Informal Argumentative Fallacies
I developed this table to help my Rhetoric class apply these in analyzing persuasive texts. I tried to define them as simply as I could for a new-to-rhetoric audience. I also tried to curate the clearest examples from the dozens of fallacy websites out there.
I thought I'd share, in case this is helpful to others. I know, looking at this, you are thinking that there is NO WAY this will be helpful. Still, this is the Internet. Something for everyone...
There are many more informal fallacies. There are also plenty of formal ones.
The examples below are cited with hyperlinks. Most of those sources are good catalogs of the dozens, probably hundreds of fallacies. Some of the examples below are taken from websites with agendas, and those will be less helpful. For example, I have a few examples from both Christian and atheist wikis that seem to have it out for each other. These are organized by the fallacy family innovated by www.FallacyFiles.org, except the first five, which have no family.
family
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fallacy
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definition
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examples
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Black or White
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A false
dilemma that asserts an untrue “either-or” or forced choice.
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“Well, it's time for a decision. Will you contribute
$20 to our environmental fund, or are you on the side of environmental
destruction?” IEP
“You ask how I can know that you're
struggling financially? It's simple: in a capitalist economy, you
either win big or you lose big, and I know you're not one of the big
winners.” TSU Philosophy
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Appeal to Ignorance
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Something is
true because there is no evidence for it.
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“If I were adopted, then I would know about it by
now.
I don't know that I'm adopted. Therefore, I wasn't adopted.” Fallacy Files
“She hasn't said she doesn't like you,
right? So she's probably interested. Call her up.” TSU Philosophy
“Although
we have proven that the moon is not made of spare ribs, we have not proven
that its core cannot be filled with them; therefore, the moon’s core is
filled with spare ribs.” Logically Fallacious
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Begging the Question
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A circular
argument. The conclusion is part of a premise.
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“Bill: "God must exist."
Jill: "How do you know." Bill: "Because the Bible says so." Jill: "Why should I believe the Bible?" Bill: "Because the Bible was written by God." Nizkor Project
“Paranormal
activity is real because I have experienced what can only be described as
paranormal activity.” Logically Fallacious
“People who deny
the truth of Marxism are simply dancing to the tune of their capitalist
masters, as Marx understood so well.” TSU Philosophy
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Slippery Slope
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A series of
steps in a casual chain and the support/ probabilities for each is omitted in
an argument that A basically causes Z.
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“You know what happens when people take drugs! Pretty
soon the caffeine won't be strong enough. Then you will take something
stronger, maybe someone's diet pill. Then, something even stronger.
Eventually, you will be doing cocaine. Then you will be a crack addict! So,
don't drink that coffee.” IEP
“If Texas adopts a personal income tax, I'm
moving away. An income tax at the state level is just a first step to
communism.” TSU Philosophy
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Accident
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A sweeping
generalization of a fact or a rule, presented as if it has no exception.
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“People should keep their promises,
right? I loaned Dwayne my knife, and he said he'd return it. Now he is
refusing to give it back, but I need it right now to slash up my neighbors
who disrespected me.” IEP
“(1) Children
should be seen and not heard.
(2) Little Wolfgang Amadeus is a child. Therefore: (3) Little Wolfgang Amadeus shouldn’t be heard.” Logical Fallacies |
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Red Herrings
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Red Herring
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The
premises of the argument are logically unrelated to the claim.
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Cars kill more people than guns, and no one suggests we ban them.
Senator
Clark: "Why are you not willing to support the antiabortion amendment?
Don't you have any feelings at all for the unborn children whose lives are
being indiscriminately blotted out?" Senator Rich: "I just don't
understand why you people who get so worked up about lives being blotted out
by abortion don't have the same feelings about the thousands of lives that
are blotted out every year by the indiscriminate use of handguns. Is not the
issue of the sanctity of human life involved in both issues? Why have you not
supported us in our efforts at gun-control legislation?" TSU Philosophy
“Jack: "Bob Dylan is the greatest
performer of our time." Jill: "Well, Dylan is a fine writer, but as
a performer, he stinks. I saw a concert of his once and we was singing
unintelligibly and looked like he was falling asleep." Jack: "Well,
Fleetwood Mac, one of your favorite groups, is not so great in concert
either." TSU Philosophy
.
