The brief article of 1910 which is translated here is, as the prefatory note explains, significant for understanding both the way in which ?ukasiewicz came to many-valued logic and the influences under which he stood at the time.

This paper reports some attempts undertaken in Poland in the 1930s to modernize Thomism by means of modern logic. In particular, it concerns J.M. Bocheński and J. Salamucha, the leading members of the CracowCircle. They attempted to give precise logical form to the Five Ways of Thomas Aquinas. Other works concerned the concept of transcendentals, the levels of abstraction, and the concept of essence.

In this article the author first described the developments which brought to focus the importance of consistency proofs for mathematics, and which led Hilbert to promote the science of metamathemat-ics. Further comments and remarks concern the (partly analogous) beginnings of the work on the decision problem, Gödel?s theorems and related matters, and general metamathematics. An appendix summarizes a text by the author on completeness and categoricity.

The relevance of metamathematical researches for philosophy of math- ematics is an indubitable matter. In the paper I shall speak about impli- cations of metamathematics for general philosophy, especially for classical epistemological problems. Let us start with a historical observation con- cerning Hilbert's programme, the rst research programme in metamathe- matics as a separate study of formal systems. This programme was strongly in uence by epistemological considerations. In fact, Hilbert wanted to se- cure all classical mathematics against inconsistencies and this (...) aim had be achieved with the help of nitary consistency proof. Hilbert's claim is like the Cartesian project of reduction of all concepts to clarae et distinctae ideae. The epistemological commitment of original Hilbert's programme may be treated as a prelim- inary heuristic motivation for looking for epistemological implications of metamathematical results. It seems reasonable to examine in this respect three so-called limitative theorems: the rst Godel's incompleteness theo- rem , the second Godel's incom- pleteness theorem consistency of S, cannot be proved in S, providing that S is consistent) and Tarski's undenability theorem ; \S" stands for formal system containing elementary number theory. From the above-mentioned theorems we obtain an important, from philosophical point of view, conclusion: semantics of S cannot be expressed in S. Now, I shall present three applications of limitative theorems to the analysis of classical epistemological problems. (shrink)

Adolf Lindenbaum Adolf Lindenbaum was a Polish mathematician and logician who worked in topology, set theory, metalogic, general metamathematics and the foundations of mathematics. He represented an attitude typical of the Polish Mathematical School, consisting of using all admissible methods, independently of whether they were finitary. For example, the axiom of choice was freely applied, … Continue reading Lindenbaum, Adolf →.

The Semantic Theory of Truth The semantic theory of truth was developed by Alfred Tarski in the 1930s. The theory has two separate, although interconnected, aspects. First, it is a formal mathematical theory of truth as a central concept of model theory, one of the most important branches of mathematical logic. Second, it … Continue reading Semantic Theory of Truth →.

This paper discusses the main logical ideas put forward by Jan Łukasiewicz within their historical context and further development.

Jan Łukasiewicz a élaboré un programme de recherche portant sur l’histoire de la logique. À son avis, la logique mathématique contemporaine (modern) est en continuité directe avec la logique formelle du passé. En conséquence, une interprétation correcte et fidèle des idées anciennes exige une application des outils logiques contemporains. Autrement dit, de bonnes études historiques sur la logique doivent consister à examiner la logique d’autrefois à travers les lunettes logiques contemporaine...

It is a Preface to Volume 8:2 (2019) consisting of articles presented at the International Interdisciplinary Conference anniversary of the birth of Jan Łukasiewicz, Rzeszów, Poland.

