Do the terms “logical positivism” and “logical empiricism” mark a philosophically real and significant distinction? There is, of course, no doubt that the first term designates the group of philosophers known as the Vienna Circle, headed by Moritz Schlick and including Rudolf Carnap, Herbert Feigl, Philipp Frank, Hans Hahn, Otto Neurath, Friedrich Waismann and others. What is debatable, however, is whether the name “logical positivism” correctly distinguishes their doctrines from related ones called “logical empiricism” that emerged from the Berlin Society (...) for Scientific Philosophy around Hans Reichenbach which included Walter Dubislav, Kurt Grelling, Kurt Lewin and a young Carl Gustav Hempel.1 The .. (shrink)

One of the key events in the relations between the Central European philosophers and those of the Nordic countries was the Second International Congress for the ...

This paper deals with a relatively recent trend in the history of analytic philosophy, philosophical logic, and theory of science: the philosophical study of the role of inconsistency in empirical science. This paper is divided in three sections that correspond to the three types of inconsistencies identified: (i) factual, occurring between theory and observations, (ii) external, occurring between two mutually contradictory theories, and (iii) internal, characterising theories that entail mutually contradictory statements.

This paper investigates how the doctrine of the epistemological given—long associated with empiricism and positivism and also informing Carnap’s first major work in 1928—was challenged and overcome by Neurath and Carnap in subsequent years. Particular attention is paid to the controversial issue of how precisely the dialectic between Neurath and Carnap played out: whether Neurath’s argumentation correctly engaged with Carnap’s actual positions, whether Carnap’s change of positions in turn fully engaged with Neurath’s challenge, and what all this may tell us (...) about the compatibility of their philosophical projects. (shrink)

In the late 1930s, a few years before the start of the Second World War, a small number of European philosophers of science emigrated to the United States, escaping the increasingly perilous situation on the continent. Among the first expatriates were Rudolf Carnap and Hans Reichenbach, arguably the most influential logical empiricists of their time. In this two-part paper, I reconstruct Carnap’s and Reichenbach’s surprisingly numerous interactions with American academics in the decades before their move in order to explain the (...) impact of their arrival in the late 1930s. This second part traces Reichenbach’s development and focuses on his frequent interactions with American academics throughout the 1930s. I show that Reichenbach was quite ignorant about developments in Anglophone philosophy in the first stages of his career but became increasingly focused on the United States from the late 1920s onwards. I reconstruct Reichenbach’s efforts to find a job across the Atlantic and show that some of his English publications—most notably Experience and Prediction—were attempts to change the American narrative about logical empiricism. Whereas U. S. philosophers identified scientific philosophy with the views of the Vienna Circle, Reichenbach aimed to market his probabilistic philosophy of science as a subtler alternative. (shrink)

In the years before the Second World War, Rudolf Carnap and Hans Reichenbach emigrated to the United States, escaping the quickly deteriorating political situation on the continent. Once in the U. S., the two significantly changed the American philosophical climate. This two-part paper reconstructs Carnap’s and Reichenbach’s surprisingly numerous interactions with American academics in the decades before their move in order to explain the impact of their arrival in the late 1930s. Building on archival material of several key players and (...) institutions, I take some first steps toward answering the question why logical empiricism became so successful in the United States after the War. This first part reconstructs Carnap’s development between 1923, when he first visited New York, and 1936, when he was offered a position at the University of Chicago. I describe Carnap’s first substantive contacts with American philosophers as well as the events leading up to his decision to emigrate. In addition, I argue that some of Carnap’s work from the mid-1930s—in particular “Testability and Meaning”—can be better understood if we take into account his attempts to correct the American narrative about logical positivism and his increasingly desperate efforts to find a position in the United States. (shrink)

This paper deals with a relatively recent trend in the history of analytic philosophy, philosophical logic, and theory of science: the philosophical study of the role of inconsistency in empirical science. This paper is divided in three sections that correspond to the three types of inconsistencies identified: (i) factual, occurring between theory and observations, (ii) external, occurring between two mutually contradictory theories, and (iii) internal, characterising theories that entail mutually contradictory statements.

