Logic and Philosophy in Science

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Logic and Philosophy in Science
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Lesson Objective To compare SENSE...
with NONSENSE.
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Logic at the Food Store
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If both items cost 4, which one is the better
value?
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(No Transcript)
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Unit Price
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What is Logic?

• Logic is the study of arguments
• Logic tells us whether or not something makes
  sense
• Logic is a tool we can use to make powerful
  decisions in science AND in everyday life

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Consider the Following Example

• 1. If it is light outside, it is daytime.
• 2. If it is dark outside, it is nighttime.
• 3. It is dark outside.
• 4. Therefore, it is nighttime.
• Does this conclusion make SENSE?

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NO!

• Why?
• Because the argument makes poor assumptions.
• Is it possible for it to be dark outside during
  the daytime hours?
• YES!
• Heavy cloud cover / shade
• Eclipse
• Volcanic ash in atmosphere
• We could be in Northern Alaska in January

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Another Example

• Hey Joe, will you please give me a dollar?
• Why?
• Because I asked you nicely.

Is this request reasonable?
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The Dollar

• Hey Joe, will you please give me a dollar?
• Why?
• Because you owe me a dollar.

We can prove whether or not Joe owes a dollar.
Therefore, we have a valid reason for requesting
the dollar.
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Another Example

• Hey mom, can I go to the party on Friday night?
• No.
• Mom, you should let me go to the party on Friday
  night because.
• How can we persuade mom?

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Form a Logical Argument!

• Hey mom, can I go to the party on Friday night?
• No.
• Mom, you should let me go to the party on Friday
  night because my best friend is moving to New
  York and I wont get to see her again. Also, the
  party will be supervised at all times by my
  friends parents and there will be no drugs,
  alcohol or inappropriate activities.
• Is it more likely that mom will let you go?

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Another Example

• We should save the whales.
• Why?
• Because they are magnificent creatures.
• This is a strong argument, but does it make
  LOGICAL SENSE?

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Saving the Whales

• We should save the whales.
• Why?
• Because they are an important part of the
  ecosystem and the health of many other species
  depends upon saving the whales.
• Can this argument be proved or disproved?
• Yes we can determine the truth of the
  argument.

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Fact vs. Opinion

• A fact is a statement that can be proved or
  disproved. Facts do not have to be true, they
  just need to be verifiable.
• Today is Sunday.
• An opinion is a statement that cannot be proved
  or disproved.
• It would be better if today was Saturday.

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Objective vs. Subjective

• An objective statement discusses an idea as an
  object and is unbiased.
• Scientific evidence suggests that we should take
  better care of the Earth.
• A subjective statement discusses an idea from the
  point of view of the subject (observer) and is
  biased.
• I believe we should take better care of the
  Earth.

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Biased vs. Unbiased

• A biased statement results from a personal
  opinion.
• I think I should win the prize because I am
  better than everyone else.
• An unbiased statement results from a fact.
• I will probably win the prize because I am the
  only person entered in the drawing!

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Another Example Do Aliens Exist?

• IF aliens exist, we should be able to find
  proof.
• We dont have any proof that aliens exist.
• THEN, aliens do not exist.
• Is this argument LOGICAL?

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NO!

• The argument makes silly assumptions.
• Assumption No. 1 if aliens exist, we should be
  able to find proof. What if we simply havent
  found proof YET?
• Assumption No. 2 just because we cant prove
  aliens exist, they cannot exist.
• In other words, we
• cannot prove that
• they DONT exist!

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Deduction vs. Induction

• Deductive statements are logical.
• All blue birds are birds.
• Inductive statements are illogical.
• All birds are blue.
• Venn Diagram Demonstration

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Summary Good vs. Bad Science

• Bad Science
• Opinions
• Biased
• Subjective
• Induction
• Dogs are better than cats.

• Good Science
• Facts
• Unbiased
• Objective
• Deduction
• Dogs and cats are different.

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Important!

• When offering an opinion-based statement, you may
  use opinions as long as you support them with
  logical reasoning.
• I think summer is the best season because it is
  warm and I like the warmth.
• If you are writing a scientific statement, you
  cannot use opinion.
• Summer is the best season for growing crops
  because it is the season that offers the most
  sunlight and warmth.

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In Summary

• A logical argument makes sense because it uses
  factual, unbiased, objective and deductive
  statements in order to persuade an audience.
• Illogical arguments dont make sense because they
  use opinionated, biased, subjective and inductive
  statements in order to persuade an audience.

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The Big Idea

• Be sure to carefully evaluate every statement you
  hear to be sure that it MAKES LOGICAL SENSE.
• In other words QUESTION REALITY.