Bring on the tough stuff - there’s not just one right answer.
Let's start with the big one. Is this a racist book? Does it actually believe that black people are inferior—even if it doesn't believe that they should be slaves—or is it making fun of the racist culture it represents?
What's up with the last few chapters? When Tom Sawyer strolls into the story, the tone takes a major turn toward comedy. Do these chapters ruin the book's otherwise serious events? Or do they complement it in some way?
Does Huck actually change over the course of the novel? He starts out wanting to run away from civilization, and he ends by wanting to set out toward unsettled territory. So, has he grown or matured in any way?
What's up with Twain's claim that there's no plot and no moral to this story? We kind of understand why he'd say there's no plot, but how could he possibly say there's no moral?
That river. It's obviously important, so what does the Mississippi River do for the book? What does it symbolize? What role does it play in the plot?
Huckleberry Finn deals with some serious themes: murder, revenge, slavery, betrayal, conscience, abuse, and alcoholism. Is this really a book for high school students? Would a contemporary novel dealing with the same issues be assigned reading?
Does anything seem distinctively "American" about this book? (Besides the slavery issue, of course.) Does it seem to draw from or help create any mythology about American individualism that you might be familiar with from contemporary debates?
What's up with all the weird gender business, like Huck dressing up as a girl, and women being associated with "civilization" and men being associated with, well, being drunken, vengeful murderer?