The Vienna Circle articulated a philosophical vision, the “scientific world-conception,” that combined logic and an appreciation for science to ‘overcome’ metaphysics. Members of the Circle viewed their work as explicitly political; their goal was to increase international understanding to prevent tragedies like World War I from happening again, to alleviate suffering, and to reform society. As fascism rose in Europe, several members of the Circle emigrated to the USA, where the political scientific world-conception slowly transformed into apolitical analytic philosophy. The debate about why this happened centers on whether it was due to McCarthyism, or to other factors like the particular personalities of those who emigrated, or the desire to win money from the NSF and the DoD.
To shed light on this question, I will examine the case of Feigl, which is particularly interesting because he was the first Circle member to emigrate to the USA in 1931, a time when left-wing political groups were more prominent in America than they would be post-War. Moreover, because his career spans both the pre- and post-war periods, and because was quite successful in mid-Century philosophy, he also presents a case of a politically-active Circle member who adapted well to his new environment. This talk will present his activity, including his interactions with the American Unitarian Society and the American Humanist Association, and their relation to the politicized understanding of Logical Empiricism.

Alfred Tarski (1901–1983) and Heinrich Scholz (1884–1956) were prominent figures working in mathematical logic. They were in contact by letters between 1938 and 1953, as we know from correspondence found in a collection called Nachlass Scholz (Münster, Germany). It contains eight letters written by Tarski and nine copies of letters written by Scholz. One of the letters was sent to a Polish logician, A. Mostowski, via Scholz. At least five of Scholz's and two Tarski’s letters have been lost.
Only excerpts from Tarski’s three letters to Scholz have been published. My aim is to inform about the content of the unknown correspondence, which could help reconstruct their biographies and the development of mathematical logic in Poland, Germany and the USA (since 1939, Tarski lived in the USA).
Some topics from the letters:
Academic cooperation: Tarski made 15 remarks on Scholz’s student H.Hermes’s unpublished work Semiotik (1938); early version of Tarski’s Calculus of Relation, later published as On the Theory of Relation.
Prospects for publications, future publishing plans: since 1941, an English edition of Tarski’s concept of truth had been considered.
Current research topics: Decision problem, Boole Algebra, completeness of mathematical theories, calculus of relations, topology.
Organization of the scholarly environment: Tarski promised to read a work of Scholz’s Chinese student Hu Shihua (1912–1960); Tarski’s doctor-students L.Chin, J.Robinson were also in letter contact with Scholz.
Academic trips: Scholz refused to stay as a visiting professor in Berkeley (1950); Tarski’s lecture on Relation Algebra in Münster (1953).

This essay begins by discussing a change that has influenced the basis and justification of several philosophical proposals of the last century, especially in the philosophy of science: Some assumptions and arguments, traditionally based on previous philosophical proposals, have been finding a place also in theses and proposals of physics. Physics is a science that has detached from natural philosophy since it has developed its concepts independently, and has worked based on its own methods. As a discipline, physics is highly reliable, so it is understandable that, in philosophy, physics is taken as a source of examples and that its theses are used as a starting point and argumentative tool. However, when thinking about philosophical problems from physics, challenges arise in the difficulty of recognizing certain problems present in physics, which has to do with the assumptions and concessions that have to be granted due to the things we do not know about physical reality. In addition, there is a profound inability of professional philosophers to assimilate the physical thesis adequately. This paper presents some of these problems by analyzing a case: experimental realism. We will see three methodological problems present in experimental realism, which can easily be repeated in other philosophical proposals based on physics: 1) the lack of fairly defined categories that allow the adequate incorporation of physical concepts into philosophical reasoning, 2) the lack of distinction between the interpretation of an experiment and physical reality, and 3) the inconsistency about what is considered "real".