Instrumentalism, in American philosophy, variety of pragmatism developed at the University of Chicago by John Dewey and his colleagues. Thought is considered by instrumentalists a method of meeting difficulties, particularly such difficulties as arise when immediate, unreflective experience is interrupted by the failure of habitual or instinctive modes of reaction to cope with a new situation. According to the doctrine, thinking consists of the formulation of plans or patterns of both overt action and unexpressed responses or ideas; in each case, the goals of thought are a wider experience and a successful resolution of problems. In this view, ideas and knowledge are exclusively functional processes; that is, they are of significance only as they are instrumental in the development of experience. The realistic and experimental emphasis of instrumentalism has had a far-reaching effect on American thought; Dewey and his followers applied it with conspicuous success in such fields as education and psychology.