Post Hoc Fallacy

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Post Hoc Fallacy

• (Faulty Casualty/Non-Sequitur)
• Evan Payne

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Definition

• Simply where one past event is used to explain a
  current one, though they may be completely
  unrelated
• Ex. I crashed my car into a tree. The tree was a
  cedar. So cedar trees must cause car crashes.

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• Post hoc, ergo propter hoc, meaning After
  this, therefore because of this.
• Used to explain an event by saying a previous
  event caused it

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• This graph shows the apparent correlation between
  the number of Firefox downloads and new WICCA
  members. WICCA is a modern cult/religion of
  witchcraft. The creators of this ad (as it is an
  ad, since its promoting Internet Explorer seen in
  the left) are trying to show that Firefox leads
  to following WICCA. The Keep the Faith is an
  appeal to Christians, designated by a cross.

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The Crucible

• Type Post Hoc
• Character Giles Corey
• Quote Last nightmark thisI tried and tried
  and could not say my prayers. And then she close
  her book and walks out of the house, and
  suddenlymark thisI could pray again! Act 1,
  pg. 186

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The Crucible

• Explanation In the frenzy of witchcraft
  accusations, Giles Corey states that he believes
  his wife is guilty, saying that he couldnt pray
  when she had her books out. Just because A
  happened (she read her books) doesnt mean that
  it caused B (Giles couldnt pray). Could also be
  seen as since she stopped reading, he could pray.

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The Crucible

• Type Post Hoc
• Character Mrs. Putnam
• Quote I knew it! Goody Osburn were mid-wife to
  me three times. I begged you Thomas, did I not?
  I begged him not to call Osburn because I feared
  her. My babies always shriveled in her hands!
  Act 1, pg. 189

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The Crucible

• Explanation Mrs. Putnam is backing Titubas
  accusation of Goody Osburn, claiming that she was
  responsible for the death of her babies. Even
  though she was her mid-wife three times, that
  doesnt mean it caused the deaths of the babies.

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The Crucible

• Type Post Hoc
• Character Danforth
• Quote Hale speaking There is a prodigious
  fear of this court in the country
• Danforth Then there is a prodigious guilt in
  the country. -Act 3, pg. 214

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The Crucible

• Explanation Danforth believes that the fear of
  the court comes from guilt. However, the fear is
  caused by the courts actions, not personal
  guilt. So fear does not mean a presence of
  guilt, with guilt also meaning witchcraft. So
  fear of the court does not necessarily come from
  guilt of witchcraft.

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Modern Society

• Type Post Hoc
• Speaker Al Gore
• Quote During my service in the United States
  Congress, I took the initiative in creating the
  internet.
• Bluedorn, Hans. Post Hoc Al-Gore Propter Hoc.
  fallacydetective. Fallacydetective. 20 Apr.
  1999. Web. 15 Feb. 2012

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Modern Society

• Explanation Al Gore was attempting to explain
  how he was different that his opponent in this
  quote. However, he claims that during his time
  in Congress, he decided to make the internet.
  This implies that the idea and inspiration for
  making the internet was result of being in
  Congress, which are not necessarily related.

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Modern Society

• Many modern superstitions were born of and based
  around a post hoc fallacy. Many of the bad
  luck superstitions are sustained because when
  people do these unlucky actions, they blame any
  resulting unfortunate event on the unlucky act.
  Thus, the current action is not really a result
  of a previous event.

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Works Cited

• Logical Fallacies. Niyamaklogic.
  Niyamaklogic. May 2009. Web. 14 Feb. 2012
• Keep the Faith. Jazzroc. Jazzroc. Nov.
  2008. Web. 14 Feb. 2012
• Post Hoc Examples. Hub Image. Hub Image.
  n.d. Web. 14 Feb. 2012