The doctrine of leader centrism, supported by the concept of methodological individualism, dominates contemporary accounts of leadership in education and is generally applied as the default option that explains how organizations such as schools function. We argue that methodological individualism is not defensible and that as a result, the explanatory value of leadership is an open empirical question, not a default option. Leadership, and especially problem-solving, is always exercised under a set of constraints. Making the study of these constraints the focal point for determining leadership not only requires the resources of sciences not usually employed in leadership research, but leads to a reconceptualizing how leadership ought to be studied. In this paper we identify three broad contexts that help determine the constraint sets that define problems and their solutions. A defensible theory of educational leadership, we argue, must incorporate context as sets of constraints and develop empirical procedures to investigate context. Only after investigation is it possible to determine who or what the unit of leadership was, or whether leadership occurred at all. There are no default options.