Logical Fallacies What is a logical fallacy? A logical fallacy is an error in logic that can make a plausible, but misleading argument. Inductive fallacies: Inductive fallacies are the result of the incorrect use of evidence. Ex: “This chalk is white; therefore, all chalk is white.” *With inductive fallacies, an arguer leaps to a conclusion based on insufficient evidence* Deductive fallacies: Deductive fallacies are the result of a failure to follow the logic of a series of statements. Ex: “The rooster crows at 5:00 AM, and the sun rises at 5:00 AM; therefore the rooster makes the sun rise.” *With deductive fallacies, an arguer makes an incorrect or unsupported link between cause and effect* Logical Fallacies (cont.) While there are two main categories of logical fallacies, it is important to note that there is often overlap. Some fallacies may fit into both categories. However, it is important to note that logical fallacies occur when : a)An arguer incorrectly links cause and effect. b)An arguer leaps to a conclusion based on insufficient evidence. #1.) HASTY GENERALIZATION: Prematurely jumping to a presumptuous conclusion. Prejudices and superstitions are the result of making a hasty generalization. Ex: “There was a news story about a guy in a fraternity who was a rapist, so now I carry mace if I know I’ll be going anywhere near a frat house.” How is this an example of the Hasty Generalization logical fallacy? It’s a prejudiced point of view. The arguer assumes that because one person in a fraternity is a rapist, all people in fraternities are rapist. The arguer is jumping to a presumptuous conclusion about people in fraternities. #2.) FALSE AUTHORITY: Falsely recognizing someone as an authority on something. Accepting someone’s credentials without careful evaluation. EX: http://www.youtube.com/watch?v=bZIzRqDOSZo How is this commerical an example of the Faulty Use of Authority logical fallacy? Each commercial assumes a connection between the specific celebrity’s popularity and their authority on the product or service they are promoting. #3.) POST HOC/FALSE CAUSE Post Hoc, Ergo Propter Hoc: “after this, therefore because of this.” Assuming that because one event follows another, the first event is the cause of the second. Ex: “The rooster crows at 5:00 AM, and the sun rises at 5:00 AM; therefore the rooster makes the sun rise.” How is this an example of the Post Hoc logical fallacy? The arguer assumes that simply because these two events occur sequentially, there is a cause and effect relationship between them. Ex: “A tornado hit my town after a group of Satan worshippers moved in, so god sent the tornado to punish us for allowing them to move here.” How is this an example of the Post Hoc logical fallacy? The arguer assumes a connection between the Satan worshippers and the tornado. Post Hoc- Correlation vs Causation • Just because two things are related (correlated) doesn’t mean that one caused the other. • For example– the murder rate has decreased, while the average temperature has increased steadily since 1975. Therefore, global warming prevents murder. Post Hoc- Correlation vs. Causation Post Hoc- Magical Thinking • “Last time I walked past a black cat, I tripped and hurt my arm, so now it must have been the cat.” • Mr. Governor issues a proclamation for the people of his state to pray for rain. Several months later, it rains. Praise the gods! • I knew I should have helped that old lady across the road. Because I didn’t, I have been having bad Karma all day. #4.) FALSE ANALOGY: Drawing an analogy or comparison between two situations that are totally dissimilar. Ex: “We know that overweight people have a higher mortality rate than thin people. We also know that black people have a higher mortality rate than white people. Do we subject black people to torturous treatments to bleach their skin? Of course not. We have enough sense to know that skin-bleaching will not eliminate sickle-cell anemia. So why do we have blind faith that weight loss will cure the diseases associated with obesity?” -Susan Wooley, Director of eating disorders clinic at The University of Cincinnati. How is this an example of the False Analogy logical fallacy? The arguer assumes that skin color and weight are analogous. She assumes that diseases that are specific to people of a certain skin color can be treated just like diseases that are specific to people of a certain weight. #5.) AD HOMINEM: Attacking a person’s character rather than their statements. Latin for “against the man.” Ex: “Ernest Hemingway was an alcoholic and a terrible father, so I won’t read his books.” How is this an example of the Ad Hominem logical fallacy? The arguer is attacking Ernest Hemingway’s character rather than his intellectual output. Ex: "She asserts that we need more military spending, but that is false, since she is only saying it because she is a Republican." A person's interests and circumstances have no bearing on the truth or falsity of the claim being made. While a person's interests will provide them with motives to support certain claims, the claims stand or fall on their own. #6.) FALSE DILEMMA: Poses an “either/or” situation by suggesting that only two options are possible. *Sometimes called the “black/white” fallacy* Ex: “If you don’t watch football, you’re not a real man.” How is this an example of the False Dilemma logical fallacy? This statement poses an “either/or” scenario in which a person either watches football (therefore making them a “real man”) or that