Logical Fallacies Beginning our foray into the world
Logical Fallacies Beginning our foray into the world of Argumentation Courtesy of: http: //www. unc. edu/depts/wcweb/handouts/fallacies. html
What is Fallacy? The term "fallacy" is not a precise term. One reason is that it is ambiguous. It can refer either to (a) a kind of error in an argument, (b) a kind of error in reasoning (including arguments, definitions, explanations, and so forth), (c) a false belief, or (d) the cause of any of the previous errors including what are normally referred to as "rhetorical techniques. " Philosophers who are researchers in fallacy theory prefer to emphasize (a), but their lead is often not followed in textbooks and public discussion. Second, it is sometimes hard to evaluate whether an argument is fallacious.
What is Fallacy? Fallacies are defects that weaken arguments. First, fallacious arguments are very, very common and can be quite persuasive, at least to the causal reader or listener. You can find dozens of examples of fallacious reasoning in newspapers, advertisements, and other sources. Second, it is sometimes hard to evaluate whether an argument is fallacious. An argument might be very weak, somewhat strong, or very strong. An argument that has several stages or parts might have some strong sections and some weak ones.
Affirming the Consequent Description: An error in formal logic where if the consequent is said to be true, the antecedent is said to be true, as a result. If P then Q. Q. Therefore, P. If taxes are lowered, I will have more money to spend I have more money to spend Therefore, taxes must have been lowered. Explanation: I could have had more money to spend simply because I gave up scratch-off tickets, crack-cocaine, and Sasquatch sighting expeditions.
Denying the Antecedent Description: It is a fallacy in formal logic where in a standard if/then premise, the antecedent (what comes after the “if”) is made not true, then it is concluded that the consequent (what comes after the “then”) is not true. If P, then Q. Not P. Therefore, not Q. If it barks, it is a dog. It doesn’t bark. Therefore, it’s not a dog. Since it doesn’t bark, we cannot conclude with certainty that it isn’t a dog -- it could be a dog who just can’t bark. It is not that clear that a fallacy is being committed, but because this is a formal argument following a strict form, even if the conclusion seems to be true, the argument is still invalid. This is why fallacies can be very tricky and deceptive.
Inconsistency Description: In terms of a fallacious argument, two or more propositions are asserted that cannot both possibly be true. In a more general sense, holding two or more views/beliefs that cannot be all be true together. Quotes from Yogi Berra are great examples of fallacies, especially inconsistencies. Example: "I never said most of the things I said. " - Yogi Berra I know this requires no explanation, and I don't mean to insult your intelligence, but for consistency's sake, I will explain. If he had said those things, then he said them, which is a contradiction to his claim that he never said them.
Post hoc (false cause) This fallacy gets its name from the Latin phrase "post hoc, ergo propter hoc, " which translates as "after this, therefore because of this. " Definition: Assuming that because B comes after A, A caused B. sometimes two events that seem related in time aren't really related as cause and event. That is, correlation isn't the same thing as causation. Examples: "President Jones raised taxes, and then the rate of violent crime went up. Jones is responsible for the rise in crime. “ The increase in taxes might or might not be one factor in the rising crime rates, but the argument hasn't shown us that one caused the other.
Red Herring Definition: Partway through an argument, the arguer goes off on a tangent, raising a side issue that distracts the audience from what's really at stake. Often, the arguer never returns to the original issue. Example: "Grading this exam on a curve would be the most fair thing to do. After all, classes go more smoothly when the students and the professor are getting along well. " Let's try our premise-conclusion outlining to see what's wrong with this argument: Premise: Classes go more smoothly when the students and the professor are getting along well. Conclusion: Grading this exam on a curve would be the most fair thing to do. When we lay it out this way, it's pretty obvious that the arguer went off on a tangent-the fact that something helps people get along doesn't necessarily make it more fair; fairness and justice sometimes require us to do things that cause conflict. But the audience may feel like the issue of teachers and students agreeing is important and be distracted from the fact that the arguer has not given any evidence as to why a curve would be fair.
Ad Hominem-Character Definition: Attacking the person making the argument, rather than the argument itself, when the attack on the person is completely irrelevant to the argument the person is making. Person 1 is claiming Y. Person 1 is a moron. Therefore, Y is not true. My opponent suggests that lowering taxes will be a good idea -this is coming from a woman who eats a pint of Ben and Jerry’s each night! The fact that the woman loves her ice cream, has nothing to do with the lowering of taxes, and therefore, is irrelevant to the argument. Ad hominem attacks are usually made out of desperation when one cannot find a decent counter argument.
