This paper re-contextualises Popper within a Kantian tradition by examining his interaction with the Vienna Circle. The complexity of Popper's relationship to the Vienna Circle is often a point of confusion as some view him as a member of the Vienna Circle while others minimise his association with this group. This paper argues that Popper was not a member of the Vienna Circle or a positivist but shared many neo-Kantian philosophical tendencies with the members of the Circle as well as (...) many of their philosophical problems and interests. By better understanding the influence of the Circle's members upon Popper, we not only remove the myths surrounding Popper's positivism, but also place the logical positivism of the Vienna Circle within its proper philosophical context. This paper further argues that it was Popper's friend during his formative philosophical years in Vienna, Julius Kraft (1921–1960) who was responsible for the way in which Popper approached Kant. Through Kraft, Popper was introduced to the thought of Leonard Nelson (1882–1927) and Jakob Fries (1773–1843) as well as a tradition of critical rationalism which Popper would continue both in his methodological orientation as well as through his late German Enlightenment intellectual values. (shrink)

I characterize the deductivist ideal of justification and, following to a great extent Toulmin’s work The Uses of Argument, I try to explain why this ideal is erroneous. Then I offer an alternative model of justification capable of making our claims to knowledge about substantial matters sound and reasonable. This model of justification will be based on a conception of justification as the result of good argumentation, and on a model of argumentation which is a pragmatic linguistic reconstruction of Toulmin’s (...) model of argument. (shrink)

This paper is about the topic of psychologism in the work of Kazimierz Twardowski and my aim is to revisit this important issue in light of recent publications from, and on Twardowski’s works. I will first examine the genesis of psychologism in the young Twardowski’s work; secondly, I will examine Twardowski’s picture theory of meaning and Husserl’s criticism in Logical Investigations; the third part is about Twardowski’s recognition and criticism of his psychologism in his lectures on the psychology of thinking; (...) the fourth and fifth parts provide an overview of Twardowski’s paper “Actions and Products” while the sixth part addresses the psychologism issue in the last part of this paper through the delineation of psychology and the humanities. I shall conclude this study with a brief assessment of Twardowski’s solution to psychologism. (shrink)

The Introduction outlines, in a concise way, the history of the Lvov-Warsaw School – a most unique Polish school of worldwide renown, which pioneered trends combining philosophy, logic, mathematics and language. The author accepts that the beginnings of the School fall on the year 1895, when its founder Kazimierz Twardowski, a disciple of Franz Brentano, came to Lvov on his mission to organize a scientific circle. Soon, among the characteristic features of the School was its serious approach towards philosophical studies (...) and teaching of philosophy, dealing with philosophy and propagation of it as an intellectual and moral mission, passion for clarity and precision, as well as exchange of thoughts, and cooperation with representatives of other disciplines.The genesis is followed by a chronological presentation of the development of the School in the successive years. The author mentions all the key representatives of the School (among others, Ajdukiewicz, Lesniewski, Łukasiewicz,Tarski), accompanying the names with short descriptions of their achievements. The development of the School after Poland’s regaining independence in 1918 meant part of the members moving from Lvov to Warsaw, thus providing the other segment to the name – Warsaw School of Logic. The author dwells longer on the activity of the School during the Interwar period – the time of its greatest prosperity, which ended along with the outbreak of World War 2. Attempts made after the War to recreate the spirit of the School are also outlined and the names of followers are listed accordingly. The presentation ends with some concluding remarks on the contribution of the School to contemporary developments in the fields of philosophy, mathematical logic or computer science in Poland. (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)

This volume examines the entire logical and philosophical production of Nikolai A. Vasil’ev, studying his life and activities as a historian and man of letters. Readers will gain a comprehensive understanding of this influential Russian logician, philosopher, psychologist, and poet. The author frames Vasil’ev’s work within its historical and cultural context. He takes into consideration both the situation of logic in Russia and the state of logic in Western Europe, from the end of the 19th century to the beginning of (...) the 20th. Following this, the book considers the attempts to develop non-Aristotelian logics or ideas that present affinities with imaginary logic. It then looks at the contribution of traditional logic in elaborating non-classical ideas. This logic allows the author to deal with incomplete objects just as imaginary logic does with contradictory ones. Both logics are objects of interesting analysis by modern researchers. (shrink)

