The Carnap/Neurath-Correspondence

The principal aim of this project is to produce an edition containing a more than representative selection of the scholarly correspondence between Rudolf Carnap and Otto Neurath. Rudolf Carnap (18911970) and Otto Neurath (18821945) were undoubtedly next to Moritz Schlick the dominant figures of the Vienna Circle. The close relationship and collaboration between both is mirrored in the enormous scale of the correspondence, which comprises a total of ca. 650 partly rather long letters. Because the correspondence is held by two different archives and there is no exact estate register for any of the holdings, no-one has been able to gain an accurate overview. Despite of this regrettable situation, the academic import of the correspondence is completely beyond dispute. The long-time prevailing view according to which the Vienna Cirlce is a uniform and philosophical naive movement has since been proved a cliché. Notwithstanding the common ground of scientific and anti-metaphysical stance, a closer look reveals fundamental differences even within the so-called Circles left wing, a position usually assigned even today to Carnap, Neurath, Philipp Frank, Hans Hahn and Edgar Zilsel. These differences and controversies have been completely ignored by the post-positivistic Philosophy of Science. This is in so far remarkable as Neurath himself anticipated much of the criticism that became popular quite later by the work of philosophers like Thomas Kuhn or Paul Feyerabend. In the letters, a great deal of attention is dedicated to issues like the development and historical position of logical empiricism, the structure of empirical knowledge, and above all the question of how to develop an empiricist, anti-metaphysical position. Some of the issues are discussed in the correspondence exclusively, concerning the publicity discussed issues the correspondence contains information about the connections of ideas, the motives of the authors and, generally speaking, the background to their philosophical viewpoints. This information is first hand and without the reserve usual in publications und therefore an indispensable source for understanding both authors as well as the development of the highly influential movement of logical empiricism in general. Furthermore, the correspondence sheds light on scientific as well as non- scientific backgrounds and settings, especially helps toward the history of emigration of science from central Europe in the thirtees. The project aims at the edition of a number (ca. 80) of letters selected according to comprehensible scientific criteria. Annotations of the editors will make this valuable philosophical and historical source accessible.

Rediscovery and re-evaluation of the Vienna Circle have been underway for some time, showing that the astonishing plurality within the movement of logical empiricism cannot be overlooked any longer. The project focussed on Rudolf Carnap (1891-1970) und Otto Neurath (1882-1945) and their relationship. Extremely close cooperation was intertwined with deep differences from the beginning. For strategic reasons, controversies are not stressed in their publications. The interaction, which lasted for two decades, till Neurath's sudden death, is above all documented in their correspondence, encompassing almost 600 letters. The value of this source, also for the development of the logical empiricist's movement as a whole, has been acknowledged by pertinent scholars for some time. By publishing the Carnap/Neurath-Correspondence, the project aimed at closing a gap painfully felt for a long time. Beyond the field of scientific philosophy, the correspondence also sheds light on the social, cultural, and political background of inter-war Central Europe as well as on the situation and difficulties of intellectual émigrés. As the most important result of the project now an edition of the correspondence is available on https://doi.org/10.48666/872268. This version meets the standards of a critical edition; each letter is supplemented by a short editorial report, critically edited and content-related commented (the latter not completely finalised yet). Annotations of the receiver are also considered. A printed edition of a selection of letters, to be published by Meiner, is in preparation. A second aim of the project, built on the edition task, has been to utilize the correspondence to shed light on the development of the respective conceptions, to state the differences in a profound way, and to contextualize them. This applies to central items like the emergence and the elaboration of physicalism, the protocol-sentence debate, the concept of truth, or the formation and historical classification of the logical empiricist's movement, which is already discussed by the authors themselves. The debates by letter of all these questions are mostly connected with the consideration of positions of contemporaries like Karl Popper, Bertrand Russell, Moritz Schlick, Alfred Tarski, and Ludwig Wittgenstein. In the course of the project, some of these issues have been discussed in the framework of single lectures, and within a minor symposium (at the large-scaled HOPOS-conference at Groningen 2018), above all at the project's main scientific event, the conference Ways of the Scientific World-View at Graz, September 2019 (proceedings are to appear). Already published are papers on the problem of realism in young Carnap's philosophy or on the relationship between the Vienna Circle and Wittgenstein.