Modernism, in its broadest definition, is modern thought, character, or practice. More specifically, the term describes the modernist movement in the arts, its set of cultural tendencies and associated cultural movements, originally arising from wide-scale and far-reaching changes to Western society in the late 19th and early 20th centuries. In particular the development of modern industrial societies and the rapid growth of cities, followed then by the horror of World War I, were among the factors that shaped Modernism. Related terms are modern, modernist, contemporary, and postmodern.
In art, Modernism explicitly rejects the ideology of realism and makes use of the works of the past, through the application of reprise, incorporation, rewriting, recapitulation, revision and parody in new forms. Modernism also rejects the lingering certainty of Enlightenment thinking, as well as the idea of a compassionate, all-powerful Creator.
In general, the term modernism encompasses the activities and output of those who felt the "traditional" forms of art, architecture, literature, religious faith, social organization and daily life were becoming outdated in the new economic, social, and political conditions of an emerging fully industrialized world. The poet Ezra Pound's 1934 injunction to "Make it new!" was paradigmatic of the movement's approach towards the obsolete. Another paradigmatic exhortation was articulated by philosopher and composer Theodor Adorno, who, in the 1940s, challenged conventional surface coherence, and appearance of harmony typical of the rationality of Enlightenment thinking. A salient characteristic of modernism is self-consciousness. This self-consciousness often led to experiments with form and work that draws attention to the processes and materials used (and to the further tendency of abstraction).
The modernist movement, at the beginning of the 20th century, marked the first time that the term avant-garde, with which the movement was labeled until the word "modernism" prevailed, was used for the arts (rather than in its original military and political context).