 Quine’s direct arguments against the distinction between logical and empirical truth (1963) have been found to beg the question against Carnap and his way of conceiving of philosophy (Creath 2003). This way of responding to Quine’s objection requires us to specify still more precisely just what Carnap thought he was doing when he employed the distinction between analytic and synthetic propositions. To be sure, in (1955) he gave broadly behavioural criteria for when meaning ascriptions could be deemed accepted in linguistic practice, but he also noted that this was not a general requirement for the acceptability of explicatory discourse. To repeat, explications did not seek to model natural language concepts in their tension-filled vividness, but to make proposals for future use and to extract and systematize certain aspects for constructive purposes. Thus Carnap clarified (1963b, §32) that he regarded the distinction between analytic and synthetic statements—just like the distinction between descriptive or factual and prescriptive or evaluative statements—not as descriptive of natural language practices, but as a constructive tool for logico-linguistic analysis and theory construction. It is difficult to overstress the significance of this stance of Carnap’s for the evaluation of his version of the philosophical project of the Vienna Circle. Carnap’s understanding of philosophy has thus been aptly described as the “science of possibilities” (Mormann 2000). 