This dissertation offers a proof of the logical possibility of testing empirical/factual theories that are inconsistent, but non-trivial. In particular, I discuss whether or not such theories can satisfy Popper's principle of falsifiablility. An inconsistent theory Ƭ closed under a classical consequence relation implies every statement of its language because in classical logic the inconsistency and triviality are coextensive. A theory Ƭ is consistent iff there is not a α such that Ƭ ⊢ α ∧ ¬α, otherwise it is inconsistent. (...) We say, instead, that Ƭ is non-trivial iff there is at least one α such that Ƭ ⊢ α, otherwise we say that it trivial. This happens because classical logic satisfies the principle of explosion, according ex contradictione sequitur quodlibet (from a contradiction anything follows). Under these conditions inconsistent classical theories would be compatible with any well-formed formula, which makes them useless for science. There are, however, so-called paraconsistent logics in which the principle of explosion does not generally hold and in which a theory can be (simply) inconsistent, but also absolutely consistent. It is in this logical framework that we can prove that some inconsistent theories can be falsifiable. (shrink)

Verificationism has had a bad press for many years. The view that the meaning of our words is bound up with the discernible difference it would make if what we say, think or write were true or false, nowadays is scorned as “positivist” though it was shared by eminent empiricists and pragmatists. This paper seeks to sort through some of the complexities of what is often portrayed as an unduly simplistic conception. I begin with an overview of its main logical (...) empiricist varieties before considering which aspects of it fall victim to which of the three major types of objection that have been raised against it. I will conclude that what is left standing is a modest proposal that seems worth further investigation. (shrink)

Im Zentrum dieses Bandes stehen die Beiträge einer Tagung, die im Oktober 2017 an der Universität Konstanz stattgefunden hat. Thema der Tagung war ein den historischen Kontext einbeziehender Blick auf den frühen Rudolf Carnap, vom Ende des Ersten Weltkriegs bis zur Emigration Ende 1935. Der 1891 in Ronsdorf bei Wuppertal geborene Rudolf Carnap entschloss sich erst relativ spät zu einer Karriere als akademischer Philosoph, nämlich 1920, nachdem er sein durch den Krieg unterbrochenes Studium der Physik und Philosophie in Jena und (...) Freiburg abgeschlossen und kurze Zeit überlegt hatte, als Lehrer in der Schulreform-Bewegung zu arbeiten. Es folgte die philosophische Promotion im Jahr 1921, bei Bruno Bauch in Jena, mit einer Doktorarbeit zum Raumproblem. 1923 organisierte Carnap, gemeinsam mit Hans Reichenbach und anderen, eine für die Entstehung des Logischen Empirismus bedeutsame kleine Tagung in Erlangen. Auf Einladung von Moritz Schlick habilitierte er sich 1926 an der Universität Wien und verbrachte die Zeit bis 1931 zumindest teilweise in Wien, als eines der Kernmitglieder des Wiener Kreises um Moritz Schlick. Seine Habilitationsschrift erschien 1928 unter dem Titel Der logische Aufbau der Welt (hier immer Aufbau). 1931 folgte Carnap einem Ruf an die Deutsche Universität Prag. In den darauffolgenden Jahren blieb aber der enge Kontakt mit Wien und dem Wiener Kreis erhalten. Carnaps hauptsächliche Arbeit in dieser Zeit war seinem zweiten großen Buchprojekt gewidmet, der 1934 publizierten Logischen Syntax der Sprache. Daneben verfasste Carnap in seiner Zeit in Wien und Prag auch zahlreiche Aufsätze, zu unterschiedlichen Aspekten der Logik, der Metaphysikkritik und der Wissenschaftstheorie. Er war Mitautor des Manifests Wissenschaftliche Weltauffassung: Der Wiener Kreis und nahm regen Anteil an den zahlreichen wissenschaftlichen Aktivitäten des Logischen Empirismus, von der Gründung der Zeitschrift Erkenntnis bis hin zum Projekt einer Enzyklopädie der Einheitswissenschaft. Spätestens ab 1933 musste Carnap jedoch feststellen, dass an eine weitere wissenschaftliche Karriere in dem von Faschismus und Nationalsozialismus geprägten politischen Klima in Kontinentaleuropa nicht zu denken war. Er strebte deshalb die Emigration ins englischsprachige Ausland an, die schließlich Ende 1935 gelang, als Carnap ein Angebot von der Universität Chicago erhielt. Obwohl Carnap nur den kleineren Teil der in diesem Band abgedeckten eineinhalb Jahrzehnte in Wien verbracht hat, widmet sich der Großteil der hier versammelten Beiträge schwerpunktmäßig der für Carnaps philosophische Karriere zentralen Wiener Zeit. (shrink)

Contrary to a common opinion, some theses of scientific anarchism are historically connected not only to Popper's and "second" Wittgenstein's thoughts, but also to some ideas affirmed by the advocates of "physicalism" (like Neurath) during the neopositivistie debate on protocol sentences. The common basis of "physicalism" and "anarchism" is a repulse of the "atomistic" theory of meaning. That is making more adequate the epistemological description of knowledge. But both Neurath and Feyerabend err in thinking that this repulse entails a conception (...) of "truth" as "coherence" instead of "correspondence". Against such a conviction the "realistic" requirement expressed by SchHck through the concept of "Konstatiemng" is still very valid. (shrink)

