Try to learn why. If you criticize it, you must do so in an informed, sophisticated manner, not just expressing your personal distaste. You must directly address the material, not focus on tangential matters it reminds you of. You can discuss the relevance of an older text for modern times, but make sure you are not writing a paper about modern times as such, failing to discuss throughly the assigned text in its own context. These papers are text-based.
Close reading is required.
If you are using research sources, there are certain important considerations to keep especially in mind. Don't restrict yourself to Web sites and common reference tools such as dictionaries and encyclopedias unless your teacher specifically allows you to. When drawing on sources, don't just string quotations together, or paraphrase what they have to say by changing a few words. Master the material and incorporate it into your own argument, still remembering to cite the source you've drawn on whether you quote it or not. This is not such memorable wording that it's worth quoting directly.