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Fallacies Fallacies are Flaws in Reasoning, Appeals, Language.

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Presentation on theme: "Fallacies Fallacies are Flaws in Reasoning, Appeals, Language."— Presentation transcript:

1 Fallacies Fallacies are Flaws in Reasoning, Appeals, Language

2 Fallacies in Reasoning Hasty Generalization Composition Division Non-Sequiter Circular Reasoning Ad Hominem False Dichotomy Post Hoc Ergo Propter Hoc Slippery Slope

3 Hasty Generalization (secundum quid) Offers conclusion based on insufficient information Too few or non-representative examples

4 Hasty G All Native Americans walk single file, at least the one I saw did. The first five women I saw in town were women. Only women live here. My first paper was an “A” so I will probably get an “A” in the course.

5 Refutation using hasty generalization My opponent tells you that many innocent people have been executed with the death penalty. However, if you examine her evidence, there is only one innocent person presented. She can’t establish a reasonable pattern of generalization with only one case.

6 Fallacy of composition Unwarranted assumption that what is true of the part is true of the whole.

7 Compostion Some Americans are poor so all Americans must have a poor standard of living. If you like eggs, peanut butter, bananas and tuna, I’m sure will like this dish I just made from all four. John McCain, a Republican favors campaign finance reform so all Republicans must favor campaign finance reform.

8 Refutation using composition John tries to get you to believe that Greece was a militaristic nation. But note that his evidence only demonstrates that a single Greek state, Sparta, was war oriented. So I would say he hasn’t proven that all of Greece was warlike, only Sparta. His conclusion in unwarranted.

9 Fallacy of division Unwarranted assumption that what is true of the whole is true of the parts

10 Division The U.S. has a high standard of living. So, no American is poor. If you like cake, I’m sure you will like pure carbon,oxygen, and hydrogen, as cake is made of all three. The ball is blue, therefore the atoms that make it up are blue.

11 Refutation using division The reasoning from Mary is wrong when she tells you the entire brain is capable of consciousness. I will grant that she is right when she says that there are cells in the brain that are capable of consciousness. But, my evidence will demonstrate that there are only a few of these cells in the brain and claiming that the entire brain is a conscious organ clearly overclaims her position.

12 Non-sequiter Irrelevant arguments that make assumptions that do not follow from the information provided.

13 Non-sequiter Sex crimes are often the result of an unrestrained libido, so castration is an appropriate punishment for such crimes. The Los Angeles times recently won 5 Pulitzer prizes. USA Today has one of the best sport sections in America. You should watch The Real World on MTV because it is a great program.

14 Refuting a non-sequiter Look, Enrique’s argument just doesn’t make sense. The fact that the L.A. Times and USA today are good newspapers has no connection at all to why you should watch The Real World. So what gives? Besides, I will show you several reasons why TRW sucks.

15 Circular Reasoning (petitio principi or begging the question) Offers as warrants and grounds statements equivalent to or identical to the claims they are supposed to support.

16 Circular Mohammed is the messenger of Allah because Allah caused the Koran to be written and the Koran says Mohammed is the messenger of Allah. It’s wrong to make animals suffer to further scientific knowledge because making animals suffer is clearly wrong.

17 Refutation of circular reasoning When our opponents argue that gaming is good for Native Americans they offer a circular argument. They tell you this several times but if you examine the argument they never offer you any proof. They just keep claiming it is good but they never offer evidence. We prove our claims.

18 Ad Hominem Attacking the person, rather than the argument.

19 Ad Hominem Ross Perot didn’t know anything about NAFTA, besides, he had big ears, Siskel and Ebert were jerks. I didn’t believe any of their movie reviews.

20 Refuting ad hominem I don’t disagree with Dieu when she says that Pete Rose lied about betting on baseball. However, the fact that he is a liar is not what qualifies him for the hall of fame. There are many liars in the hall. The standard for entry is how well you played. Pete was a great player. Period.

21 False Dichotomy Forces listener to choose between oversimplified either/or options.

22 False Dichotomy Every person is either wholly good or wholly evil. The U.S. must choose to support either Israel of Palestine.

23 Refuting a false dichotomy Let me tell you where our positions are different. Manny says we have to make a choice between conservation and energy independence. But I think that is wrong. Clearly, we don’t have to chose one or the other. I think that hybrid vehicles prove that. They show we can try to meet both goals. There is plenty of middle ground.

24 Post Hoc Ergo Propter Hoc (after this then therefore because of this) Unwarranted assumption mistaking temporal succession for causal sequence

25 Post hoc, etc. Its raining because I washed my car yesterday. Every depression followed a Republican administration.

26 Refuting Post Hoc Saying every war followed a Democratic administration is about as unreasonable as saying every depression followed a Republican administration. There are numerous cause for a war, just as there are numerous causes for depressions. Besides, the Viet Nam war followed a Republican administration.

