Twenty-five years ago, field theory was among the most contested issues in argumentation studies. Today, the situation is very different. In fact, field theory has almost disappeared from disciplinary debates, a development which might suggest that the concept is not a useful aspect of argumentation theory. In contrast, I argue that while field studies are rarely useful, field theory provides an essential underpinning to any close analysis of an argumentative controversy. I then argue that the conflicting approaches to argument fields (...) were in fact not inconsistent, but instead reflected different aspects of field practices. A coherent approach to field theory can be developed by considering the way that all aspects of argumentative practice develop based on the purposes of arguers in an argumentative context. I then extend that position to argue that a justifiable theory of argumentation, which makes claims beyond the descriptive, must have at its core an analysis of the way that purpose constrains argumentation practice. In this view, the ultimate justification of principles found in a prescriptive or evaluative theory of argument must be in the way those principles fulfill practical problem-solving purposes related to the epistemic function of argument. (shrink)