Value judgments are meaningless. This thesis was one of the notorious tenets of Carnap’s mature logical empiricism. Less well known is the fact that in the Aufbau values were considered as philosophically respectable entities that could be constituted from value experiences. About 1930, however, values and value judgments were banished to the realm of meaningless metaphysics, and Carnap came to endorse a strict emotivism. The aim of this paper is to shed light on the question why Carnap abandoned his originally positive attitude concerning values. It is argued that his non-cognitivist attitude was the symptom of a deep-rooted and never properly dissolved tension between conflicting inclinations towards Neokantianism and Lebensphilosophie. In America Carnap’s non-cognitivism became a major obstacle for a closer collaboration between logical empiricists and American pragmatists. Carnap’s persisting adherence to the dualism of practical life and theoretical science was the ultimate reason why he could not accept Morris’s and Kaplan’s pragmatist theses that cognitivism might well be compatible with a logical and empiricist scientific philosophy.