The paper examines the interplays between logic and politics in the Polish School of Logic starting from 1914. The Polish School of Logic flourished between 1920 and 1939. Philosophically, it was influenced by Kazimierz Twardowski (1866–1938). For Twardowski logic is fundamental for every kind of human activity, professional and private and this means that every argument should be formulated and proceed by correct inferential rules. These rules involve semiotics, formal logic and methodology of science. The paper shows how this position (...) was shared by Twardowski’s students, including Jan Łukasiewicz, Stanisław Leśniewski, Kazimierz Ajdukiewicz and Tadeusz Kotrabiński, as well as by the next generation of logicians and philosophers and especially by Alfred Tarski. These authors considered logic, philosophy and science as completely neutral with respect to politics and ideology but they also considered logical skills as indispensable in political activities. (shrink)

Formal semantics is understood either as a formal analysis of semantical features of natural language or as model‐theoretic semantics of formal languages. This paper focuses on the second understanding. The problem is how to identify the formal aspects of formal semantics, if we understand ‘formal’as ‘independent of content’. This is done by showing that the form of semantical interpretation of a language L is given by its syntax and the parallelism of the signature of L and its interpretative structure SI. (...) However, the content of interpretation, that is, the way of correlating of L‐expressions with extralinguistic items depends of informal factors. The discussion shows that semantics is prior to syntax. (shrink)

The larger part of Yearbook 6 of the Institute Vienna Circle constitutes the proceedings of a symposium on Alfred Tarski and his influence on and interchanges with the Vienna Circle, especially those on and with Rudolf Carnap and Kurt Gödel. It is the first time that this topic has been treated on such a scale and in such depth. Attention is mainly paid to the origins, development and subsequent role of Tarski's definition of truth. Some contributions are primarily historical, others (...) analyze logical aspects of the concept of truth. Contributors include Anita and Saul Feferman, Jan Wolenski, Jan Tarski and Hans Sluga. Several Polish logicians contributed: Gzegorczyk, Wójcicki, Murawski and Rojszczak. The volume presents entirely new biographical material on Tarski, both from his Polish period and on his influential career in the United States: at Harvard, in Princeton, at Hunter, and at the University of California at Berkeley. The high point of the analysis involves Tarski's influence on Carnap's evolution from a narrow syntactical view of language, to the ontologically more sophisticated but more controversial semantical view. Another highlight involves the interchange between Tarski and Gödel on the connection between truth and proof and on the nature of metalanguages. The concluding part of Yearbook 6 includes documentation, book reviews and a summary of current activities of the Institute Vienna Circle. Jan Tarski introduces letters written by his father to Gödel; Paolo Parrini reports on the Vienna Circle's influence in Italy; several reviews cover recent books on logical empiricism, on Gödel, on cosmology, on holistic approaches in Germany, and on Mauthner. (shrink)

The book provides a historical and systematic exposition of the semantic theory of truth formulated by Alfred Tarski in the 1930s. This theory became famous very soon and inspired logicians and philosophers. It has two different, but interconnected aspects: formal-logical and philosophical. The book deals with both, but it is intended mostly as a philosophical monograph. It explains Tarski’s motivation and presents discussions about his ideas as well as points out various applications of the semantic theory of truth to philosophical (...) problems. (shrink)

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)

Józef M. Bocheński began his philosophical career as an eclectic philosopher, then switched to Thomism and finally became a representative of the analytic school. As a Thomist he wanted to reform this orientation by the resources of modern formal logic. This tendency culminated in the establishment of the Cracow Circle (established in 1936) whose members were Bocheński, Jan F. Drewnowski, Jan Salamucha, and Bolesław Sobociński. However, the program of the Cracow Circle was rejected by most Thomists who considered traditional logic (...) as an entirely sufficient device of philosophy. Bocheński was very disappointed by this attitude of his Thomist fellows. His evolution toward analytic philosophy, free of any ideological pressure, can be regarded as his reaction to the conservatism of Thomism. (shrink)

Jan Woleński criticizes the ideology and politics of the catholic church. He thinks that Polish Catholicism turns out to be ideologically expansive, dogmatic, orthodox and arrogant. Unfortunately it is not open to non conventional streams, treating them as dangerous heresies. The so called new evangelization is nothing but the expression of the old catholic ideological expansionism.