person does not watch football (in which case they are not a “real man”). #6.) FALSE DILEMMA (Cont.): Ex: “Trust fund babies and corporate weasels are not allowed to read this book…if you are in one of these categories, here’s my first piece of advice: you must learn to be a problem solver not a problem creator.” -Bill O’Reilly, Who’s Looking Out For You? How is this an example of the False Dilemma logical fallacy? Bill O’Reilly poses a situation in which one is either a “problem solver” or a “problem creator” without evaluating any middle ground in between the two. #7.) SLIPPERY SLOPE: Claiming that one event will trigger a series of similar, undesirable events. *If an arguer fails to provide evidence to support his or her claim that one event will lead to a similar, undesirable event, then they are guilty of the “slippery slope” fallacy. Ex: “Cloning animals should be illegal because that would lead to cloning humans, and then we would have a race of clones.” How is this an example of the slippery slope logical fallacy? The arguer assumes that if cloning of animals is allowed, then cloning of humans will be too. Then, the arguer assumes that this hypothetical cloning of humans will grow out of control. #7.) SLIPPERY SLOPE (Cont): Ex: “If they legalize gay marriage, then they will legalize bestiality and pedophilia.” How is this an example of the Slippery Slope logical fallacy? The arguer jumps to the conclusion that if gay marriage is legalized, then other undesirable things will also be legalized. #8.) BEGGING THE QUESTION/CIRCULAR LOGIC A circular argument. When an arguer makes a statement that assumes that the very question being argued is already answered. The premises assume that the conclusion is true. Ex: “Women should not be permitted into the men’s club because the club is only for men.” How is this an example of the Begging the Question logical fallacy? The arguer does not adequately answer the original question (“why shouldn’t women be permitted into men’s clubs?”). Instead, the arguer treats the question as if it has already been answered. • Ex: Paranormal activity is real because I have experienced what can only be described as paranormal activity. • EX: If such actions were not illegal, then they would not be prohibited by the law. #9.) STRAW MAN: Setting up an extreme example of an opposing view to argue against. Ex: “Listen, you trust-fund babies and children of privilege, if you’re going to drink a quart of bourbon every day and smoke crack, this book is not for you.” -Bill O’Reilly, Who’s Looking Out For You? How is this an example of the Straw Man logical fallacy? Bill O’Reilly sets up an extreme example of “trust-fund babies” and “corporate weasels.” His example is so extreme that it becomes very easy to argue against. Ex: "Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why he wants to leave us defenseless like that." Attacking a distorted version of a position simply does not constitute an attack on the position itself. #10.) Tu Quoque: A rebuttal to an argument which does not refute the allegations, but simply counterattacks. Ex: “My step dad says I’m irresponsible, but I’m not. Besides, he’s a jerk.” How is this an example of the Tu Quoque fallacy? The arguer does not refute the allegations that they are irresponsible; instead, they simply counterattack. Ex: • 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. # 11.) NON-SEQUITUR: A totally illogical connection between cause and effect. Ex. People generally like to walk on the beach. Beaches have sand. Therefore, having sand floors in homes would be a great idea! As cool as the idea of sand floors might sound, the conclusion does not follow from the premises. The fact that people generally like to walk on sand does not mean that they want sand in their homes, just like because people generally like to swim, they shouldn’t flood their houses. Ex. 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. • I bet Phil makes one heck of a burger, but it does not follow that he should be President. #12.) AD POPULUM/BANDWAGON: When an arguer assumes that he or she can neglect properly supporting his or her argument by appealing to a thread of commonly held beliefs Ex: “If leprechauns aren’t real, then why do so many people believe in them?” No amount of believing in them will make leprechauns real. Ex: “Ten million (and counting) Americans can't be wrong, can they?“ Ten million Americans can be wrong, though. #13) Equivocation • When a key term or phrase in an argument is used in an ambiguous way, with one meaning in one portion of the argument and then another meaning in another portion of the argument. • EX: A warm beer is better than a cold beer. After all, nothing is better than a cold beer, and a warm beer is better than nothing. We used two meanings of the word “nothing interchangeably. Equivocation (continued) • EX: I have the right to watch "The Real World." Therefore it's right for me to watch the show. So, I think I'll watch this "Real World" marathon tonight instead of studying for my exam. • EX: Noisy children are a real headache. Two aspirin will make a headache go away. Therefore, two aspirin will make noisy children go away. #14) Middle Ground • Assumes that the middle position between two extremes must be correct simply because it is the middle position. This sort of "reasoning" has the following form: • Position A and B are two extreme positions. • C is a position that rests in the middle between A and B. • Therefore C is the correct