These are: ontology, domain tolerated by an ontology, ontological commitments type 1 (categorical), (...) ontological commitments type 2 (individual). Then, the procedure itself is reconstructed. It is argued that it consists of three stages: (1) the reduction of the analyzed theory to so-called basic existential propositions; (2) the paraphrase of the basic existential propositions into the formulae of the I order logic; (3) the reconstruction of the ontology presupposed by the given theory as well as of the ontological commitments type 1 and type 2. The final part of the paper contains three objections against Quine's conception. It is argued, first, that it is impossible to reconstruct the ontology presupposed by the given theory as it requires that the same or a richer ontology is already in use. Second, Quine's procedure is based on a vicious circle: one needs to know the ontological commitments in order to reconstruct them. Third, if one assumes that Quine's procedure is applicable to uninterpreted theories, it is impossible to determine the domain of these theories. The conclusion of the paper is that Quine's criterion seem useless. (shrink)

The aim of the article is to answer the four following questions concerning a proof of Church's Thesis (CT). (1) Can CT be treated as a synthetic definition? (2) How should CT not be understood? (3) How can one understand the expression proof by CT? (4) Is any proof of CT possible at all?

The aim of the paper is twofold. First, we want to recapture the genesis of the logics of order. The origin of this notion is traced back to the work of Jerzy Kotas, Roman Suszko, Richard Routley and Robert K. Meyer. A further development of the theory of logics of order is presented in the papers of Jacek K. Kabziński. Quite contemporarily, this notion gained in significance in the papers of Carles Noguera and Petr Cintula. Logics of order are named (...) there _logics of weak implications_. They play a crucial role in their monograph (Noguera and Cintula _Logic and Implication. An Introduction to the General Algebraic Study of Non-Classical Logics_, Trends in Logic 57, Springer, Berlin, 2021). But, more importantly, the other goal is to define some subclasses of the logics of order in reference to later results of Jacek K. Kabziński and Michael Dunn. The original conception of implication is due to Kabziński. Implication is a stronger notion than the notion of the connective of order aka weak implication. As a result, the three subclasses of logics of order are isolated: logics of implication, logics of symmetry, and tonoidal logics. These notions are uniformly defined and investigated from various viewpoints in terms of consequence operations. The emphasis is put on their semantics. (shrink)

This collection of essays - written by philosophers, logicians, and theologians - is devoted to the problem of the utilization of logic in theological discourse. Viewed from the perspective of logic, the issues covered include such topics as the logic of miracles, the problem of God's omniscience, the application of non-classical logics to theology, and the relationships between science and theology.

Marie Duží, Bjørn Jespersen, and Pavel Materna: Procedural Semantics for Hyperintensional Logic. Foundations and Applications of Transparent Intentional Logic, vol. 17 of series “Logic, Epistemology, and the Unity of Science”, Springer, Dordrecht, Heidelberg, London, New York, 2010; xiii+552 pages, ISBN 978-90-481-8811-6, e-ISBN 978-90-481-8812-3. DOI: 10.1007/978-90-481-8812-3.

In the section ‘Further reading’, I listed a book that arrived on my desk just as I was sending IGT off to the press, namely Church’s Thesis after 70 Years edited by Adam Olszewski et al. On the basis of a quick glance, I warned that the twenty two essays in the book did seem to be of ‘variable quality’. But actually, things turn out to be a bit worse than that: the collection really isn’t very good at (...) all! After I sent my book to press, I gave a paper-by-paper review on my blog, at http://logicmatters.blogspot.com. It is probably more fun to chase up the reviews ‘in the wild’, so to speak, starting from the entry for May 14, 2007. But here they are wrapped up into a single document, only marginally tidied. Some of the points made here should help further explain and support the general line on the Thesis taken in.. (shrink)

The World Bank is committed to “work[ing] with countries to improve the health, nutrition and population outcomes of the world's poor, and to protect[ing] the population from the impoverishing effects of illness, malnutrition and high fertility”.1 Ethical issues arise in the interpretation of these objectives and in helping countries formulate strategies and policies. It is these ethical issues—which are often not acknowledged by commentators—that are the subject of this paper. It asks why there should be a focus on the poor, (...) and explores the link between improving the health of the poor, and reducing health inequalities between the poor and better-off. It discusses difficult ethical issues at both the global level and the country level. (shrink)

In addition to being uncertain about what the world is like, one can also be uncertain about one’s own spatial or temporal location in the world. My aim is to pose a problem arising from the interaction between these two sorts of uncertainty, solve the problem, and draw two lessons from the solution.

