Fallacies
A fallacy is an error in reasoning. It is a weak argument. To be more specific, a fallacy is an "argument" in which the premises given for
the conclusion do not provide the needed degree of support. By becoming aware of the most common fallacies, you can hopefully avoid
them in your own speech.
Evidential Fallacies
Slippery Slope
Arguing that one bad thing will result in
many others. The Slippery Slope is a fallacy
in which a person asserts that some event
must inevitably follow from another without
any argument for the inevitability of the
event in question. In most cases, there are a
series of steps or gradations between one
event and the one in question and no reason
is given as to why the intervening steps or
gradations will simply be bypassed.
Also know as Camel’s Nose. If you let the
camel put his nose in the tent, next thing you
know his whole body will be in there.
1. If we pass laws against fully-automatic weapons, then it won't be long
before we pass laws on all weapons, and then we will begin to restrict other
rights, and finally we will end up living in a communist state. Thus, we
should not ban fully-automatic weapons.
2. You should never gamble. Once you start gambling, you find it hard to stop.
Soon you are spending all your money on gambling, and eventually you will
turn to crime to support your earnings.
3. If I make an exception for you, then I have to make an exception for
everyone.
4. We have to stop the tuition increase! The next thing you know, they'll be
charging $60,000 a semester!
5. The US shouldn't get involved militarily in other countries. Once the
government sends in a few troops, it will then have to send in thousands to
die.
6. You can never give anyone a break. If you do, they'll walk all over you.
7. We've got to stop them from banning pornography. Once they start banning
one form of literature, they will never stop. Next thing you know, they will be
burning all the books!
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Evidential Fallacies
Red Herring
Distracting listeners with sensational, irrelevant
material. “The name of this fallacy comes from the
sport of fox hunting in which a dried, smoked herring,
which is red in color, is dragged across the trail of the
fox to throw the hounds off the scent. Thus, a "red
herring" argument one which distracts the audience
from the issue in question through the introduction of
some irrelevancy.” An irrelevant topic is presented in
order to divert attention from the original issue. The
basic idea is to "win" an argument by leading attention
away from the argument and to another topic. (fallacy
files)
Myth of the Mean
Using an average to hide a problem
1. "We admit that this measure is popular. But we also urge you to note that there are so
many bond issues on this ballot that the whole thing is getting ridiculous."
2. "Argument" for a tax cut: "You know, I've begun to think that there is some merit in the
Republican's tax cut plan. I suggest that you come up with something like it, because If
we Democrats are going to survive as a party, we have got to show that we are as
tough-minded as the Republicans, since that is what the public wants."
1. The average depth of a stream in the mountain is six inches. (There are
some really deep places in the stream and several shallow. Trusting
this information could lead someone into ‘deep trouble’).
2. The average person makes 32,000 a year. (The reality is there are a few
really rich people and many very poor. The mean is not reflective.)
3. This community does not need aid because "the average monthly
income is well over $6,000." (In fact, high salaries skew the number and
in reality many families are far below the poverty line.
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Flawed Proofs
Ad Hominem
Attacking the person rather than the point
There are three major forms of Attacking
the Person:



ad hominem (abusive): instead of
attacking an assertion, the argument
attacks the person who made the
assertion.
ad hominem (circumstantial): instead of
attacking an assertion the author points
to the relationship between the person
making the assertion and the person's
circumstances.
ad hominem (tu quoque): this form of
attack on the person notes that a
person does not practice what he
preaches.
Poisoning the Well
Poisoning the well may be considered a
type of ad hominem attack. It involves
trying to discredit what a person might
later claim by presenting unfavorable
information about the person. The intent is
to bias listeners against the person in
question and hence that they will reject
any claims he might make.
1. You may argue that God doesn't exist, but you are just following a fad. (ad
hominem abusive)
2. We should discount what Premier Klein says about taxation because he won't
be hurt by the increase. (ad hominem circumstantial)
3. We should disregard Share B.C.'s argument because they are being funded by
the logging industry. (ad hominem circumstantial)
4. You say I shouldn't drink, but you haven't been sober for more than a year. (ad
hominem tu quoque)
5. "In order to maintain a civil debate, I will not mention my opponent's drinking
problem." (ad hominem abusive)
6. Sometimes the attack is on intelligence. For example, "If you weren't so stupid
you would have no problem seeing my point of view." Or, dismissing a
comment with "Well, you're just smarter than the rest of us.”
7. We have a vice president who learns fast...so fast indeed that he invented the
internet -- at the ripe old age of 12. Just last week, Vice-President Gore
claimed, falsely, that children "can walk into any gun shop, any pawn shop, any
gun show, anywhere in America and buy a handgun." Now I don’t know what
Vice President Gore wasn’t inhaling, because the fact is, it’s been illegal for
anyone under the age of 21 to go into a gun store and buy a handgun since
1968. But I suppose that in 1968, Al Gore was too busy inventing the Internet
to know the current law! (Ad hominem abusive) (Political Disobedience by
Charlton Heston)
8. These, they aren’t patriots. They are HATE-riots and they believe in the politics
of HATE-riotism. (Michael Moore in Cambridge, Mass)
1. Don't listen to him, he's a scoundrel.
2. Before turning the floor over to my opponent, I ask you to remember that
those who oppose my plans do not have the best wishes of the university at
heart.
