Lesson 12

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Lesson 12

• What Reasonable Conclusions are Possible?

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Same Reasons, Different Conclusions Why?

• Assumptions
• An assumption is an unstated belief that supports
  the explicit (clearly stated) reasoning.
• Dichotomous Thinking
• Occurs when we assume that there are only two
  possible answers to a question that has multiple
  possible answers.
• Also known as the either-or (or false dilemma)
  fallacy (pg. 78).

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Same Reasons, Different Conclusions Why?

• Dichotomous thinking
• Can have a negative impact on our thinking and
  choices.
• Sharply reduces the possibilities that careful
  reasoning could produce.
• We restrict our ability to be good critical
  thinkers.
• Overly simplifies complex situations.
• This type of thinking needs to be avoided.

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Same Reasons, Different Conclusions Why?

• Please help us resist the proposed noise
  ordinance. Those of us who are concerned about
  the number of jobs in our community want to
  attract as much industry as possible to our town.
  The proposed ordinance would prevent some
  industries from operating within our city limits.
  A little noise may be necessary for social
  progress.
• What is the conclusion? The reasons?
• What are some alternative conclusions?

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Same Reasons, Different Conclusions Why?

• To help avoid dichotomous thinking and discover
  alternative conclusions ask and answer three
  questions
• When is the conclusion accurate?
• Where is the conclusion accurate?
• Why or for what purpose is the conclusion
  accurate?

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Searching For Multiple Conclusions

• Conclusion Congress should not decriminalize
  marijuana.
• Reasons
• A group of British scientists has shown that
  smoking marijuana may causes serious brain
  damage.
• Marijuana smokers risk decreasing their
  fertility.
• Marijuana smokers often become heroin users.
• What alternative reasonable conclusions are
  possible?

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Searching For Multiple Conclusions

• Possible alternative reasonable conclusions
• Legalize marijuana in one area and observe the
  impact before making a national rule.
• Congress could sponsor research designed to
  develop a substance that would produce effects
  similar to those produced by marijuana without
  the possible side-effects.
• Congress could permit pot to be sold in stores
  along with other possibly hazardous materials.

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Productivity of If-Clauses

• If-clause
• States a condition that we are assuming to be
  true in order to enable us to reach a particular
  conclusion.
• Ex If you eat Cheerios on a daily basis, you are
  less likely to suffer from high cholesterol.
• Condition, If you eat Cheerios on a daily basis
• Conclusion, Eating Cheerios daily helps lower
  cholesterol.
• Assumption, Cheerios helps lower cholesterol.
• We are assuming the condition is true in order to
  reach our conclusion.

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Productivity of If-Clauses

• Further Examples
• If freedom of religion is meant when the writer
  speaks of the loss of our basic freedom, then
• If the birthrate continues to rise over the next
  five years, then
• If it can be proven that most of those using the
  insanity defense today are truly mentally ill,
  then
• If-Clauses point out that our conclusion is based
  on particular claims or assumptions.

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Productivity of If-Clauses

• Summary of If-Clauses
• Present us with multiple conclusions that we may
  wish to consider before making up our minds about
  an issue.
• Broaden the list of possible conclusions from
  which we can choose our opinion.

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Alternative Solutions as Conclusions

• Many times we are presented with issues that are
  put in the following form
• Should we do X?
• Is X desirable?
• Such questions are trying to get us to answer in
  a yes/no way (dichotomous).
• The real issue is what should be done about the
  problem that X proposed as a solution for?
• By going directly to the problem we are able to
  generate multiple conclusions which increases
  the flexibility of our thinking.

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Alternative Solutions as Conclusions

• When reasons in a prescriptive argument are
  statements of practical problems
• Look for different solutions to the problems as
  possible conclusions.
• Example (Next Slide)

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• Should we outlaw those nudist beaches on the
  edge of our community? We certainly should. Look
  at the traffic problems they are causing and the
  hundreds of cars that have been parking illegally
  since the beach opened.
• What is the real problem here?

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Example, cont

• If we change the question to,
• What should we do about the traffic and parking
  problems?
• Several possible solutions come to mind.
• For example,
• No, we should not outlaw the nudist beaches we
  should have police vigorously enforce the
  no-parking rules and have the park service
  restrict the number of people allowed on the
  beach.

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Conclusion

• Three ways of identifying alternative
  conclusions
• Try to identify as many conclusions as possible
  that would follow from the reasons.
• Use if-clauses to qualify alternative
  conclusions.
• Reword the issue to What should we do about Y?
• Some conclusions can be better justified than
  others, and the most believable ones should be
  the ones that most affect your reaction to the
  reasoning.
• As critical thinkers we should have standards of
  careful reasoning that we can apply to identify
  the strongest reasoning.

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In Class Practice

• Identify the issue, conclusion, and reasons.
• Identify other possible reasonable conclusions in
  the following paragraph.
• Are Jessica and Bill still seeing each other? I
  guess so. I saw them last week, and they were
  holding hands and smiling at one another. And
  just three days ago some friends of mine and I
  went to a party, and those two were there
  together. I haven't heard anything about them
  breaking up from any of the usual gossips. It
  looks to me like they're doing just fine.

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THE END

• Make sure your presentations are ready.
• Read chapter 14 for next meeting.