Argumentum ad populum
An argumentum ad populum (Latin: "appeal to the people"), in logic, is a fallacious argument that concludes a proposition to be true because many or all people believe it; it alleges that "If many believe so, it is so." In ethics this argument is stated, "If many find it acceptable, it is acceptable."
This type of argument is known by several names, including appeal to the masses, appeal to belief, appeal to the majority, appeal to the people, argument by consensus, authority of the many, and bandwagon fallacy, and in Latin by the names argumentum ad populum ("appeal to the people"), argumentum ad numerum ("appeal to the number"), and consensus gentium ("agreement of the clans"). It is also the basis of a number of social phenomena, including communal reinforcement and the bandwagon effect, and of the Chinese proverb "three men make a tiger".
- "Snob Appeal": the fallacy of attempting to prove a conclusion by appealing to what an elite or a select few (but not necessarily an authority) in a society thinks or believes.
- "Bandwagon": the fallacy of attempting to prove a conclusion on the grounds that all or most people think or believe it is true.
http://nizkor.org/features/fallacies/ap ... arity.html
http://atheism.about.com/od/logicalfall ... umbers.htm