I address three interrelated issues concerning the contents of experiences. First, I address the preliminary issue of what it means to say that experiences have contents. Then I address the issue of why we should believe that experiences have contents. Finally, I address the issue of what the contents of experiences are.

In this paper I propose an account of representation for scientific models based on Kendall Walton’s ‘make-believe’ theory of representation in art. I first set out the problem of scientific representation and respond to a recent argument due to Craig Callender and Jonathan Cohen, which aims to show that the problem may be easily dismissed. I then introduce my account of models as props in games of make-believe and show how it offers a solution to the problem. Finally, I demonstrate (...) an important advantage my account has over other theories of scientific representation. All existing theories analyse scientific representation in terms of relations, such as similarity or denotation. By contrast, my account does not take representation in modelling to be essentially relational. For this reason, it can accommodate a group of models often ignored in discussions of scientific representation, namely models which are representational but which represent no actual object. (shrink)

Dr. Evil learns that a duplicate of Dr. Evil has been created. Upon learning this, how seriously should he take the hypothesis that he himself is that duplicate? I answer: very seriously. I defend a principle of indifference for self-locating belief which entails that after Dr. Evil learns that a duplicate has been created, he ought to have exactly the same degree of belief that he is Dr. Evil as that he is the duplicate. More generally, the principle shows that (...) there is a sharp distinction between ordinary skeptical hypotheses, and self-locating skeptical hypotheses. (shrink)

I argue that the contrast between models and theories is important for public policy issues. I focus especially on the way a mathematical model explains just one aspect of the data.

D. D. Raphael and A. L. Macfie (1976) II An Inquiry into the Nature and Causes of the Wealth of Nations, ed. R. H. Campbell and A. S. Skinner; textual editor W. B. Todd, 2 vols. (1976) III Essays on Philosophical Subjects, ed. W. P. D. Wightman  ...

This highly readable book is a collection of critical papers on Otto Neurath. It comprehensively re-examines Neurath’s scientific, philosophical and educational contributions from a range of standpoints including historical, sociological and problem-oriented perspectives. Leading Neurath scholars disentangle and connect Neurath’s works, ideas and ideals and evaluate them both in their original socio-historical context and in contemporary philosophical debates. Readers will discover a new critical understanding. Drawing on archive materials, essays discuss not only Neurath’s better-known works from lesser-known perspectives, but also (...) his lesser-known works from the better-known perspective of their place in his overall philosophical oeuvre. Reflecting the full range of Neurath's work, this volume has a broad appeal. Besides scholars and researchers interested in Neurath, Carnap, the Vienna Circle, work on logical empiricism and the history and philosophy of science, this book will also appeal to graduate students in philosophy, sociology, history and education. Readers will find Neurath’s thoughts described and evaluated in an accessible manner, making it a good read for those beyond the academic world such as social leaders and activists. The book includes the edited 1940-45 Neurath-Carnap correspondence and the English translation of Neurath's logic papers. (shrink)

Growing concern has been expressed that we have entered a “post-truth” era in which each of us willfully believes whatever we choose, aided and abetted by alternative and social media that spin alternative realities for boutique consumption. A prime example of the belief in alternative realities is said to be acceptance of “conspiracy theories”—a term that is often used as a pejorative to indict claims of conspiracy that are so obviously absurd that only the unhinged could believe them. The epistemological (...) standard often involved in this indictment, however—the standard of “obvious” falsity—invites subjectivity in its application, because what is obviously false to one person can be common sense to another. This is not just a truism; considerable research suggests that people’s political beliefs, in general, and their acceptance or rejection of conspiracy theories in particular, tends in large part to be determined by partisan, ideological, and other priors. (shrink)

This book reconceives virtue epistemology in light of the conviction that we are essentially social creatures. Virtue is normally thought of as something that allows individuals to accomplish things on their own. Although contemporary ethics is increasingly making room for an inherently social dimension in moral agency, intellectual virtues continue to be seen in terms of the computing potential of a brain taken by itself. Thinking in these terms, however, seriously misconstrues the way in which our individual flourishing hinges on (...) our collective flourishing. Green’s account of virtue epistemology is based on the extended credit view, which conceives of knowledge as an achievement and broadens that focus to include team achievements in addition to individual ones. He argues that this view does a better job than alternatives of answering the many conceptual and empirical challenges for virtue epistemology that have been based on cases of testimony. The view also allows for a nuanced interaction with situationist psychology, dual processing models in cognitive science, and the extended mind literature in philosophy of mind. This framework provides a useful conceptual bridge between individual and group epistemology, and it has novel applications to the epistemology of disagreement, prejudice, and authority. (shrink)