In class, I read an excerpt from Voltaire's "Poem on the Lisbon Disaster." Here's the text in full. For the exam, it's obviously mandatory that we are familiar with Voltaire's opinions (and they're pretty bluntly stated in Candide). This poem further showcases his opinion, and the full article presents a slightly dissenting opinion by Rousseau. Having some context to backup opposing ideologies can beef up your essay, so it's worth the read.