REASONING

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REASONING

• AND COOKIES

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Theoretical and Practical reasoning

• Theoretical Reasoning
• Objective truth.
• Example
• P1. My cookie has chocolate chips.
• P2. Cookies with chocolate chips are called
  chocolate chip cookies.
• C. My cookie is a chocolate chip cookie.

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Theoretical and Practical reasoning

• Practical Reasoning
• Objective achieve a goal
• Example
• P1. To get your cookie Ill have to steal it.
• P2. I want your cookie.
• C. I have to steal your cookie.

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Philosophical Reasoning

• is theoretical.
• Example
• P1. If God exists, God is all powerful.
• P2. If God exists, God is all good.
• P3. Such a God would not allow evil.
• P3. Evil exists.
• C. God does not exist.

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Cookie Reasoning

• is practical.
• Example
• P1. If I want cookies I will come to philosophy
  gammas.
• P2. I want cookies.
• C. I will come to philosophy gammas.

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Deductive, Inductive and Abductive Arguments

• 1. Deductive Arguments are
• made up of statements called premises and
  conclusions which are TRUE or FALSE
• valid when they follow a form where if the
  premises are true, the conclusion must be true.

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Validity

• Example
• P1. All cookies are delicious.
• P2. Everything delicious is nutritious.
• C. All cookies are nutritious.

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Validity

• This is valid because
• P1. IF it is true that All cookies are
  delicious. And,
• P2. IF it is true that Everything delicious is
  nutritious.
• C. Then it MUST BE TRUE that All cookies are
  nutritious.

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Validity

• Because this argument has a valid form
• P1. All As are Bs
• P2. All Bs are Cs
• C. All As are Cs
• Where A cookies, B Delicious, C nutritious

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Validity

• If we thought of it as a Venn diagram, it would
  look like this

As
Cs
Bs
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Invalid

• Deductive arguments are invalid when, even if the
  premises are true, the conclusion isnt
  necessarily true.

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Invalid

• Example
• P1. Most people like cookies.
• P2. Peter is a person.
• C. Peter likes cookies.

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Soundness

• A deductive argument is sound if it has a valid
  form, AND all the premises are, in fact, TRUE.
• NOTE thus it is not necessary to say an argument
  is valid and sound. Just sound will do.

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100 Certainty

• Is thus possible with a sound, deductive
  argument.
• However, this certainty is gained at the cost of
  not really leaning anything new the conclusion
  is really just an analysis of the premises.

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2. Inductive Arguments

• 1. Inductive Arguments are
• made up of statements called premises and
  conclusions which are TRUE or FALSE
• Strong when they provide a high probability that
  the conclusion is true.

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Strong Inductive arguments

• Example
• P1. In a survey of 175 Pearson students, 170 said
  they like cookies.
• P2. There are a total of 200 Pearson students.
• C. Of the remaining 25, most will say they like
  cookies.

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Weak inductive arguments

• Inductive arguments are weak when they dont
  provide sufficient evidence
• E.g. if only 10 of 200 students were surveyed,
  the sample would be too small to make strong
  conclusions about.

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100 Certainty

• Is not possible with inductive arguments.
• At best they give us a high probability of truth.
• However, with this lack of certainty comes
  learning something new the conclusion cannot be
  derived from an analysis of the premises.

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Abductive arguments

• An abductive argument is reasoning to the best
  explanation
• Abductive arguments provide explanatory
  hypotheses.

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Abductive arguments

• The characteristics of a good abductive argument
  include
• Predictive power
• Coherence
• Comprehensiveness
• Simplicity
• Generation of new ideas

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Abductive arguments

• Example Which one is best?
• Andrew didnt bake the cookies, so
• Aliens made them.
• They came into existence spontaneously.
• He bought them at a bakery.

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Fallacies

• Mistakes in deductive and inductive arguments.
• See handout