An Introduction to Critical Thinking and Creativity - always yours

FALLACIES OF IRRELEVANCE 177
If you answer either yes or no, you confess that you are a killer. But if it has not
been proven that you have killed anyone, it would be wrong to force you to give
either an affirmative or a negative answer. A loaded question combines more than
one question that should be broken up: Did you kill the victim? If so, did you wash
your hands afterward?
19.4 FALLACIES OF IRRELEVANCE
In fallacies of irrelevance, irrelevant information is used in reasoning or a discussion.
Personal attack (ad hominem arguments) is one example, in which a claim
is criticized not by evaluating the claim itself but by attacking the background or
the character of the person who made the claim:
BUSINESSMAN: The government should lower profit tax.
COMMENTATOR: NO way. You say that because you are a greedy capitalist.
It might be true that the businessman is greedy, but the personal attack is irrelevant
to the issue of whether the tax should be lowered. A rational discussion
about the correctness of the businessman's claim should focus on the real issues
instead. Would the proposal cause more harm than good? Does the current tax
rate hinder the economy, or is it already very low? This is not to say that motive
and character are always irrelevant. It is legitimate to consider these factors if they
bear on the reputation and reliability of the person.
There are many related fallacies by which something is argued to be true based
on an inappropriate appeal to irrelevant sources. Here are some such arguments:
• It has been an established tradition in the Japanese town of Taiji to hunt and
kill thousands of dolphins every year. It is therefore wrong for foreigners to
criticize it. (appeal to tradition)
• Arthur Conan Doyle, who created Sherlock Holmes, probably had a drinking
problem. His father was an alcoholic, (fallacy of origin, or equivalently,
genetic fallacy)
• MIT Professor Negroponte said (in 2010) that physical books will be dead in
five years. So that must be true, (appeal to authority)
It is not always a fallacy to appeal to tradition, origin, or authority. But we
should do so only if we have good independent reasons for taking them into account.
We should not follow traditions blindly. But if traditions promote harmony
or other positive values, we might have a reason to preserve and respect them.
Appealing to origin can also be legitimate—a fish from a heavily polluted lake is
likely to be polluted as well, but only because we know nasty chemicals can transfer
from the water to the fish. Likewise, we should not trust an expert just because
he or she is famous, as there are other factors to consider as well (recall Section
13.2).