 It could likewise be asked concerning physicalism whether it represented, on a different basis, the pursuit of a foundationalist agenda. But that Carnap later in (1936/37) called his non-eliminative definitions of disposition terms “reduction sentences” already indicates that it was enough for him to provide a basis for the applicability of these terms by merely sufficient but not necessary conditions. Likewise, Carnap’s proposal (1939) to conceive of theoretical terms as defined by implicit definition in a non-interpreted language, selected terms of which were, however, linked via non-eliminative reductive chain to the observational language, suggests that what concerned him primarily was the capture of indicator relations to sustain in principle testability of statements containing the terms in question. This is best understood as an attempt to preserve the empirical applicability of the formal languages constructed for high-level theory, but not as reductivism with regard to some foundational given.