 This concession to the foundationalist misinterpretation of Vienna Circle philosophies generally must not, however, be taken to tell against the new reading of the Aufbau or the epistemologies developed from 1930 onwards on the physicalist wing of the Circle. In fact, the Aufbau itself fails when it is read as a foundationalist project, as it was by Quine (1951a) who pointed out that no eliminative definition of the relation ‘is at’ was provided (required for locating objects of consciousness in physical space). Yet other failures of reduction were detected by Richardson (1998, Ch.3), further questioning the Aufbau’s supposed foundationalist intent. Ultimately it was a still different failure of reduction that prompted Carnap to abandon as mistaken reconstructions of the scientific language on the basis of methodological solipsism (though not logical investigations of such languages for their own sake, as noted in his 1961a). Initially Carnap had not been prepared to draw this conclusion even though Neurath (1931b, 1932a) argued that such a type of rational reconstruction traded on objectionable counterfactual presuppositions (methodological solipsism did not provide a correct description of the reasoning involved in cognitive commerce with the world around us). At the time Carnap merely conceded that it was more “convenient” to reconstruct the language of science on a physicalistic basis (1932e). Only the failure of reducing dispositional predicates to observational ones convinced him to abandon the methodologically solipsist approach (1936–37, 464 and 10) and to adopt an exclusively physicalist basis for his reconstructions of the language of science from then on (a decision explicitly reaffirmed in 1963b).  Carnap’s initial reluctance to draw this conclusion is best interpreted, not as hankering after epistemological foundations, but as indicating the growing conviction that philosophical methodology had to be built on logical reasons and should not be “entangled with psychological questions” (1934/37, §72). Moreover, already Carnap’s initial hope for a phenomenalist reduction in the Aufbau as well as his decision in (1932e) to loosen the methodologically solipsist claim on epistemology were motivated by logical considerations, the former by mistaken ideas in Untersuchungen zur allgemeinen Axiomatik (2000, unpublished at the time) and the latter partly as a consequence of Gödel’s advice on a faulty definition of analyticity in a draft of Logical Syntax (see Ricketts 2010 and Awodey and Carus 2007 respectively).