482 Part 4 Public Speaking
Logical Fallacies
In a predictable scene from any number of movies, TV shows, or actual lives,
a teenager argues with her parents that she should be allowed to go to a party
because all her friends are going. The exasperated parents roll their eyes and
counter, “If your friends were all jumping off a bridge, would you jump too?” In
their attempts to persuade the other, both the parents and the child fail miserably.
In the eyes of the parents, “All of my friends are going” is not a valid reason
why their kid should go to the party, whereas comparing a party to jumping off
a bridge makes no sense to the teenager either.
Logical fallacies are invalid or deceptive forms of reasoning. Although
they may, at times, be effective in persuading uncritical listeners, active audi-
ence members will reject you as a speaker as well as your argument when they
hear a fallacy creep into your speech (Hansen, 2002). So be on the lookout for
several types of logical fallacies as you listen to a speaker’s arguments.Bandwagoning
When our teenager uses “All of my friends are going” as an argument, she’s guilty
of using the bandwagon fallacy—accepting a statement as true because it is
popular. Unfortunately, bandwagoning can sometimes persuade passive audience
members who assume that an argument must be correct if others accept it (Hansen,
2002). But credible speakers and critical audience members must be careful not
to confuse consensus with fact. A large number of people believing in ghosts is
not proof that ghosts exist.Reduction to the Absurd
When parents counter their daughter’s request to go to a party with her friends
by comparing it to following them off a bridge, they are doing little to per-
suade her. That’s because they have extended their argument to the level of
absurdity, a fallacy known as reduction to the absurd. Pushing an argument
beyond its logical limits in this manner can cause it to unravel: the teenager
sees no connection between going to a party (which is fun) and jumping off a
bridge (which is committing suicide).Red Herring
When a speaker relies on irrelevant information for his or her argument, thereby
diverting the direction of the argument, he is guilty of the red herring fallacy
(so named for a popular myth about a fish’s scent throwing hounds off track of
a pursuit). If you say, for example, “I can’t believe that police officer gave me a
ticket for going 70! Yesterday, I saw a crazy driver cut across three lanes of traffic
without signaling while going at least 80. Why aren’t cops chasing down these
dangerous drivers instead?” you would be using a red herring. There may well be
worse drivers than you, but that doesn’t change the fact that you broke the law.Personal Attacks
A speaker who criticizes a person rather than the issue at hand is guilty of the ad
hominem fallacy—an attack on the person instead of on the person’s arguments.