 The programmatic impact of the distinction drawn here by Feigl between ‘logical positivism’ and ‘logical empiricism’ might be doubted (see Uebel 2013). However, in order to adequately understand the line of Feigl’s philosophical development, the distinction is quite apt. Thus, in the first instance, it was the liberalization of the logical positivist criterion of meaning which caused a shift in Feigl’s general philosophical outlook. According to the early, logical positivist, conceptions of language and science, the meaning of a proposition must be anchored in observable facts. More precisely, the meaning of a given proposition is entirely exhausted by its verification on a purely observational basis. Yet it turned out, as a major consequence of the Vienna Circle’s protocol-sentence debate (see Uebel 2007), that this criterion was far too strict. Direct verifiability was (by Carnap, Hempel, and others) substituted through weaker criteria such as (at least indirect) testability (see Carnap 1936/37) or confirmability and disconfirmability (see Hempel 1935; 1945; 1950a). Nevertheless, the logical positivists’ rejection of metaphysics remained quintessentially intact. As Feigl points out in a paper titled “Scientific Method without Metaphysical Presuppositions” (1954), there are two senses in which the term ‘metaphysics’ appears objectionable also from the liberalized, logical empiricist, perspective; namely a) the assertion of transcendent, i.e., in principle untestable statements, and b) the belief in factual truths that could be validated a priori, i.e., in complete independence of the data of observation. In both cases, the realm of the meaningful is distinguished from these two objectionable regions.