1
IV. FAULTY
REASONING
2
FAULTY REASONING
• The problem with these fallacies lies in the logic
– the reasoning process
• Rather than the data
• 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 you’re 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, ‘What’s wrong with authority? Is
anarchy better?’ So, it’s 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 “doesn’t make sense”
– an inference that “does not follow” from the evidence
7
FAULTY REASONING
* WHY IT’S 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 (Occam’s Razor)
• unspecified contributing causes, alternate theories or explanations
• A + B does not necessarily = C (faulty “causal chain”)
• A + B = Z (“How you’d 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 you’ll 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 Master’s degrees, so that equals a PhD.
 Because there are no class meetings, online courses are easier.
• “We don’t 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
it’s not my fault; it’s yours
• We talk ourselves into something -- Do we ever
rationalize something good?
13
FAULTY REASONING
3) RATIONALIZATION:
FREUD’S EGO DEFENSE MECHANISM:
• Rationalization is one of Freud’s 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 can’t hand in my paper today because the dumb computer
wouldn’t print it.” (blame scapegoat, like Scarecrow)
• “You can’t make an omelette without breaking a few shells.”
(blame virtue)
• “Yeah, I knocked over the garbage can, but you shouldn’t have
put it in my way.” (blame another)
 “It’s OK if I have another piece of cake; I’ll just go for a run
tomorrow.” (self-serving justification)
15
FAULTY REASONING
*EXAMPLES of RATIONALIZATION:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
It’s only this one time.
OK, but this is the last time.
Just one more.
It’s Spring Break.
I’m away at college.
I’m an adult now.
No one will ever know.
My parents will never know.
Who’s ever going to see those pictures?
I needed the money.
It doesn’t hurt anybody.
It’s in the privacy of my own home.
I’m entitled:
– age, class, race
– I worked hard all week or semester.
It’s my life!
•
•
Everyone else is doing it. (like Tu
Quoque)
It’s on sale.
I’ll just cram the night before.
I’ll go out tonight and just study all day
tomorrow.
I’ll just….
CHEATING excuses:
– Everyone’s 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.
– It’s not my major.
16
FAULTY REASONING
*EXAMPLE from Blues Brothers:
< http://www.youtube.com/watch?v=9TuLBa-rgBk >
• Jake: “Oh, please, don’t kill us. Please, please don’t
kill us. You know I love you baby. I wouldn’t leave
ya. It wasn’t my fault.
• Mystery Woman: You miserable slug! You think you can talk your
way out of this? You betrayed me.
• Jake: No I didn’t. Honest... I ran out of gas. I, I had a flat tire. I
didn’t have enough money for cab fare. My tux didn’t 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 WASN’T 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, I’ll 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 he’d be
addicted to it for life.”
• “If we legalize marijuana, then more people would start to take
crack and heroin, and we’d 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, what’s next?! Rifles and other hunting
weapons?!”
• “Allowing gays to marry will inevitably lead to the collapse of the
social security system.”
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 XP is better than Windows 2003 because WXP 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
<http://www.nizkor.org/features/
fallacies/>
THE END