ABSTRACT
Early in their careers, students of social science commonly learn an exercise resembling the scales and arpeggios every beginning violinist must master: essential for gaining a sense of the discipline, but by no means the heart of virtuoso violin performance. The exercise consists of identifying a phenomenon—nationalism, revolution, balance of power, or something else—then lining up two or three ostensibly competing explanations of the phenomenon. An effective performer of the exercise then proposes to adjudicate among competing positions by means of logical tests, crucial cases, observations of covariation across cases, or perhaps a whole research program whose results the newcomer can report in a doctoral dissertation.
