Modernism was the major literary and artistic movement of the first half of the twentieth century. It was an international and interdisciplinary movement that saw itself as responding to the new situation of modernity. It constructed modernity often in terms of change and loss. It was generally an urban movement, and saw "modernity" as associated with the city, while the countryside was seen as a relic of an older more natural order. Modernity was also concerned with the artificial and constructed as opposed to the natural. Many modernists focused on the loss of the "old verities", whether religious, political, or even scientific (the certainty of Newtonian vs. uncertainty of quantum physics).
In terms of literary modernism, authors of the mid- to late 20th century were more interested in the modern possibilities of language, style, narrative teniques, etc. than content or social issues (compared to the 19th century). Writers such as Joyce, Beckett, Proust, and Robbe-Grillet changed forever what the reading experience is; "plot", "character", dialogue" all took a back seat to linguistic exploration. The reader is challenged to follow an ur-logical combination of sounds and signifiers, even the exhaustive variations on syntactical combinations, as in Joyce's Finnegan's Wake; Beckett removed psychology from character; Proust juggled narrative time itself.
Literary modernism originated in the late 19th and early 20th centuries in answer to the call of Ezra Pound: "Make it new." Modernism rejects Realism, instead examining realms of the consciousness and subjective states in characters.
Writers such as Virginia Woolf and James Joyce exemplify Modernist writers as they employ such techniques as stream-of-consciousness, or internal monologues, in order to allow readers into the characters' subconsciouses. The theories of Sigmund Freud and Carl Jung regarding the unconscious mind allowed these writers to explore such things as repressed feelings, subliminal thoughts, complexes, desires and fears. Modernist writers opened up new avenues of literary composition.
In addition to the examination of the unconscious mind, Modernist writers also explored both the positive and negative affects of urban life with its anonymity, industrialization, power, and darkness. Clearly, Modernism was a great departure from the traditional views, presenting a darker picture of "a culture in disarray." Such writers as T.S. Eliot felt that language failed to convey meaning fully. "That's not it at all; that's what I meant at all," Prufrock complains in Eliot's poem "The Love Song of J. Alfred Prufrock." Because of this failure of language, therefore, Modernist writers explored form instead. Non-chronological, fragmented, poetic forms utilized by T. S. Eliot and Ezra Pound revolutionized poetic language.