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IV. FAULTY REASONING

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Title: FALLACIES Author: shousenick Last modified by: Stephen Housenick Created Date: 2/22/2006 9:17:03 PM Document presentation format: On-screen Show – PowerPoint PPT presentation

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Title: IV. FAULTY REASONING


1
IV. FAULTY REASONING
2
FAULTY REASONING
  • The problem with these fallacies lies in the
    logic
  • the reasoning process
  • Rather than the data
  • They contain false premises.

3
FAULTY REASONING
  • 1) FALSE DILEMMA
  • either/or thinking
  • HINT the words either/or are often used
  • aka
  • bifurcation, the black and white fallacy, and
    false dichotomy
  • similar to
  • Oversimplification, Loaded Language

4
FAULTY REASONING
  • 1) FALSE DILEMMA
  • assumes only 2 sides to an issue exist
  • presents a situation or argument as having only 2
    sides
  • BUT more than 2 options, causes, sides to an
    issue
  • ignores other options, explanations, sides
  • both sides may be unpleasant, but the 2nd usually
    is
  • the or is so bad that you are guilted into
    siding with the either side

5
FAULTY REASONING
  • EXAMPLES of FALSE DILEMMA
  • You either support Feminism or youre a sexist
    pig.
  • Either man was created, as the Bible tells us,
    or he evolved from inanimate chemicals by pure
    random chance, as scientists tell us. The latter
    is incredibly unlikely, so...
  • You are either for unilateral nuclear
    disarmament or for nuclear war.
  • In a 1975 interview, the Shah of Iran was asked
    why he could not introduce into his authoritarian
    regime greater freedom for his subjects. He
    replied, Whats wrong with authority? Is anarchy
    better? So, its either authoritarianism or
    anarchy.

6
FAULTY REASONING
  • 2) NON SEQUITUR
  • it does not follow
  • the Conclusion does not follow from the
    Premises
  • it is not supported by the evidence, proof
  • it is therefore faulty, arbitrary, invalid,
    unconnected, unwarranted
  • it doesnt make sense
  • an inference that does not follow from the
    evidence

7
FAULTY REASONING
  • WHY ITS FALLACIOUS
  • Fallacious because
  • premise(s) is unrelated to the Conclusion
  • premise(s) is unfounded, unwarranted, unproven
  • a Big Leap in logic
  • missing evidence (proof)
  • perhaps missing a step in the argument
  • needs additional support
  • the writer/arguer has failed to connect the
    dots
  • to establish a connection between ideas
  • missing evidence (Occams Razor)
  • unspecified contributing causes, alternate
    theories or explanations
  • A B does not necessarily C (faulty causal
    chain)
  • A B Z (How youd come up with that?!)

8
FAULTY REASONING
  • ERROR in REASONING
  • Faulty INDUCTION
  • too big of a leap from the Specific to the
    General
  • like Overgeneralization
  • Faulty DEDUCTION
  • 2 unrelated premises are asserted (but not
    proven) as true
  • one premise may be untrue
  • both premises may be true individually, but the
    combination of them does not necessarily yield
    validity (fact, certainty)
  • Major Premise unrelated to the Conclusion is
    asserted (but not proven) as true
  • Minor Premise (related or unrelated to the
    Conclusion) is asserted as true
  • Conclusion is arbitrary, does not follow from/is
    not supported by the premises

9
FAULTY REASONING
  • RELATED FALLACIES
  • Fallacy of the Undistributed Middle
  • All A are B. All C are B. Therefore, all A are C.
  • Affirming the Consequent
  • If A then B. B is true. Therefore, A is true.
  • Denying the Antecedent
  • If A, then B. A is false. Therefore, B is false.

10
FAULTY REASONING
  • EXAMPLES of NON SEQUITUR
  • Past performance does not guarantee future
    results
  • It would fallacious to assume that it does
    predict success or failure
  • I did well in high school English therefore, I
    will do well in college English.
  • I failed high school English therefore, I will
    fail college English as well.
  • From the writers/producers/creators/director of
    the hit
  • From the team that brought you the 1 movie of
    last summer
  • SUBTEXT of ads
  • If you buy this product, then youll be popular,
    sexy, beautiful, successful, whatever happens to
    the people in the ads will happen to you.