The dominant theory of judgment in 1870 was one or other variety of combination theory: the act of judgment is an act of combining concepts or ideas in the mind of the judging subject. In the decades to follow a succession of alternative theories arose to address defects in the combination theory, starting with Bolzano’s theory of propositions in themselves, Brentano’s theory of judgment as affirmation or denial of existence, theories distinguishing judgment act from judgment content advanced by Brentano’s students (...) Twardowski, Husserl and Meinong, and finally, Adolf Reinach’s addition of a linguistic dimension to the Brentano-Husserlian theory of judgment – an account of judgments as ways of doing things with words in what Reinach called ‘social acts’. (shrink)

This paper traces the intellectual trajectories of the first stand-alone theories of action, understood as both axiologically neutral and quasi-scientific from a methodological point of view. I argue that the rise of action theory of this kind corresponds to a particular moment of dissatisfaction within Western thought, and as such, it tells us far more about the history of philosophy than the subject itself. I conclude by explaining why subsequent failures to provide an acceptable theory of action are not accidental. (...) On the contrary, such failures owe themselves probably to the fact that formulating a theory of action is neither propitious nor useful. Thus, the most valuable lesson we can learn from philosophical desires for a theory of action is that we should take co-action as the starting point in our normative investigations, rather than positing action simpliciter as a problem to solve. That is, we should move away from propounding a theory of action, and instead focus on a paradigm shift, whereby we move away from a representational, towards a co-actional, model of action. (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)

The short answer to this question is a firm and unambiguous “yes and no”. The long answer will take the whole talk. Indeed, it could easily take an entire book. It is therefore unavoidable to take recourse here and there to simplifying shortcuts and polemical exaggerations, in order to get the message clear.

I shall elaborate more on the idea of anti-irrationalism proposed by the Polish analytic philosopher Kazimierz Ajdukiewicz, a prominent member of the Lvov-Warsaw School of philosophy and logic. In my reading, anti-irrationalism stands in opposition not only to overt irrationalism, which is made clear by the term itself, but also to all forms of rationalism that tip toward something like worship of reason. Having characterized anti-irrationalism as it originally appeared in Ajdukiewicz’s works, I shall propose a certain reformulation of it, (...) so as to capture a broader philosophical legacy in Poland, primarily, yet not exclusively the Lvov-Warsaw School. (shrink)

Introduction to the special issue including papers about Susan Stebbing, Susanne Langer and Maria Kokoszyńska.

The aim of the paper is presentation and critical analysis of Kazimierz Ajdukiewicz’s concept of the world-view. Ajdukiewicz’s philosophy was strongly inspired by the rationalism of Kazimierz Twardowski as well as by some ideas of the Vienna Circle. However, in contrast to the latter's logical empiricism, Ajdukiewicz could be interpreted as holding that beliefs constituting our world-view have both logical value and cognitive content—they cannot be construed as mere expression of some emotions.

Ajdukiewicz’s account of mathematical theories is presented and analyzed. Theories consist of primary and secondary theorems. Theories go through three phases or stages: preaxiomatic and intuitive, axiomatic but intuitive, axiomatic and abstract, whereas the final stage takes two forms: definitional and formal. Each stage is analyzed. The role of the concepts of truth, evidence, consequence, and existence is examined. It is claimed that the second stage is apparent or transitory, whereas the initial and final stages are vital and constitute two (...) salient attitudes to mathematics, focused on truth or consequence respectively. It is also claimed they are attitudes rather than stages, and the crucial difference between them concerns effectiveness. The chief question of philosophy of mathematics turns out to be to determine whether mathematical theories are assertive or hypothetical. (shrink)

In On the Content and Object of Presentations, Kasimir Twardowski presents an interesting line of thought concerning the content of a presentation and its relation to the object of that presentation. This way of thinking about content is valuable for understanding phenomenal intentionality, and it should also be important for the project of “naturalizing” the mental (or at least for discovering the neural correlates of the phenomenal). According to this view, content is that by virtue of which a presentation of (...) an object presents a certain object and no other. In the cases in which an object is presented as simple, there is nothing more that can be said about the relation of content and object. It is sui generis: the relation of content to an object by virtue of which it presents that object. Further, the content of a presentation is never itself directly presented. The content can only be gotten at indirectly, as the content by which such and such object is presented. Where the presented object is complex—as is of course the normal case—a lot that is useful can be said about the structure of the content. In this paper, I lay out Twardowski's theory of the content of presentations. Since the business of content is to present its object, I briefly present the basics of Twardowski's mereology of objects. (shrink)

