Hans Vaihinger tried to explain how mathematical theories can be useful without being true or even coherent, arguing that mathematicians employ a special kind of fictional or “as if” reasoning that reliably extracts truths from absurdities. Moritz Pasch insisted that Vaihinger was wrong about the incoherence of core mathematical theories, but right about the utility of fictional discourse in mathematics. This essay explores this area of agreement between Pasch and Vaihinger. Pasch’s position raises questions about structuralist interpretations of mathematics.

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)

In this paper I investigate how intellectual problems concerning an epistemology of history and a historical view of knowledge played a role in the network of logical empiricist philosophers between 1930 and 1945. Specifically, I focus on the practical efforts of Hans Reichenbach and Otto Neurath to incorporate these intellectual stakes concerning history. I argue that Reichenbach was mainly concerned with creating more institutional space for scientific philosophy. Consequently, he was interested in determining his relation to historically oriented philosophy on (...) the practical level only. Otto Neurath, I claim, was interested in promoting an intellectual incorporation of an epistemology of history and a historical view of knowledge into the Unity of Science movement. His attempts, however, largely failed. I conclude that the intellectual stakes concerning history did have an effect within the network of logical empiricist philosophers, but that, by 1945 these stakes were entirely dissolved. The displacement of the network to the United States removed Reichenbach’s practical problems, while Neurath was unable to persuade enough actors before his death. (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)

Hans Vaihinger tried to explain how mathematical theories can be useful without being true or even coherent, arguing that mathematicians employ a special kind of fictional or "as if" reasoning that reliably extracts truths from absurdities. Moritz Pasch insisted that Vaihinger was wrong about the incoherence of core mathematical theories, but right about the utility of fictional discourse in mathematics. This essay explores this area of agreement between Pasch and Vaihinger. Pasch's position raises questions about structuralist interpretations of mathematics.

In this article, I seek to shed new light on a lesser-known stage of the development of Hans Reichenbach’s thought, namely his research, output and teaching activities at Istanbul University. I argue that the experience of Turkish exile was decisive in the elaboration of Reichenbach’s probability theory of meaning and knowledge. His work Experience and Prediction, produced while in Istanbul, should therefore be put in its Turkish context of elaboration and reception. To this end, I will take into consideration not (...) only Reichenbach’s efforts to popularize and extend the Berlin Group’s program of scientific philosophy in Turkey and throughout Europe in the 1930s, but also the forgotten work of Reichenbach’s students—most of them women—at Istanbul University. (shrink)

: Considerable unclarity exists in the literature concerning the origin and authorship of Wissenschaftliche Weltauffassung. Der Wiener Kreis, the Vienna Circle's manifesto of 1929 and on the extent of and the reasons for the mixed reception it received in the Circle itself. This paper reconsiders these matters on the light of so far insufficiently consulted documents.

Considerable unclarity exists in the literature concerning the origin and authorship of Wissenschaftliche Weltauffassung. Der Wiener Kreis, the Vienna Circle’s manifesto of 1929 and on the extent of and the reasons for the mixed reception it received in the Circle itself. This paper reconsiders these matters on the light of so far insufªciently consulted documents.

Ever since the first meeting of the proponents of the emerging Logical Empiricism in 1923, there existed philosophical differences as well as personal rivalries between the groups in Berlin and Vienna, headed by Hans Reichenbach and Moritz Schlick, respectively. Early theoretical tensions between Schlick and Reichenbach were caused by Reichenbach’s Kantian roots, who himself regarded the Vienna Circle as a sort of anti-realist “positivist school”—as he described it in his Experience and Prediction. One result of this divergence was Schlick’s preference (...) of Carnap over Reichenbach for a position at the University of Vienna, and his decision not to serve as a co-editor with Reichenbach for the journal Erkenntnis that they jointly established in 1930. A second split rooted in different views on induction and probability, which culminated in the Hans Reichenbach’s refusal to serve as an invited author on probability within the International Encyclopedia of Unified Science series ed. by Rudolf Carnap, Charles Morris and Otto Neurath from 1938 onwards. In this regard it is remarkable that also Richard von Mises, who was the second leading figure of Logical Empiricism in Turkish exile, criticized the theory of probability put forward by his former Berlin colleague. In this paper I analyse this controversial exchange, drawing on the relevant correspondence and asking whether these philosophical differences were a typical feature of the pluralism inherent in Logical Empiricism in general. (shrink)

Ever since the first meeting of the proponents of the emerging Logical Empiricism in 1923, there existed philosophical differences as well as personal rivalries between the groups in Berlin and Vienna, headed by Hans Reichenbach and Moritz Schlick, respectively. Early theoretical tensions between Schlick and Reichenbach were caused by Reichenbach's (neo) Kantian roots (esp. his version of the relativized a priori), who himself regarded the Vienna Circle as a sort of anti-realist "positivist school"—as he described it in his Experience and (...) Prediction (1938). One result of this divergence was Schlick's preference of Carnap over Reichenbach for a position at the University of Vienna (in 1926), and his decision not to serve as a co-editor with Reichenbach for the journal Erkenntnis that they jointly established in 1930 (which was then co-edited by Carnap and Reichenbach from 1930 to 1938). A second split rooted in different views on induction and probability, which culminated in the Hans Reichenbach's refusal to serve as an invited author on probability within the International Encyclopedia of Unified Science series ed. by Rudolf Carnap, Charles Morris and Otto Neurath from 1938 onwards. In this regard it is remarkable that also Richard von Mises, who was the second leading figure of Logical Empiricism in Turkish exile, criticized the theory of probability put forward by his former Berlin colleague. In this paper I analyse this controversial exchange, drawing on the relevant correspondence and asking whether these (meta) philosophical differences were a typical feature of the pluralism inherent in Logical Empiricism in general. (shrink)