 However, Feigl’s mature conception of a synthesis of scientific realism and logical empiricism is to be found in his 1950 article “Existential Hypotheses” (published in Philosophy of Science). There, it was semantics which served as the vehicle for Feigl’s promotion of the realist project. By ‘semantics,’ Feigl meant (in a nutshell) the formal scrutiny of reference and truth (see Feigl 1950a, p. 36). As such, it had nothing to do with the concrete methods of testing hypotheses. Rather, “semantic realism,” as Feigl pointed out at another place, “is concerned only with the most abstract and formal features of the semiotic situation” (1950b, p. 192). This implied, in particular, that a) reference must be sharply distinguished from evidence, and that b) truth must be sharply distinguished from verification. It was on this basis that Feigl saw himself in a position to avoid “the reductive fallacies of phenomenalism” (1950a, p. 35). By the “reductive fallacies of phenomenalism,” he meant the logical constructionist accounts of Bertrand Russell (1914) and the early Carnap (1928). In Russell’s and Carnap’s view, the theoretical statements of the empirical sciences were, at least according to Feigl, “considered as translatable into statements concerning the data of direct experience” (1950a, p. 35). This conception was, in Feigl’s eyes, “fallacious” because the assumption of complete translatability was, he thought, semantically misguided. Theoretical sentences should be invested with what Feigl called their (so to say ‘untranslatable’) “surplus meaning.” This surplus meaning he considered to consist in the “factual reference” of theoretical terms (ibid., p. 48). More concretely, Feigl was convinced that terms like ‘atom,’ ‘force,’ or ‘electromagnetic field’ cannot be reduced to purely observational terms describing our direct experiences. Rather, theoretical terms were supposed to refer to unobservable, mind-independent entities, so that, for example, the referent of the term ‘atom’ would be real atoms and not samples of ‘logical constructions’ out of sense data (or other kinds of directly perceivable things). Therefore, Feigl urged that “we must distinguish between the radical empiricist’s meaning of ‘meaning’ (i.e., epistemic reduction) and another, more common-sensical meaning of ‘meaning’ (factual reference)” (ibid., p. 49).