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By Mrs. Cardoza Cover A Know Book is a creative way to show your knowledge about a topic. On each page of your Know Book, you will take notes about a different logical fallacy. As you take notes, you should draw pictures, use color, and be as creative as you can be. Your Know Book will be displayed after you make it, and you will be able to use your Know Book on the test.
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Logical Fallacies
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1. Ad Hominem 2. Bandwagon 3. Begging the Question 4. False Dilemma 5. Hasty Generalization 6. Post Hoc 7. Red Herring 8. Relativist Fallacy 9. Slippery Slope 10. Straw Man
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What are logical fallacies? Logical fallacies are common errors in thinking that people make during attempts to persuade. They usually happen when the person trying to persuade has -weak, unsupported opinions -sloppy or immature thinking Page 1
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Avoid logical fallacies and point them out when others use them. Should we learn about logical fallacies in order to add them to our own arguments? NO!
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Logical Fallacy #1: Ad Hominem
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Ad Hominem In Latin, "Ad Hominem" means "against the man" or "against the person." When a person makes an Ad Hominem fallacy, he rejects the claim of another person based on some irrelevant information about the person making the claim. –Person A makes claim X. –Person B makes an attack on person A. –Therefore A's claim is called false. The reason why an Ad Hominem is a fallacy is that the character, circumstances, or actions of a person do not (in most cases) have a bearing on the truth or falsity of his/her claims. Page 2
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Example of Ad Hominem Bill: I believe that abortion is morally wrong. Dave: Of course you would say that, you're a priest. Bill: What about the arguments I gave to support my position? Dave: Those don't count. Like I said, you're a priest, so you have to say that abortion is wrong. Further, you are just a yes-man to the Pope, so I can't believe what you say. Page 2
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Ad Hominem attacks are usually committed by lazy or desperate people. Page 2
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Logical Fallacy #2: Bandwagon
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Bandwagon The Bandwagon is a fallacy in which a threat of rejection by one's peers (or peer pressure) is substituted for evidence in an "argument.“ This line of "reasoning" is flawed because peer pressure and threat of rejection do not form evidence for rejecting a claim. Page 3
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Example of Bandwagon Bill: I like classical music and I think it is of higher quality than most modern music. Jill: That stuff is for old people. Dave: Yeah, only weirdoes listen to that. Besides, Anthrax rules! Bill: Well, I don't really like it that much. Anthrax is much better. Page 3
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Example of Bandwagon Everyone’s saying that SeaSplash cologne is hot, the others are not. So, buy SeaSplash today! Page 3
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Logical Fallacy #3: Begging the Question
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Begging the Question (Also known as Circular Reasoning) Begging the Question is a fallacy in which people try to prove their argument by repeating their own argument in the explanation. This means that they basically repeat their argument over and over, going around in circles. Logical argument: You should obey the law because laws are made for your safety. Begging the Question: You should obey the law because it is the law. VS. BAD REASONING Page 4
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Example of Begging the Question Mayor Johnson is the most successful mayor the town has ever had because he's the best mayor in our history. Notice how the conclusion (he’s the best mayor in our history) is the same thing as the original argument (he’s the most successful mayor the town has ever had)? Page 4
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Example of Begging the Question Jill: "How do you know that God exists?" Bill: "Because the Bible says so." Jill: "Why should I believe the Bible?" Bill: "Because the Bible was written by God." Jill: “So, how do you know He exists?" Bill: "Because the Bible says so." Jill: "Why should I believe the Bible?" Bill: "Because the Bible was written by God." With Circular Reasoning, we get nowhere! Page 4
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Logical Fallacy #4: False Dilemma
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False Dilemma A False Dilemma is a fallacy in which a person makes it seem like there are only two possibilities. These two possibilities might actually be only two choices out of many, or they might both be wrong. -Either X or Y, -You did not choose X. -Therefore, you must choose Y. This line of "reasoning" is incorrect because there might be more options. Also, both claims could be false. So, you cannot conclude that one is true because the other is false. Check out this example in which both options are false: –Either 1+1=4 or 1+1=12. –It is not true that 1+1=4. –Therefore, 1+1=12. Page 5
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Example of False Dilemma Senator Jill: We'll have to cut education funding this year. Senator Bill: Why? Senator Jill: Well, either we cut education funding or we live with a huge deficit and we can't live with the deficit. Problem: Are there really only 2 options here? How about cutting money from other parts of the budget? Or increasing taxes? Cut education funding Live with huge deficit Dilemma: Page 5
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Example of False Dilemma Your grades show that you are obviously not trying. Either study more, or drop out of school and be a bum for the rest of your life! OR Page 5
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Logical Fallacy #5: Hasty Generalization