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Straw Man
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A person’s
actual beliefs are misrepresented as something easier to attack and then
attacked.
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“Opponent: Because of the killing and suffering of
Indians that followed Columbus's discovery of America, the City of Berkeley
should declare that Columbus Day will no longer be observed in our city.
Speaker: This is ridiculous, fellow members of the
city council. It's not true that everybody who ever came to America from
another country somehow oppressed the Indians.” IEP
“Ted: Biological
evolution is both a theory and a fact.
Edwin: That is
ridiculous! How can you possibly be absolutely certain that we evolved
from pond scum!” Logically Fallacious
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Appeal to Misleading Authority (w/ Appeal to Celebrity & Appeal to
Tradition)
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Using an
authority to affirm a conclusion when the authority is not expert enough, in
the context, to assure the conclusion.
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I'm
not a doctor, but I play one on the hit series "Bimbos and Studmuffins
in the OR." You can take it from me that when you need a fast acting,
effective and safe pain killer there is nothing better than MorphiDope 2000.
That is my considered medical opinion.” Nizkor Project
“Sure I believe in God. People have believed
in God for thousands of years so it seems clear that God must exist. After
all, why else would the belief last so long?” Nizkor Project
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Guilt by Association (w/ The Hitler Card)
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An idea is
wrong because a “bad” person agrees with it.
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“Secretary of State Dean
Acheson is too soft on communism, as you can see by his inviting so many
fuzzy-headed liberals to his White House cocktail parties.” IEP
“For instance, in the 1960s some
anti-communists attacked support for civil rights by pointing out that the
Communist Party of the United States also supported the civil rights
movement. It was then argued that supporting civil rights was tantamount to
supporting communism.” Fallacy Files
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Ad Hominem
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An
irrelevant attack on a person makes one of their arguments false.
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“What she says about
Johannes Kepler's astronomy of the 1600s must be just so much garbage. Do you
realize she's only fifteen years old?” IEP
“Student: Hey, Professor Moore, we shouldn't
have to read this book by Freud. Everyone knows he used cocaine.” TSU Philosophy
“Bill:
"I believe that abortion is morally wrong."
Dave: "Of course you would say that, you're a priest." Bill: "What about the arguments I gave to support my position?" Dave: "Those don't count. Like I said, you're a priest, so you have to say that abortion is wrong. Further, you are just a lackey to the Pope, so I can't believe what you say." Nizkor Project |
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Poisoning
the Well
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A preemptive ad hominem.
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“Tim:
Boss, you heard my side of the story why I think Bill should be fired and not
me. Now, I am sure Bill is going to come to you with some pathetic
attempt to weasel out of this lie that he has created.” Logically Fallacious
"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." Nizkor Project
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Tu
Quoque
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An argument must be
untrue since the author of the argument has acted inconsistently with the
argument’s conclusions.
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“Look who's talking. You say I
shouldn't become an alcoholic because it will hurt me and my family, yet you
yourself are an alcoholic, so your argument can't be worth listening to.” IEP
“Jill: "I think the gun control bill
shouldn't be supported because it won't be effective and will waste
money."
Bill: "Well, just last month you supported the bill. So I guess you're wrong now." Nizkor Project
“Alice: Canada's health care policies
are more effective than those of the United States.
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Appeal
to Consequences
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A proposition is true
because belief in it leads to good things or it is untrue because that belief
will lead to bad things.
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“Reducing
greenhouse gas emissions would require policies we don't like, therefore
anthropogenic greenhouse gasses don't
have any effect on the climate.” RationalWiki
As long as I believe in Santa I will get presents.
“Belief in evolution and animal kinship leads normally to selfishness,
aggressiveness, and fighting between groups, as well as animalistic attitudes
and behaviour by individuals.” Fallacy Files
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Appeal
to Force/Fear
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The conclusion should be
accepted or I/we will do something bad to you.
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“(1) If you don’t accept that the Sun
orbits the Earth, rather than the other way around, then you’ll be
excommunicated from the Church.
