Let's start with
Noun 1. logical fallacy -
a fallacy in logical argumentation
fallacy, false belief - a misconception resulting from incorrect
Clearly, based on this
definition, logical fallacies are something to avoid in our
efforts to discern reality.
So here's a list
of these logical fallacies that obstruct our view of reality
Yep, the list is long
(we counted 87). Sorry about that, but there simply are a
LOT of ways that folks are illogical. So...we tried to
list them in order of importance and frequency of occurrence.
In the end, this is just a
reference list, and elsewhere on this web site, we will mention
one, or more of these fallacies when we do our reality checks.
Here's where you can look at them, one at a time, or whenever
you are so inclined.
Also, let it be known,
we cobbled this list together by doing an online search of
various lists of logical fallacies. Some of these are
classic fallacies, ones that have been around for a long time.
Others are rather new ways that folks have found to be
illogical. You can do a similar search on your own, but
here are some sites that we found useful:
And now, here's our
Ad Hominem (Argument To
The Man): attacking the person instead of attacking his, or
Examples: True believers
will often commit this fallacy by countering the arguments of
skeptics by stating that skeptics are closed minded. Skeptics,
on the other hand, may fall into the trap of dismissing the
claims of UFO believers, for example, by stating that people who
believe in UFO’s are crazy or stupid.
Killing the messenger
is a form of this fallacy, the intent being to eliminate the
message by eliminating the person who brings it.
A common form is an attack
on sincerity and/or motivation. For example, "How can you
believe what he's saying, when you know he's just trying to get
you vote for him in the upcoming election.." The two wrongs make
a right fallacy is related.
A variation (related to Argument By Generalization) is to
attack a whole class of people. For example, "Evolutionary
biology is a sinister tool of the materialistic, atheistic
religion of Secular Humanism." Similarly, one notorious net.kook
waved away a whole category of evidence by announcing "All the
scientists were drunk."
Another variation is attack by innuendo: "Why don't
scientists tell us what they really know; are they afraid of
Another variation is attack on the person's intelligence: "Why don't
scientists tell us what they really know; are they afraid of
public panic ?" "If you weren't so stupid you would
have no problem seeing my point of view." Or, "Even you should
understand my next point."
There may be a pretense that the attack isn't happening: "In
order to maintain a civil debate, I will not mention my
opponent's drinking problem." Or "I don't care if other people
say you're [opinionated/boring/overbearing."
Attacks don't have to be
strong or direct. It is possible to merely show disrespect, or cut down
his stature by making an irrelevant but negative remark about
Some examples: "If you
ever manage to more experience, you'll see my point." "Why
on earth would you say that ?" "Try listening to me
this time.." You're letting your emotions get the best of you."
Ad Hominem is not fallacious if the attack goes to the
credibility of the argument. For instance, the argument may
depend on its presenter's claim that he's an expert. (That is,
the Ad Hominem is undermining an Argument From Authority.) Trial
judges allow this category of attacks.
Straw Man (Fallacy Of Extension): attacking an exaggerated or caricatured version of your
opponent's position. This involves defining the opposing
point of view in an incorrect way, a way that is obviously one
no one would agree with.
For example, the claim
that "evolution means a dog giving birth to a cat."
Another example: "People who
believe society creates criminals don't believe in prisons."
Another example: "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."
On the Internet, it is common to exaggerate the opponent's
position so that a comparison can be made between the opponent
Excluded Middle (False Dichotomy, Faulty Dilemma,
assuming there are only two alternatives when in fact there are
For example, assuming
Atheism is the only alternative to Fundamentalism, or being a
traitor is the only alternative to being a loud patriot.
Circular Reasoning (AKA: Begging The Question, Assuming The Answer, Tautology):
Reasoning in a circle. The thing to be proved is used as one of
your assumptions. For example: "We must have a death penalty to
discourage violent crime". (This assumes it discourages crime.)
Or, "The stock market fell because of a technical adjustment."
(But is an "adjustment" just a stock market fall ?)
Claiming that two situations are highly similar, when they
For example, "The solar
system reminds me of an atom, with planets orbiting the sun like
electrons orbiting the nucleus. We know that electrons can jump
from orbit to orbit; so we must look to ancient records for
sightings of planets jumping from orbit to orbit also."
Or, "Minds, like rivers, can be broad. The broader the river,
the shallower it is. Therefore, the broader the mind, the
shallower it is."
Or, "We have pure food and drug laws; why can't we have laws to
keep movie-makers from giving us filth?"
The claim that two things, both analogous to a third thing, are
therefore analogous to each other.
For example, this debate:
"I believe it is always wrong to oppose the law by breaking it."
"Such a position is odious: it implies that you would not have
supported Martin Luther King."
"Are you saying that cryptography legislation is as important as
the struggle for Black liberation ? How dare you !"
A person who advocates a particular position (say, about gun
control) may be told that Hitler believed the same thing. The
clear implication is that the position is somehow tainted. But
Hitler also believed that window drapes should go all the way to
the floor. Does that mean people with such drapes are monsters?
