SBM Thinking Critically

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SBM - Thinking Critically
Recognizing Fallacies (Lesson 1A)
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DEFINITIONS OF 1A

• LOGIC - the study of the methods and principles
  of reasoning.
• ARGUMENT - set of facts or assumptions/otherwise
  known as PREMISES.
• FALLACY - a deceptive argument a conclusion is
  not well supported by its premises.

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Fallacy 1

• The best clothes to wear are Abercrombie and
  Fitch. After all,more people wear Abercrombie in
  Grand Rapids, than any other brand.
• The conclusion is that Abercrombie Fitch is the
  best brand of clothes to wear.
• The premise is that more people in Grand Rapids
  wear Abercrombie than any other clothing.

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Appeal to Majority

• P statement
• Many people believe p is true
• therefore
• p is true.

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Example 2

• I ate three worms and in an hour, my stomach
  problems were gone. The worms made my stomach
  problems go away.
• PREMISE I ate 3 worms./In an hour, my stomach
  problems were gone.
• CONCLUSION The worms made my stomach problems
  go away.

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False Cause

• A event of eating the worms
• B event of stomach ache going away
• A came before B
• therefore
• A caused B.

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Example 3

• Researchers have not proved that eating a 2000
  calorie diet will keep you healthy. Therefore,
  eating 2000 calories on a daily basis will not
  help you maintain your weight.
• PREMISE There is no proof eating 2000 calories
  will keep you on a healthy diet.
• CONCLUSION Eating 2000 calories will not help
  you maintain/loose weight.

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Appeal To Ignorance

• P statement
• P has not been proven false
• therefore
• p is true or exists.
• (VICE/VERSA)

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Example 4

• Two people got into two different accidents in
  the mall parking lot. The mall parking lot must
  be the cause of accidents.
• PREMISE 2 people got into accidents _at_ the mall
  parking lot.
• CONCLUSION The mall parking lot is the cause of
  the accidents.

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Hasty Generalization

• A B two linked events
• A B are linked one
• or a few times
• therefore
• A causes B.

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Example 5

• You dont support the Red Wings, so you are not
  a true hockey fan.
• PREMISE You dont support the Red Wings.
• CONCLUSION You are not a true hockey fan.

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Limited Choice

• P is false
• therefore
• only q can be true.

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Example 6

• In a commercial for Michelin tires, a picture of
  a baby is shown with the words because so much
  is riding on your tires .
• PREMISE You love/adore your baby.
• CONCLUSION You should buy Michelin Tires.

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Appeal to Emotion

• P is associated with a
• positive emotional
• response
• therefore
• p is true.

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Example 7

• PERSON 1 You should really stop spending money
  so much because your going in debt, your
  borrowing tons of money from others, and you
  slowly slipping away from some of your goals.
• PERSON 2 Ive seen you spend a lot of money at
  the mall too!!!

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Personal Attack

• P statement
• I have a problem with the person
• claming p.
• therefore
• p is not true.

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Example 8

• Society has an obligation to shelter the
  homeless because the needy have a right to the
  resources of the community.
• PREMISE the needy have a right to the resources
  of the community.
• CONCLUSION society has an obligation to shelter
  the homeless.

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Circular Reasoning

• Both statements are basically saying the same
  statement - its restated in different words.
• Society has an obligation to provide shelter only
  if the needy have a right to societal resources.

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Example 9

• We shouldnt fund genetic research because it
  goes against our ethics and has many ethical
  issues attached. Ethics is a basis of our society
  - so we cant afford to have to many ethical
  problems.

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Diversion (Red Herring)

• P genetic research
• Q ethical issues
• p is related to q and I have
• an argument concerning q
• therefore
• p is true.

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Example 10

• Amy has written many articles on pro-abortion. A
  speaker who opposes pro-abortion begins with
  saying Ms. Amy doesn't think there is anything
  wrong with abortion and all babies should be
  killed if needed, but I disagree.

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Straw Man

• P abortion topic
• I have an argument concerning
• a distorted version of p
• therefore
• I have you are fooled into concluding I have an
  argument concerning the real version of p.

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Homework

• 1A s 1 - 12