A Norwegian translation is here offered of Eugenie Ginsberg’s paper «Zur Husserlschen Lehre von den Ganzen und den Teilen» (in Archiv für systematische Philosophie und Soziologie 32, 1929, 108–120). The paper discusses Husserl’s six theorems from Logical Investigations III, §14. Ginsberg provides new proofs for theorems 1 and 3, and also endorses theorem 5. In contrast, a counter example is given to theorems 2, 4, and 6: However, proofs are supplied for a modified version of these theorems. Furthermore, an additional (...) three theorems are defended based upon Ginsberg’s modified theorems. Also, a brief introduction is given discussing Ginsberg’s pioneering role as part of the Lvov-Warsaw school—in spite of her being murdered by the Nazis in 1942—especially her role as the first commentator on Husserl’s third logical investigations, which is a pioneering work on mereology and ontology; but also her later publication from 1931 where she developed several notions of ontological dependence (for instance foreshadowing the work of Roman Ingarden as well as Kit Fine). (shrink)

Although Łukasiewicz and Quine do not share many common views, they agreed on one important point in the 1950s: they both denied the distinction between empirical and a priori sciences. This agreement might be surprising as this denial was rather controversial at that time. This paper focuses on Quine’s and Łukasiewicz’s denials of the distinction between empirical and a priori sciences, and proposes three possible answers to the question of why both formulated the same conclusion at a similar time. Firstly, (...) it discusses Quine’s possible influence on Łukasiewicz as Łukasiewicz agreed with Quine’s criticism of modality at that time. Secondly, it considers the possibility that Quine was affected by Łukasiewicz via his debates with Łukasiewicz’s student, Tarski. Lastly, it takes into account the possibility that both philosophers were inspired by an external source, namely the rise of quantum mechanics. (shrink)

In the nineteenth century, philosophy was at a crossroads. While the natural and technical sciences were developing in an unprecedented fashion, philosophy seemed to be stalled. Inspired by the progress of the natural sciences, many philosophers attempted to make such progress in philosophy and make philosophy a truly scientific discipline. This effort was also reflected in the philosophy of the Lvov-Warsaw school. While its founder, Kazimierz Twardowski, following his teacher Franz Brentano, promoted psychology as a method of scientific philosophy, one (...) of his first students, Jan Łukasiewicz, was convinced that mathematical logic was such a method. To use mathematical logic as a tool, Łukasiewicz had to, however, argue convincingly that logic is an independent science and hence is not a part of psychology, i.e., arguing for anti-psychologism in logic. He initially adopted the arguments provided by Husserl, then celebrated as a proponent of anti-psychologism, and Frege’s views. When Łukasiewicz developed, however, his systems of many-valued logic, he denied almost all the principles that characterise Husserl and Frege’s anti-psychologism, i.e., the objectivity of the laws of logic, the existence of apodictic propositions, and the distinction between a priori and empirical sciences. He was, however, a proponent of anti-psychologism up to the end of his life. The aim of my paper is to introduce Łukasiewicz’s unique concept of anti-psychologism that significantly affected the views of mathematical logic in the Lvov-Warsaw School, and the views of his colleagues which helped him develop the concept. (shrink)

Arthur Prior was one of the logicians who participated in the invention of the possible worlds’ semantics. The ontology, which is connected with his systems of modal logic, is unique. Prior tried to reduce the number of abstract entities as much as possible. Hence he did not elect to introduce possible worlds and possibilia into his ontology. In addition, he held a reductionist view, which is called modal actualism by Fine or modalism by Melia. Prior was inspired by various authors (...) but this paper mainly discusses the influence of two prominent sources, Wittgenstein and logicians from Warsaw School. Prior acknowledged Wittgenstein’s influence, when he discuss the view that possible worlds consist of propositions. The second important feature of Prior’s concept is the denial of the real existence of possible worlds and the denial of the existence of entities which are in them. It was probably enabled by Prior’s adoption of some systems of logic invented by logicians from the Warsaw school, especially Lesniewski’s and Łukasiewicz’s systems. (shrink)

