PLEASE DO NOT WRITE ON THIS QUIZ

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1 PLEASE DO NOT WRITE ON THIS QUIZ Critical Thinking: Quiz 4 Chapter Three: Argument Evaluation Section I. Indicate whether the following claims (1-10) are either true (A) or false (B). 1. If an arguer precedes his or her conclusion with the phrase it very likely that, then the argument is probably meant to be deductive. 2. Categorical syllogisms are generally intended to be deductive arguments. 3. Arguments from definition are typically inductive arguments. 4. Predictive arguments are a common pattern of inductive reasoning. 5. An argument from analogy is common pattern of deductive reasoning. 6. An argument must have true premises in order to be sound. 7. An argument may be valid even if the conclusion of the argument is false. 8. Deductive arguments are either 100% valid or 100% invalid 9. In a cogent inductive argument, there will always remain some room for doubt about whether the conclusion of the argument is true. 10. Valid means basically the same thing as true. Section II. Multiple Choice 11. The argument Frogs and other amphibians are ectothermic. An ectotherm is an organism in which internal metabolic sources of heat are of relatively small or quite negligible importance in controlling body temperature. Thus, it necessarily follows that amphibians do not maintain their body heat from internal metabolic processes. is a. an argument by definition. b. an inductive generalization. c. a hypothetical syllogism. d. an argument by elimination. 12. The argument If Denise plays first base, then Laura plays shortstop; if Laura plays shortstop, then Tess plays catcher; so, if Denise plays first base, then Tess plays catcher is a. a modus ponens argument. b. a modus tollens argument. c. an affirming the consequent argument. d. a chain argument 13. The argument Jim is either a Buddhist or Jim is a Christian. I happen to know Jim is not a Christian. So, it follows that he must be a Buddhist, is a. an argument by elimination. b. an inductive generalization. c. a categorical syllogism. d. an argument by mathematics.

2 14. A three-statement argument in which all the premises begin with the words all, some, or no is called a(n) a. argument from analogy. b. hypothetical syllogism. c. modus ponens argument. d. categorical syllogism. 15. If an argument fails the strict necessity test, the argument should a. always, without exception, be treated as an inductive argument. b. always, without exception, be treated as a deductive argument. c. sometimes be treated as a deductive argument provided the language or context makes clear the author intended to offer a logically conclusive argument. d. none of the above. 16. Terms such as definitely, conclusively, this logically implies that, and this entails that are examples of a. inductive indicator words b. conclusion indicator words c. premise indicator words d. deductive indicator words 17. Inductive inferences can be either a. valid or invalid. b. sound or unsound. c. true or false. d. strong or weak. 18. Which inductive pattern does the following argument best represent? The human brain is like a very complex computer. Both computer and the brain receive and store data for future reference. Both make calculations and draw conclusions from data they have collected. But when a computer is filled with inaccurate information, it will nearly always yield inaccurate calculations and yield false conclusions. Hence, it seems likely the same is true of the human brain. For these reasons, it is imperative that we avoid filling our brains with inaccurate and misleading information. a. Statistical argument. b. Argument from authority c. Predictive argument d. Argument from analogy 19. The argument All men are women; Justin Bieber is a man; so, Justin Bieber is a woman is a. valid but unsound. b. invalid and unsound. c. strong and uncogent. d. weak and uncogent. 20. In order for an argument to be sound, the argument must a. have true premises b. be strong c. be valid d. both a and b e. both a and c

3 21. In order for an argument to be cogent, the argument must a. have true premises b. be strong c. be valid d. both a and b e. both a and c 22. The primary difference between a deductive and an inductive argument is that a. in a deductive argument, the conclusion is always certain or necessary, whereas an inductive argument often has a false conclusion. b. an inductive argument can only establish mere opinions, but deductive arguments establish facts. c. the author of a deductive argument intends for their conclusion to follow from the premises with strict logical necessity, whereas the author of an inductive argument intends for their conclusion to follow with probability. d. all of the above 23. Consider the following argument: Some SRJC instructors are Republican. Some SRJC instructors are Democrats. So, All SRJC instructors are either Republicans or Democrats. a. This argument is Sound. b. This argument is Unsound due to an invalid inference. c. This argument is Unsound because the first premise is probably false. d. This argument is Unsound because the second premise is probably false. 24. Ninety percent of instructors at Santa Rosa Junior College ride bikes to work, even in the rain. Sean Martin is an instructor at Santa Rosa Junior College. So, Sean Martin likely rides a bike to work, even when it s raining. a. This argument is Cogent. b. This argument is Uncogent due to a weak inference. c. This argument is Uncogent because the first premise is probably false. d. This argument is Uncogent because the second premise is probably false. Section III: For problems 25-34, indicate whether the given argument is best treated as deductive (A) or inductive (B). 25. No government has the right to force people to pay taxes. Therefore, the United States government has no right to force people to pay taxes. 26. On Monday, Irene wore a New York Mets jacket to class. On Wednesday, Irene wore a New York Mets hat to class. On Friday, Irene wore a New York Mets sweatshirt to class. It's pretty clear Irene is a New York Mets fan. 27. There is loud music blaring from Matt's house, lots of cars are parked out front, and I just saw two dudes carrying kegs of beer into the house. Let's check it out. It looks like Matt is having a party. 28. I think it s safe to assume that Jason Israel will be our starting point guard next year. Both of our starting guards are graduating this spring and no one else on the team has Jason s speed and ball handling skills. 29. If Wendy got an A in her Calculus class, then her boyfriend took her out to celebrate. Her boyfriend did take her out to celebrate. Clearly, therefore, Wendy did get an A in her Calculus class.

