 It must be noted, then, that the topics chosen for this article do not exhaust the issues concerning which the members of the Vienna Circle made significant contributions (which continue to stimulate work in the history of philosophy of science). Important topics like that of the theory and practice of unified science, of the nature of the empirical basis of science (the so-called protocol-sentence debate) and of the general structure of the theories of individual sciences can only be touched upon selectively. Likewise, while the general topic of ethical non-cognitivism receives only passing mentions, the Circle’s varied approaches to value theory cannot be discussed here (for an overview see Rutte 1986, for detailed analyses see Siegetsleitner 2014). Other matters, like the contributions made by Vienna Circle members to the development of probability theory and inductive logic, the philosophy of logic and mathematics (apart from the guiding ideas of Carnap) and to the philosophy of individual empirical sciences (physics, biology, psychology, social science), cannot be discussed at all (see Creath and Friedman 2007 and Richardson and Uebel 2007 for relevant essays with further references). But it may be noted that with his “logic of science” Carnap counts among the pioneers of what nowadays is called “formal epistemology”.