 Vienna became an international capital of psychological research while logical empiricism started to develop a scientific epistemology and an epistemology of science with normative demarcation goals. Freud’s psychoanalysis was more popular than J.B. Watson’s American behaviorism and Gestalt psychology was dominant neither in psychology nor scientific philosophy. The members of the Vienna Circle collectively adopted its framework of scientism and anti-metaphysics, of logic and empiricism, and aimed to select their intellectual allies and targets accordingly. Yet, individually, they tailored their considerations of the different sciences to their respective agendas, shifting projects and development. In the Vienna Circle manifesto, the official programmatic position was to point to the defects of much contemporary psychological language, plagued by metaphysical burden, conceptual imprecision and logical inconsistency. The emphasis on perception selected behaviorist psychology as intellectual ally consistent with the Circle’s scientific world-conception (Carnap, Hahn and Neurath 1929/1973, 314-5, Hardcastle 2007).