World Changes contains papers presented at a 1990 conference, held at the Massachusetts Institute of Technology, devoted to the work of historian and philosopher of science Thomas Kuhn. Among those whose business is thinking about the nature and history of science, Kuhn's 1962 classic The Structure of Scientific Revolutions is beyond question the most widely influential book of this era.
Structure was written against the backdrop of the dominant positivistic view that science proceeds by the hyperrational process of strictly deriving observational predictions from candidate theories and then testing them against observations made in experimental settings. In this manner, crucial experiments effectively decide among competing theories, and science gradually converges upon the univocal truths of nature. The positivists themselves were among the first to see the logical and epistemological problems with this simplistic view, but responded by developing probabilistic accounts of confirmation and language-relative accounts of observation to shore it