This does not mean, as is commonly supposed, to evade a straight answer to a question. It means to form a conclusion by making an assumption which is as much in need of proof as the conclusion itself. Logicians call this petitio principii. " Thus to say that parallel lines will never meet because they are parallel is simply to assume as a fact the very thing you profess to prove " (Brewer). A single word can be used in a question-begging way: Reactionary, victimisation, aggression, imperialism and warmonger are common examples.