Literary theory
Literary theory is an umbrella term for many different movements in the formal study of texts.
Specific theories are distinguished not only by their methods and conclusions, but even by how they define "text." For many, "texts" means "literary (i.e. 'high' art) texts" (see literature). But different principles and methods of literary theory have been applied to non-fiction, pop fiction, film, historical documents, law, advertising, etc. In fact, some theories (e.g. structuralism) treat cultural events like fashion, football, riots, etc treated as "texts."
Literary theorists are generally professors of English. There are many popular schools of literary theory, which take different approaches to understanding texts (which can also mean non-fiction, film, and and practically anything else that can be 'read' or interpreted). Most actual theorists combine methods of more than one approach. Schools that have been historically important include formalism (sometimes called 'new critical formalism' or 'the new criticism'), structuralism, post-structuralism, marxism, feminism, historicism, new historicism, deconstruction, reader-response criticism, and psychoanalytic criticism.
Famous practitioners from the various schools
Hermeneutics: Wilhelm Dilthey, Hans-Georg Gadamer,
Formalism: John Crow Ransom, Cleanth Brooks, Robert Penn Warren
Structuralism: Johnathan Culler, Roland Barthes
Post-Structuralism: Michel Foucault
Marxism: Terry Eagleton, Fredric Jameson, Ian Watt, Georg Lukacs, Theodor Adorno, Walter Benjamin, Raymond Williams, Antonio Gramci
Feminism: Julia Kristeva, Susan Sontag
Historicism:
New Historicism: Stephen Greenblatt
Deconstruction: Jaques Derrida, Stanley Fish, Paul de Mann
Reader-Response Criticism: Wolfgang Iser, Norman Holland
Psychoanalytic Criticism: Jaques Lacan
History
The practice of literary theory became a profession in the 20th century, but it has historical roots that run as far back as ancient Greece (Longinus' On the Sublime is an often cited early example as is Aristotle's Poetics</a>). Philosophers throughout the ages have commented on the nature of literature and of interpretation. So, in many ways, literary theory can be seen as a sub-school of philosophy as well as of literary history.
Differences between the Schools
For some schools (expecially formalism), the distinction between 'literary' and other sorts of texts is of paramount importance. Other schools (particuarly post-structuralism in its various forms: new historicism, deconstruction, some strains of Marxism and feminism) have sought to break down distinctions between the two and have applied the tools of textual interpretation to a wide range of 'texts', including film, non-fiction, historical writing, and even cultural events.
Another crucial distinction among the various schools is the amount of weight given to the author's own opinions about and intentions for a work. For historicism (and, in general, for most pre-20th century approaches) the author's intentions are the guiding factor and an important determiner of the 'correct' interpretation of texts. The New Criticism was the first school to disavow the role of the author in interpreting texts, preferring to focus on "the text itself". In fact, as much contention as there is between formalism and later schools, they share the tenet that the author's interpretation of a work is no more inherently meaningful than any other.
In many contexts, the terms 'literary criticism' and 'literary theory' are interchangeable. Both concern determining meaning in literary texts.
External Links Aristotle's Poetics: http://www2.cddc.vt.edu/gutenberg/etext99/poetc10.txt