Argumentum ad Verecundiam

Also known as Appeal to Improper Authority.

An appeal to an improper authority, such as a famous person or a source that may not be reliable.

This is often used in advertising when a famous person is used to advertise, however it is not a fallacy if the person's field of expertise covers the subject.


Wheeler , Kip. "Logical Fallacies Handlist." Dr. Wheeler's Website. 1 March 2007. 1 Apr 2007 <http://web.cn.edu/kwheeler/fallacies_list.html>.

Recent use in written text

"If Jesus said it is so, it is so."
http://en.wikipedia.org/wiki/Appeal_to_authority

Medicine advertisements in magazines.


Use in speech

This is a commercial for McDonalds with Michael Jordan, who probably never ate McDonalds but had to advertise for them because they were his sponsor.




Visuals


lancearmstrong1.jpg
Lance probably knows nothing about Subarus and has nothing to do with them other than being sponsored, however Subaru refers to him in this ad.
http://www.cars101.com/subaru/lancearmstrong1.jpg

superman-got-milk-ad-commercial.jpg
The "Got Milk?" ads are another example of this. They simply ask celebrities for a picture even if the celebrity really had nothing to do with milk before that time.
http://www.adpunch.org/images/superman-got-milk-ad-commercial.jpg

Additional information

http://en.wikipedia.org/wiki/Appeal_to_authority
Official Wiki Page

http://web.cn.edu/kwheeler/fallacies_list.html
Cheat Sheet with information