The paper is devoted to the discussion of some philosophical and historical problems connected with the theorem on the undefinability of the notion of truth. In particular the problem of the priority of proving this theorem will be considered. It is claimed that Tarski obtained this theorem independently though he made clear his indebtedness to Gödel’s methods. On the other hand, Gödel was aware of the formal undefinability of truth in 1931, but he did not publish this result. Reasons for (...) that are also considered. (shrink)

The aim of this paper is to show that it is the explicativecharacter of Tarski's semantic definition of truth given in his study of 1933 that allows forconsideration of a philosophical background of this definition in the proper sense. Given the explicativecharacter of this definition it is argued that the philosophical tradition that should be taken intoaccount with regard to this philosophical background is the tradition of the Lvov-Warsaw Schoolin its connections with the School of Brentano. As an example of (...) the explanatory power ofconsidering this tradition as far as Tarski's philosophical choices are concerned I use here thenotion of sentence-inscription, i.e., the notion of that entity of which truth is predicated inthe definition in question. One of the consequences of these statements is that philosophicaldiscussions concerning the semantic definition of truth can be regarded from two points ofview. On the one hand, they may take the perspective of its explicational function, i.e., theperspective of its philosophical background. On the other hand, they might consider the philosophicalconsequences of the definition with respect to the goal of the explication, i.e., they may considerits philosophical content independently of its historical background. (shrink)

Leśniewski’s metalogic is often considered to be difficult to understand because it differs greatly from its standard formulation. In this paper I try to explain the reasons of these idiosyncrasies. I claim that they have mainly two sources. First of all there is Leśniewski’s conviction that a formal system should be conceived as a set of concrete marks that can always physically and syntactically be expanded by the addition of new theses. Secondly there is Leśniewski’s conviction that definitions should neither (...) be formulas belonging to the metalanguage, nor deduction rules, but formulas belonging to the object-language and expressed with the help of the biconditional functor. The realisation of the first point is linked to the second one in so far as the metalinguistic rule for the writing out of definitions has to be formulated in a way that makes it possible to build the formal system in agreement with Leśniewski’s conception. While explaining these points I give an overview of the main peculiarities of Leśniewski’s metalogic. (shrink)

The article explores the following question: which among the most often examined in the literature method of constructing Hilbert-type axiom systems for finite-valued propositional logics of Łukasi...

The article concerns two axiom systems of Słupecki for the functionally complete three-valued propositional logic: W1–W6 and A1–A9. The article proves that both of them are inadequate—W1–W6 is semantically incomplete, on the other hand, A1–A9 governs a functionally incomplete calculus, and thus, it cannot be a semantically complete axiom system for the functionally complete three-valued logic.

This article presents the development of the phenomenological movement in Poland in the period 1895–1945. It focuses on the early reactions to phenomenology and the later consolidation of the group of phenomenologists in Lvov. The article also explores the context of Polish phenomenology, its main figures, and their texts. The author suggests that early phenomenology in Poland was a pluralistic discipline that developed in polemical discussions, including discussions with members of the Lvov–Warsaw school. Finally, the article summarizes the major contributions (...) of phenomenologists to philosophy, psychology, and aesthetics in Poland. (shrink)

Summary The article explores psychological motives in Leopold Blaustein’s philosophy. Blaustein was educated in Lvov, Freiburg im Breisgau and Berlin. In his original explorations, he attempted to connect a phenomenological perspective with descriptive psychology. As trained by Twardowski, he took over some motives of understanding the method of philosophy (psychology), its objectives and aims. The author situates Blaustein also in a dialogue with Stumpf and next to the context of Dilthey’s humanistic psychology is examined. Finally, the article explores the influences (...) of Gestalt psychology on Blaustein. The ultimate thesis of the article is that Blaustein’s method can be grasped as a phenomenologically oriented descriptive psychology. (shrink)

The aim of the article is to define and investigate an interpretative framework for the philosophy of Leopold Blaustein, a student of Twardowski in Lwów and Husserl in Freiburg im Breisgau. The author defends the thesis that it is justified to refer to Blaustein’s philosophy not as phenomenology sensu stricto, but as a phenomenologically-oriented descriptive psychology related but not equivalent to the project expounded by Husserl in the first edition of Logische Untersuchungen as well as in his project of phenomenological (...) psychology. The article traces Blaustein’s critique of Husserl’s phenomenological methods, putting it in the historical context of the discussion with Ingarden. Next, the author juxtaposes Blaustein’s understanding of psychology with Husserl’s project of 1925, which makes it possible to identify not only the differences between the two projects, but also their similarities. The article also raises questions about the scope of descriptive-psychological analyses. (shrink)

