I put this statement on the screen: Working hard is more important than getting good grades. Then I used a great activity I learned from the book , Total Participation Techniques (Himmele) called Debate Team Carousel. Students work in groups (ideally groups of 4). Each student folds a piece of paper into quarters and numbers the boxes. In box 1 students write their own opinion and explain it. The paper then gets passed to the next student who adds a supporting argument in box 2 (whether or not they actually agree). The third student must write an opposing argument in the 3rd box. Then the paper gets passed back to the 1st person who can add their own two cents.
I like this activity because it forces students to see different perspectives and push themselves beyond their own bubble. It also engages them in writing and reading because they know that their peers will be looking at it.
Here are a couple examples: