Although the opposition between realism and idealism is exhibited in their different assumptions on objectivity, in the field of social theory, John Anderson's social realism and Jürgen Habermas's social idealism are united in their rejection of positivism's separation of theory from praxis. Social realism's agreement with social idealism's critique of Popper's ?positivism?, on logical, methodological, ethical and ontological grounds, does not mean, however, a dissolution of the conflict between these two traditions. Indeed, social idealism's and social realism's rejection of the (...) fact/value dichotomy and synthesis of theory and praxis take different forms. Accordingly, social idealism advances a prescriptive ethic and rejects objectivity whilst social realism advances a descriptive ethic, and accepts objectivity. The strength of social realism, as an objective basis upon which positivist sociology might be reconstructed, lies in its refutation of social idealism. Through immanent critique, social idealism is shown to rest on an ontological mistake, a mistake of synthesis, a subjective mistake, and a substantive mistake. (shrink)