3. You are told, prior to meeting him, that your friend's boyfriend is a decadent
wastrel. When you meet him, everything you hear him say is tainted.
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Flawed Proofs
Begging the question
Assuming as decided what has actually
not been proved.
Aka Circular Reasoning
1.
2. Since I'm not lying, it follows that I'm telling the truth.
3. "Marijuana is illegal in every state in the nation. And we all know that
you shouldn't violate the law. Since smoking pot is illegal, you shouldn't
smoke pot. And since you shouldn't smoke pot, it is the duty of the
government to stop people from smoking it, which is why marijuana is
illegal!"
4. The fact that we believe pornography should be legal means that it is a
valid form of free expression. And since it's free expression, it shouldn't
be banned,"
5. No sane person would consider suicide, because it’s insane to want to
take your own life.
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Defective Argument
Post Hoc Ergo Propter Hoc
Assuming because one event follows
another, it was caused by it. The name in
Latin means "after this therefore because
of this".
Faulty Analogy
Comparing things that are dissimilar in
some important way
1. "Most rapists read pornography when they were teenagers;
obviously, pornography causes violence toward women." The
conclusion is invalid, because there can be a correlation between
two phenomena without one causing the other.
2. I had been doing pretty poorly this season. Then my girlfriend gave
me this neon laces for my spikes and I won my next three races.
Those laces must be good luck...if I keep on wearing them I can't
help but win!
3. Bill purchases a new PowerMac and it works fine for months. He
then buys and installs a new piece of software. The next time he
starts up his Mac, it freezes. Bill concludes that the software must be
the cause of the freeze.
4. The Republicans pass a new tax reform law that benefits wealthy
Americans. Shortly thereafter the economy takes a nosedive. The
Democrats claim that the tax reform caused the economic woes and
they push to get rid of it. Jane gets a rather large wart on her finger.
Based on a story her father told her, she cuts a potato in half, rubs it
on the wart and then buries it under the light of a full moon. Over the
next month her wart shrinks and eventually vanishes. Jane writes her
father to tell him how right he was about the cure.
1. Employees are like nails. Just as nails must be hit in the head in
order to make them work, so must employees.
2. Government is like business, so just as business must be sensitive
primarily to the bottom line, so also must government. (But the
objectives of government and business are completely different, so
probably they will have to meet different criteria.)
3. "Minds, like rivers, can be broad. The broader the river, the shallower
it is. Therefore, the broader the mind, the shallower it is."
4. "We have pure food and drug laws; why can't we have laws to keep
movie-makers from giving us filth?"
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Defective Argument
Non sequitur
Reasoning in which principles and
observations are unrelated to each other
or to the conclusion drawn.
Literally means “it does not follow”
Hasty generalization
Drawing conclusions bases on insufficient or nonrepresentative observations
The size of the sample is too small to support the
conclusion
People often commit Hasty Generalizations
because of bias or prejudice. For example,
someone who is a sexist might conclude that all
women are unfit to fly jet fighters because one
woman crashed one. People also commonly commit
Hasty Generalizations because of laziness or
sloppiness. It is very easy to simply leap to a
conclusion and much harder to gather an adequate
sample and draw a justified conclusion. Thus,
avoiding this fallacy requires minimizing the
influence of bias and taking care to select a sample
that is large enough. (Nizkor Project)
1. If we legalize marijuana, the next thing you know we'll legalize heroin, LSD,
and crack cocaine.
2. If the mill were polluting the river then we would see an increase in fish deaths.
And fish deaths have increased. Thus, the mill is polluting the river.
3. From Speaker of the House Newt Gingrich on why men are more suited than
women to traditional military combat roles: “If combat means living in a ditch,
females have biological problems staying in a ditch for 30 days because they
get infections…(Moreover,) males are biologically driven to go out and hunt for
giraffes.” Rep. Pat Schroeder responded: “I have been working in a male
culture for a very long time, and I haven’t met the first one who wants to go out
a hunt a giraffe.”
4. "Bill lives in a large building, so his apartment must be large."
1. Fred, the Australian, stole my wallet. Thus, all Australians are thieves. (Of course, we shouldn't
judge all Australians on the basis of one example.)
2. I asked six of my friends what they thought of the new spending restraints and they agreed it is a
good idea. The new restraints are therefore generally popular
3. Smith, who is from England, decides to attend graduate school at Ohio State University. He has
never been to the US before. The day after he arrives, he is walking back from an orientation
session and sees two white (albino) squirrels chasing each other around a tree. In his next letter
home, he tells his family that American squirrels are white.
