- Slides: 14
LOGICAL FALLACY What is a logical fallacy? A logical fallacy is a mistake made when arguing a claim or argument because the speaker/author has incorrectly used information to support why he/she has the correct viewpoint. § The effect of the logical fallacy is that it can weaken the claim or argument. § In other words…a fallacy is an error in reasoning. Typically, a fallacy is based on an incorrect inference or misuse of evidence.
1 ST LOGICAL FALLACY • Irrelevant Authority (Appeal to commonly held opinion) • A claim or argument that something is true because many people believe it to be true. • Example: “Mom, why can’t I get my tongue pierced? Everyone else is doing it. ”
2 ND LOGICAL FALLACY False Dilemma § A choice that presents only two options when there is really at least one other option. Example: “America: Love it or leave it”.
3 RD LOGICAL FALLACY • Appeal to Pity • An appeal that relies on emotion instead of evidence. Example: “I should receive an ‘A’ in this class. After all, if I don’t get an ‘A’ I won’t get the car that I want. ”
4 TH LOGICAL FALLACY • Ad Hominem (Personal Attack) • Disparaging remarks about a person used instead of evidence against the other person’s position. Example: Student: “Hey, Mrs. Smith, we shouldn’t have to read this short story by Edgar Allen Poe. Everyone knows he was a drunk. ”
5 TH LOGICAL FALLACY Hasty Generalization § A conclusion drawn from insufficient evidence. Example: “I know this will be a horrible class. They tell me the teacher is old. Old teachers are unable to talk with today’s high school students. ”
6 TH LOGICAL FALLACY Moral Equivalence This fallacy compares minor misdeeds with major atrocities. Example: “That parking attendant who gave me a ticket is as bad as Hitler. ”
7 TH LOGICAL FALLACY Red Herring Introducing a topic not related to the subject at hand. Example: “I know your car isn't working right. But, if you had gone to the store one day earlier, you'd not be having problems. ”
8 TH LOGICAL FALLACY Appeal to Hypocrisy (tu quoque) One attempts to defend oneself or another from criticism by turning the critique back against the accuser. Example: “Wilma: You cheated on your income tax. Don't you realize that's wrong? Walter: Hey, wait a minute. You cheated on your income tax last year. Or have you forgotten? ”
9 TH LOGICAL FALLACY Bandwagon Appeals (ad populum) Trying to get everyone on board. Example: "Since Harvard, Stanford, and Berkeley have all added a multicultural component to their graduation requirements, Notre Dame should get with the future. "
10 TH LOGICAL FALLACY Straw Man The arguer sets up a weak version of the opponent’s position and tries to score points by knocking it down. Example: “We know that evolution is false because we did not evolve from monkeys. ”
11 TH LOGICAL FALLACY Slippery Slope Suggests that one step will inevitably lead to more, eventually negative steps. Example: "We have to stop the tuition increase! The next thing you know, they'll be charging $40, 000 a semester!"
12 TH LOGICAL FALLACY Fallacy of Composition (Part-to. Whole) Inferring that something is true of the whole from the fact that it is true of some part of the whole. Example: “Each brick in that building weighs less than a pound. Therefore, the building weighs less than a pound. ”