Historical-biographical literary criticism argues that the events that take place in a person's life play a part--a large part--in determining the meaning behind literary works. While I once believed this whole-heartedly, I have since wavered back and forth on the influence of a person's life on his/her writing.
Part of what has changed my mind are the kinds of things I write about--while I was once writing a story about a modern-day prophet who ends up spending quite a bit of time in a psychiatric ward, I don't think that a listing of my life's events would show where my interest in both faith and mental illness come into play.
Some recent things I've read, however, are making me re-think this stance. For example, read "Guts" by Chuck Palahniuk and tell me if you believe Palahniuk has led a sunshine-and-rainbows kind of life, or if you find it difficult to believe that some of the more painful things he has experienced haven't had a profound effect on him:
He also began volunteering at a homeless shelter, then as a escort for a hospice where he transported terminally ill patients to their support meetings. He stopped volunteering after a patient with whom he had developed a friendship died. [...] During this time also, Palahniuk joined the Cacophony Society (described by themselves as “a randomly gathered network of individuals united in the pursuit of experiences beyond the pale of mainstream society through subversion, pranks, art, fringe explorations and meaningless madness”). [...] 1999 may have been the year where Palahniuk became a cult figure but it was also a difficult year for Chuck because his father and his father’s girlfriend were found murdered. The girlfriend’s ex-husband was subsequently charged and convicted for the murders, and Palahniuk apparently began the novel Lullaby during all this time later stating that he used the writing process to help him cope with his decision to help get the murderer a death sentence. (Emphasis mine)
I would argue, of course, that, though exposure to painful things and writing twisted things may be connected, it does not necessarily follow that Palahniuk is a tortured, twisted person. While the events of his life explain where he gets his inspiration, it may be unfair to write up a biographical sketch in broad strokes that defines Palahniuk as a one-dimensional, terminally unhappy character in history.
On the other hand, we have examples like Sylvia Plath, who based the events of the novel The Bell Jar on her own experiences in a psych ward in "an autobiographical apprentice work which [she] had to write in oder to [herself] from the past." As she once told her mother, "What I've done [...] is to throw together events from my own life, fictionalizing to add color--it'a pot boiler really, but I think it will show how isolated a person feels when he is suffering a breakdown... I've tried to picture my world and the people in it as seen through the distorting lens of a bell jar."* While is true that the entire book is not factual, it is also true that Plath committed suicide not long after it was written, so her frame of mind was obviously very close to that of Esther Greenwood's in The Bell Jar. In this case, one almost cannot appreciate the real strength of the book without knowing what happened in Plath's life.
Perhaps it is safe to say, then, that some biographical criticism is both appropriate and necessary, but it is inappropriate to scour authors' biographies, grasping at details in order to understand where they got their ideas. After all, does it really matter where an idea originated if it has value in the minds of readers?
*From "The Bell Jar and the Life of Sylvia Plath: A Biographical Note by Lois Ames."