Begging the question, also known as circular reasoning, is when the author assumes the conclusion of the argument to be proven within the argument’s premise. This device is considered an informal logical fallacy because there is a lack of proof in order to validate the premise. However, begging the question can be considered logically valid if not caught as a fallacy, but is still nevertheless unpersuasive in general since it does not have a solid base as its argument rooted in cold, hard facts.
Smoking can kill you because smoking is deadly.
Visual Example:For more information, see here.