If you consider the definition of ideology presented in post #2 then you could think about the fact that literature represents ideology through its setting, characters, their actions, and other elements of the story. Authors create a reality in their work and we read to better understand that reality. It could be considered part of the intellectual process of reading to discover the work's ideology and how it represents the meaning of the work as a whole.
I guess I always thought of literature as any written work. There are different categories of literature, such as classic literature. In order to categorize literature, you have to adopt some type of ideology. However, a definition of literature itself doesn't involve ideology at all. Anything that is written is literature. It might not be good literature or lasting literature, but that's a different question.
Hmmmm, I'm a bit stumped as to why you feel it is a usual thing to employ ideology when citing a definition of literature. Without looking things up, it seems to me that literature would simply be a piece of writing of excellent quality that stands the test of time. This would merit the writing worthy of study. There are tons of examples that would NOT qualify as literature, then: writing of mediocre quality that is not universal enough and falls by the wayside of more current works.
It is always a fun discussion to determine whether current and popular works will someday be classified as literature. Let me give you an example: Twilight. Is it of excellent quality? It is universal enough to be interesting and relevant to teens and adults one hundred years from now? I have my own opinion (that I will not reveal here), but because Twilight is a current novel, it is impossible to determine whether it will stand the test of time; therefore, the possiblitity of it becoming actual "literature" that teens will continually study in the classroom remains open to debate. We only know whether a work of literature is truly literature in hindsight.
Literature is a body of work that brings to light the strength and weaknesses of the human condition. The nature of mankind is expressed through the complexity of the interwoven emotions as expressed by the characters, and it is the study of this type of literature that helps mankind become more empathetic and knowledgable.
The most suitable definition of "ideology" is found in World English Dictionary: "the set of beliefs by which a group or society orders reality so as to render it intelligible." An ideology in relation to literature would entail the literary criticism theory(ies) that an individual adheres to or employs while analyzing literature, for example, and to make the point clear, such as Marxist criticism or Feminist criticism. A definition of literature that does not employ ideologies would be one without a critical bias. World English Dictionary does a very good job of defining literature without reference to any ideological bias other than quality of writing and substance of theme: "written material such as poetry, novels, essays, etc, esp works of imagination characterized by excellence of style and expression and by themes of general or enduring interest."
I agree with the last post that was made about this topic, literture would be nothing more than a collection of stories of a high quality but without looking up on certain aspects its unwise to give an idealogy of something without knowing anything about it.