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 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 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.

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)

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 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)

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?

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.