Positivism originated from separate movements in nineteenth-century social science and early twentieth-century philosophy. Key positivist ideas were that philosophy should be scientific, that metaphysical speculations are meaningless, that there is a universal and a priori scientific method, that a main function of philosophy is to analyse that method, that this basic scientific method is the same in both the natural and social sciences, that the various sciences should be reducible to physics, and that the theoretical parts of good science must be translatable into statements about observations. In the social sciences and the philosophy of the social sciences, positivism has supported the emphasis on quantitative data and precisely formulated theories, the doctrines of behaviourism, operationalism and methodological individualism, the doubts among philosophers that meaning and interpretation can be scientifically adequate, and an approach to the philosophy of social science that focuses on conceptual analysis rather than on the actual practice of social research. Influential criticisms have denied that scientific method is a priori or universal, that theories can or must be translatable into observational terms, and that reduction to physics is the way to unify the sciences. These criticisms have undercut the motivations for behaviourism and methodological individualism in the social sciences. They have also led many to conclude, somewhat implausibly, that any standards of good social science are merely matters of rhetorical persuasion and social convention.
