To kill a mockingbird?

You could try to point out the non-violence motive the book contains and use some of those quotes and scenes. I listed some of the quotes here, but you'll most likely want to exchange a few ones. I personally really liked the scene in which Scout's teacher is talking about how Hitler treats the Jewish people in Germany, and doesn't realize that she's just as much of a racist. It should be pretty easy to work, too.

“I wanted you to see what real courage is, instead of getting the idea that courage is a man with a gun in his hand. It's when you know you're licked before you begin, but you begin anyway and see it through no matter what."

“I was born good but had grown progressively worse every year."

“You never really understand a person until you consider things from his point of view... Until you climb inside of his skin and walk around in it.”

“Until I feared I would lose it, I never loved to read. One does not love breathing.”

“They're certainly entitled to think that, and they're entitled to full respect for their opinions... but before I can live with other folks I've got to live with myself. The one thing that doesn't abide by majority rule is a person's conscience.”

“People generally see what they look for, and hear what they listen for.”

You could probably use the scene in which Miss Maudie explain why it's a sin to kill a mockingbird ("Mockingbirds don’t do one thing except make music for us to enjoy. They don’t eat up people’s gardens, don’t nest in corn cribs, they don’t do one thing but sing their hearts out for us. That’s why it’s a sin to kill a mockingbird.”) and the 'original' mockingbird-quote.

“It was times like these when I thought my father, who hated guns and had never been to any wars, was the bravest man who ever lived.”