This paper presents the life and work of Alfred Tarski, one of the most distinguished and influential logicians in the entire history.

Logical theory codifies rules of correct inferences. On the other hand, logical reasoning is typically considered as one of the most fundamental cognitive activities. Thus, cognitive science is a natural meeting-point for investigations about the place of logic in human cognition. Investigations in this perspective strongly depend on a possible understanding of logic. This paper focuses on logic in the strict sense; that is, the theory of deductive inferences. Two problems are taken into account, namely: do humans apply logical rules (...) in ordinary reasoning?; the genesis of logic. The second issue is analyzed from the naturalistic point of view. (shrink)

Ancien etudiant de Brentano et de Zimmerman, Kazimierz Twardowski, apres son election a la chaire de philosophie a Lvov en 1895, crea autour de lui un cercle d'etudiants et de collaborateurs exceptionnel, connu aujourd'hui sous le nom d'Ecole de Lvov-Varsovie. A mi-chemin entre Vienne et Cambridge, c'est a Lvov, et puis partiellement a Varsovie, que Jan Lukasiewicz, Stanislaw Lesniewski, Alfred Tarski, Kazimierz Ajdukiewicz, Tadeusz Kotarbinski et bien d'autres encore, repenserent dans un esprit d'analyse les questions fondamentales de la philosophie du (...) langage, de la logique, de la philosophie des sciences et des mathematiques. Plus qu'une simple traduction, ce livre est une version revisee de la monographie desormais classique que Jan Wolenski, connu pour ses travaux non seulement en histoire de la philosophie analytique, mais aussi en epistemologie et en theorie de la verite, a consacree a l'Ecole de Lvov-Varsovie. (shrink)

This volume is a result of the international symposium “The Tradition of the Lvov-Warsaw School in European Culture,” which took place in Warsaw, Poland, September 2015. It collects almost all the papers presented at the symposium as well as some additional ones. The contributors include scholars from Austria, the Netherlands, Ireland, and Poland. The papers are devoted to the history and reception of the Lvov-Warsaw School, a Polish branch of analytic philosophy. They present the School’s achievements as well as its (...) connections to other analytic groups. The contributors also show how the tradition of the School is developed contemporarily. The title will appeal to historians of analytic philosophy as well as historians of philosophy in Central Europe. (shrink)

This volume contains papers on truth, logic, semantics, and history of logic and philosophy. These papers are dedicated to Jan Wolenski to honor his 60th birthday. Jan Wolenski is professor of philosophy at the Department of Philosophy of the Jagiellonian University in Cracow, Poland. He is likely to be the most well-known Polish philosopher of this time, best known for his work on the history of the philosophy and logic of the Lvov-Warsaw School.

This paper investigates the concept of aletheia in ancient philosophy from the pre-Socratics until Aristotle. The meaning of aletheia in archaic Greek is taken as the starting point. It is followed by remarks about the concept of truth in the Seven Sages. The author discusses this concept as it appears in views and works of philosophers and historians. A special section is devoted to the epistemological and ontological understanding of truth. On this occasion, influential views of Heidegger are examined. The (...) paper is concluded by a review of various meanings of truth in Aristotle. (shrink)

