This article explores the development of three features of positivism from the 1800s to the present: the unity of science, the verification criterion of meaning, and the empiricist observation language. The development of these features is demonstrated in the mid-20th century public administration (PA) literature and in the self-reflective literature of the last three decades. Contemporary positivism has been substantially moderated: The verification criterion of meaning has been abandoned, but the unity of science remains a presupposition, and the empiricist observation language remains an important tool. By presenting this intellectual history, some clarity may be added to the philosophical discourse in PA.