4 30. It s a good bet there are other advanced civilizations elsewhere in our galaxy. Consider the following facts: There are billions of stars in our galaxy. We know of many such stars that have planets orbiting them. Some of these planets may have developed life, and over many millions of years some of those planets will probably develop intelligent life capable of producing advanced technology. (Adapted from Carl Sagan on Advanced Civilization ) 31. Determinism is the view that everything that happens is fully determined by the laws of nature and the way the world was long before we were born. Either determinism is false or humans have no free will. But humans do have free will, so determinism is false. (Adapted from Peter van Inwagen, The incompatibility of Free Will and Determinism) 32. Everything that comes to exist must have a cause of its coming to be. Thus, the universe itself must necessarily have a cause, since it obviously came to exist. 33. In a recent Gallup poll, 72 percent of Californians said they support the death penalty for minor crimes such as drug possession and petty theft. Gallup polls are, in general, highly reliable. Thus, approximately 72 percent of Californians probably do approve of using the death penalty to punish minor crimes such as drug possession and petty theft. 34. Many teenagers who listen to heavy metal music act violently later on. So, it seems likely that listening to heavy metal music causes young people to engage in violent behavior. Section IV: For problems 35-39, determine whether the following deductive arguments are either valid (A) or invalid (B). 35. Yesterday, the professor said that anyone caught cheating on the exam would receive an F on the test. And I happen to know that several students did receive an F on the exam. So it follows that some students must have been caught cheating. 36. All Republicans are opposed to the federal healthcare law. Barack Obama is a Republican. So, Barack Obama is opposed to the federal healthcare law. 37. Some Asian American voters are Republicans. Many Republicans voted for Donald Trump. Hence, it follows that at least some Asian Americans voted for Donald Trump. 38. Whatever Oprah says is true. Oprah said that eating meat is dangerous. So eating meat must be dangerous. 39. Some animals are blue. Some animals are birds. So, at least some animals must be blue birds. Section IV: For problems Indicate whether each of the following inductive arguments are strong (A) or weak (B). 40. If it rains, the ceremony will be moved indoors. According to the National Weather Service, there s a 75 percent chance of rain. So, it would be sensible to prepare to set up for the ceremony indoors.

5 41. Last Tuesday I went to the Icky Enchilada for lunch. I ordered a burrito that turned out to have a cockroach in it. I ate there again on Thursday evening and I found fingernail clippings in my refried beans. On Saturday, I decided not to order food there, yet they served my beer in a glass that had lipstick on it. I d have to say the Icky Enchilada is not a very sanitary place to dine. 42. For the last 3 years, I ve visited Chicago on the Fourth of July, and the weather was always sunny and beautiful. My cousin Jim, who visits Chicago for a Blues music festival every June, has always commented on the mild and pleasant weather. I think I ll take the family to Chicago for Christmas this year since the weather there is always so nice and warm. 43. Four out of my five professors this semester are women. I guess most professors are women. 44. Last Monday evening I crashed my car. Just before the accident, I noticed the moon was full. A few weeks ago, I was walking across the quad and I tripped on a rock. Oddly, this happened just as I was noticing the moon was full. So, I suppose I ought to make sure I mark my calendar so that I ll remember to stay home during the next full moon. 45. According to my dentist, Dr. Snow, fluoride helps prevent tooth decay by making the tooth more resistant to acid attacks from plaque bacteria and sugars in the mouth. Moreover, the American Dental Association and virtually every other major association of professional dentists as well as faculty at dentistry colleges agree that fluoride is a safe and effective method of reducing the occurrence of tooth decay. Admittedly, a minority of experts disagree with this conclusion. Yet, it seems reasonable to accept that fluoride likely does help prevent tooth decay.