Nabeel Hamid


University of Pennsylvania

S.S. Stevens, operationalism, and logical positivism

This paper argues for two related theses. First, I submit that the arrival of logical positivism in North America in the mid-1930s influenced the development of operationalism in psychology, as evidenced in a series of papers by S.S. Stevens from 1935 to 1939. Stevens in this period takes up three key logical positivist ideas: the distinction between formal and empirical statements, Carnap's distinction between the material and formal modes of speech, and a broadly Russellian conception of class formation. I thus push back on recent scholarship (esp.