There are two main objectives that you would want to achieve in a conclusion paragraph. First, the conclusion gives you an opportunity to restate the main ideas of your text. This allows the reader to analyze your ideas once more and to judge whether the argument has been persuasive or not. The second purpose is to leave a lasting impression on the reader. The way in which you can do that is by ending the conclusion mentioning something memorable or persuasive that you mentioned earlier in your text.