11
FAULTY REASONING
  • EXAMPLES of NON SEQUITUR
  • Since half a million copies were sold and it was
    a best-seller for two decades, it must be a great
    book.
  • The book was great, so the movie will be, too.
  • I have two Masters degrees, so that equals a
    PhD.
  • Because there are no class meetings, online
    courses are easier.
  • We dont need books and libraries anymore
    because the Internet has so much information.
  • Since Egyptians did so much excavation to
    construct the pyramids, they were well versed in
    paleontology.
  • Since the President is away from the White House
    so often, the Vice President must run the
    country.
  • Since e-mail is so popular, we might as well
    stop making envelopes, stamps, and paper.

12
FAULTY REASONING
  • 3) RATIONALIZATION
  • rationalize
  • blame someone/thing else
  • self-serving excuse
  • flimsy justification
  • its not my fault its yours
  • We talk ourselves into something
  • Do we ever rationalize something good?

13
FAULTY REASONING
  • 3) RATIONALIZATION
  • FREUDS EGO DEFENSE MECHANISM
  • Rationalization is one of Freuds EDM
  • denial, displacement, projection,
    intellectualization, sublimation, repression,
    regression, reaction formation
  • think of these as conflict resolution
    techniques the Ego uses to settle tensions
    between the Id and the Super Ego
  • If we do or consider doing something that the
    Super Ego (which houses our morals values)
    objects to, disapproves, discourages, or takes
    exception to,
  • usually something the pleasure-seeking Id wants
  • If something happens that we find difficult to
    accept or that causes us discomfort or anxiety,
  • Then the Ego defends itself by making that
    something acceptable to the Super Ego through
    rationalization.
  • Then we create logical justifications (excuses,
    explanations, apologies) for it.
  • Like the other defense mechanisms,
    rationalization distorts reality (or at least
    transforms, alters, misrepresents it).

14
FAULTY REASONING
  • EXAMPLES of RATIONALIZATION
  • I cant hand in my paper today because the dumb
    computer wouldnt print it. (blame scapegoat,
    like Scarecrow)
  • You cant make an omelette without breaking a
    few shells. (blame virtue)
  • Yeah, I knocked over the garbage can, but you
    shouldnt have put it in my way. (blame another)
  • Its OK if I have another piece of cake Ill
    just go for a run tomorrow. (self-serving
    justification)

15
FAULTY REASONING
  • EXAMPLES of RATIONALIZATION
  • Its only this one time.
  • OK, but this is the last time.
  • Just one more.
  • Its Spring Break.
  • Im away at college.
  • Im an adult now.
  • No one will ever know.
  • My parents will never know.
  • Whos ever going to see those pictures?
  • I needed the money.
  • It doesnt hurt anybody.
  • Its in the privacy of my own home.
  • Im entitled
  • age, class, race
  • I worked hard all week or semester.
  • Its my life!
  • Everyone else is doing it. (like Tu Quoque)
  • Its on sale.
  • Ill just cram the night before.
  • Ill go out tonight and just study all day
    tomorrow.
  • Ill just.
  • CHEATING excuses
  • Everyones doing it.
  • Look at the business world!
  • The technology was made to help us cheat.
  • If the teacher were smart enough to catch me
    cheating.
  • The teacher grades on a curve, so I have to
    cheat.
  • I have to because of Affirmative Action.
  • I really need an A.
  • Its not my major.

16
FAULTY REASONING
  • EXAMPLE from Blues Brothers
  • lt http//www.youtube.com/watch?v9TuLBa-rgBk gt
  • Jake Oh, please, dont kill us. Please, please
    dont
  • kill us. You know I love you baby. I wouldnt
    leave
  • ya. It wasnt my fault.
  • Mystery Woman You miserable slug! You think you
    can talk your way out of this? You betrayed me.
  • Jake No I didnt. Honest... I ran out of gas. I,
    I had a flat tire. I didnt have enough money for
    cab fare. My tux didnt come back from the
    cleaners. An old friend came in from out of town.
    Someone stole my car. There was an earthquake. A
    terrible flood. Locusts. IT WASNT MY FAULT, I
    SWEAR TO GOD!

