Logical Fallacies in Persuasion

1. Logical Fallacies in Persuasion When Good Use of Appeals Goes Wrong

2. Attack Ad Hominem Attacking a Person

3. Attack Ad Hominem • When someone uses attack ad hominem, they are attacking a person instead of the person’s argument or actions. • Attack ad hominem is used frequently with political campaign ads, so be looking for it when you watch television! • For example, if a candidate says, “You shouldn’t believe ________ because he is a bad person,” is an example of attack ad hominem. The candidate is not criticizing an argument and he has no basis or evidence for his claim.

4. Noticing Ad Hominem Whether you agree with this ad or not is not the point. Notice that the original ad does not give a basis for the argument whatsoever.

5. False Causality It’s just a fancy way of saying because B comes after A, A caused B.

6. False Causality • Sometimes, things cause other things to happen. That’s why we study cause and effect in language arts. However, sometimes two events are merely coincidental, so one cannot be blamed for the other. • For example, let’s say I gave a pop quiz one day in class. During the pop quiz, two students get a physical fight. Saying that I caused the fight is false causality, even if the students were both stressed already because of the quiz.

7. False Causality Common sense usually helps us see straight through ads that use false causality.

8. Red Herring Doesn’t it seem fishy to you when an ad jumps around from topic to topic?

9. Red Herring • Red herring is when someone goes completely off on a tangent in the middle of his argument. • The point of red herring is to distract the audience from what’s really at stake. • Oftentimes, the speaker never goes back to the original issue.

10. Red Herring What does that silly duck standing on one leg have to do with the flying spaghetti monster?

11. Overgeneralization Because everyone loves them.

12. Overgeneralization • Think of stereotypes: that is an overgeneralization. • This is when someone makes an assumption about an entire group based on one inadequate sample. • All teachers are mean. • Well, that’s not necessarily true. One based that opinion on the small sample of teachers to which he has been exposed.

13. Overgeneral-ization Of course all horses are cats…

14. Bandwagon Effect Because everyone’s doing it

15. Bandwagon Effect • This is definitely use of pathos, as it is the tendency that advertisers have to make the audience believe they want something by showing that everyone has it. • Ads that use bandwagon attempt to appeal to a person’s innate desire to “fit in.”

16. Bandwagon Effect For what do you think this is advertising?

17. Find the logical fallacy… People who believe in UFOs are either crazy or stupid. Which logical fallacy does this example represent?

18. Find the logical fallacy… I took EZ-No-Cold, and two days later, my cold disappeared. Which logical fallacy does this example represent?

19. Find the logical fallacy… Jim comes home over an hour late. Sally says, “I was worried. Why are you late? Why didn’t you call?” Jim replies, “Have you seen the weather lately?” Which logical fallacy does this example represent?

20. Find the logical fallacy… Tina bought a used camera while she was up in Portland, and got a great deal. Portland must be a good place to buy used cameras. Which logical fallacy does this example represent?

21. Find the logical fallacy… “But officer, I don’t deserve a ticket; everyone goes this speed. If I went any slower, I wouldn’t be going with the stream of traffic.” Which logical fallacy does this example represent?