Over four decades, research and policy have created layers of understandings in the quest for Bgood^corporate governance. The corporate excesses of the 1970s sparked a search for market mechanisms and disclosure to empower shareholders. The UK-focused problems of the 1990s prompted board-centric, structural approaches, while the fall of Enron and many other companies in the early 2000s heightened emphasis on director independence and professionalism. With the financial crisis of 2007-09, however, came a turn in some policy approaches and in academic literature seeking a different way forward. This paper explores those four phases and the discourse each develops and then links each to assumptions about accountability and cognition. After the financial crisis came pointers n policy and practice away from narrow, rationalist prescriptions and toward what the philosopher Stephen Toulmin calls Breasonableness^. Acknowledging that heightens awareness of complexity and interdependence in corporate governance practice. The paper then articulates a research agenda concerning what Breasonably^good corporate governance might entail.