Therefore: (2) The Sun orbits the Earth, rather than the other way around.” Logical Fallacies
"You know,
Professor Smith, I really need to get an A in this class. I'd like to stop by
during your office hours later to discuss my grade. I'll be in your building
anyways, visiting my father. He's your dean, by the way. I'll see you
later." Nizkor Project
Lucy makes a fist during this scene inducing her brother to do the
Christmas play… “Lucy Van Pelt: "I'll
give you five good reasons. One, two, three, four, FIVE!" Linus Van
Pelt: "Those are good reasons. Christmas is not only getting too
commercial, it's getting too dangerous." Hark
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Bandwagon
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A popular idea is correct.
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“Why should you feel guilty for seeking your own
happiness when that's what everyone else is doing, too?” Fallacy Files
“How
could you not believe in virgin births? Roughly two billion people
believe in them, don’t you think you should reconsider your position?” Logically Fallacious
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Emotional
Appeal
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Something is true because it makes us feel
good or untrue because it doesn’t.
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“Photographs of crippled or hungry children are shown
in order to arouse one's desire to help them, with the charity trying to
motivate you to write a check” Fallacy Files
“There
must be objective rights and wrongs in the universe. If not, how can
you possibly say that torturing babies for fun could ever be right?” Logically Fallacious
"I should receive an 'A' in this
class. After all, if I don't get an 'A' I won't get the fellowship that I
want." Nizkor Project
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Wishful
Thinking
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Something is true because I want it to be.
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“There's got to be an error here in the history book.
It says Thomas Jefferson had slaves. I don't believe it. He was our best
president, and a good president would never do such a thing. That would be
awful.” IEP
“I believe
that when we die, we are all given new, young, perfect bodies, and we spend
eternity with those whom we love. I can’t imagine the point of life if
it all just ends when we die!” Logically Fallacious
“If special creation is true, then humans
are made in the image of an all-powerful creator. I want to be have been made
in the image of a creator. Therefore, special creation is true.” EvolutionWiki
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Weak Analogies
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Weak Analogy
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The two terms
in the analogy are weakly or unrelated.
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“Not believing in the
literal resurrection of Jesus because the Bible has errors and
contradictions, is like denying that the Titanic sank because eye-witnesses
did not agree if the ship broke in half before or after it sank.” Logically Fallacious
“The book Investing for Dummies really helped me understand my
finances better. The book Chess
for Dummies was written by the
same author, was published by the same press, and costs about the same
amount. So, this chess book would probably help me understand my finances,
too.” IEP
During the Cold
War, Congressman Charles Rose (Democrat, North Carolina) answered (in part)
the arguments of those opposed to government-sponsored research to develop
"remote-viewing" the ability to see a distant place telepathically
by stating, "It seems to me that it would be a hell of a cheap radar
system. This country wasn't afraid to look into the strange physics behind
lasers and semiconductors, and I don't think we should be afraid to look into
this.” TSU Philosophy
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Unrepresentative Sample
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A conclusion is drawn from an
insufficiently representative sample.
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“It
has been concluded from a recent study involving more that 100,000 people in
Florida that 43 percent of the American people now spend at least two hours a
day in some form of recreational activity.” TSU Philosophy
“The Literary
Digest, which began its famous straw poll with the 1916 presidential
campaign, mailed out millions of mock ballots for each of its surveys. …The results that
poured in during the months leading up to the [1936 presidential] election
showed a landslide victory for Republican Alf Landon.…Roosevelt was
re-elected by an even greater margin than in 1932….The mailing lists the
editors used were from directories of automobile owners and telephone
subscribers… [which] were clearly weighted in favor of the Republicans in
1936. People prosperous enough to own cars have always tended to be somewhat
more Republican than those who do not, and this was particularly true in
[the] heart of the Depression.” Fallacy Files
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Hasty Generalization
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A conclusion is drawn from too small
a sample of evidence.
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“My
father smoked four packs of cigarettes a day since age fourteen and lived
until age sixty-nine. Therefore, smoking really can’t be that bad for
you.” Logically Fallacious
Californians are rude. Have you met Vrooman?
“Children of faculty are brats. I baby-sit
for one of my professors and his children are spoiled and demanding.” TSU Philosophy
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Anecdotal Fallacy/
Misleading Vividness
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A Hasty Generalization that relies
on the availability heuristic (we generalize from vivid stories more
readily).
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"There's abundant
proof that God exists and is still performing miracles today. Just last week
I read about a girl who was dying of cancer. Her whole family went to church
and prayed for her, and she was cured." SecularWeb
“[T]ravel insurance…is now purchased by half of American leisure
travelers―a fivefold increase since 2001…” Fallacy Files
“Jane: "… I've been
thinking about getting a Kiwi Fruit 2200. I read in that consumer magazine
that they have been found to be very reliable in six independent industry
studies."
Bill: "I wouldn't get the Kiwi Fruit. A friend of mine bought one a month ago to finish his master's thesis. He was halfway through it when smoke started pouring out of the CPU. He didn't get his thesis done on time and he lost his financial aid. Now he's working over at the Gut Boy Burger Warehouse." Nizkor Project |
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False Cause
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Cum Hoc
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Two things
that happened at the same time must have a causal relationship.
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“Charging that
welfare causes child poverty, [Gary Bauer] cites a study showing that
"the highest increases in the rate of child poverty in recent years have
occurred in those states which pay the highest welfare benefits. The lowest
increases—or actual decreases—in child poverty have occurred in states which
restrain the level of AFDC payments." Fallacy Files
“He sometimes
behaves violently when I am around him. I don't know what it is that I am
doing to make him become so violent.” Out of the
Fog
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Post Hoc
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A thing that
happens before another thing caused that.
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“The only
policy that effectively reduces public shootings is right-to-carry laws.
Allowing citizens to carry concealed handguns reduces violent crime. In the
31 states that have passed right-to-carry laws since the mid-1980s, the
number of multiple-victim public shootings and other violent crimes has
dropped dramatically. Murders fell by 7.65%, rapes by 5.2%, aggravated
assaults by 7%, and robberies by 3%.” Fallacy Files
…[E]vidence
shows that even state and local handgun control laws work. For example, in
1974 Massachusetts passed the Bartley-Fox Law, which requires a special
license to carry a handgun outside the home or business. The law is supported
by a mandatory prison sentence. Studies by Glenn Pierce and William Bowers of
Northeastern University documented that after the law was passed handgun
homicides in Massachusetts fell 50% and the number of armed robberies dropped
35%. Fallacy
Files
“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!” Nizkor
Project
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Regression
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Mistaking
statistical regression to the man as a causal relationship.
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“You are
investigating the average heights of groups of people living in the United
States. You sample some people living in Columbus, Ohio and determine their
average height. You have the numerical figure for the mean height of people
living in the U.S., and you notice that members of your sample from Columbus
have an average height that differs from this mean. Your second sample of the
same size is from people living in Dayton, Ohio. When you find that this
group's average height is closer to the U.S. mean height [as it is very
likely to be due to common statistical regression to the mean], you falsely
conclude that there must be something causing people living in Dayton to be
more like the average U.S. resident than people living in Columbus.” IEP
“I had a real
bad headache, then saw my doctor. Just by talking with him, my headache
started to subside, and I was all better the next day. It was well
worth the $200 visit fee.” Logically
Fallacious
“After surgery,
my wife was not doing too well -- she was in a lot of pain. I bought
these magnetic wristbands that align with the body's natural vibrations to
reduce the pain, and sure enough, a few days later the pain subsided!
Thank you magic wristbands!” Logically
Fallacious
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Texas Sharpshooter
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Causal
attributions are made about a cluster you analytically create. But the
clustering effect make be chance or another cause.