Argument From Spurious Similarity (False Equvalency):
This is a relative of Bad Analogy. It is suggested that some
resemblance is proof of a relationship. There is a WW II story
about a British lady who was trained in spotting German
airplanes. She made a report about a certain very important type
of plane. While being quizzed, she explained that she hadn't
been sure, herself, until she noticed that it had a little man
in the cockpit, just like the little model airplane at the
False Cause (arguing from coincidence):
Assuming that because two things happened, the first one caused
the second one. (Sequence is not causation.)
"Before women got the vote, there were no nuclear weapons." Or,
"Every time my brother Bill accompanies me to Fenway Park, the
Red Sox are sure to lose."
Essentially, these are arguments that the sun goes down because
we've turned on the street lights.
Confusing Correlation And Causation:
Earthquakes in the Andes were correlated with the closest
approaches of the planet Uranus. Therefore, Uranus must have
caused them. (But Jupiter is nearer than Uranus, and more
When sales of hot chocolate go up, street crime drops. Does this
correlation mean that hot chocolate prevents crime ? No, it
means that fewer people are on the streets when the weather is
The bigger a child's shoe size, the better the child's
handwriting. Does having big feet make it easier to write ? No,
it means the child is older.
Unfortunately, there simply isn't a common-sense answer for many
questions. In politics, for example, there are a lot of issues
where people disagree. Each side thinks that their answer is
common sense. Clearly, some of these people are wrong.
The reason they are wrong
is because common sense depends on the context, knowledge and
experience of the observer. That is why instruction manuals will
often have paragraphs like these:
When boating, use common sense. Have one life preserver for each
person in the boat.
When towing a water skier, use common sense. Have one person
watching the skier at all times.
If the ideas are so obvious, then why the second sentence? Why
do they have to spell it out ? The answer is that "use common
sense" actually meant "pay attention, I am about to tell you
something that inexperienced people often get wrong."
Science has discovered a lot of situations which are far more
unfamiliar than water skiing. Not surprisingly, beginners find
that much of it violates their common sense. For example, many
people can't imagine how a mountain range would form. But in
fact anyone can take good GPS equipment to the Himalayas, and
measure for themselves that those mountains are rising today.
Argument By Laziness (Argument By Uninformed Opinion):
The arguer hasn't bothered to learn anything about the topic. He
nevertheless has an opinion, and will be insulted if his opinion
is not treated with respect. For example, someone looked at a
picture on one of our web pages, and made a complaint which
showed that he hadn't even skimmed through the words on the
page. When we pointed this out, he replied that we shouldn't have
had such a confusing picture.
Argument By Selective Observation:
Also called cherry picking, the enumeration of favorable
circumstances, or as the philosopher Francis Bacon described it,
counting the hits and forgetting the misses. For example, a
state boasts of the Presidents it has produced, but is silent
about its serial killers. Or, the claim "Technology brings
happiness". (Now, there's something with hits and misses.)
This is closely related to
Confirmation Bias, which means seeking only that information
that confirms a pre-existing belief, or desired outcome.
Casinos encourage this human tendency. There are bells and
whistles to announce slot machine jackpots, but losing happens
silently. This makes it much easier to think that the odds of
winning are good.
Argument By Selective Reading:
Making it seem as if the weakest of an opponent's arguments was
the best he had. Suppose the opponent gave a strong argument X
and also a weaker argument Y. Simply rebut Y and then say the
opponent has made a weak case.
This is a relative of Argument By Selective Observation, in that
the arguer overlooks arguments that he does not like. It is also
related to Straw Man (Fallacy Of Extension), in that the
opponent's argument is not being fairly represented.
Needling: simply attempting to make the other person angry, without trying
to address the argument at hand. Sometimes this is a delaying
Needling is also Ad
Hominem if it includes and insult directed at the person. You may instead insult
something the other person believes in ("Argumentum Ad YourMomium"), interrupt, clown to show disrespect, be noisy,
fail to pass over the microphone, and numerous other tricks. All
of these work better if you are running things - for example, if
it is your radio show, and you can cut off the other person's
microphone. If the host or moderator is firmly on your side,
that is almost as good as running the show yourself. It's even
better if the debate is videotaped, and you are the person who
will edit the video.
If you wink at the audience, or in general clown in their
direction, then we are shading over to Argument By Personal
Charm. Ronald Reagan once famously did this in a
televised debate, when he replied to a point made by Jimmie
Carter by saying, "There you go again."
Inflation of Conflict: arguing that scholars debate a certain point. Therefore, they
must know nothing, and their entire field of knowledge is "in
crisis" or does not properly exist at all.
For example, two historians debated whether Hitler killed five
million Jews or six million Jews. A Holocaust denier argued that
this disagreement made his claim credible, even though his death
count is three to ten times smaller than the known minimum.
Similarly, in "The Mythology of Modern Dating Methods" (John
Woodmorappe, 1999) we find on page 42 that two scientists
"cannot agree" about which one of two geological dates is "real"
and which one is "spurious". Woodmorappe fails to mention that
the two dates differ by less than one percent.
