Over four decades, research and policy have created layers of understandings in the quest for "good" 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 in policy and practice away from narrow, rationalist prescriptions and toward what the philosopher Stephen Toulmin calls "reasonableness". Acknowledging that heightens awareness of complexity and interdependence in corporate governance practice. The paper then articulates a research agenda concerning what "reasonably" good corporate governance might entail. (shrink)