1º_ It is said of the reason put forward with the sole endorsement of a recognized author, because it has already been expounded by an expert in the matter. This is a common occurrence in practical life, as no one has all the knowledge on all subjects and a specialist is always called upon to obtain an opinion and thus make a decision. Beyond what has been stated in the previous point, the 'argument from authority' does not prove per se that a statement is true. That is why in philosophy, rhetoric or debates it is considered a fallacy, also known as argumentum ad verecundiam or magister dixit. See cognitive bias.
