Abstract: Mainstream economists now consider their discipline to be a technical one that is free from ethical concerns. I argue that this view only arose in the twentieth century. In this paper I set out a brief history of economics as a moral science. First, I sketch the evolution of economics before Adam Smith, showing that it was generally (with the exception of the mercantilists) conceived of as a part of moral philosophy. Second, I present elements of the new interpretation of Smith, which show him as a developer of economics as a moral science. Third, I show that even after Smith, up to the beginning of the twentieth century, a number of leading economic theorists envisioned economics as a moral science, either in theory or in practice. Fourth, I sketch the decline of economics as a moral science. The key factor was the emergence and influence of positivism. Overall, I show that the current view of the detachment of economics from morals is alien to much of the history of the discipline.