El Positivismo Lógico a menudo ha sido presentado como una corriente filosófica monolítica obviando las profundas disensiones que hubo en su seno. El presente artículo pretende corregir esta visión. Los dos primeros apartados de este artículo describen la constitución del movimiento y los elementos supuestamente nucleares de la concepción filosófica positivista. El tercer apartado discute las discrepancias sobre el papel de la filosofía entre los autores más representativos del movimiento. Para concluir se sugiere que la vigencia del legado positivista reside (...) no tanto en alguna tesis filosófica en particular, sino más bien en su compromiso metafilosófico con valores como la precisión y la claridad. (shrink)

The "standard account" of Wittgenstein’s relations with the Vienna Circle is that the early Wittgenstein was a principal source and inspiration for the Circle’s positivistic and scientific philosophy, while the later Wittgenstein was deeply opposed to the logical empiricist project of articulating a "scientific conception of the world." However, this telegraphic summary is at best only half-true and at worst deeply misleading. For it prevents us appreciating the fluidity and protean character of their philosophical dialogue. In retrospectively attributing clear-cut positions (...) to Wittgenstein and his interlocutors, it is very easy to read back our current understanding of familiar distinctions into a time when those terms were used in a much more open-ended way. The paper aims to to provide a broader perspective on this debate, starting from the protagonists’ understanding of their respective positions. Too often, the programmatic statements about the nature of their work that are repeated in manifestoes, introductions, and elementary textbooks have occupied center stage in the subsequent secondary literature. Consequently, I focus on a detailed examination of a turning point in their relationship. That turning point is Wittgenstein's charge, in the summer of 1932, that a recently published paper of Carnap's, "Physicalistic Language as the Universal Language of Science", made such extensive and unacknowledged use of Wittgenstein's own ideas that Wittgenstein would, as he put it in a letter to Schlick, "soon be in a situation where my own work shall be considered merely as a reheated version or plagiarism of Carnap’s." While the leading parties in this dispute shared a basic commitment to the primacy of physicalistic language, and the view that all significant languages are translatable, there was a remarkable lack of mutual understanding between them, and deep disagreement about the nature of the doctrines they disputed. Three quarters of a century later, we are so much more conscious of the differences that separated them than the points on which they agreed that it takes an effort of historical reconstruction to appreciate why Wittgenstein once feared that his own work would be regarded as a pale shadow of Carnap’s. (shrink)

Otto Neurath's thesis concerning the structure of protocol sentences is central to the famous Protocol Sentence Debate in the Vienna Circle. However, its precise nature is far from easy to discern in Neurath's writings. So far, only Thomas Uebel has attempted a closer analysis of Neurath's contribution to the debate. I argue that Uebel's interpretation is problematic in some respects and propose a novel analysis, which hopefully brings into a clearer light Neurath's position in the Protocol Sentence Debate as well (...) as his relevance to contemporary philosophies of science. (shrink)

Carnap’s work was instrumental to the liberalization of empiricism in the 1930s that transformed the logical positivism of the Vienna Circle to what came to be known as logical empiricism. A central feature of this liberalization was the deployment of the Principle of Tolerance, originally introduced in logic, but now invoked in an epistemological context in “Testability and Meaning”. Immediately afterwards, starting with Foundations of Logic and Mathematics, Carnap embraced semantics and turned to interpretation to guide the choice of a (...) theoretical language for science. The first thesis of this paper is that recourse to an intended interpretation led to a partial retrenchment of the conventionalism implied by the Principle of Tolerance. It required that the choice of a language be based on abstraction from a context; this procedure later became a component of the process of explication that was distinctive to Carnap’s mature views. The interpretive origin of formal systems also ensured their likely syntactic consistency, an issue on which Carnap was strongly criticized by figures such as Beth and Gödel. The second thesis of this paper is that this reliance on an intended interpretation enabled constructed formal systems to be relevant to the development of empirical science. (shrink)

I examine the thesis that Otto Neurath anticipated the programme of naturalised epistemology already at the time of the Vienna Circle and consider the relation between Neurath's proposals and those of two contemporary theorists whose research programmes he would thus have broadly anticipated. The thesis is confirmed by reference to Neurath's own writings. The connection between Neurath's programme and the programmes of his two successors considered here, however, is found to be highly indirect in one case and nonexistent in the (...) other — despite their undeniable overlap. (shrink)

Hartry Field has argued that Alfred Tarski desired to reduce all semantic concepts to concepts acceptable to physicalism and that Tarski failed to do this. In the two succeeding decades, Field has been charged with being too lenient with Tarski; but it has been almost universally accepted that an objection at least as strong as Field's is telling against Tarski's theory. Close examination of the relevant literature, most of it printed in this journal in the 1930s, reveals that Field's conception (...) of physicalism is anachronistic. Tarski did succeed in furthering the sort of physicalist program he had in mind. (shrink)