Induction

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(No Transcript)
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Homework
The Study Guide will be available Friday online

• Reading pp. 145-152
• Recommended Exercises(do the starred problems)
• 3.3.III (of relevance weak induction)
• 3.4 (of presumption, ambiguity, whole/part)
• 3.4.III (of any kind)

• Study Tip
• What type of fallacy does the argument commit ,
  if fallacious?
• Where are the offending elements in the argument?

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Attendance Quiz
Put your name, section number and todays date
(4/22) on a blank sheet of paper

• My dog and my neighbors tea-cup chihuahua are
  both domestic pets, house trained, and well loved
  members of the family. I know that my dog has
  food issues. So my neighbors dog likely has
  eating issues like mine.
• Identify
• Explain your answer.

• fallacy of relevance
• fallacy of weak induction
• fallacy of presumption
• fallacy of ambiguity or whole/part
• none of the above

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Quick Review

• Informal Fallacies

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Kinds of Informal Fallacies

• Fallacies of
• Relevance
• Weak Induction
• Presumption
• Ambiguity or Whole/Part
• Ambiguity
• Whole/Part

• Where premises do not support the conclusion
• Distraction from evidence supporting conclusion
• Arguer turns attention away from genuine evidence
• Evidence is put forward, but for a different
  conclusion
• No evidence provided

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Kinds of Informal Fallacies

• Fallacies of
• Relevance
• Weak Induction
• Presumption
• Ambiguity or Whole/Part
• Ambiguity
• Whole/Part

• Where premises do support the conclusion
• Insufficient evidence to warrant conclusion
• Truth of conclusion unlikely
• Fallacies of induction

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Attendance Quiz

• My dog and my neighbors tea-cup chihuahua are
  both domestic pets, house trained, and well loved
  members of the family. I know that my dog has
  food issues. So my neighbors dog likely has
  eating issues like mine.
• Identify

• fallacy of relevance
• fallacy of weak induction
• fallacy of presumption
• fallacy of ambiguity or whole/part
• none of the above

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Fallacies of Relevance

• Example straw man?
• Darwin's theory of evolution asserts that human
  beings developed after a long process of change,
  from pre-hominid ancestors who are also the
  source for our primate relatives - chimpanzees,
  gorillas, etc. If Darwin's theory is correct,
  then we can no longer assert with such arrogance
  that we are above the animals rather, human
  beings and human intelligence are simply
  different, but related results of the same
  evolutionary process that has produced the rest
  of the animal kingdom.

Not Fallacious
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Fallacies of Relevance

• Straw Man
• Someone misrepresents anothers argument
• Presents weaker argument
• Straw man vs. real man
• Attacks weaker argument as if it were the
  original
• Distorted argument often a fabrication

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Fallacies of Relevance

• Example red herring?
• Appearing on ABC's This Week, the Ohio Republican
  (Minority Leader John Boehner) was asked what to
  describe the GOP plan to dealing with greenhouse
  gas emissions, "which every major scientific
  organization said is contributing to climate
  change."
• Boehner replied "The idea that carbon dioxide is
  a carcinogen that is harmful to our environment
  is almost comical. Every time we exhale, we
  exhale carbon dioxide. Every cow in the world,
  you know when they do what they do you've got
  more carbon dioxide."
• "It's clear we've had change in our climate," he
  added. "The question is how much does man have to
  do with it and what is the proper way to deal
  with this? We can't do it alone as one nation."

The Huffington Post, Boehmer Cites Cow Farts to
Downplay Global Warming
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Fallacies of Relevance

• Red Herring (stinky fish)
• Someone diverts attention from subject at hand
• Introduction of a controversial, hot-button issue
• The original argument tied illegitimately to
  controversial position (the stinky fish)
• Controversial position attacked for its
  outlandishness

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Fallacies of Presumption

• Informal Fallacies

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Fallacies of Presumption

• Begging the Question
• Complex Question
• Either or (false dichotomy)
• Suppressed Evidence

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Fallacies of Presumption

• Begging the Question
• Conclusion is restatement of some premise
• Simple In same words
• Complex In different words of same meaning
• Deceptive Key premise missing but asserted as
  premise
• Circular argument
• Premises presuppose conclusion which, itself,
  presupposes premises

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Fallacies of Presumption
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Fallacies of Presumption

• BQ (restatement)
• We have a brain in our skulls but no mind. The
  mind is a myth, since the mind is just a fairy
  tale we tell ourselves to believe in life after
  death.

A myth and a fairy tale are one and the same thing
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Fallacies of Presumption

• BQ (circular)
• Of course I can pay you the ten dollars you owe
  me. However, can you lend me five dollars? If you
  give it to me, I can pay James back. James owes
  John, and John owes David. Once David gets paid,
  he can pay back the money he owes me. So I can
  pay you back that way, at least half of what I
  owe you. But David won't be able to give me what
  he owes me unless John gives him what he owes
  him. And unless James gives John money, I wont
  be able to begin to pay you back.