27 Fallacies of Appeal Appealing to emotion rather than reason

28 Fallacies of Appeal include: Ad ignoratum Ad populum Appeal to pity Appeal to fear Appeal to authority Appeal to tradition Appeal to humor

29 Ad ignoratum (appeal to ignorance) Asks audience to accept claim solely because no evidence exists to deny its validity.

30 Ignorant Since scientists can’t prove global warming will happen, it probably won’t. Nicole Brown’s murderer is still at large because O.J. hasn’t found him.

31 Refutation of appeal to ignorance In their first claim they say “evolution is an unproven theory so it is invalid.” But think about this for a minute. It’s called the “THEORY” of evolution. Of course its not proven. However, there are many aspects of the theory that have been proven so lets look at some of those. Those aspects are valid.

32 Ad Populum Asks for acceptance of a claim because it is supported by the majority of the people.

33 Ad populum Most people support the death penalty so it must be right Gore should be president because he won the popular vote.

34 Refutation of ad populum Certainly, Sam is correct when he says many people oppose gay marriage. However, many people also opposed inter- racial marriage. Today, that idea is accepted. Something is not necessarily wrong because many people oppose it. Most people used to believe the earth was flat.

35 Appeal to pity ( argumentum ad misercordiam) Arousal of sympathy in the place of reason

36 Pity I hope you will accept this late paper. I was up all night working on it. Look how cute this bunny is. How could someone use it for research?

37 Refuting appeal to pity Eileen says we should give these kids a break because they are so young. That is true. They are young. But the principles of justice don’t change just because someone is young. If they killed someone, they should pay the price.

38 Appeal to Fear Arousal of fear in the place of reason

39 Fear If we take the guns from the people only the criminals will have guns. Social Security is once again threatened by Republicans.

40 Refuting fear appeals The opposing team tells us we needed to invade Iraq because we were threatened by weapons of mass destruction. This was a an appeal to fear. There is no evidence of such weapons.

41 Appeal to authority (argumentum ad vericundiam) Authority in place of reasoning

42 Authority Dr. Fraser Crane recommends the EZ Rest Hot Tub The Rock supported George Bush so he must have been the best candidate.

43 Refuting appeal to authority The ad shows Tiger Woods driving a Buick. I seriously doubt that this is Tiger’s everyday ride. But, maybe a golfer doesn’t know that much about cars. If I was Tiger I would probably be driving a Porsche.

44 Appeal to tradition Expresses a customary belief or action rather than reasoning

45 Tradition Well, that the way we have always done it. The Yankees will win the series.

46 Refuting appeal to tradition Fred contends that American cars have always been superior and so they are now as well. Our position is that there have been many superior cars world wide both in the past and today. In addition, most of today’s cars are made with parts produced all over the world.

47 Appeal to humor Reduces another’s claim to its most absurd conclusion

48 Humor The utilities commission says we need to raise rates to get people to conserve. Soon, people will have to refinance to pay their electric bill.

49 Refuting appeal to humor Sergei claims that if global warming is accurate we will soon have beachfront property in Phoenix. Not actually. But we can expect an increase in tides. This will have an affect in the U.S. Let’s take a look at how.

50 Fallacies of language The intentional or unintentional use of language that obscures or confuses the meaning of an argument.

51 Fallacies of Language include: Ambiguity Equivocation Emotionally loaded language Technical language

52 Ambiguity Use of a term in a legitimate but different sense by two or more people involved in an argument.

53 Ambiguous I enthusiastically recommend this candidate with no qualifications at all.

54 Refuting ambiguity Let’s be clear. We are being told that no candidate would be better for this job. I agree. Having no one would be better than the candidate being supported by our opposition.

55 Equivocation Using a term in different ways in the context of the same argument. Don’t take an argumentation course, you are much too argumentative now.

56 Refuting equivocation. We all know many words have more than one meaning. I believe my opponent is using the same term in more than one here. That contorts the meaning of the argument. Let me restate it for you.

57 Emotionally loaded language Using language that avoids reasoning and seeks to alter the beliefs or actions of others through emotion

58 Loaded Once in a generation there is a breakthrough so revolutionary it can forever change the way you tan. This is a miracle product.

59 Refuting emotionally loaded language Identification theft is a crime as Celina tells you. It is not however,”the most heinous crime”one could be affected by. I would think murder or rape might be heinous. ID theft is a money crime.

60 Technical jargon Overwhelming an audience with new and unfamiliar terms in place of reasoning.

61 Jargon Our hedge fund has a great P/E ratio so you should go big into it. The LOC is of unknown duration.

62 Refuting technical jargon The President said “I did not have sexual relations with that woman.” For him, those words may technically be true. For most of us, I don’t think that is the case.

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