Just because you’re an expert it doesn’t mean everything you say about it has to be right.
Even though it may sometimes be appropriate to quote an authority on the subject to reinforce a point, many times it is not; since that’s not an argument or reasoning in itself.
Appealing to a voice of authority is particularly inappropriate if:
-The person is not qualified to emit an educated opinion on the matter.
-Not every authority in the field agrees on the argument.
-The quoted authority was joking, drunk or somehow not being serious about the subject.
A variation on this false use of authority is “hearsay quotes”, by which a second or even a third source of authority is appealed to.
Examples
The economist John Kenneth Galbraith claims that austerity is the best cure for recession. (Even though Galbraith is an expert, not every economist agrees with him on this matter).
We’re heading to a nuclear war. Last week, Ronald Reagan announced he would start nuking Russia in five minutes. (He was actually joking about it while testing a microphone).
A friend of mine heard in the news the other day that Canada is declaring war on Serbia. (This is hearsay; as a matter of fact the anchor said Canada would NOT declare war on Serbia).
The “Ottawa Citizen” reported that its sales rose 5.9%. (This is hearsay, since there’s no way to verify the publisher’s sources).
To refute it
Prove there’s actually no logical no argument of logic, just an appealing to a voice of authority as the source of truth.
Whenever the source is not referenced, both definitions and examples have been extracted from a translation of Jaime Wilson jwilson@bytecr.com based on Stephen’s Guide to the Logical Fallacies. Copyright 1995-1998 Stephen Downes. Brandon, Manitoba, Canada.
These texts have been modified by Miguel A. Lerma and now by us to adapt them -and those taken from Wikipedia- to our format.