Friday, November 06, 2009


Faulty logic: Appeal to Authority

Continuing the series on faulty logic, today we’ll look at:

Appeal to Authority

In our society, we hold various people up as authority figures, those we’re inclined to pay attention to. It’s not always clear why we have some folks on that list, really. Political leaders, such as presidents, prime ministers, kings, queens, senators, and governors are obvious. Educators and other academics — professors, scientists, and the like — also make sense. I’m never sure why actors and sports figures are there, but they do seem to be.

And so we have things like the 1970s advertisements for Mr Coffee, where former baseball player Joe DiMaggio told us what a great cup of coffee it made. Or more recently, when former Senator Bob Dole hawked Viagra.

Ads such as those are quintessential examples of appeal to authority: basing an argument on the support of an authority figure, without regard to the actual issue at hand.

  • Joe DiMaggio likes Mr Coffee, so it must be good.
  • The president said it; it must be true.
  • That guy has a PhD; he must be right.

A key point, though, is that the speakers credentials are often not irrelevant, and it’s often proper to cite them. When a doctor tells you about a medical issue that falls within her specialty, you should consider that along with other data. The appeal to authority hits us as a fallacy when the credentials aren’t relevant to the issue at hand (if DiMaggio had told us which baseball mitt to buy, that would have been great, but he wasn’t authoritative about coffee), or when they’re used to claim that other evidence is unnecessary (even a cancer specialist will support her statements about cancer treatment with real data).

Arguments that something is so because it’s in the Bible (or the Koran, or the Talmud, or other religious writings) are also faulty appeals to authority — mixed with other errors that we’ll get to later in the series.

We’re seeing the effects of appeal-to-authority arguments with the many “celebrity spokesmen” who stand behind pseudoscience and pseudomedicine. Oprah Winfrey, Jim Carrey, Robert Kennedy, and others contribute to a false fear of vaccination. Deepak Chopra and Andrew Weil are among those who use their real credentials as medical doctors to promote bogus “medicine”, talking about “removing toxins” and “boosting the immune system”, with no clinical data to back it up.

Of course, the “good guys” trot out authority figures as well. Musician Bono toured Africa in support of AIDS prevention and treatment. Former Senator and former Vice President Al Gore made a movie about global climate change. The difference is that these guys showed the data to back up what they were saying. An Inconvenient Truth is full of charts and figures and photographs that make the arguments clear. There’s no false appeal to authority there.

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