Under postmodernity, all knowledge comes to be seen as "constructed" within historical self-contained systems of understanding.
Marxist, feminist, and postmodern thought have brought about the incorporation of all human discourses (that is, interlocking fields of language and knowledge) as a subject matter for analysis by the literary theorist.
"Theoria" indicates a view or perspective of the Greek stage.
This is precisely what literary theory offers, though specific theories often claim to present a complete system for understanding literature.
"Higher," or "source criticism," analyzed biblical tales in light of comparable narratives from other cultures, an approach that anticipated some of the method and spirit of twentieth century theory, particularly "Structuralism" and "New Historicism." In France, the eminent literary critic Charles Augustin Saint Beuve maintained that a work of literature could be explained entirely in terms of biography, while novelist Marcel Proust devoted his life to refuting Saint Beuve in a massive narrative in which he contended that the details of the life of the artist are utterly transformed in the work of art.
(This dispute was taken up anew by the French theorist Roland Barthes in his famous declaration of the "Death of the Author." See "Structuralism" and "Poststructuralism.") Perhaps the greatest nineteenth century influence on literary theory came from the deep epistemological suspicion of Friedrich Nietzsche: that facts are not facts until they have been interpreted.
Lastly, literary theory in recent years has sought to explain the degree to which the text is more the product of a culture than an individual author and in turn how those texts help to create the culture.Nietzsche's critique of knowledge has had a profound impact on literary studies and helped usher in an era of intense literary theorizing that has yet to pass.Attention to the etymology of the term "theory," from the Greek "theoria," alerts us to the partial nature of theoretical approaches to literature.It is literary theory that formulates the relationship between author and work; literary theory develops the significance of race, class, and gender for literary study, both from the standpoint of the biography of the author and an analysis of their thematic presence within texts.Literary theory offers varying approaches for understanding the role of historical context in interpretation as well as the relevance of linguistic and unconscious elements of the text.
The current state of theory is such that there are many overlapping areas of influence, and older schools of theory, though no longer enjoying their previous eminence, continue to exert an influence on the whole.