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Hasty Generalization (Also known as Leaping to a Conclusion) This fallacy is committed when a person makes a generalization about a group based on too little evidence. -a few members of group X have this characteristic -therefore, all members of group X have this characteristic People often commit Hasty Generalizations because of bias or prejudice. For example, someone who is a sexist might conclude that all women are unfit to fly jet fighters because one woman crashed one. People also commonly commit Hasty Generalizations because of laziness – they do not want to do the research necessary to make a logical conclusion. Page 6
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Example of Hasty Generalization Smith, who is from England, decides to attend school at Ohio State University. He has never been to the US before. The day after he arrives, he is walking back to his dorm room and sees two white (albino) squirrels chasing each other around a tree. In his next letter home, he tells his family that American squirrels are white. Page 6
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Logical Fallacy #6: Post Hoc
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Post Hoc (Also known as False Cause) A Post Hoc is a fallacy with the following form: –A occurs before B. –Therefore A is the cause of B. The Post Hoc fallacy derives its name from the Latin phrase "Post hoc, ergo propter hoc.“ This has been traditionally interpreted as "After this, therefore because of this." This fallacy is committed when a person concludes that one event causes another simply because it preceded the other. Page 7
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Example of Post Hoc I had been doing pretty poorly this season. Then my girlfriend gave me these neon laces for my spikes and I won my next three races. Those laces must be good luck. If I keep on wearing them, I will win for sure! Many superstitions start with a Post Hoc fallacy. Page 7
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Logical Fallacy #7: Red herring
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Red Herring (Also known as Wild Goose Chase) A Red Herring is a fallacy in which an irrelevant topic is presented in order to draw away attention from the original issue. This sort of "reasoning" has the following form: –Topic A is under discussion. –Topic B is introduced under the guise of being relevant to topic A (when topic B is actually not relevant to topic A). –Topic A is abandoned. This sort of "reasoning" is incorrect because merely changing the topic of discussion does not create a logical argument. Page 8
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Example of Red Herring Reporter: Is it true that your wife, the first lady, called Prime Minister Harper a moron? President: No, no, he’s a friend of mine. He’s not a moron at all – he’s a friend. I had a good time with him today. Problem: True, the president may be friends with the prime minister. True, they may have had a good time together. However, this information has nothing to do with the issue at hand: whether his wife called the prime minister a moron! the real issue Look here! Page 8
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Logical Fallacy #8: Relativist Fallacy
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Relativist Fallacy (Also known as the Subjectivist Fallacy) The Relativist Fallacy is committed when a person rejects a claim by asserting that the claim might be true for others but is not for him/her. This sort of "reasoning" has the following form: –Claim X is presented. –Person A asserts that X may be true for others but is not true for him/her. –Therefore A is justified in rejecting X. This is the view that a claim could be true for one person and false for another at the same time. However, as long as truth is objective (that is, not relative to individuals), then the Relativist Fallacy is a fallacy. Page 9
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Example of Relativist Fallacy Jill: Driving while drunk is dangerous. Bill: That may be true for you, but it is not true for me. Page 9
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Logical Fallacy #9: Slippery Slope
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Slippery Slope The Slippery Slope is a fallacy in which a person says that some event must directly follow from another. In most cases, there are a series of steps between one event and the other, but all of these steps get ignored with a Slippery Slope. This "argument" has the following form: –Event X has occurred (or will or might occur). –Therefore event Y is bound to happen. Never mind all the in-between stages. Page 10
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Examples of Slippery Slope We have to stop the tuition increase! The next thing you know, they'll be charging $40,000 a semester! You can never give anyone a break. If you do, they'll walk all over you. How did I get here so fast? Page 10
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Logical Fallacy #10: Straw Man
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Straw Man The Straw Man fallacy is committed when a person simply ignores a person's actual position and substitutes a distorted, exaggerated, or misrepresented version of that position. This sort of "reasoning" has the following pattern: –Person A has position X. –Person B presents position Y (which is a distorted version of X). –Person B attacks position Y. –Therefore position X is called false/incorrect/flawed. This sort of "reasoning" is incorrect because attacking a distorted version of a position simply does not equal an attack on the position itself. You might as well expect an attack on a poor drawing of a person to hurt the person! Page 11
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Example of Straw Man Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why she wants to leave us defenseless like that. Page 11
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Example of Straw Man Bill and Jill are arguing about cleaning out their closets. Jill: We should clean out the closets. They are getting a bit messy. Bill: Why? We just went through those closets last year. Do we have to clean them out every day? Jill: I never said anything about cleaning them out every day! Page 11
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On the last page of your Know Book... Imagine that you are trying to explain what a logical fallacy is to your 5-year-old cousin. Using language he or she would understand, define logical fallacy. (1-2 sentences) Now, draw a symbol that you think represents logical fallacies.
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