Twenty-five years after Hedley Bull and Morton Kaplan debated in the pages of World Politics the relative merits of “scientific” and “classical” (or “traditional”) approaches to the study of international relations, the nearly simultaneous appearance of Kratochwil (1989), Onuf (1989), Hollis and Smith (1991), each of them a philosophically self-aware effort to redefine the discipline of international relations, allows a reconsideration of some of the key issues involved. Because Hollis and Smith rely heavily for their philosophical framework on Hollis' earlier text in the philosophy of social science, The Cunning of Reason (Hollis 1987), and that book also clarifies the connections between Hollis and Smith, and Kratochwil and Onuf, I have included it too in this review.

Contrary to earlier, self-flattering, largely North American “scientific” scholarly self-assessments, the evidence of these four mature works of international relations scholarship supports the interpretation that neither side has yet decisively won the debate. Rather, it now appears that all the mentioned authors have made considerable, interdisciplinary progress in combining both classical and contemporary social scientific theorizing modalities to address the key judgmental issues that Bull emphasized as central to the classical approach.

They have done so, I wish to show, by following the lead of post-Wittgensteinian philosophy in resurrecting, with reformulations and against considerable intellectual resistance, the Aristotelian notion of “practical reason.” They deploy their renewed sense of practical activity for a variety of purposes, including the productive reframing of realists' “perennial” problem of anarchic order.