Fallacies

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Fallacies

• Minds Machines

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Fallacies

• Bad arguments are called fallacies.
• Fallacies tend to exploit common psychological
  aspects of our mind many people think that they
  are good arguments.
• Fallacies usually follow certain patterns, so
  there are several categories of common fallacies.
• You can see fallacies around you all the time
  once you recognize these patterns.

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Truth-Seeking vs Persuading

• One reason why there are so many fallacies is
  that many people use arguments to persuade other
  people, and to win debates, rather than to find
  the truth.
• As someone said Arguments are to people as what
  lampposts are for drunks they are used for
  support rather than illumination.
• There is probably a good evolutionary reason for
  why people want to persuade, rather than find the
  truth it is much easier to persuade, and there
  are immediate pay-offs to persuading others,
  while finding the truth is hard, and even if you
  find it, there may not be an immediate pay-off.
• Since we are doing philosophy in this course, our
  goal of arguments is to find the truth, not to
  win or persuade.
• Accordingly, in this course a good argument is
  understood as an argument that gets us closer to
  the truth, i.e. an argument that is sound.
• Of course, lawyers, politicians, car sales
  people, and basically everyone else (!) defines a
  good argument as one that is persuasive, sound or
  not.

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Fallacies of Relevance

• Fallacies that violate the first criterion of
  good arguments (the premises should support the
  conclusion) are fallacies of relevance. In other
  words, any time the conclusion cannot reasonably
  be drawn from the premises, we are dealing with a
  fallacy of relevance.
• Ad Hominem
• Appeal to Authority
• Red Herring
• Appeal to Fear, Force, Pity, Vanity, etc.
• Appeal to Ignorance

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Ad Hominem

• The Ad Hominem Fallacy is committed when someone
  rejects a belief or argument based on its source.
  Examples
• Bill Clintons proposal is bad, because he had
  sex in the White House (abusive ad hominem)
• Of course he opposes rent control. He owns two
  apartment buildings himself! (circumstantial ad
  hominem)
• John Kerry criticizes George Bushs military
  record? Wait, didnt Kerry get those 3 purple
  hearts by blowing up some innocent Vietnamese?
  (inconsistency ad hominem, pseudorefutation or
  tu quoque)

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Appeal to Authority

• Inappropriate Authority
• According to my dad
• Einstein said something about evolution
• Unidentified Authority
• Studies show
• Experts agree
• Science says
• Appeal to the Masses
• Everybody knows

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Red Herring

• Sometimes the premises seem related to the
  conclusion, but they really arent you are being
  led down the wrong path. Example
• I can't believe you thought that latest Disney
  movie was ok for children to watch. Disney pays
  12-year old girls 31 cents an hour to sow their
  products together.

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Appeal to Emotions (Fear, Pity, Vanity, etc)

• Fear
• If you dont believe in God, God sure wont be
  happy about that!
• Pity
• I deserve an A in the class because my mom was
  really sick and so I couldnt concentrate
• Vanity
• Intelligent people like yourself deserve fill in
  any product here

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Appeal to Ignorance

• An appeal to ignorance is made when one argues
  that something is the case since no one has shown
  that it is not the case
• Smoking is ok, since no one has proven that it is
  bad for your health.
• Our factory output shouldnt be restricted for
  environmental reasons, since no one has shown
  that the green house effect really exists.

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Fallacies of Assumption

• A fallacy of assumption violates the second
  criterion of a good argument (the premises should
  be plausible). Thus, a fallacy of assumption is
  an argument that makes a dubious assumption.
• False Dilemma
• Perfectionist Fallacy
• Line-Drawing Fallacy
• Straw Man
• Slippery Slope
• Begging the Question

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False Dilemma

• An argument assumes a false dilemma when it
  assumes that one of two cases must be true, where
  in fact there are other options as well.
  Examples
• Since youre not a capitalist, you must be a
  communist!
• Youre either with us, or against us.
• Are you a Democrat or a Republican?
• Nature or nurture?

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Perfectionist Fallacy

• The perfectionist fallacy presents us with a kind
  of all or nothing false dilemma
• We shouldnt give aid to countries where people
  are starving, because we cant eradicate hunger
  completely.
• Since no one has proven with absolute certainty
  that God exists, it is just as rational to
  believe that God does not exist as it is to
  believe that God does exist.

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Line-Drawing Fallacy

• Another kind of false dilemma Either we can draw
  a line between two things, or there is no
  difference between the two at all
• Abortion is murder from the moment of conception,
  since we cant draw the line before which the
  fetus is not a person, and after which the fetus
  is.

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Straw Man

• A Straw Man argument attacks something by
  attacking a helpless caricature of that
  something it often distorts the original by
  exaggeration. Example
• The movement to allow prayer in public school
  classrooms is a major threat to our freedom. The
  advocates of prayer in school want to require
  every school child to participate in a Christian
  religious program prior to every school day.

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Slippery Slope

• A slippery slope fallacy makes a dubious
  assumption that one thing will lead to another
• If the experts decide today that we should have
  fluorides in our tea, coffee, frozen orange
  juice, lemonade, and every cell of our bodies,
  whats next? Tranquilizers to avoid civil
  disorders? What about birth-control chemicals to
  be routed to the water in certain ethnic
  neighborhoods?

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Begging the Question

• Circular reasoning
• God exists because the bible says so. What, why
  we can trust what the Bible says? Easy, the Bible
  is the word of God.
• Of course my salary is higher than yours, because
  my work is more important. Youre asking me why
  it is more important? Well, my salary is higher,
  isnt it?
• The True Scotsman Fallacy
• All Germans like sauerkraut. Oh, your
  brother-in-law is German and he doesnt like
  sauerkraut? Well, he is not a true German then,
  is he?

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Other Fallacies

• Rhetorical Fallacies
• The One Big Ethical Fallacy

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Rhetorical Fallacies

• Simply by using certain words to frame an
  issue, question, or position, you can sway people
  one way or the other.
• Technical Note Maybe these are not so much
  fallacies, as they dont constitute any
  argument, but simply ploys to persuade people.
• Examples
• Yay and Boo words
• Exaggerating and Minimizing
• Proof Surrogates
• And many more!!!! Take my Methods of Reasoning
  course in the spring!

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Euphemisms and Dysphemisms

• Are we fighting terrorists or are we helping
  freedom fighters?
• Are you pro-life or pro-choice?
• Do you have a rendez-vous in the back of a
  Limosine or an affair in the back of a Buick?
• Feminist or feminazi?
• Etc.

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Hyperbole and Downplayers

• That was the biggest ever!!
• I was just trying to
• So, he got his degree from , did he?
• Etc.

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Proof Surrogates

• Obviously,
• Clearly
• As everyone knows,
• Anyone with half a brain would agree that
• Etc.

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And the One Big Ethical Fallacy

• Ought from Is!
• Well, thats how we should behave, because
  everyone behaves that way!
• Subclasses
• Naturalistic Fallacy Its natural, so its
  good
• Normalistic Fallacy Its normal, so its good
• Traditionalistic Fallacy Its always been that
  way, so its good