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)