LESSON #8
Reading Assignment: 3.3 (pp. 138-148)
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All of these fallacies are problems with inductive arguments. The premises don't provide nearly enough logical evidence to support the conclusion, though there might be emotional reason to believe it. The fact that there isn't really a strong connection between premises and conclusion is hidden in some way.
9. Appeal to unqualified authority - This is only a fallacy when the person being put forth as an authority has no special qualification or is biased in some way, or else only one authority is cited on an issue where there is considerable disagreement between authorities, (such as philosophy or religion) This fallacy is often exploited by advertisers. A famous musician claiming that Sparkle toothpaste prevents cavities better than others is an invalid authority. A dentist conducting an independent study would be a valid authority as long as she was not getting paid by Sparkle Toothpaste Company.
10. Appeal to Ignorance - One of the premises admits that nothing is known about a subject and then the conclusion purports to assert definitely something one way or the other about the subject, on the basis of this ignorance.
11. Hasty generalization - The arguer makes a claim about an entire group based upon too small a sample.
12. False cause - The arguer tries to claim a cause and effect relationship about two events that are most likely just coincidental.
13. Slippery slope - this argument proceeds by warning of "snowball effect" that is probably not true. Argument usually goes to exaggerated extremes.
14. Weak analogy - An analogy is a comparison. This is a comparison that is not strong enough to support the conclusion. Just because two things or situations are similar in some respect does not mean they will be similar in relevant respects. Check analogies to make sure that similarities being cited are relevant to conclusion being drawn
Logic Coach Assignment: 3.3 I all questions, III 1-20
Assignment 1: (10 points each)
Identify the fallacies in the following arguments from the six listed in this exercise or else determine that there is no fallacy. If you are not certain of your answer, explain your reasoning.
1. There can't be life on other planets because we have never detected any.
2. Slim-Fast must work. After all, Tommy Lasorda endorses it.
3. Parking your car on campus is risky. I know three people who have had their stereos ripped off.
4. Every time I get paid I blow all my money. It's amazing how having a little cash can make a person so irresponsible.
5. My last cocker spaniel was a parti-colored female and she was an excellent hunter. It follows that this parti-colored cocker spaniel will be an excellent hunter, too.
Assignment 2: (10 points each)
Identify the fallacy in the following arguments from any of the 19 fallacies covered so far or else determine that there is no fallacy. Again, you may want to explain your reasoning.
1. Surely you will not hold architect Norris responsible for the collapse of the building. Norris has had nothing but trouble lately. His daughter eloped with a junkie, his son committed suicide, and his alcoholic wife recently left for Las Vegas with his retirement savings.
2. None of my grandchildren play a musical instrument, so it must be that young people just don't care about music anymore.
3. When you wear Type Z designer jeans you stand out from the crowd. Type Z jeans--not for just anyone.
4. Unless we maintain severe penalties for possession of small amounts of marijuana, it is inevitable that penalties for possession of large amounts of the drug will eventually be lowered. After that, the penalties for possession of hard drugs will become lighter. We can expect that hallucinogenics and opiates will become as common on our streets as candy.
5. TV commentators are always attacking big business for making "obscene profits" but the companies they work for have higher profits than almost any other industry. Ignore them.