 To see a striking example, consider their overarching conceptions of philosophy itself. Some protagonists retained the idea that philosophy possessed a separate disciplinary identity from science and, like Schlick, turned philosophy into a distinctive, albeit non-formal activity of meaning determination. Others, like Carnap, agreed on the distinction between philosophy and science but turned philosophy into a purely formal enterprise, the so-called logic of science. Still others went even further and, like Neurath under the banner of “unified science”, also rejected philosophy as a separate discipline and treated what remained of it, after the rejection of metaphysics, as its partly empirical meta-theory, to be set beside the logic of science. With Schlick, then, philosophy became the activity of achieving a much clarified and deepened understanding of the cognitive and linguistic practices actually already employed in science and everyday discourse. By contrast, for Carnap, philosophy investigated and reconstructed existing language fragments, developed new logico-linguistic frameworks and suggested possible formal conventions for science, while, for Neurath, the investigation of science was pursued by an interdisciplinary meta-theory that encompassed empirical disciplines, again with a pragmatic orientation. Thus we find in apparent competition different conceptions of post-metaphysical philosophy: the projects of experiential meaning determination, of formal rational reconstruction and of naturalistic explications of leading theoretical and methodological notions. (For roughly representative early essay-length statements of their positions see Schlick 1930, Carnap 1932a and Neurath 1932a; later restatements are given in Schlick 1937, Carnap 1936b and Neurath 1936b.) In the more detailed discussions below these differences of overall approach will figure repeatedly (see also section 3.6 below).