Tarski, Carnap and Quine spent the academic year 1940?1941 together at Harvard. In their autobiographies, both Carnap and Quine highlight the importance of the conversations that took place among them during the year. These conversations centred around semantical issues related to the analytic/synthetic distinction and on the project of a finitist/nominalist construction of mathematics and science. Carnap's Nachlaß in Pittsburgh contains a set of detailed notes, amounting to more than 80 typescripted pages, taken by Carnap while these discussions were taking (...) place. In my article, I present a survey of these notes with special emphasis on Tarski's rejection of the analytic/synthetic distinction, the passage from typed languages to first-order languages, Tarski's finitism/nominalism, and the construction of a finitist language for mathematics and science. (shrink)

Tadeusz Kotarbiski is widely recognized as a major philosopher of theLvov–Warsaw school. His reism, which is a contribution to semantics andontology, is still discussed and debated, and his most original creation, praxiology,has grown into an entire research field. However, Kotarbiski's philosophy ofscience has not received much attention by later commentators. This paper attemptsto correct this situation by considering the hypothesis that Kotarbiski succeededalready in 1929 in formulating a position that can be regarded as an early version ofscientific realism. Unlike most (...) other ``scientific philosophers'' before the mid-thirties,he was able to combine ontological realism (by defending a form of physicalism andnominalism) and semantical realism (by defending the classical correspondence theoryof truth). He was also a critical epistemological realist. Further, in spite of theinstrumentalist flavour of his reductionist programme in eliminating terms apparentlyreferring to abstract entities, Kotarbiski accepted theories as statements with truth values and theoretical entities as long as they can be understood as physical bodies. (shrink)

The paper is devoted to the presentation and analysis of the philosophical views concerning logic and mathematics of the leading members of Cracow Circle, i.e., of Jan Salamucha, Jan Franciszek Drewnowski and Józef Maria Bocheński. Their views on the problem of possible applicability of logical tools in metaphysical and theological researches is also discussed.

The aim of this paper is to present and discuss main philosophical ideas concerning logic and mathematics of a significant but forgotten Polish philosopher Benedykt Bornstein. He received his doctoral degree with Kazimierz Twardowski but is not included into the Lvov–Warsaw School of Philosophy founded by the latter. His philosophical views were unique and quite different from the views of main representatives of Lvov–Warsaw School. We shall discuss Bornstein’s considerations on the philosophy of geometry, on the infinity, on the foundations (...) of set theory and his polemics with Stanisław Leśniewski as well as his conception of a geometrization of logic, of the categorial logic and of the mathematics of quality. (shrink)

The thesis of the paper holds that some future developments of argumentation theory may be inspired by the rich logico-methodological legacy of the Lvov–Warsaw School (LWS), the Polish research movement that was most active from 1895 to 1939. As a selection of ideas of the LWS which exploit both formal and pragmatic aspects of the force of argument, we present: Ajdukiewicz’s account of reasoning and inference, Bocheński’s analyses of superstitions or dogmas, and Frydman’s constructive approach to legal interpretation. This paper (...) does not aim at exhaustive elaboration of any of these topics or their usefulness in current discussions within argumentation theory. Rather, we intend to indicate chosen directions of a potentially fruitful research program for the emerging Polish School of Argumentation which would consist in application of methods and conceptions elaborated by the LWS to selected open problems of contemporary research on argumentation. (shrink)

In this paper, we will explore two initiatives that focus on the importance of employing logical theories in educating people how to think and reason properly, one in Poland: The Lvov-Warsaw School; the other in North America: The Informal Logic Initiative. These two movements differ in the logical means and skills that they focus on. However, we believe that they share a common purpose: to educate students in logic and reasoning (logical education conceived as a process) so that they may (...) be able to apply their skills to analyze the issues in their society (logical culture as a result of logical education). The aim of the paper is to justify this claim by exploring research objectives and products that are common to both movements. (shrink)

The aim of the present study is (1) to show, on the basis of a number of unpublished documents, how Heinrich Scholz supported his Warsaw colleague Jan ?ukasiewicz, the Polish logician, during World War II, and (2) to discuss the efforts he made in order to enable Jan ?ukasiewicz and his wife Regina to move from Warsaw to Münster under life-threatening circumstances. In the first section, we explain how Scholz provided financial help to ?ukasiewicz, and we also adduce evidence of (...) the risks incurred by German scholars who offered assistance to their Polish colleagues. In the second section, we discuss the dramatic circumstances surrounding the ?ukasiewiczes' move to Münster in the summer of 1944. (shrink)

Special Issue: What is Analytic Philosophy.