position. Middle Ground (continued) • Example: Congressman Jones has proposed cutting welfare payments by 50% while Congresswoman Shender has proposed increasing welfare payments by 10% to keep up with inflation and cost of living increases. I think that the best proposal is the one made by Congressman Bumple. He says that a 30% decrease in welfare payments is a good middle ground, so I think that is what we should support. #15) Moving the Goalposts • Demanding from an opponent that he or she address more and more points after the initial counter-argument has been satisfied refusing to conceded or accept the opponent’s argument. Example: The moon landing were a hoax because we have no photos of the sites. Okay, we now have photos of the sites, but those are clearly photoshopped. #16) No True Scotsman • When a universal (“all”, “every”, etc.) claim is refuted, rather than conceding the point or meaningfully revising the claim, the claim is altered by going from universal to specific, and failing to give any objective criteria for the specificity. Logical Form: • All X are Y. • (it is clearly refuted that all X are not Y) • Then all true X are Y. No True Scotsman (continued) • Example : • John: Members of the UbaTuba White Men's Club are upstanding citizens of the community. • Marvin: Then why are there so many of these members in jail? • John: They were never true UbaTuba White Men's Club members. • Marvin: What’s a true UbaTuba White Men's Club member? • John: Those who don't go to jail. No True Scotsman (continued) • "Real men eat meat“ • "Real Americans don't question the existence of God" • "Real artists don't use a computer“ • Angus declares that Scotsmen do not put sugar on their porridge, to which Lachlan points out that he is a Scotsman and puts sugar on his porridge. Furious, like a true Scot, Angus yells that no true Scotsman sugars his porridge. #17) Appeal to Tradition Assumes that something is better or correct simply because it is older, traditional, or "always has been done." This sort of "reasoning" has the following form: • X is old or traditional • Therefore X is correct or better. • EX: Of course this mode of government is the best. We have had this government for over 200 years and no one has talked about changing it in all that time. So, it has got to be good. #18) Biased Sample • When a person draws a conclusion about a population based on a sample that is biased or prejudiced in some manner. • EX: Large scale polls were taken in Florida, California, and Maine and it was found that an average of 55% of those polled spent at least fourteen days a year near the ocean. So, it can be safely concluded that 55% of all Americans spend at least fourteen days near the ocean each year. #19) Cherry Picking • When only select evidence is presented in order to persuade the audience to accept a position, and evidence that would go against the position is withheld. • EX: My political candidate gives 10% of his income to the needy, goes to church every Sunday, and volunteers one day a week at a homeless shelter. Therefore, he is honest and morally straight. #20) Appeal to Ignorance • The burden of proof is placed on the wrong side, or a lack of evidence for side A is taken to be evidence for side B in cases in which the burden of proof actually rests on side B. EX: • Bill: "I think that some people have psychic powers." Jill: "What is your proof?" Bill: "No one has been able to prove that people do not have psychic powers." • The absence of evidence does not constitute evidence. Appeal to Ignorance (continued) • • • • John: Unicorns exist. Jane: Can you prove that unicorns exist? John: Can you prove that they don’t? The burden of proof is not on Jane to prove that unicorns don’t exist. John has made a claim and it is his job to back up his claim. • Note: The burden of proof is the obligation to prove one’s assertion. The burden of proof belongs to the side making a claim. #21) Loaded Language • Substituting facts and evidence with words that stir up emotion, with the attempt to manipulate others into accepting the truth of the argument. • The phrase “family values“ immediately invokes the feelings of warmth, security, honesty and support that a family brings, even though the term really means a few pet social issues - hatred of gays, being anti-abortion, and restricting roles for women. Loaded Language (continued) • “Insurgent,” “freedom fighter,” and “terrorist” can all be applied to the same group depending on the speaker's perspective. • The "USA PATRIOT Act" is a (brutally forced) acronym for Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act, but due to the title, it implies that those opposed to the Act are inherently unpatriotic. #22) Erroneous Appeal to Emotion • This is the general category of many fallacies that use emotion in place of reason in order to attempt to win the argument. It is a type of manipulation used in place of valid logic. • Emotions manipulated can include pity, fear, flattery, and others. • Appealing to emotion is a necessary rhetorical strategy (think pathos), but is not a substitute for logical thinking. Erroneous Appeal to Emotion (continued) • Ex. Power lines cause cancer. I met a little boy with cancer who lived just 20 miles from a power line who looked into my eyes and said, in his weak voice, “Please do whatever you can so that other kids won’t have to go through what I am going through.” I urge you to vote for this bill to tear down all power lines and replace them with monkeys on treadmills.