Let's talk morality! This article is high interest, a bit controversial, and offers awesome brain candy and intriguing scenarios. Pinker's New York Times essay, "The Moral Instinct" makes for an excellent opener to a college level comp class. The article offers an engaging and informative look at what morality is, and if, perhaps, there could be a moral gene.
Looking at situations involving issues from vegetarianism to incest, a close discussion of Pinker's content can easily cover two class periods!
His style is amazing--conversational and humorous at times while also being impressively academic. (He's a Harvard professor.)
I have the best luck with discussions when I have students do a guided reading the day before. The URL for the article is with the attached lesson.