Fallacies
Anonymous Authority

 Definition 

Also called appeal to Rumor. Includes Hearsay.

An Appeal to Anonymous Authority is a fallacy with the following form:

 Explanation 

The person making the claim is not named. This is a type of appeal to authority because when an authority is not named it is impossible to confirm that the authority is an expert. However the fallacy is so common it deserves special mention.

A variation on this fallacy is the appeal to rumour. Because the source of a rumour is typically not known, it is not possible to determine whether to believe the rumour. Very often false and harmful rumours are deliberately started in order to discredit an opponent.

 Examples 

On another list someone asked: "Who is that nitwit?"

A government official said today that the new gun law will be proposed tomorrow.

Experts agree that the best way to prevent nuclear war is to prepare for it.

It is held that there are more than two million needless operations conducted every year.

Rumour has it that the Prime Minister will declare another holiday in October.

My friend heard on the news the other day that Canada will declare war on Serbia.
This is a case of hearsay; in fact, the reporter said that Canada would not declare war.

The Ottawa Citizen reported that sales were up 5.9 percent this year.
This is hearsay; we are not in a position to check the Citizen's sources.

 Counter-examples 

None.

 Advices 

Argue that because we don't know the source of the information we have no way to evaluate the reliability of the information.