What makes good literature?

I have been pondering this question for the last few weeks and still have no answer.  I remember starting the Da Vinci Code and not being able to get passed the second page as I just found the writing so dire.  I certainly know bad literature when I read it!


I am currently reading a Man Booker Prize short listed novel and I can not stop mulling it over in my mind.  There is absolutely no doubt the author is an artist with words.  The vivid descriptions, particularly of unpleasant smells, are phenomenal and make me gasp.  Boy, can she write!


However, the writing also contains oddities that have me confused.  The odd (non) sentence added in which doesn't flow with the rest of the novel...yet I'm sure there is a reason for this considering the control the author has in other parts.  Are they thoughts thrown in by the now older narrator? After thoughts?


On top of this, there are significant changes in the style of writing at different points of the book.  One section is particularly slow going and slightly laborious.  Normally I would think that this would mean I couldn't class it in my idea of good literature.  But, and this is where I am rethinking...the style always completely reflects the setting and scene.  So for example, in the section I just mentioned, the characters are on a long, slow, laborious journey by ship.  Has the author then, consciously shaped the style of writing to reflect what is happening to the characters and instil in the reader an appreciation of the characters' feelings?  Is she placing me directly in the shoes of her character? In which case, it must surely be classed as an example of great literature.  It certainly works when we feel a character's joy and pain but does conveying laboriousness and a sense of time moving slowly push a reader to far?


I am made to think yet again with the graphic description of an act that, we, in our twenty first century, comfy cultural westernised world, find unacceptable and immoral.  However, the author has NOT set her book in the current day but in the historical past, most likely the Victorian era (judged from the strong Dickensian feel).


I know that some readers have found this scene upsetting and have been critical in their reviews of the detailed description and its graphic nature.  However, as uncomfortable as I was reading it, I could only appreciate it for the realistic depiction of the scene and for the author not pandering to this century's expectations and instead remaining in the time frame of which her novel was set.  Surely she deserves only praise for this consistency?  It certainly can not be easy to cast off the conditioning of our own cultural upbringing to write a novel based on another!


Anyone who has read the book, may well guess what it is but I have chosen not to reveal the title yet as I have yet to finish it.  Once I have, I will write a full review.  By this time I hope to have decided on where I would place this novel.  For now I am left questioning every time I pick it up and read a few pages.


Surely an excellent novel should make us question our judgements and make us think? Or should an author leave us in no doubt as to their excellence?