In this paper, I use Thomas S. Kuhn’s model of scientific change to frame a brief, broad-brushed biographical sketch of the career of Warren B. Hamilton. I argue that Hamilton’s career can usefully be interpreted as encompassing a full “Kuhn cycle,” from a period of crisis in his early work, to one of normal science in midcareer, and back to something resembling crisis in his later research. Hamilton entered the field around mid-twentieth century when earth science can plausibly be described as being in a period of crisis. The then dominant fixist paradigm was facing an increasing number of difficulties, an alternative mobilist paradigm was being developed, and Hamilton played an important role in its development. The formulation of plate tectonics in the 1960s saw the overthrow of the fixist paradigm. This inaugurated a new phase of normal science as scientists worked within the new paradigm, refining it and applying it to different regions and various geological phenomena. Hamilton’s mid-career work fits largely into this category. Later, as the details of the plate-tectonic model became articulated more fully, and several of what Hamilton perceived as weakly supported conjectures became incorporated into the paradigm, problems began again to accumulate, and earth science, in Hamilton’s estimation, entered a new period of crisis. Radically new frameworks were now required, and Hamilton’s later work was dedicated principally to developing and articulating these frameworks and to criticizing mainstream views.

Small incremental improvements are constantly being made, but larger and more fundamental upgrades are incorporated only erratically.

—Hamilton (2011b)