Logical Fallacies

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Logical Fallacies
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Syllogism (not a fallacy)

• A logical argument presented in terms of two
  statements and a conclusion which must be true if
  the two statements are true.
• EX
• A-Mammals are warm blooded.
• B-Dogs are mammals.
• C-Therefore, dogs are warm blooded.

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Syllogisms continued

• Major Premise A-Mammals are warm blooded.
• Minor Premise B-Dogs are mammals.
• Conclusion C-Therefore, dogs are warm blooded.

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Logical Fallacies

• Fallacies are statements that resemble a logical
  argument but are actually flawed.
• They are often persuasive, but they (unfairly)
  manipulate the audience in order to win
  agreement.
• An error of reasoning based on faulty use of
  evidence or incorrect inference.

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Begging the Question

• Making a statement that assumes that the issue
  being argued has already been decided.

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Ad Hominem (Against the Man) Attacks

• Simply put, these are personal attacks.
• Attacking the arguer rather than the argument.

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Hasty or Sweeping Generalization

• Drawing conclusion from insufficient evidence, or
  applying a conclusion too broadly.

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False Dilemmas

• Also known as the Either/Or Fallacy.
• Simplifying a complex problem into an either/or
  dichotomy.

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Red Herring

• When an irrelevant topic is presented in order to
  divert attention from the main topic being
  argued.
• Changing the subject

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You Also (Tu Quoque)

• A logical fallacy that tries to discredit an
  argument by asserting that since the arguer does
  not abide by their argument, the argument is
  invalidated.
• A presents argument x
• A does not abide by argument x.
• Therefore, x is not true.
• A type of ad hominem.

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Post Hoc Reasoning

• A logical fallacy that involves looking back at
  two events that occurred in chronological order
  and wrongly assuming that the first event caused
  the second.

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Non Sequiturs

• It does not follow
• Using irrelevant premises to buttress a
  conclusion.
• The conclusion does not logically follow from the
  premises.

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Distorting Statistics

• It is what it sounds like.

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Faulty Use of Authority

• Failing to acknowledge disagreement among experts
  or otherwise misrepresenting the trustworthiness
  of sources.

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Straw Man Argument

• Disputing a view similar to, but not the same as,
  the view of ones opponent.
• Misrepresenting the other argument, attacking
  that misrepresented argument, and thinking you
  have attacked the real argument.
• Attacking a weak defender of an argument and
  acting as if the entire argument has been
  defeated.