The larger part of Yearbook 6 of the Institute Vienna Circle constitutes the proceedings of a symposium on Alfred Tarski and his influence on and interchanges with the Vienna Circle, especially those on and with Rudolf Carnap and Kurt Gödel. It is the first time that this topic has been treated on such a scale and in such depth. Attention is mainly paid to the origins, development and subsequent role of Tarski's definition of truth. Some contributions are primarily historical, others (...) analyze logical aspects of the concept of truth. Contributors include Anita and Saul Feferman, Jan Wolenski, Jan Tarski and Hans Sluga. Several Polish logicians contributed: Gzegorczyk, Wójcicki, Murawski and Rojszczak. The volume presents entirely new biographical material on Tarski, both from his Polish period and on his influential career in the United States: at Harvard, in Princeton, at Hunter, and at the University of California at Berkeley. The high point of the analysis involves Tarski's influence on Carnap's evolution from a narrow syntactical view of language, to the ontologically more sophisticated but more controversial semantical view. Another highlight involves the interchange between Tarski and Gödel on the connection between truth and proof and on the nature of metalanguages. The concluding part of Yearbook 6 includes documentation, book reviews and a summary of current activities of the Institute Vienna Circle. Jan Tarski introduces letters written by his father to Gödel; Paolo Parrini reports on the Vienna Circle's influence in Italy; several reviews cover recent books on logical empiricism, on Gödel, on cosmology, on holistic approaches in Germany, and on Mauthner. (shrink)

This paper reports some attempts undertaken in Poland in the 1930s to modernize Thomism by means of modern logic. In particular, it concerns J.M. Bocheski and J. Salamucha, the leading members of the CracowCircle. They attempted to give precise logical form to the Five Ways of Thomas Aquinas. Other works concerned the concept of transcendentals, the levels of abstraction, and the concept of essence.

This paper provides an interpretation of Father Bocheński’s saying “Beyond logic there is only nonsense.” He considered the battle against superstitions of various kinds as one of the most important intellectual and social duties. The phrase in itself suggests that logic is a weapon in the mentioned battle. Logic is understood broadly, that is, as semantics, formal logic and the methodology of science, and was considered by Bocheński as the main instrument of rational philosophy. Hence, the formula under discussion has (...) an explicit metaphilosophical significance, although Bochenski’s understanding of the concept of differs from that of the Vienna Circle. (shrink)

. This papers examines formal properties of logical squares and their generalizations in the form of hexagons and octagons. Then, several applications of these constructions in philosophical analysis are elaborated. They concern contingency (accidentality), possibility, permission, axiological concepts (bonum and malum), the generalized Hume thesis (deontic and epistemic modalities), determinism, truth and consistency (in various senses. It is shown that relations between notions used in various branches of philosophy fall into the same formal scheme.

Tadeusz Kotarbinski is one of towering figures in contemporary Polish philosophy. He was a great thinker, a great teacher, a great organizer of philosophical and scientific life, and, last but not least, a great moral authority. He died at the age of 96 on October 3, 1981. Kotarbinski was active in almost all branches of philosophy. He made many significant contributions to logic, semantics, ontology, epistemology, history of philosophy, and ethics. He created a new field, namely praxiology. Thus, using an (...) ancient distinction, he contributed to theoretical as well as practical philoso~hy. Kotarbinski regarded praxiology as his major philosophical "child". Doubtless, praxiology belongs to practical philosophy. This collection, howewer, is mainly devoted to Kotarbinski' s theoretical philosophy. Reism - Kotarbinski' s fundamental idea of ontology and semantics - is the central topic of most papers included here; even Pszczolowski' s essay on praxiology considers its ontological basis.,Only two papers, namely that of Zarnecka-Bialy and that of Wolenski, are not linked with reism. However, both fall under the general label "Kotarbinski: logic, semantics and ontology". The collection partly consists of earlier published papers. (shrink)

Popper's definition of verisimilitude was criticized for its paradoxical consequences in the case of false theories. The aim of this paper is to show that paradoxes disappear if the falsity content of a theory is defined with help of dCn or Cn –1.

This paper examines two arguments againstpsychologism advanced by Frege andHusserl. The first argument says that thelaws of logic cannot be justified by thelaws of psychology, because the formerand a priori and certain, but the latterare probable only. The second argumentpoints out that the status of logicallaws as universal principles of thinking isnot intelligible on the psychologisticinterpretation of logic. The author tries toshow how to examine both arguments bymetalogical devices.

Hence, the title The Heritage of Kazimierz Ajdukiewicz seems to reflect the general idea of this collection. Most papers collected here were specially ...