Argument Types: Deduction and Induction

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Argument TypesDeduction and Induction

• Deduction specifies for validity
• induction generalizes for strength.

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Can you match the vocabulary?

• Use coherence, confine, depression,
  exploitation, persistent
• 1. Its hard to __ a cat to a pet carrier.
• 2. The instructions have no __ or meaning
  whatsoever.
• 3. The salesman was so __ that I finally bought
  something.
• 4. Justin suffered __ when his girlfriend broke
  up with him.
• 5. The news reporter exposed the __ of the
  workers.

• Use assurance, collapse, devote, infrastructure,
  nuclear
• 6. The workers will build the country's __ .
• 7. You have my __ that all will be done on time.
• 8.Would you rather have a __ power plant or a
  solar energy plant?
• 9.The huge truck made the old bridge __.
• 10.Priests __ their lives to their religion.

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Here are the vocabulary matches

• 1. Its hard to confine a cat to a pet carrier.
• 2. The instructions have no coherence or meaning
  whatsoever.
• 3. The salesman was so persistent that I finally
  bought something.
• 4. Justin suffered depression when his girlfriend
  broke up with him.
• 5. The reporters exposed the exploitation of the
  poor workers.

6. Workers will build the national
infrastructure. 7. You have my assurance that
everything will be done on time. 8.Would you
rather have a nuclear power plant or a solar
energy plant? 9.The huge truck made the old
bridge collapse. 10.Priests devote their lives to
their religion.
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What are deduction and induction?

• Deductive argument makes a general assertion and
  tries to apply that to a specific case.
• It creates a valid or invalid argument.
• The intention is the certainty of the truth of
  the conclusion and the logic delivered.
• Inductive argument identifies a specific truth
  and attempts to generalize about it.
• It creates strong or weak argument.
• The logic is limited to establishing the highest
  possible probability of the truth of the
  conclusion.

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Why classify argument type?

• To help develop a strategy for analysis
• To establish confidence expectations

Are cats always expected to land on their feet?
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Deduction specifies.

• Chain argument example
• If Ed wanted a garden, hed have one.
• If he had a garden, hed feel much pride.
• If he felt pride, hed throw great parties.
• So, if Ed wanted a garden, hed throw great
  parties.

Do penguins always dress formally at their
parties?
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Deduction tries to be valid.

• An argument is valid when the truth of the
  premises guarantees the truth of the conclusion.
• The truth of the conclusion of any argument does
  not logically guarantee the truth of the premises
  used to infer it.

Who in court tries to be valid?
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Is this deductive logic valid?

• All human beings are spiders.
• All spiders are mammals.
• Therefore, all human beings are mammals.
• Is the logic valid?

Is the spiders assumption that his friend has
been drinking valid?
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What about the assumption?
All human beings are spiders. All spiders are
mammals. Therefore, all human beings are
mammals. The logic is valid and the conclusion is
true, but those features alone obviously dont
guarantee the truth of the premises.
Is the salesman honest?
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Deductive if then reasoning
All human beings are mammals. Therefore, if there
is a human being in Chico, that person is a
mammal. This is a valid argument, because the
truth of the lone premise guarantees the truth of
the conclusion. In other words, if the premise
is true, the conclusion must be true.
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What is sound argument?

• A sound argument is a valid deduction whose
  premises are actually true.

Individuals will be antagonistic toward each
other when they perceive conflicting
interests. Individuals working individually
cannot escape coming into conflict with
others. So, individuals organized into a rational
society may escape some of the destructive
effects of conflicts. Even with its unstated
background knowledge premises, this is a weak
argument.
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Relevant Premises Matter.
Washington believed we should avoid foreign
alliances. Canada is a foreign country. So,
Washington would have wanted the United States to
avoid an alliance with Canada. The premises in
this argument are relevant.
How well does loud English really work with
foreigners?
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Induction can be strong or weak.

• While validity is either proved or not, strength
  and weakness are less precise categorizations.
• Sufficient background knowledge and good judgment
  are important factors in evaluating inductive
  arguments.

• The conclusions of inductive arguments may be
  acceptable if they meet a minimum standard the
  evidence.

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What are inductive fallacies?
Inductive fallacies are patterns of inductive
reasoning that are known to be deceptively
weak. They violate the rules of good
argumentation by having premises that are either
insufficiently probable or insufficiently
relevant.

• Fallacy of Division
• Inferring that what is true of a group is also
  true for all of its individuals.
• Fallacy of Composition
• Inferring that what is true for individuals is
  also true for a group of such individuals.

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Division and Composition Examples

• Fallacy of Division America is known for its
  freedom. So every American who plays a role in
  American history loves freedom.
• Fallacy of Composition Communities of Muslims
  are peaceful. Communities of Jews are peaceful.
  
• So a community of Muslims and Jews will be
  peaceful.

The End.