Please give clear definitions of Marxism, Modernism, New Criticism and Postcolonialism.

Marxist criticism considers
literature as inseparable from history and from the social practices of the era in which
literary works are produced and/or interpreted. Because history is the field of struggle
between those who own the means of production (the bourgeosie) and those who work for
this class (the working class), literature bears the mark of such
struggle.

Modernism is the
collective name usually given to the avant-garde movements that developed at the
beginning of the twentieth century and revolutionized cultural production. Because of
the diversity of these movements (Symbolism, Post-Impressionism, Expressionism,
Futurism, Imagism, Vorticism, Dada and Surrealism), it is sometimes argued that we
should speak of Modernisms in the plural. However, all these movements share a concern
with experimentation and with artists' freedom from realist constraints. The move away
from realism takes Modernist investigation towards the human psyche.
Modernist production tends to reflect this investigation with literary techniques such
as the stream of consciousness, the interior monologue and the non-linear,
non-chronological and fragmented character of its
narratives.

New Criticism is a
(mainly) American school of criticism that developed after the Second World War and was
founded by critics such as John Crowe Ransom, Cleanth Brooks, R. P. Blackmur, Allen Tate
and Robert Penn Warren. It privileged poetry above other literary genres and, building
on T.S. Eliot's words, it aimed to understand "poetry as poetry and not another thing").
New Criticism thus reacted against historicism and the efforts to make the historical
context relevant to the reading of a work of art. According to the new critics, a work
of art must be read as a closed system whose significance resides within itself. New
Critics valued in particular poems that made use of ambiguity, paradox
and irony.

Initially inspired by the work of Edward Said,
Postcolonialism critiqued the cultural assumptions of
imperialism and the West's supposedly civilizing mission towards the East. It exposed
the systematic stereotyping of the East. More recent developments, however, also
celebrated the cultural difference of former colonial subjects, thus decentering the
literary canon in favor of the contributions coming from the margins of the
empire.