Conclusion you should give me five dollars
Why? Because you will get some of the money I
owe you.
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Fallacies of Presumption

• Complex Question
• After J. Gordon Liddy served time in prison for
  his role in the Watergate scandal that brought
  down President Nixon, he made an appearance on
  the Dick Cavett show. On the show, Cavett
  mentioned the high rate of homosexual activity in
  US prisons.
• Cavett Did you have any trouble adjusting to
  homosexuality in prison?
• Liddy No.
• Cavett There you have it folks. Mr. Liddy had
  no trouble adjusting to homosexuality in prison.

• The two questions in one
• Did you adjust to a homosexual lifestyle in
  prison?
• Was it difficult?

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Fallacies of Presumption

• Either or fallacy
• You should just drop out of school. Either take a
  full course load or youll have to drop out. And
  you cant take a full course load with all the
  drama occurring now in your life.

• Standard Features
• Express disjunction
• Reasonable alternatives ignored or suppressed

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Fallacies of Presumption

• Suppressed Evidence
• Cough syrup is an effective remedy for adults
  suffering from common respiratory distress. Kids
  will benefit as equally.

• Recognition of suppressed evidence can be
  challenging?
• Obvious instances are, of course, simple to
  identify
• More difficult cases background knowledge often
  necessary

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Fallacies of Presumption

• "The Second Amendment to the Constitution states
  that the right of the people to keep and bear
  arms shall not be infringed. But a law
  controlling handguns would infringe the right to
  keep and bear arms. Therefore, a law controlling
  handguns would be unconstitutional.
• "In fact, the Second Amendment reads, "A well
  regulated militia being necessary to the security
  of a free state, the right of the people to keep
  and bear arms shall not be infringed." In other
  words, the amendment states that the right to
  bear arms shall not be infringed when the arms
  are necessary for the preservation of a
  well-regulated militia. Because a law controlling
  handguns (pistols) would have little effect on
  the preservation of a well-regulated militia, it
  is unlikely that such a law would be
  unconstitutional. (p. 144 of our text)

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Fallacies of Presumption

• "The Second Amendment to the Constitution states
  that the right of the people to keep and bear
  arms shall not be infringed. But a law
  controlling handguns would infringe the right to
  keep and bear arms. Therefore, a law controlling
  handguns would be unconstitutional.
• "In fact, the Second Amendment reads, "A well
  regulated militia being necessary to the security
  of a free state, the right of the people to keep
  and bear arms shall not be infringed." In other
  words, the amendment states that the right to
  bear arms shall not be infringed when the arms
  are necessary for the preservation of a
  well-regulated militia. Because a law controlling
  handguns (pistols) would have little effect on
  the preservation of a well-regulated militia, it
  is unlikely that such a law would be
  unconstitutional. (p. 144 of our text)

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Fallacies of Presumption

• "The Second Amendment to the Constitution states
  that the right of the people to keep and bear
  arms shall not be infringed. But a law
  controlling handguns would infringe the right to
  keep and bear arms. Therefore, a law controlling
  handguns would be unconstitutional.
• "In fact, the Second Amendment reads, "A well
  regulated militia being necessary to the security
  of a free state, the right of the people to keep
  and bear arms shall not be infringed." In other
  words, the amendment states that the right to
  bear arms shall not be infringed when the arms
  are necessary for the preservation of a
  well-regulated militia. Because a law controlling
  handguns (pistols) would have little effect on
  the preservation of a well-regulated militia, it
  is unlikely that such a law would be
  unconstitutional. (p. 144 of our text)

"The Supreme Court, splitting along ideological
lines, on June 26 declared the District
of Columbia's ban on handgun ownership
unconstitutional." (Washington
Post) http//www.washingtonpost.com/wp-dyn/content
/story/2008/06/23/ST2008062300649.html?hpidtopnew
s
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Fallacies (on exam)

• (i) Identify the fallacy or fallacies committed
  in each of the following arguments. (ii) Explain
  clearly how this argument is fallacious. If you
  believe no fallacy is committed, explain this
  choice. (Each question is worth 10 points)
• Identify
• Explanation

• fallacy of relevance
• fallacy of weak induction
• fallacy of presumption
• fallacy of ambiguity or whole/part
• none of the above

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Homework
The Study Guide will be available Friday online

• Reading pp. 145-152
• Recommended Exercises(do the starred problems)
• 3.3.III (of relevance weak induction)
• 3.4 (of presumption, ambiguity, whole/part)
• 3.4.III (of any kind)

• Study Tip
• How is each specific fallacy a fallacy of that
  type?
• e.g. how is the fallacy of division a fallacy
  of ambiguity or whole/part