Abstract

An examination of Carnap's Aufbau in the context of Schlick's Allgemeine Erkenntnislehre of ten years earlier, suggests that Carnap's focus there on the sign-relation (Zeichenbeziehung) is an effort to retrieve a verificationist account of the meaning of individual scientific statements from the abyss of meaning-holism entailed by Schlick's proposal that scientific concepts be implicitly defined. The Aufbau's antipodal aspects, its reductive phenomenalism and quasi-Kantian concern with the constitution of objectivity, are seen as complementary moments of the marriage of empiricism and a new emphasis on scientific concepts as "free creations of the human mind".