 Even granted the model in outline, questions arise both concerning its observational base as well as its theoretical superstructure. We already discussed one aspect of the former topic, the issue of protocols, in the previous section; let’s here turn to the latter topic. Talk of correspondence rules only masks the problem that is raised by theoretical terms. One of the pressing issues concerns their so-called surplus meaning over and above their observational consequences. This issue is closely related to the problem of scientific realism: are there truth-evaluatable matters of fact for scientific theories beyond their empirical, observational adequacy? Even though the moniker “neo-positivism” would seem to prescribe an easy answer as to what the Vienna Circle’s position was, it must be noted that just as there is no consensus discernible today there was none in the Circle beyond certain basics that left the matter undecided.