Argumentum ad populum

Argumentum ad populum (Latin: argumentum ad populum, proof speech for the people " ) refers to a rhetorical tactic, in which something is true as claimed, because it corresponds to the opinion of a relevant majority of people, such as public opinion.

It is a special form of authority argument, in which a majority is cited as authority. A special special case with high credibility is the consensus gentium. In the political populism, the probative value of the ad populum is claimed, but even without that it is ascertained whether in fact the opinion that a clear majority is taken as a basis. This is not merely by compelling evidence. Will it be treated as such, it is a fallacy.