Ad Hominem-Circumstance Definition: Suggesting that the person who is making the argument is biased, or predisposed to take a particular stance, and therefore, the argument is necessarily invalid. Person 1 is claiming Y. Person 1 has a vested interest in Y being true. Therefore, Y is false. Salesman: This car gets better than average gas mileage and is one of the most reliable cars according to Consumer Reports. Will: I doubt it—you obviously just want to sell me that car. The fact that the salesmen has a vested interest and selling Will the car does not mean that he is lying. He may be, but this is not something you can conclude solely on his interests. It is reasonable to assume that salespeople sell the products and services they do because they believe in them.
Tu Quoque A form of Ad Hominem Definition: Claiming the argument is flawed by pointing out that the one making the argument is not acting consistently with the claims of the argument. Person 1 is claiming that Y is true, but person 1 is acting as if Y is not true. Therefore, Y must not be true. Helga: You should not be eating that. . . it has been scientifically proven that eating fat burgers are no good for your health. Hugh: You eat fat burgers all the time, so that can’t be true. It doesn’t matter (to the truth claim of the argument at least) if Helga follows her own advice or not. While it might appear that the reason she does not follow her own advice is because she doesn’t believe it’s true, it could also be that those fat burgers are just too damn irresistible.
Argument from Ignorance Definition: In the appeal to ignorance, the arguer basically says, "Look, there's no conclusive evidence on the issue at hand. Therefore, you should accept my conclusion on this issue. " Example: "People have been trying for centuries to prove that God exists. But no one has yet been able to prove it. Therefore, God does not exist. " Here's an opposing argument that commits the same fallacy: "People have been trying for years to prove that God does not exist. But no one has yet been able to prove it. Therefore, God exists. " In each case, the arguer tries to use the lack of evidence as support for a positive claim about the truth of a conclusion. There is one situation in which doing this is not fallacious: If qualified researchers have used well-thought-out methods to search for something for a long time, they haven't found it, and it's the kind of thing people ought to be able to find, then the fact that they haven't found it constitutes some evidence that it doesn't exist.
Straw Man Definition: One way of making our own arguments stronger is to anticipate and respond in advance to the arguments that an opponent might make. The arguer sets up a wimpy version of the opponent’s position and tries to score point by knocking it down. Example: "Feminists want to ban all pornography and punish everyone who reads it! But such harsh measures are surely inappropriate, so the feminists are wrong: porn and its readers should be left in peace. " The feminist argument is made weak by being overstated--in fact, most feminists do not propose an outright "ban" on porn or any punishment for those who merely read it; often, they propose some restrictions on things like child porn, or propose to allow people who are hurt by porn to sue publishers and producers, not readers, for damages. Gun control = government will take all your guns
Irrelevant Conclusion Definition: An argument which purports to prove one thing instead proves a different conclusion. "I think that we should make the academic requirements stricter for students. I recommend that you support this, because we are in a budget crisis and we do not want our salaries affected. “ Topic A is the proposal that academic requirements be raised. Topic B is the possible effects of a budget crisis on teacher salaries. Topic A is abandoned and the unrelated topic B is introduced. Therefore, the author has not proven Topic A as intended.
Begging the Question Definition: A complicated fallacy, an argument that begs the question asks the reader to simply accept the conclusion without providing real evidence Examples: "Active euthanasia is morally acceptable. It is a decent, ethical thing to help another human being escape suffering through death. " Let's lay this out in premise-conclusion form: the argument either relies on a premise that says the same thing as the conclusion (which you might hear referred to as "being circular" or "circular reasoning"), or simply ignores an important (but questionable) assumption that the argument rests on. Sometimes people use the phrase "beg the question" as a sort of general criticism of arguments, to mean that an arguer hasn't given very good reasons for a conclusion, but that's not the meaning we're going to discuss here. Premise: It is a decent, ethical thing to help another human being escape suffering through death. Conclusion: Active euthanasia is morally acceptable. If we "translate" the premise, we'll see that the arguer has really just said the same thing twice: "decent, ethical" means pretty much the same thing as "morally acceptable, " and "help another human being escape suffering through death" means "active euthanasia. " So the premise basically says, "active euthanasia is morally acceptable, " just like the conclusion does! The arguer hasn't yet given us any real reasons why euthanasia is acceptable; instead, she has left us asking "well, really, why do you think active euthanasia is acceptable? " Her argument "begs" (that is, evades) the real question (think of "beg off").
