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An argument from authority (argumentum ab auctoritate), also called an appeal to authority, or argumentum ad verecundiam, is a form of defeasible argument in which the opinion of an authority on a topic is used as evidence to support an argument. It is well known as a fallacy, though some consider that it is used in a cogent form when all sides of a discussion agree on the reliability of the authority in the given context. Other authors consider it a fallacy to cite an authority on the discussed topic as the primary means of supporting an argument.

Forms