When you think about 20th Century English Literature and Modern English Literature, you are essentially thinking about what might be termed a literary period and a literary sub-period. The 20th century hosted two major literary periods. The first, from about 1910 to 1940-45, was the Modernist period while the second, from about 1945 to the end of the century, was the Postmodernist period. Induced by the two World Wars, Modernism and Postmodernism are too complex and vast to do more than provide representative overviews here. Yet, these overviews will illustrate the answer to your question: The difference between 20th Century Literature and Modern Literature is that Modern Literature is one half of the major literary movements of the 20th century while Postmodernism is the second half of the major literary movements in that century. Since half of 20th Century Literature is Modernism, what are the traits defining it?
Modernism is defined by the disillusionment brought about by World War I and the total devastation of modern technological warfare; as T.S. Eliot explains, even the land was laid to seemingly irremediable waste. Modernists were driven by the events around them to (1) reject old belief and value systems and to (2) try to find, create, locate or discover new belief and value systems--if such could be found or created. As a result, philosophies, perceptions, concentrations, all took new focuses as they were incorporated into the new literature of the century. Some of the primary focuses were:
- self-consciousness expressed in literary style and form
- a sense of chaos and futility
- both (1) loss and despair and (2) literary freedom as the role of the artist was explored
- effects of new sciences like Freudian psychology and Einstien's relativity (PBS, 1880-1940 Modernism)
- perspectivism internalizing individual viewpoints and relocating omniscient narrators to interior, experiencing narrators
- examination and detailed texturizing of the experience and process of knowing and perceiving: internal characterization instead of external
- chronological restructuring with broken cause-and-effect chains for discontinuous fragmentation of time
- linguistic emphasis on the "thickening" of language that constructs reality instead of illuminates it
- the flow of internal thought and experience processes especially significant to expressing the stream of conscious thought and being: stream of consciousness
- externalization of "interior landscapes" contradicting the Romantic and Realist reliance on external landscape (John Lye, Ph.D., Brock University)
Postmodernism filled the latter half of the 20th century following World War II and had many of the same characteristics of Modernism yet was distinguished by one or two significant further developments. Briefly, the despair was increased and angst deepened resulting in an intensified alienation from self, others, and nature. Fragmentation of time and personality took on heightened effects and, while Modernists still hoped to remedy the fragmentation, Postmodernists yielded to it, accepted it as the new reality, experimented with it and tried to develop its artistic potential from the perspective of an ironical, satirical self-ridicule. Thus from this desperation of despair came such literary developments as the Theatre of the Absurd.