Logical Fallacies Exercise
I. Identify the fallacies of sufficiency committed by the following arguments, giving a brief explanation for your answer. If no fallacy is committed, write “no fallacy. “1 1. The Daily News carried an article this morning about three local teenagers who were arrested on charges of drug possession. Teenagers these days are nothing but a bunch of junkies. Hasty Generalization – not enough examples. 2. If a car breaks down on the freeway, a passing mechanic is not obligated to render emergency road service.
For similar reasons, if a person suffers a heart attack on the street, a passing physician is not obligated to render emergency medical assistance. Weak Analogy – a physician has taken an oath to help people, but a mechanic hasn’t. 3. There must be something to psychical research. Three famous physicists, Oliver Lodge, James Jeans, and Arthur Stanley Eddington, took it seriously. Appeal to unqualified authority. Physicists aren’t authorities on psychical research. 4. The secretaries have asked us to provide lounge areas where they can spend their coffee breaks. This request will have to be refused.
Logical Fallacies Exercise Essay Example
If we give them lounge areas, next they’ll be asking for spas and swimming pools. Then it will be racquetball courts, tennis courts, and fitness centers. Expenditures for these facilities will drive us into bankruptcy. Straw Man. The real issue, lounge areas, is distorted to include pools and other things. 5. The accumulation of pressure in a society is similar to the build-up of pressure in a boiler. If the pressure in a boiler increases beyond a critical point, the boiler will explode. Accordingly, if a government represses its people beyond a certain point, the people will rise up in revolt.
Analogy – The similarity between psychological pressure and pressure in a boiler seems reasonable, so this one seems relatively strong. 6. A few minutes after Governor Harrison finished his speech on television, a devastating earthquake struck southern Alaska. For the safety of the people up there, it is imperative that Governor Harrison make no more speeches. False Cause – there is no causal connection between the speeches and the earthquake. 7. No one has ever been able to prove the existence of extrasensory perception. We must therefore conclude that extrasensory perception is a myth. Appeal to Ignorance. 8.
Lester Brown, universally respected author of the yearly State of the World report, has said that the destruction of tropical rain forests is one of the ten most serious worldwide problems. Thus, it must be the case that this is indeed a very serious problem. Argument by Authority – since Brown would be educated and informed about worldwide problems, this would be a relatively strong argument and not a fallacy. 9. Federal officers assaulted the family of Randy Weaver in northern Idaho, killing his wife, and they were also involved in the destruction of the Branch Davidian compound in Waco, Texas, with great loss of life.
The conclusion is clear that federal officials are just a pack of killers. Hasty generalization – not enough samples are cited. One might argue that this is a case of Missing the point or Suppressed Evidence, since the fact that that Federal officers have done these things is not enough evidence to conclude that they are killers – there would be other relevant information needed to make this conclusion from the premises given. 10. Pianist Ray Charles says that Sinclair paints are groovy. We can only conclude that Sinclair paints are very groovy indeed. Appeal to Unqualified Authority.
Ray Charles is a (blind) singer, so he has no relevant authority about the “grooviness” of paints. 11. Probably no life exists on Venus. Teams of scientists have conducted exhaustive studies of the planet’s surface and atmosphere, and no living organisms have been found. Argument by Authority – since scientists who have studied Venus are cited, they are the people who know this information better than anyone else. 12. We don’t dare let the animal rights activists get their foot in the door. If they sell us on the idea that dogs, cats, and dolphins have rights, next it will be chickens and cows. That means no more chicken Kiev or prime rib.
Next it will be worms and insects. This will lead to the decimation of our agricultural industry. The starvation of the human race will follow close behind. Straw Man. The real issue (that dogs, cats, and dolphins have rights) is exaggerated and the exaggeration is used to discredit the real issue. 13. No one would buy a pair of shoes without trying them on. Why should anyone be expected to get married without premarital sex? Analogy. The issue here is whether trying on a pair of shoes is a good analogy for sex. It has the similarity of someone trying something before they decide whether they like it or not.
But it has major weaknesses; sex involves another person, not just an inanimate object; sex involves caring for the feelings of the other person, while wearing shoes does not involve caring for the feelings of the shoes; and studies have shown that trying sex before marriage has no real connection with the level of sexual satisfaction within marriage. 14. No one has proved conclusively that America’s nuclear power plants constitute a danger to people living in their immediate vicinity. Therefore, it is perfectly safe to continue to build nuclear power plants near large metropolitan centers.
Appeal to ignorance. 15. There are more churches in New York City than in any other city in the nation, and more crimes are committed in New York City than anywhere else. So, if we are to eliminate crime, we must abolish the churches. False Cause Fallacy. There is no causal connection between number of churches and amount of crime. II. Answer “true” or “false” to the following statements: 1. If an arguer cites a statement by a recognized expert in support of a conclusion and the statement falls within the expert’s range of expertise, then the arguer commits an appeal to unqualified authority.
