Historian of science Thomas Kuhn famously argued that scientific progress comes not from an incremental, stepwise accumulation of knowledge, but rather from a "paradigm shift," the relatively sudden collapse of an old paradigm under the weight of new evidence and new insights. Kuhn's idea has implications beyond scientific research. Historical changes as well often reflect an abrupt shift, as the old received wisdom is no longer adequate for understanding new events.
For example, the collapse of the Soviet Union was anticipated by at most a handful of analysts and historians. Indeed, in 1984 esteemed economist J.K. Galbraith claimed, "The Russian system succeeds because, in contrast to the Western industrial economies, it makes full use of its manpower." Yet in a few years looming economic collapse swept away the communist superpower that for half a century threatened liberal democracy. In an instant, the seemingly permanent Cold War geostrategical paradigm disappeared, taking with it the whole academic discipline of Sovietology.