Examples are also useful for explaining the notions that play a central role in your argument. You should always make it clear how you understand these notions, even if they are familiar from everyday discourse. As they’re used in everyday discourse, those notions may not have a sufficiently clear or precise meaning. For instance, suppose you’re writing a paper about abortion, and you want to assert the claim “A fetus is a person.” What do you mean by “a person”? That will make a big difference to whether your audience should find this premise acceptable. It will also make a big difference to how persuasive the rest of your argument is. By itself, the following argument is pretty worthless: