Critical Thinking Lecture 5b More Fallacies

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Critical ThinkingLecture 5bMore Fallacies

• By David Kelsey

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Ad Hominem

• To commit this fallacy is to think that some
  consideration about a person refutes the claims
  that he or she makes.
• Confusing the person and the claim
• Criticizing the person not the claim itself

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Ad Hominem again

• A personal attack ad hominem
• claiming that because someone has certain
  negative features it follows that a claim she
  makes is false.
• Examples

• Inconsistency ad hominem
• to hold that what someone says is false because
  it is inconsistent with something else she has
  said or done.
• Examples

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Circumstantial Positive ad hominem

• Circumstantial ad hominem
• holding that because a persons circumstances are
  a certain way it follows that some claim she
  makes is false.
• Priest example

• Positive ad hominem
• holding that the claim a person makes follows
  from some positive consideration about the
  person.
• Einstein example

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Poisoning the Well

• To poison the well
• an in advance ad hominem.
• For example,
• Rumors

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Genetic Fallacy

• When one tries to refute a claim based on its
  origin or history she has committed the genetic
  fallacy.
• Belief in Gods existence
• Genetic fallacy vs. Circumstantial ad Hominem

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Straw Man

• Straw man fallacy
• trying to refute a claim or argument by
  distorting it or oversimplifying it or
  misrepresenting it in such a way that it can be
  easily refuted.
• Reconfiguring a claim
• Knocking down a straw man
• Knocking down a straw man is easy business but
  knocking down a good argument is not.

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False Dilemma

• False dilemma
• limits considerations to a choice between only
  two alternatives although other reasonable
  alternatives are available.
• The form of a false dilemma
• Using a false dilemma for the purpose of
  deception
• Example
• Prayer in public schools

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Perfectionist fallacy

• Perfectionist fallacy
• Rejecting a policy or claim because it isnt
  perfect.
• A kind of false dilemma
• Example
• Instant replay

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Line Drawing Fallacy

• The Line-Drawing fallacy
• insisting that a conceptual line must be drawn at
  a particular point when drawing such a line isnt
  necessary.
• Examples
• Rich
• Bald
• Excessive force
• Line drawing and Vagueness

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Slippery Slope

• Slippery Slope
• Claiming that if we let some thing X occur it
  follows that something else Y will occur, yet
  there is no reason to think that if X occurs so
  must Y.
• Causation and slippery slope arguments
• Example
• Hand gun laws

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Misplacing the Burden of Proof

• Misplacing the burden of proof
• Misplacing the burden of proof on the wrong side
  of an issue.
• The 2 sides of an issue
• Example
• Should we go to war with Iraq?

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The burden of proof

• To say the burden of proof rests on a claim
• This just means that if one is to hold this
  position, then she must support it with
  argumentation.
• Example
• Iraq again
• Temporal Priority

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Where does the burden lie?

• Placing the burden
• Plausibility
• The burden ought to be placed on whichever side
  of an issue is less plausible.
• Example
• Affirmative
• The burden, in general, ought to be placed on the
  affirmative side of an issue.
• Example

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The burden of proof 3

• Special Circumstances
• Under special circumstances the burden of proof
  is placed on a particular side of an issue.
• The court
• The defendant is always innocent until proven
  guilty

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Appeal to ignorance

• Appeal to ignorance
• claiming that we should believe that some claim
  is true because no one has proved it false.
• Example
• Ghosts exist

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Begging the Question

• One begs the question when one of the premises of
  her argument assumes the truth of the conclusion.
• Examples
• Abortion
• An argument for Gods existence
• Circular reasoning