FALSE – this would an appeal to qualified authority. 2. If an arguer cites a statement in support of a conclusion and the statement reflects the strong bias of its author, then the arguer commits an appeal to unqualified authority. TRUE 3. In the appeal to ignorance, the arguer accuses the reader or listener of being ignorant. FALSE – appeal to ignorance is saying lack of proof constitutes proof. 4. If an attorney for the defense in an American or Canadian criminal trial argues that the prosecution has proved nothing beyond a reasonable doubt about the guilt of the defendant, then the attorney commits an appeal to ignorance.
In one sense this is true – but the issue in court is that your guilt has to be proven beyond a reasonable doubt, so this is an acceptable appeal to ignorance. 5. Hasty generalization always proceeds from the particular to the general. TRUE 6. The post hoc ergo propter hoc variety of the false cause fallacy presumes that X causes Y merely because X happens before Y. TRUE 7. If an argument concludes that X causes Y simply because X and Y occur over the same time interval, then the argument commits a false cause fallacy. TRUE 8.
If the conclusion of an argument depends on the occurrence of a chain reaction of events, and there is good reason to believe that the chain reaction will actually occur, the argument commits a slippery slope fallacy. FALSE – This would be a slippery slope argument, but not a slippery slope fallacy. 9. The fallacy of weak analogy always depends on an alleged similarity between two things or situations. TRUE 10. If an argument from analogy depends on a causal or systematic relationship between certain attributes, and there is good reason to believe that this relationship exists, then the argument commits no fallacy.
TRUE III. Identify the fallacies of relevance and sufficiency committed by the following arguments. If no fallacy is committed, write “no fallacy. ” 1. On our first date, George had his hands all over me, and I found it nearly impossible to keep him in his place. A week ago Tom gave me that stupid line about how, in order to prove my love, I had to spend the night with him. Men are all alike. All any of them want is sex. Hasty Generalization – sample group is too small. 2. Tagging by graffiti artists has become a terrible problem in recent years.
Obviously our schools are stifling the creative spirit of these young people. Missing the point – the obvious conclusion would be something about discipline. 3. Iraqi dictator Saddam Hussein has promised to treat the Kurds and Suni Muslims in Iraq with respect and dignity. Also, he has promised to abandon his earlier plans for becoming the dominant power in the Middle East. However, Hussein is a notorious liar and an outright murderer. Therefore, we should not trust these promises for a minute. Ad Hominem – but this one is not a fallacy – in this case Hussein’s character is relevant information.
4. Senate Majority Leader Tom Daschle argues that ethanol should be added to gasoline to reduce air pollution. But of course Daschle argues this way. He represents South Dakota, which is loaded with grain growers, and ethanol is manufactured from grain. Thus, we should ignore Daschle’s arguments. Ad Hominem Circumstantial – attacks motives. 5. World-famous paleontologist Stephen Jay Gould says that the dinosaurs were killed by a large asteroid that collided with the earth. Furthermore, many scientists agree with Gould. Therefore, we conclude that the dinosaurs were probably killed by an asteroid.
Appeal to authority – since a majority of scientists agree on this point and they are the people who would know, this is relatively strong. 6. Emily has bought over 100 tickets on the weekly state lottery, and she has never won anything. Therefore, the likelihood increases every week that she will win something if she continues to buy tickets. This is a particular example of a False Cause argument, known as the gambler’s fallacy. The fact that one has lost at a gambling game for a long time doesn’t change their chances at winning the next time.
For instance, if you are betting on a coin toss, and the coin has come up heads 5 time in a row, the chances of it coming up tails the next time is still exactly 50%. 7. Johnny, of course I deserve the use of your bicycle for the afternoon. After all, I’m sure you wouldn’t want your mother to find out that you played hooky today. Threat – appeal to force/fear. 8. As a businessperson you certainly want to subscribe to Forbes magazine. Virtually all the successful business executives in the country subscribe to it. Appeal to the people/Vanity 9.
Ellen Quinn has argued that logic is not the most important thing in life. Apparently Ellen advocates irrationality. It has taken two million years for the human race to achieve the position that it has, and Ellen would throw the whole thing into the garbage. What utter nonsense! Leads away from the real issue (Quinn’s argument that logic is not the most important thing in life) – Red Herring. 10. When water is poured on the top of a pile of rocks, it always trickles down to the rocks on the bottom. Similarly, when rich people make lots of money, we can expect this money to trickle down to the poor.
Weak Analogy – there is no particular similarity between pouring water on rocks and what happens when people earn money. 11. Extensive laboratory tests have failed to prove any deleterious side effects of the new pain killer lexaprine. We conclude that lexaprine is safe for human consumption. Appeal to ignorance 12. Environmentalists accuse us of blocking the plan to convert Antarctica into a world park. In fact, nothing could be further from the truth. Antarctica is a huge continent teeming with life. It is the home of millions of penguins, seals, sea birds, and sea lions.
Also, great schools of finfish and whales inhabit its coastal waters. Red Herring. Real issue: Blocking the plan to convert Antarctica into a world park. 13. Marge Schott, minority owner of the Cincinnati Reds, has argued that professional baseball should be exempt from federal antitrust legislation. But consider this: Schott is a disgusting racist bigot who speaks approvingly of Adolf Hitler. Clearly, we should ignore her antitrust arguments. Ad Hominem Abusive. If the arguer showed that Schott’s position as the minority lead of the Reds affected his argument, it could be a strong Ad Hominem Circumstantial.
