2. An Example
Mu’ammar Gaddafi said that Barack Obama was
a Muslim, so he probably is.
We are going to think of appeals to authority
(abbreviated ‘AA’) as statistical syllogisms. Can
you put the argument above into the form of
a statistical syllogism?
3. Here’s one way
1. Most of what Gaddafi said about Obama is true.
2. “Obama is a Muslim” is something Gaddafi said about
Obama.
3. So, “Obama is a Muslim” is true.
See if you can say how the parts of this argument line up
with the components of Statistical Syllogism.
One advantage to reconstructing AA as Statistical
Syllogisms is that we already know how to evaluate
those. See if you can apply the criteria for Statistical
Syllogism in evaluating this argument.
4. Another Example
Just so you don’t think all AA are as bad as the last one,
here’s a strong one:
According to Stephen Hawking, the super-massive
black holes at the center of most galaxies formed when
a star collapsed. So, I believe that’s how they
originated.
In form,
1. Most of what Hawking says about black holes is true.
2. “The black holes at the center of galaxies formed when a
star collapsed” is something Hawking says about black
holes.
3. So, “The black holes…collapsed” is true.
5. Another Way to Evaluate AA
• Another common method of evaluating the
strength of AA checks them for three criteria: (1)
the authority must really be an expert, (2) the
authority must be a disinterested party (she
doesn’t gain from your believing her), and (3)
there must not be widespread disagreement
among the experts.
• Can each of these three criteria be captured with
one of our two criteria (Hi%, and no reason to
think x is an unusual A wrt B)? If so, how? If not,
is our method of evaluating AA flawed?
6. Experts
• There are several arguments that the word of experts
doesn’t provide evidence at all.*
• One argument is ancient (from Sextus Empiricus). It
concludes that there can’t be good AA:
1. Non-experts can’t judge the word of experts because they
are unqualified to judge it.
2. Experts can’t judge the word of other experts because
they are biased by their own views and can’t judge fairly.
3. So, no one (non-experts or experts) can judge the word of
experts. (So it can’t be evidence for anyone.)
Is anything wrong with this argument? If so, what?
*Both the Sextus Empiricus argument and the documentary on the next slide
came to my attention on a website by Moti Mizrahi.
(http://thinkjustdoit.blogspot.com/2012/05/pl-211-can-we-trust-experts.html)
7. A Second Argument
• The second argument is less conceptual and more
practical. (It’s also inductive rather than deductive.)
• Watch the (~45 min.) documentary ‘The Trouble With
Experts.’
(http://www.youtube.com/watch?v=nW3wQdo3sg4)
Answer the following questions as you watch.
1. In the film, several sampling arguments are given to
undermine the credibility of experts. How many of
them can you put into the form of sampling
arguments? (There’s at least one in each segment.)
2. What explanations are given that experts are wrong so
often?
3. Is the documentary self-refuting? Why or why not?
8. Advertisements
• Many advertisements can be evaluated as arguments
from authority.
• Construct an arg. from authority based on this classic.
(http://www.youtube.com/watch?v=QtA0v2Wd4lM)
• Moore and Parker argue (see pdf) that because
advertisements always come from interested parties,
they can never provide good reason for purchase. Is
anything wrong with their argument? Can you think of
any counterexamples? Find an ad online and post a
link to it on the discussion board for Credibility Part I.
• Here’s my attempt at a counterexample to Moore and
Parker: (http://www.adforum.com/creative-
work/ad/player/12660893/sxi:2153735). It’s not really
a reason for purchase, but it is a reason to behave in
the way the advertisers want you to.
