22 LOGICAL FALLACIES

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22 LOGICAL FALLACIES
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What are logical fallacies?

• When trying to make a case or argument where
  logic is missing or something in the case is not
  clear
• Is not necessarily a false statement
• Can be useful in debates

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Why learn logical fallacies?

• Point them out when an opponent uses one or offer
  reasoning if you use them
• Make you look smart
• Impresses judges
• Can remove an argument from the table not just
  weaken it
• You can know when you are using them and prepare
  for your opponents argument rather than being
  taken off guard and unprepared

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How do you point them out?

• State the name of fallacy in Latin and English
  making sure to use the phrase logical fallacy
• Tell everyone what the fallacy means and why it
  is wrong but do it without sounding pedantic
  (smarter than everyone else)
• Give a really obvious example of why the fallacy
  is incorrect, preferably the example should also
  be an unfavorable analogy for your opponents case
• Point out why the fallacy matters to the debate
  round

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Argumentun ad antiquitatem

• The argument to antiquity or tradition
• Argument that a policy, behavior or practice is
  right or acceptable because its always been done
  that way
• Example every great civilization in history has
  provided states subsidies for art and culture
• Try to avoid it but if you do use it, try to give
  a reason why it should be considered

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Argumentum ad hominem

• Argument directed at the person
• Attacking the character or motives of a person
  who has stated and idea rather than the idea
  itself can also be an attack on the source of
  information
• my opponents are fascists or Richard Nixon was
  liar and a cheat
• Can also be used when the person talking has
  something to gain from the policy (example Bill
  Gates talking against anti-trust legislation)

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Argumentum ad ignorantiam

• Argument to ignorance
• Assuming something is true simple because it
  hasnt been proven false (example global warming
  is true because nobody has demonstrated
  conclusively it is not)
• Which ever team/person has burden of proof
  (usually affirmative) has to be more careful in
  using this fallacy
• Example Prosecution who says that no alibi means
  guilty vs.. Defense saying prosecution didnt
  prove case so defendant is not guilty

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Argument ad logicam

• Argument to logic
• Assuming that something is false simply because
  proof or argument that someone has offered for it
  is invalid
• Also known as Straw Man argument
• Burden of proof determines whether it is fallacy
  or not (if affirmative team fails to provide
  sufficient support for its case, the burden of
  proof dictates they should lose the debate even
  if there exist other arguments not presented that
  could have supported the case)

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Argumentum ad misericordian

• Argument or appeal to pity
• Example Think of all the poor, starving people
  in Ethiopia. How can we not help them?
• This doesnt mean you cant argue for something
  like aid to Ethiopia, what it does mean is that
  you cant just use emotional pleas
• Do not use it unless the opposition has ONLY
  offered emotional pleas

10
Argumentum ad nauseam

• Argument to the point of disgust (repetition)
• Trying to prove something by saying it again and
  again
• Stating a main point over and over again instead
  of real arguments
• Make sure you SUPPORT your main points

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Argumentum ad numerum

• Argument or appeal to numbers
• Attempt to prove something by showing how many
  people think that its true
• Example 70 of all Americans support
  restrictions on access to abortions
• Dont confuse this with argumentum ad populum

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Argumentum ad populum

• Appeal to people or to popularity
• Trying to prove something by showing that the
  public agrees with you
• Narrowly designates an appeal to the opinions of
  people in the immediate vicinity like your judges

13
Argumentum ad verecundiam

• Argument or appeal to authority
• Someone tries to demonstrate the truth of a
  proposition by citing some person who agrees,
  even though that person may have no expertise in
  the given area
• Example Quoting Einstein on politics
• Only use this when they dont use qualified
  quotes to support the same point and/or imply
  some policy is right because so-and-so thought so

14
Circulus in demonstrando

• Circular argument
• Someone uses what they are trying to prove as
  part of the proof of that thing
• Always illegitimate but hard to spot

15
Complex Question

• Question that implicitly assumes something to be
  true by its construction
• Example Have you stopped beating your wife or
  Inasmuch as the majority of black Americans live
  in poverty, do you really think that self-help
  within the black community is sufficient to
  address their problems?
• Only a fallacy when used for something that
  hasnt been proved

16
Cum hoc ergo propter hoc

• With this, therefore because of this
• Mistaking correlation for causation (because two
  things occur simultaneously, one must be a cause
  of the other)
• Example President Clinton has great economic
  policies, just look at how great the economy is
• Usually called post hoc

17
Dicto simpliciter

• Sweeping generalization
• Making a sweeping statement and expecting it to
  be true of every specific case aka
  stereotyping
• Example Women on average are not as strong as
  mean and less able to carry a gun. Therefore
  women cant pull their weight in a military unit.
• When pointing it out in a round, try not to use
  the Latin and just attack the generalization

18
Nature, appeal to

• Assuming that whatever is natural or consistent
  with nature is good or that whatever conflicts
  with nature is bad
• Fairly rare, but usually seen in environmentalist
  argument

19
Naturalistic Fallacy

• Trying to derive conclusions about what is right
  or good (about values) from statements of fact
  alone
• Any inference of fact is another fact NOT a value
• The medicine will prevent you from dying does
  not lead to you should take this medicine
• Examples include argumentum ad antiquities or
  appeal to nature

20
Non Sequitur

• It does not follow
• Stating as a conclusion, something that does not
  strictly follow from the premises
• Example Racism is wrong, therefore, we need
  affirmative action
• Try to to use this for every argument but use it
  when the opposition is trying to construct A lead
  to B leads to C without justifying each step in
  the chain

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Petitio Principii

• Begging the question
• Assuming, when trying to prove something, what it
  is that your are trying to prove
• Very similar to circular argument
• Occurs when a question has been asked before in
  the discussion then a conclusion is reached on a
  related matter without the question having been
  answered
• Example The fact that we believe pornography
  should be legal means that it is valid form of
  free expression. And since its free expression,
  it shouldnt be banned

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Post hoc ergo propter hoc

• After this, therefore because of this
• Assuming that A caused B simply because A
  happened prior to B
• Example most rapists read pornography when they
  were teenagers obviously, pornography causes
  violence toward women.
• Similar to cum hoc ergo prompter hoc

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Red herring

• Introducing irrelevant facts or arguments to
  distract from the question at hand
• Example The opposition claims that welfare
  dependency leads to higher crime rates - but how
  are poor people supposed to keep a roof over
  their heads without our help?
• It is not fallacious to argue that benefits of
  one kind may justify incurring costs of another
  kind

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Slippery slope

• Not always a fallacy
• Argument that says adopting one policy or taking
  one action will lead to a series of other
  policies or actions also being taken without
  showing a causal connection between the advocated
  policy and the consequent policies
• Example If we legalize marijuana, the next
  thing you know well legalize heroin, LSD and
  crack cocaine.

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Straw man

• Refuting a caricatured or extreme version of
  somebodys argument rather than the actual
  argument theyve made
• Putting words into someone elses mouth or
  misinterpreting something said

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Tu quoque

• You too
• Defending an error in ones reasoning by pointing
  out that ones opponent has made the same error
• Example They accuse us of making unjustified
  assertions. But they asserted a lot of things,
  too.
• Can be helpful if both sides have done a bad job
  of debating and you want to point that out to the
  judges