In this paper we discuss whether the relation between formulas in the relating model can be directly introduced into the language of relating logic, and present some stances on that problem. Other questions in the vicinity, such as what kind of functor would be the incorporated relation, or whether the direct incorporation of the relation into the language of relating logic is really needed, will also be addressed.

The Polish logicians' propositional calculi, which consist in a distinct synthesis of the Fregean and Boolean approaches to logic, influenced W. V. Quine's early work in formal logic. This early formal work of Quine's, in turn, can be shown to serve as one of the sources of his holistic conception of natural language.

Maria Kokoszyńska-Lutmanowa was one of the most outstanding female representatives of the Lvov-Warsaw School. After achieving her PhD in philosophy under Kazimierz Twardowski’s supervision, she was Kazimierz Ajdukiewicz’s assistant. She was also influenced by Alfred Tarski whose results in semantics she analyzed and popularized. After World War II, she got the chair of logic in University of Wrocław and she organized studies in logic in this academic center. In the 1930s, Kokoszyńska kept in contact with members of the Vienna Circle (...) and became a kind of connecting factor between Polish logicians and the Viennese group. In Poland, she presented the views of members of the Vienna Circle. In Vienna, she emphasized the results of her Polish colleagues. In the present paper, some of Kokoszyńska’s results connected with the matters discussed in the Vienna Circle are presented, namely with the problem of metaphysics, the status of logic and the idea of unity of science. (shrink)

In the paper, Jan Łukasiewicz’s program of the logicization of philosophy is presented and discussed. Łukasiewicz, known mostly for his invention of trivalent logic as well as his achievements in propositional calculus and metalogic, had always been concerned with the methodological condition of philosophy. He finally found “the measure of exactness” in mathematical logic. According to him, only the use of logical tools may provide philosophical investigations with an appropriate level of exactness. He expressed his views most firmly and directly (...) in the paper, “A call for the method of Philosophy”. Łukasiewicz proposed giving philosophical theories the form of axiomatic systems by indicating the primitive terms of their language, selecting suitable axioms, and explicitly determining the applied rules of inference. All the theses of these systems should be consequences of the accepted axioms and confronted with the data of experience and the results of science. Łukasiewicz’s program is presented together with its inspirations and prospects. (shrink)

Leon Chwistek's 1924 paper ?The Theory of Constructive Types? is cited in the list of recent ?contributions to mathematical logic? in the second edition of Principia Mathematica, yet its prefatory criticisms of the no-classes theory have been seldom noticed. This paper presents a transcription of the relevant section of Chwistek's paper, comments on the significance of his arguments, and traces the reception of the paper. It is suggested that while Russell was aware of Chwistek's points, they were not important in (...) leading him to the adoption of extensionality that marks the second edition of PM. Rudolf Carnap seems to have independently rediscovered Chwistek's issue about the scope of class expressions in identity contexts in his Meaning and Necessity in 1947. (shrink)

Both through his own work and that of his students, Franz Clemens Brentano had an often underappreciated influence on the course of 20 th - and 21 st -century philosophy. _The Routledge Handbook of Franz Brentano and the Brentano School_ offers full coverage of Brentano’s philosophy and his influence. It contains 38 brand-new essays from an international team of experts that offer a comprehensive view of Brentano’s central research areas—philosophy of mind, metaphysics, and value theory—as well as of the principal (...) figures shaped by Brentano’s school of thought. A General Introduction serves as an overview of Brentano and the contents of the volume and three separate bibliographies point students and researchers on to further avenues of inquiry. Systematic and detailed, _The Routledge Handbook of Franz Brentano and the Brentano School_ provides readers with a valuable reference to Brentano’s work, and to his lasting importance in the history of philosophy and in contemporary debates. (shrink)