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Are There Any Fallacies in the Reasoning? CO SCI 58 Asking the Right Questions.

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Presentation on theme: "Are There Any Fallacies in the Reasoning? CO SCI 58 Asking the Right Questions."— Presentation transcript:

1 Are There Any Fallacies in the Reasoning? CO SCI 58 Asking the Right Questions

2 Fallacies You’ve learned to identify issue and conclusion, reasons, ambiguities and assumptions. Now you’re ready to start evaluating the quality of the reasoning. A fallacy is a reasoning “trick” that an author uses while trying to persuade you to accept a conclusion.

3 Common Fallacies Many fallacies are so common they have been given formal names. It’s not important to memorize the names, just to be able to identify that there is a fallacy.

4 Ad Hominem Proving a point by attacking a person or group rather than ideas. Name-calling is a common practice. Sue: The sooner we get out of Afghanistan, the better. At some point we need to say “enough!” Our continued concentration on Afghanistan is hampering our overall effort against terrorism. Rick: Why is it that you gutless liberals want to see us surrender to terrorists? We need to fight until we have won the war.

5 Ad Hominem Sue: The sooner we get out of Afghanistan, the better. At some point we need to say “enough!” Our continued concentration on Afghanistan is hampering our overall effort against terrorism. Rick: Why is it that you gutless liberals want to see us surrender to terrorists? We need to fight until we have won the war. This also demonstrates another type of fallacy called straw man.

6 Appeal to Emotion Authors use words that have an emotional appeal to sway you. Appeal to pity is the most common one for Ms. Lane’s class. Please give me more time for my assignment. My beloved best friend is so sick and I am worried to death. I just can’t concentrate on school right now.

7 There are Lots of Appeal Fallacies! Appeal to Authority Appeal to Belief Appeal to Tradition Appeal to Fear Appeal to Flattery Appeal to Ridicule Appeal to Spite … We could go on.

8 Appeal to Questionable Authority or Tradition We’ve always done it this way. Or X is against/for it so you should be too. Is X a reliable Our workers have always been happy working 9-5; there’s no need to change that schedule. Wondering about your future? Ask Zena, Beverly Hills’ own phychic/clairvoyant. Zena has been sought after and quoted in entertainment magazines, from TV’s Good Morning America, to Time. Including the Palm Beach Daily News and the Palm Beach Post. (Ad from Random Lengths)

9 Ad Populum (also called an Appeal to Popularity) Appeals to group-approved attitudes. Most Americans agree that… Everybody knows that…. Americans want to be protected against terrorists. We must use face recognition systems in public gathering places. That’s not fair. All the other kids get to go to the rave! Everyone knows the governor is unreliable; if we keep trusting him not to raise taxes, we could all be in debt by next year.

10 Equivocation A key word or phrase is used with two or more meanings in an argument such that the argument fails to make sense once the shifts in meaning are recognized. When Bill Clinton claimed “I never had sex with that woman,” he was equivocating; the half-truth was that by a certain very limited definition of “having sex,” he could say that—but he did not reveal, until pressed, what definition of “having sex” he was going by.

11 Slippery Slope Making the assumption that a proposed step will set off a chain of undesirable events, when procedures exist to prevent that sequence of events. Marijuana should not be legalized for any reason; medical or otherwise. Legalization would imply that there are no dangers to drug use. Our children will get the message that it is okay to experiment with heroin and designer drugs.

12 Extension Fallacy Attacking a position that appears similar to but is actually different from an opponent’s position. Then concluding that the opponent’s real position has been refuted. I support the idea of one’s choice to have their belly button pierced. Everybody should have the freedom to express their uniqueness in a way that they really enjoy and makes them feel good about themselves. What is more of a unique way than self-expressing yourself through body decorations? Adapted from Ravy Sam’s letter to the Press Telegram page A21

13 Also called straw man The “straw man” here is the idea of freedom of expression to refute parental arguments against belly button piercing. Parents are usually concerned with health issues like infections and tearing. They’re not against self-expression.

14 Straw Man Sue: The sooner we get out of Afghanistan, the better. At some point we need to say “enough!” Our continued concentration on Afghanistan is hampering our overall effort against terrorism. Rick: Why is it that you gutless liberals want to see us surrender to terrorists? We need to fight until we have won the war. Sue says that the overall effort against terrorism is harmed by the focus on Afghanistan. Does Rick answer this?

15 Either 0r Fallacy Also called a False Dilemma The writer oversimplifies an issue by stating only two choices when there are really more. Watch for: either ….or… the only alternative is.. the two choices are… because A has not worked, only B will…

16 Example: False Dilemma The Chinese government is so fierce about controlling the information dispensed among its citizenry that it recently shut down thousands of Internet cafes and blocked search engines Google and AltaVista. Chinese citizens deserve to become full members of the Internet society. American companies must show support for our values and refuse to provide Internet services in China until these gag orders are lifted.

17 Companies must? American companies must … refuse to provide Internet services in China It’s presented as though there are two black and white options, no Internet service for the Chinese people or wide open freedom.

18 Red Herrings This fallacy diverts your attention away from the real issue. The “red herring” is the other issue he’s using to misdirect you. Kids are experts Why didn’t you call me when you didn’t come home by 11p.m. from your date? My brother doesn’t have a curfew for dates.

19 Wishful Thinking Confusing “What Should Be” and “What Is” Reality or “what is,” is often in conflict with “what should be.” Computer game makers should not be forced to participate in a rating system. Parents should review the game content to see if they deem it appropriate for their child.

20 Confusing Naming with Explaining Naming makes us think that we have identified something that the person has or is that makes him act accordingly. A different name for a behavior is presented as the cause of it. Sony, Panasonic and other electronics manufacturers are against legislation requiring recycling fees. It’s big business versus the earth. Big business is greedy and bad, earth is good

21 Perfect Solutions If a solution doesn’t completely eliminate the problem, that doesn’t make it bad. It may be superior to no solution at all. We should not go through the extra expense of installing a firewall because hackers will still find security holes.

22 Begging the Question The speaker may put the burden on you to prove that his conclusion is not correct instead of giving reasons. Isn’t is worth $10 a month to protect your home computer from hackers? Show me that space aliens don’t exist! Or he may build on an unproven assumption. Have you stopped beating your wife?

23 More Begging the Question Sometimes the “reason” is just the conclusion restated in a slightly different way. It’s circular reasoning. Internet filtering software should be installed in schools because undesirable sites will be blocked.

24 What Kind of Fallacy is it? 1. We need to get the latest iPad right away. Everyone at school has one. 2. Don’t re-elect President Obama. He is a Marxist and a racist. 3. Gays should not be allowed to marry. Marriage has always been between a man and a woman. 4. Don’t swim in the ocean. TV star Nicole "Snooki" Polizzi says "the water's all whale sperm.“ 5. You can stop eating animal products and be healthy or keep eating them and be unhealthy. 6. Why should I do my math homework? I don’t want to be a math teacher.

25 Answers 1. Ad populum 2. Ad hominem 3. Appeal to tradition 4. Questionable authority 5. False dilemma 6. Red Herring. End of Lecture


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