Appeal to Authority or Argument by Authority
An appeal to authority or argument by authority is a type of argument in logic consisting on basing the truth value of an assertion on the authority, knowledge, expertise, or position of the person asserting it. It is also known as argument from authority, argumentum ad verecundiam (Latin: argument to respect) or ipse dixit (Latin: he himself said it). It is one method of obtaining propositional knowledge, but a fallacy in regard to logic, because the validity of a claim does not follow from the credibility of the source. The corresponding reverse case would be an ad hominem attack: to imply that the claim is false because the asserter lacks authority or is otherwise objectionable in some way.