I'm a bit weary of experts, so it helps me to think of them "guessperts" - meaning they're just making their best guess based on, like Zinn said, their past experiences, and the best available "objective" information to them at the time (which, as it turns out, is still influenced by and filtered through their past experiences). Some might know a bit more, some might know a bit less, and some may just be bullshitting outright (or partially) for any given reason. But claiming to be an Expert is claiming to know all there is to know on any given matter, and no one can know all there is to know on any given matter (that is one thing I know for sure!). And, when Expert Opinions conflict, how are we to trust one over another? A few quotes I have come across that are personal favorites:
"All experts operate largely on bluff." - Cliff Irving (the guy who wrote the bullshit Howard Hughes biography)
"You become a leading Expert by acting as if everybody else's opinion deserves no attention and never even deserves the courtesy of an answer. A leading Expert knows that he has a bigger audience than any of his critics, so he can afford to bluff. Just keep a straight face and make sure the mass media gives you more coverage than it gives those who try to correct your mis-statements." - Robert Anton Wilson
Orson Welles loved toying with the notion of Experts, and had a great pseudo-documentary about a guy named Elmyr - a notorious art forger whose Picassos rivaled Picasso (and whose work has been deemed to be Picasso's by Art Experts) - called
F is for Fakes:
http://www.imdb.com/title/tt0072962/And, one more quote I enjoy from Robert Anton Wilson (from his book
Cosmic Trigger: Volume III - My Life After Death) -
"Experts cannot survive in a world conditioned to 'this looks like a Picasso to me.' Expertese demands 'This is a Picasso!' Experts create the forgers. And, similarly, Expertese cannot survive 'At the present, this looks like unsound science to me;; Expertese demands a flat 'This IS pseudo-scientific and vaporous posturing and its inventor IS a shaman, a guru and a notorious crank.'"Also, thanks a ton for Zinn's quote - hadn't seen it before, and love his insight. Bookmarking this thread.