17
FAULTY REASONING
  • 4) REDUCTIO AD ABSURDUM
  • reduce to absurdity
  • use opponents reasoning against them
  • extend their argument to its absurd conclusion
  • often employed to ridicule opponent
  • also, based on the fallacious assumption that
    more is better or that less is better

18
FAULTY REASONING
  • EXAMPLES of REDUCTIO AD ABSURDUM
  • If we allow a man to marry another man, then we
    might as well allow him to marry his dog or his
    car.
  • If 2 are good, then 5 are better, but then all
    of them would be best.
  • If 2 less is good, then 5 less would be better,
    but then getting rid of them all would be best.
  • Since my physical therapist told me to do 3 sets
    of 10 with my dumbbells, I should be cleared to
    play sooner if I do 6 sets of 20 still, if I do
    12 sets of 40, Ill be reactivated much sooner.

19
FAULTY REASONING
  • 5) SLIPPERY SLOPE
  • One step sets off
  • an unstoppable chain of events
  • that ultimately leads to disaster/ruin
  • the fallacious argument against a proposal
  • that, if we take this 1 step ? danger

20
FAULTY REASONING
  • 5) SLIPPERY SLOPE
  • step
  • pass/defeat of law, start/end war, drink/puff
  • end
  • always a bad end (highway to hell)
  • bad, but possible
  • possible, not absurd
  • chain of events
  • one thing must lead to another
  • inevitable, inescapable, unavoidable, inexorable

21
FAULTY REASONING
  • 5) SLIPPERY SLOPE
  • fallacious because
  • ignores the similarities
  • ignores checks and balances
  • ignores the complexity of life and institutions
  • only one step
  • inevitable path to destruction (determinism)

22
FAULTY REASONING
  • EXAMPLES of SLIPPERY SLOPE
  • She kept her kid away from soda because one
    drink and hed be addicted to it for life.
  • If we legalize marijuana, then more people would
    start to take crack and heroin, and wed have to
    legalize those too. Before long we'd have a
    nation full of drug-addicts on welfare.
    Therefore, we cannot legalize marijuana.
  • Legalizing abortion will lead to murder of the
    elderly and the physically and mentally
    handicapped.
  • If we ban handguns, whats next?! Rifles and
    other hunting weapons?!
  • Allowing gays to marry will inevitably lead to
    the collapse of the social security system.

23
EXTRAS
24
EXTRAS
  • Argumentum ad antiquitatem
  • (appeal to antiquity or tradition)
  • something (behavior, practice, policy)
    right/acceptable because of tradition
  • It's always been done that way.
  • Every great civilization has believed in a
    higher power.
  • Argumentum ad novitatem
  • opposite of the Argumentum ad Antiquitatem
  • something better or more correct simply because
    it is new, or newer than something else.
  • Windows 2010 is better than Windows 2003 because
    W2010 just came out."

25
EXTRAS
  • Argumentum ad nauseam
  • made to the point of disgust by repetition
  • repetition to substitute for actual, real
    arguments, w/o substantiation, w/o justification
  • Leading or loaded or complex question
  • no right way to answer assumes something to be
    true by its construction
  • Have you stopped beating your wife ?

26
EXTRAS
Appeals to Authority to Belief to Common Practice to Consequences of a Belief to Fear to Flattery to Pity to Ridicule to Spite to SEX!!! Biased Sample Burden of Proof Ad Hominem Tu Quoque Circumstantial Ad Hominem Composition Confusing Cause Effect Division Gambler's Fallacy Ignoring A Common Cause Middle Ground Misleading Vividness Poisoning the Well Questionable Cause Relativist Fallacy Special Pleading Spotlight Two Wrongs Make A Right lthttp//www.nizkor.org/features/fallacies/gt
27
THE END
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