HU 2000

Recognizing Fallacies

Constructing sound arguments requires valid logic and reasoning. If your premises (reasoning) are incorrect they are considered to be “fallacies”. There are several different types of fallacies that exist. Once you recognize the fallacies you are more likely to avoid them in your reasoning. 

(Hint: refer to textbook Chapter 11 for more information on fallacies.)

1. Match each fallacy with its definition in the chart below. 

 A. Begging the question                                 G. Appeal to fear       H. Questionable cause

 B. Hasty generalization                                    

 C. False dilemma                                               

                                                                                  I. Two wrongs make a right

 D Slippery slope                                                       J. Misidentification of the cause

 E. Appeal to authority                                                                                                                                                                                                                  

 F. Bandwagon

___. Also known as circular reasoning because the reasoning assumes the conclusion is true.

___. Sometimes occurs due to “peer pressure” or groupthink phenomenon when you may be influenced to conform to the opinion of the group.

___. A causal situation where we are unsure of the actual root cause of the issue. It’s possible to ignore a possible cause or to incorrectly assume a common cause.

___. This argument states that the action (or conclusion) is a justified response to another wrong action (or conclusion).

___. This occurs when there is no real evidence for the argument. Superstitions are a good example of this.

___. The “either/or” fallacy – the argument presents only two extreme alternatives and does not allow for alternative options.

___. Indicates that one negative action will lead to another, and then another worse one, and so on and so forth all leading to a terrible end result

___. Basing a belief on a source or person who is not qualified to give an expert opinion on the subject.

___. The argument supports its conclusion not by evidence, but by demands or threats of punishment or misfortune.

___. A general conclusion is reached based on a very small sample, so the reasons provide weak support for the conclusion.

Deductive Argument

In a deductive argument, the premises (reasoning) provide such strong support for the conclusion that, if the premises are true, then it would be impossible for the conclusion to be false. Deductive arguments are VALID or INVALID.

EXAMPLE: 

Valid – All children are young. Johnny is a child. Therefore, Johnny is young.

Invalid – All children are young. Johnny is a child. Therefore, all children are Johnny.

Complete each deductive argument below with a valid conclusion.

2. Premise 1: All humans are mortal. 

Premise 2: I am human.

Conclusion: Therefore, I am _______________ 

3. Premise 1: All birds have feathers.

Premise 2: Cardinals are birds.

Conclusion: Therefore, cardinals have _______________ 

4. Premise 1: There is a party at work today.

Premise 2: Jimmy is sick and not at work today.

Conclusion: Therefore, Jimmy will _______________ 

Inductive Argument

An inductive argument is an argument that is strong enough that, if the premises (reasoning) were to be true, then it would be unlikely that the conclusion is false. So inductive arguments are STRONG or WEAK depending on the strength and frequency of the premises (reasoning).

EXAMPLE: 

Strong - 74% of 20-year-old have a job. 89% of 30-year-olds have a job. Most 20- to 30-year-olds are employed.

Weak: John, 20, has a job. Mary, 30, has a job. Most 20- to 30-year olds are employed.

**The first argument is much stronger due to the fact that the sample size is much larger.

Complete each inductive argument below with a conclusion. Your conclusion may be strong or weak depending upon the strength of your premises.

5. Premise 1: Four-year-old Jeremiah likes to play with blocks.

Premise 2: Four-year-old Mary likes to play with blocks.

Conclusion: Four-year-old children at the daycare center probably _____________ 

6. Premise 1: Jill studies two hours a day.

Premise 2: Jill is on the honor roll.

Conclusion: Students who study two hours a day are most likely _____________ 

7. Premise 1: The houses on Washington Avenue are falling apart according to a real estate developer.

Premise 2: Christopher lives on Washington Avenue.

Conclusion: Christopher’s house is more than likely _____________ 

Evaluating Arguments

Evaluate the strength of each argument below based on the criteria for deductive and inductive arguments. Explain why you believe the argument and conclusion is valid or strong, OR invalid or weak.

8. Deductive argument: To graduate from UMA, Sally must pass all of her classes. Sally passed all of her classes at UMA. Therefore, Sally will graduate from UMA.

a. Is this argument valid or invalid? 

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b. Explain your answer 

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9. Inductive argument: I have a sore tooth. I also have a headache. Conclusion: I must have a cavity.

a. Is this argument strong or weak? 

Type answer here

b. Explain your answer 

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10. Deductive argument: All dogs are dangerous. The golden retriever is a dog. Therefore, the golden retriever is dangerous.

a. Is this argument sound or unsound? 

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b. In your words, explain your answer for 10a. 

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11. Inductive argument: When I wore my blue socks, my team won. When I wore my white socks, they lost. I have to wear blue socks so my team wins.

a. Is this argument strong or weak? 

Type answer here

b. Explain your answer for 11a. 

Type answer here

Emotion Through Action

Read the short story, Emotion Through Action, and answer the questions below.

12. Explain the wife’s inductive reasoning for determining her husband’s level of safety at work. 

Premise 1: The wife assumes that her husband works a desk job.

Premise 2: _______________.

Conclusion: The wife assumes that her husband has a safe job.

13. Explain how the husband knows that his wife is no longer comfortable with his job. 

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14. The husband says: “I know what I’m doing. It’s not my first time.” Why is his argument a generalization? Explain. (Hint: Refer to textbook pages 463-468 for more information about generalizations). 

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Reflection  

Reflect on what you have learned this week to help you respond to the question below. You may choose to respond in writing or by recording a video!



 

15. Why is it important to make decisions or draw conclusions based on true, valid, and sound reasons/arguments?

 

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