But the information given is totally irrelevant to the real issue. 14. The operation of a camera is similar in many ways to the operation of an eye. If you are to see anything in a darkened room, the pupils of your eyes must first dilate. Accordingly, if you are to take a photograph (without flash) in a darkened room, the aperture of the camera lens must first be opened. Argument by Analogy. There seem to be relevant similarities between the eye and a camera lens, so this would be relatively strong. 15. Certainly Miss Malone will be a capable and efficient manager.
She has a great figure, a gorgeous face, and tremendous poise, and she dresses very fashionably. Missing the point. The premise about her figure, etc. , is irrelevant to the conclusion about her being a good manager. 16. Dear Internal Revenue Service: I received a notice that my taxes are being audited for last year. But you have no right to do this. The deadline for filing a return was April 15, and I filed my tax return on April 12-a full three days before the deadline. Missing the Point: The premise about the filing deadlines is irrelevant to the conclusion that the IRS has made a mistake. 17.
To prevent dangerous weapons from being carried aboard airliners, those seeking to board must pass through a magnetometer and submit to a possible patdown search. Therefore, to prevent alcohol and drugs from being carried into rock concerts, it is appropriate that those entering submit to similar search procedures. Analogy. It’s not clear that this is a relevant analogy. It’s not clear that alcohol and drugs are similar enough to dangerous weapons to make the analogy work. 18. Mr. Flemming’s arguments against the rent control initiative on the September ballot should be taken with a grain of salt.
As a landlord he would naturally be expected to oppose the initiative. Ad Hominem Circumstantial. It’s likely that Flemming’s being a landlord should be taken into account, so this is relatively strong. But still, his arguments are what are at issue, not his motives. 19. India is suffering a serious drought, thousands of children are dying of starvation in their mothers’ arms, and homeless beggars line the streets of the major cities. Surely we must give these poor downtrodden people the chance of bettering their condition in America, the land of wealth and opportunity. Missing the Point.
The premise that people in India are suffering would most clearly lead to the conclusion that other people in the world should help them out, give them food, help them grow their own food, etc. , but not that we should bring them to America. 20. Members of the jury, you have heard Shirley Gaines testify that the defendant did not offer to perform acts of prostitution for the undercover police officer. But Gaines is a known prostitute herself and a close friend of the defendant. Also, only a year ago she was convicted of twelve counts of perjury. Therefore, you should certainly discount Gaines’s testimony. Strong Ad Hominem.
Since all of the information is relevant to Gaines’ trustworthiness, it is a strong argument, even though it’s an Ad Hominem. 21. It is ridiculous to hear that man from Peru complaining about America’s poverty. Peru has twice as much poverty as America has ever had. Red Herring. The issue is America’s poverty, not Peru’s poverty. 22. Angela complains that the problems on the algebra test were too hard. But have you ever seen the way Angela flirts with that good-looking quarterback on the football team? She’s constantly batting those long, black eyelashes at him, and her tight-fitting sweaters leave nothing to the imagination.
Angela should pay more attention to her studies. Red Herring. The issue is the difficulty of the exam, not Angela’s behavior. 23. Nobody has ever proved that immoral behavior by elected officials erodes public morality. Therefore, we must conclude that such behavior does not erode public morality. Appeal to ignorance. 24. Freedom of speech is guaranteed by the First Amendment. Therefore, your friend was acting within his rights when he shouted “Fire! Fire! ” in that crowded theater, even though it was only a joke. Accident. This action is specifically excluded from First Amendment rights.
25. No one, upon encountering a watch lying on a forest trail, would expect that it had simply appeared there without having been made by someone. For the same reason, no one should expect that the universe simply appeared without having been made by some being. Analogy. Whether this is a strong or weak analogy has been debated throughout history, and people are fairly evenly divided about it! 26. On Monday I drank ten rum and Cokes, and the next morning I woke up with a headache. On Wednesday I drank eight gin and Cokes, and the next morning I woke up with a headache.
On Friday I drank nine Bourbon and Cokes, and the next morning I woke up with a headache. Obviously, to prevent further headaches I must give up Coke. Missing the Point or False Cause. The obvious conclusion (and the real cause) is to give up the alcohol, not the Coke. 27. Former Senate majority leader Trent Lott announced in a press conference that homosexuality is a sin. In view of Mr. Lott’s expertise in religious matters, we must conclude that homosexuality is a sin, just as he claims. Argument from Authority. The issue here would be whether Trent Lott is an expert on the issues of homosexuality and sin.
There’s not enough information given to establish it one way or another at this point. 28. Some of the parents in our school district have asked that we provide bilingual education in Spanish. This request will have to be denied. If we provide this service, then someone will ask for bilingual education in Greek. Then it will be German, French, and Hungarian. Polish, Russian, Chinese, Japanese, and Korean will follow close behind. We certainly can’t accommodate all of them. Straw Man. The real issue is bilingual education in Spanish, which is exaggerated to include a lot of other languages.