False Dilemma aka False Dichotomy Definition: In false dichotomy, the arguer sets up the situation so it looks like there are only two choices. The arguer then eliminates one of the choices, so it seems that we are left with only one option: the one the arguer wanted us to pick in the first place. Example: "Caldwell Hall is in bad shape. Either we tear it down and put up a new building, or we continue to risk students' safety. Obviously we shouldn't risk anyone's safety, so we must tear the building down. " The argument neglects to mention the possibility that we might repair the building or find some way to protect students from the risks in question--for example, if only a few rooms are in bad shape, perhaps we shouldn't hold classes in those rooms.
Non-Sequitur It does not follow; conclusion is not the result of the facts A non-sequitur is when a conclusion doesn't follow from the premises---I don't understand how something works All men are mortal Socrates' wife was mortal Therefore, the chicken crossed the road.
Slippery Slope Definition: The arguer claims that a sort of chain reaction, usually ending in some dire consequence, will take place, but there's really not enough evidence for that assumption. Also known as “the Camel’s Nose— letting something small in, will result in larger undesirable gaining entry. The arguer asserts that if we take even one step onto the "slippery slope, " we will end up sliding all the way to the bottom; he or she assumes we can't stop halfway down the hill. Example: "Animal experimentation reduces our respect for life. If we don't respect life, we are likely to be more and more tolerant of violent acts like war and murder. Soon our society will become a battlefield in which everyone constantly fears for their lives. It will be the end of civilization. To prevent this terrible consequence, we should make animal experimentation illegal right now. " Since animal experimentation has been legal for some time and civilization has not yet ended, it seems particularly clear that this chain of events won't necessarily take place.
Can you name this Fallacy? Plagiarism is deceitful because it is dishonest. BEGGING THE QUESTION
Can you name this Fallacy? Water fluoridation affects the brain. Citywide, student’s test scores began to drop five months after fluoridation began. POST HOC (false cause)
Can you name this Fallacy? If I have cable, then I have seen a naked lady. I don’t have cable. Therefore, I have never seen a naked lady. Denying the Antecedent
Can you name this Fallacy? You support capital punishment just because you want an “eye for an eye, ” but I have several good reasons to believe that capital punishment is fundamentally wrong… STRAW MAN
Can you name this Fallacy? We have to stop the tuition increase! The next thing you know, they'll be charging $40, 000 a semester! SLIPPERY SLOPE
Can you name this Fallacy? Look, you are going to have to make up your mind. Either you decide that you can afford this stereo, or you decide you are going to do without music for a while. FALSE DILEMMA (DICHOTOMY)
Can you name this Fallacy? I'm a strong believer in freedom of speech and think artists should never be censored. However, when musicians like Marilyn Manson influence the youth, you have to draw a line and say no more. Inconsistency
Can you name this Fallacy? Of course the Senator from Maine opposes a reduction in naval spending. After all, Bath Ironworks, which produces warships, is in Maine. Ad Hominem-Circumstance
Can you name this Fallacy? Bill: "Smoking is very unhealthy and leads to all sorts of problems. So take my advice and never start. " Jill: "Well, I certainly don't want to get cancer. " Bill: "I'm going to get a smoke. Want to join me Dave? " Jill: "Well, I guess smoking can't be that bad. After all, Bill smokes. " Tu Quoque
Can you name this Fallacy? All children should have ample attention from their parents. Parents who work full-time cannot give ample attention to their children. Therefore, mothers should not work full-time. Irrelevant Conclusion
Can you name this Fallacy? Tony wants us to believe that the origin of life was an “accident. ” Tony is a godless SOB who has spent more time in jail than in church, so the only information we should consider from him is the best way to make license plates. Ad Hominem-Character
Can you name this Fallacy? Mother: It’s bedtime Jane: Mom, how do ants feed their babies? Mother: Don’t know dear. Close your eyes now. Jane: But mama, do ant babies cry when hungry? Red Herring
Can you name this Fallacy? If evolution were true, there would be DNA similarities. There are DNA similarities. Therefore, evolution is true. Affirming the Consequent
Can you name this Fallacy? You live on Sunny Street. You have a gun. Nobody else on Sunny Street has a gun. There was a murder on Sunny Street last night. You were involved. Argument from Ignorance
Can you name this Fallacy? Buddy Burger has the greatest food in town. Buddy Burger was voted #1 by the local paper. Therefore, Phil, the owner of Buddy Burger, should run for President of the United States. Non Sequitur
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