4. Sam is riding her bike in her home town in Maine, minding her own business. A station wagon
comes up behind her and the driver starts beeping his horn and then tries to force her off the
road. As he goes by, the driver yells "get on the sidewalk where you belong!" Sam sees that the
car has Ohio plates and concludes that all Ohio drivers are jerks.
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Persuasive Design Fallacy
Either-or-thinking
Also Called False Dilemma
Framing choices so that listeners think they
have only two options
Strawman
Belittling or trivializing arguments to refute them
easily. The author attacks an argument which is
different from, and usually weaker than, the
opposition's best argument. Making a symbolic
strawman from the opponent’s ideas and then
knocking it down.
This is the fallacy of refuting a caricatured or
extreme version of somebody's argument,
rather than the actual argument they've made.
"Another well known, and much used, device is
to misrepresent my position and attack things I
have never said."
Rachel Carson
1. Either you're for me or against me. America: love it or leave it.
2. Senator Jill: "We'll have to cut education funding this year."
Senator Bill: "Why?"
Senator Jill: "Well, either we cut the social programs or we live with a huge deficit and we can't live with
the deficit."
1. "Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't
understand why he wants to leave us defenseless like that."
2. Bob: "Those of our people who are forced by circumstances beyond their control to rely on Social
Security and government support such as Aid to Dependent Children, Food Stamps, etc. - these
victims of an anarchistic economy are now faced with a second threat to their very existence: their
already minimal benefits are now being reduced by inflation. If we are morally committed to supporting
these people in the first place, then we must support them consistently: either we approve the
proposed increase in Social Security and government support - or we simply turn our backs on those
who are unable to help themselves." Dale’s straw man attack: "Bob represents naive liberals who only
steal the taxpayer's hard-earned money - and throw it away on the idle. This is robbery - and I oppose
it.
3. Sarah: It's not fair that when doing the same work and with the same qualifications, women are paid
only $ .70 for every $1.00 that men are paid. Isn't it reasonable to expect that in equivalent jobs, with
equivalent work experience and education, that your sex should have no impact on your salary?
Allen’s Strawman attack: Of course not! Everyone knows that bosses go easier on women and what
they do. Besides girls are physically smaller and weaker than men, so they need to be protected from
the real world.
4. Frank: The NFL should follow the NCAA in banning the use of anabolic steroids among its players.
Prolonged steroid use has proven to be harmful with such side-effects as liver dysfunction, cancer,
heart ailments, and hormone imbalance. I hope that in the end the NFL will realize that the health of its
athletes is the most important issue. Hunter’s Strawman Attack: Frank is nothing more than a purist
who would have us go back to the days of leather helmets. Doesn't he realize that this is the year
2000? Sports technology has given athletes a chance to develop themselves to their maximum
potential. He would deny them this opportunity? An athlete owes it to himself to be the best he can be.
If he wants to compete, he'll have to use steroids because every other athlete does.
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References
A List Of Fallacious Arguments (n.d.). Retrieved February 20, 2008 from http://www.don-lindsayarchive.org/skeptic/arguments.html#hominem
Fallacy Files (n.d.). Retrieved February 20, 2008 from http://www.fallacyfiles.org/redherrf.html
Logical Fallacies and the Art of Debate (n.d.). Retrieved February 20, 2008 from
http://www.csun.edu/~dgw61315/fallacies.html#Non%20sequitur
The Nizkor Project Fallacies. (n.d.). Retrieved February 20, 2008 from http://www.nizkor.org/features/fallacies/index.html#index
Osborn and Osborn, Public Speaking (7th edition)
O’Hair, D. Stewart, R. & Rubenstein, H. (2004). A Speaker’s Guidebook Text and Reference Second Edition. Boston:Bedford.
Rachel Carson Quote from a speech to the Women's National Press Club on December 5, 1962. Quoted on page 308 in Paul Brooks,
Rachel Carson: The Writer at Work, Sierra Club Books, 1972-1989.
Sprague, J. & Stuart, D. (005). A Speakers Handbook. Thomas Wadsworth: Australia.
Steven’s guide to logical fallacies. (n.d.). Retrieved February 20, 2008 from http://www.onegoodmove.org/fallacy/toc.htm
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So what makes a good argument?
A Claim--- a statement that you are saying is true. It answers, “What are you trying to prove?”
Evidence—supporting material that provides grounds for the belief. Could be examples, narratives, testimony, facts, or statistics.
Evidence makes the claim more acceptable.
Warrants—make the link between the calim and the evidence. They sho why the link between the claim and th evidence is “warranted”
or justified.
Claim
Many herbal supplements contain powerful substances
that may interact in harmful ways with over-the-counter
(OTC) or prescription drugs.
Evidence
Warrant
Serious side effects have occurred
where people consumed prescription
blood thinners such as warfarin
(Coumadin) with herbal supplements
such as St. John’s Wort, Kava, and
valerian.
Several leading medical
journals have reposted cases
documenting harmful
interactions between a variety
of supplements and
medications.
O’Hair, D. Stewart, R. & Rubenstein, H. (2004). A Speaker’s Guidebook Text and Reference Second Edition. Bedford: Boston.
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