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“Psychic Sarah
makes twenty-six predictions about what will happen next year. When one, but
only one, of the predictions comes true, she says, "Aha! I can see into
the future." IEP
“SuperCyberDate.con
determined that Sally and Billy are a great match because they both like
pizza, movies, junk food, Janet Jackson, and vote republican.” Logically
Fallacious
“Abraham
Lincoln and John F. Kennedy were both presidents of the United States,
elected 100 years apart. Both were shot and killed by assassins who were
known by three names with 15 letters, John Wilkes Booth and Lee Harvey
Oswald, and neither killer would make it to trial. Spooky, huh? It gets
better. Lincoln had a secretary named Kennedy, and Kennedy had a secretary
named Lincoln. They were both killed on a Friday while sitting next to their
wives, Lincoln in the Ford Theater, Kennedy in a Lincoln made by Ford. Both
men were succeeded by a man named Johnson – Andrew for Lincoln and Lyndon for
Kennedy. Andrew was born in 1808. Lyndon in 1908. What are the odds? You Are Not
So Smart
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Ambiguity
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Amphiboly
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A conclusion
rests on grammatical ambiguity.
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“One morning I
shot an elephant in my pajamas. How he got into my pajamas I'll never know.” Fallacy Files
“Take this
newspaper classified ad that appears under Furnished Apartments for
Rent: “3 rooms, river view, private phone, bath, kitchen, utilities included”
[It seems like the kitchen and bath are private as well, right? Ha!] About
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Equivocation
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An ambiguous
word is used with two different meanings.
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“The humanity
of the patient's appendix is medically undeniable.
Therefore, the appendix has a right to life and should not be surgically removed.” Fallacy Files
“All living beings
come from other living beings. Therefore, the first forms of life must
have come from a living being. That living being is God.” [note that
“come from” in one case means procreation and in the other does not] Logically
Fallacious
“Sure
philosophy helps you argue better, but do we really need to encourage people
to argue? There's enough hostility in this world.” TSU
Philosophy
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Scope Fallacy
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The scope of a
word is ambiguous and shifts.
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“All that
glitters is not gold.
This rock glitters. Therefore, this rock is not gold.” Fallacy Files
“For every
contingent being, there is a time when it does not exist. Therefore, there
was a time when every contingent being did not exist. Because contingent
beings cannot cause their own existence, their existence must have been
caused by a necessary being - God.” [the 2nd sentence asserts the
non-existence period was shared, but that does not follow. This is a change
in the scope or reach of the idea in the 1st sentence.] About
“Necessarily,
whatever happens, happens. Therefore, whatever happens, necessarily happens,
so that whatever occurs could not have been otherwise.” SeekFind
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Accent
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The way you
emphasize a word makes the conclusion seem more true.
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“Jorge turned
in his assignment on time todaaaaaaaaay.
“A member of
Congress is asked by a reporter if she is in favor of the President's new
missile defense system, and she responds, "I'm in favor of a missile
defense system that effectively defends America." [”With an emphasis on
the word "favor," her response is likely to favor the
President's missile defense system. With an emphasis, instead, on the words
"effectively defends," her remark is likely to
be against the President's missile defense system”] IEP
“Suppose that
two people are debating whether a rumour about the actions of a third person
is true. The first says, “I can imagine him doing that; it’s possible.” The
second replies, “Yes, it’s possible to imagine him doing that.” This looks
like agreement.” [“If however, the second person stresses the word imagine,
then this appearance vanishes; “Yes, it’s possible to imagine him doing
that.” This now sounds like a pointed comment meaning that though it may just
about be possible to imagine him doing that, there’s no way that he would
actually do it.”] Logical
Fallacies
|
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Quantifier Shift
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A “some” statement in a premise becomes an “all” in
the conclusion.
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“Every person
has some moral values (premise). Therefore, there are some moral values which
every person shares with everyone else (conclusion).” About
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Redefinition/ No True Scotsman
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A term’s
meaning is purposefully and creatively changed.
|
“And this is
apparent, if we consider that every head of a family must look upon himself
as obliged to act in three capacities—as a prophet, to instruct: as a priest,
to pray for and with; as a king, to govern, direct, and provide for them.” Under Much
Grace;
example from Whitfield
“Scotsman
A: You know, laddie, no Scotsman puts sugar in his porridge.
Scotsman
B: Is that so? I seem to recall my cousin Angus (who is from Scotland)
puts sugar in his porridge.
“Our religion
teaches people to be kind and peaceful and loving. Anyone who does evil acts
certainly isn’t
acting in a loving manner, therefore they can’t really be a true member of
our religion, no matter what they say.” About
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