 All that said by way of embedding the Vienna Circle’s philosophy in its time, one must also ask whether its members understood their own position correctly. Here one issue in particular has become increasingly prominent and raises questions that are of importance for philosophy of science still today. That is whether, after all, logical empiricism did have the resources to understand correctly the then paradigm modern science, the general theory of relativity. According to the standard logical empiricist story (Schlick 1915, 1917, 1921, 1922), their theory conclusively refuted the Kantian conception of the synthetic a priori: Euclidean geometry was not only one geometry amongst many, it also was not the one that characterized empirical reality. With one of its most prominent exemplars refuted, the synthetic a priori was deemed overthrown altogether. As noted, Schlick convinced the young Reichenbach to drop his residually Kantian talk of constitutive principles and speak of conventions instead. Likewise Schlick rejected efforts by Ernst Cassirer (see his 1921, developing themes from his 1910) to make do with a merely relative a priori in helping along scientific self-reflection. Even though much later, and on the independent grounds of quantum physics, Frank attested to the increased proximity of his and Cassirer’s understanding of scientific theories (1938), Schlick’s disregard of Cassirer’s efforts remains notable.