The Essential Tension

CORE DEFINITION

The phrase is the title of Thomas Kuhn's essay and a recurring theme in his later work. Kuhn argued that science depends on two opposed dispositions that cannot be reduced to one another. Convergent thinking works inside an established paradigm, solving puzzles and accumulating reliable detail. Divergent thinking challenges the paradigm's assumptions and is what makes revolutionary change possible. Neither alone sustains a science: pure convergence calcifies into dogma, while pure divergence dissolves the shared framework needed to accumulate anything at all. Progress lives at the critical point where both are held together.