Camy,
  I've often wondered about that myself.  Perhaps it was such introductions that Twain had in mind when he wrote the "Notice" at the beginnning of Huckleberry Finn: "Persons attempting to find a motive in this narrative will be prosecuted; persons attempting to find a moral in it will be banished; persons attempting to find a plot in it will be shot."  To answer your question, I guess it all depends on the novel being read.  Keep in mind that most works by Dickens and Twain, as well as other authors, did not come with introductions originally.  I try to think of introductions as maps; some can be safely skipped; others are necessary to help you see where you are going when the territory is very unfamiliar.  Certainly, there is no requirement that says you have to read a novel from introduction to conclusion.  Although, a good introduction will do more than give the plot away.  I hope this helps and am eager to see what the others say.
  Welcome back,
  Sandra Littleton Uetz

Carmela Valente <[log in to unmask]> wrote:
  Dear good professors on this list:
Besides being an avid admirer of Twain, I also am devoted to Dickens. In 
our Dickens group, we read and discuss his novels. My question is this. 
Does one read the introduction at the beginning of a novel or at the end of 
the novel when after having read it, one knows the plot and thus can better 
understand the symbolism? If the intro is meant to be read at the end of a 
novel, why isn't it put at the end of a novel? After perusing the intro to 
The Old Curiosity Shop, I mentioned the upcoming death of Little knell and 
was told that I was inconsiderate for giving away the plot. I reminded 
this "gentleman" that had he read the intro, and in fact had he read any 
biography of Dickens, (and I am stating it here, because this is also true 
of Twain), the plots of novels are discussed in detail. Would it make more 
sense to read the introduction twice, both at the beginning of the novel and 
again at the end?
Thank you, thank you for welcoming me and wanting me back, and happy Easter 
to all who celebrate it.
Camy