Argument From Adverse Consequences (Appeal To Fear, Scare
saying an opponent must be wrong, because if he is right, then
bad things would ensue. For example: God must exist, because a
godless society would be lawless and dangerous. Or: the
defendant in a murder trial must be found guilty, because
otherwise husbands will be encouraged to murder their wives.
Wishful thinking is closely related. "My home in Florida is six
inches above sea level. Therefore I am certain that global
warming will not make the oceans rise by one foot." Of course,
wishful thinking can also be about positive consequences, such
as winning the lottery, or eliminating poverty and crime.
Special Pleading (Stacking The Deck):
using the arguments that support your position, but ignoring or
somehow disallowing the arguments against.
Uri Geller used special pleading when he claimed that the
presence of unbelievers (such as stage magicians) made him
unable to demonstrate his psychic powers.
Short Term Versus Long Term:
this is a particular case of the Excluded Middle. For example,
"We must deal with crime on the streets before improving the
schools." (But why can't we do some of both ?) Similarly, "We
should take the scientific research budget and use it to feed
Burden Of Proof:
the claim that whatever has not yet been proved false must be
true (or vice versa). Essentially the arguer claims that he
should win by default if his opponent can't make a strong enough
There may be three problems here. First, the arguer claims
priority, but can he back up that claim? Second, he is impatient
with ambiguity, and wants a final answer right away. And third,
"absence of evidence is not evidence of absence."
Argument By Question:
asking your opponent a question which does not have a snappy
answer. (Or anyway, no snappy answer that the audience has the
background to understand.) Your opponent has a choice: he can
look weak or he can look long-winded. For example, "How can
scientists expect us to believe that anything as complex as a
single living cell could have arisen as a result of random
Actually, pretty well any question has this effect to some
extent. It usually takes longer to answer a question than ask
Variants are the rhetorical question, and the loaded question,
such as "Have you stopped beating your wife?"
Argument by Rhetorical Question:
asking a question in a way that leads to a particular answer.
For example, "When are we
going to give the old folks of this country the pension they
deserve?" The speaker is leading the audience to the answer
"Right now." Alternatively, he could have said "When will we be
able to afford a major increase in old age pensions?"
In that case, the answer he is aiming at is almost certainly not
Fallacy of the General Rule:
assuming that something true in general is true in every
possible case. For example, "All chairs have four legs." Except
that rocking chairs don't have any legs, and what is a
one-legged "shooting stick" if it isn't a chair ?
Similarly, there are times when certain laws should be broken.
For example, ambulances are allowed to break speed laws.
Reductive Fallacy (Oversimplification): over-simplifying. As Einstein said, everything should be made as
simple as possible, but no simpler. Political slogans such as
"Taxation is theft" fall in this category.
Genetic Fallacy (Fallacy of Origins, Fallacy of Virtue):if an argument or arguer has some particular origin, the
argument must be right (or wrong). The idea is that things from
that origin, or that social class, have virtue or lack virtue.
(Being poor or being rich may be held out as being virtuous.)
Therefore, the actual details of the argument can be overlooked,
since correctness can be decided without any need to listen or
Psychogenetic Fallacy: if you learn the psychological reason why your opponent likes an
argument, then he's biased, so his argument must be wrong.
Argument of the Beard: assuming that two ends of a spectrum are the same, since one can
travel along the spectrum in very small steps. The name comes
from the idea that being clean-shaven must be the same as having
a big beard, since in-between beards exist.
Similarly, all piles of stones are small, since if you add one
stone to a small pile of stones it remains small.
However, the existence of pink should not undermine the
distinction between white and red.
Argument From Age (Wisdom of the Ancients):
snobbery that very old (or very young) arguments are superior.
This is a variation of the Genetic Fallacy, but has the
psychological appeal of seniority and tradition (or innovation).
Products labeled "New ! Improved !" are appealing to a belief
that innovation is of value for such products. It's sometimes
true. And then there's cans of "Old Fashioned Baked Beans".
Not Invented Here:
ideas from elsewhere are made unwelcome. "This Is The Way We've
Always Done It."
This fallacy is a variant of the Argument From Age. It gets a
psychological boost from feelings that local ways are superior,
or that local identity is worth any cost, or that innovations
will upset matters.
An example of this is the common assertion that America has "the
best health care system in the world", an idea that this 2007
New York Times editorial refuted.
People who use the Not Invented Here argument are sometimes
accused of being stick-in-the-mud's.
Conversely, foreign and "imported" things may be held out as
Argument By Dismissal:
an idea is rejected without saying why.
Dismissals usually have overtones. For example, "If you don't
like it, leave the country" implies that your cause is hopeless,
or that you are unpatriotic, or that your ideas are foreign, or
maybe all three. "If you don't like it, live in a Communist
country" adds an emotive element.
Argument To The Future:
arguing that evidence will someday be discovered which will
(then) support your point.
Poisoning The Wells:
discrediting the sources used by your opponent. This is a
variation of Ad Hominem.
Argument By Emotive Language (Appeal To The People):
using emotionally loaded words to sway the audience's sentiments
instead of their minds. Many emotions can be useful: anger,
spite, envy, condescension, and so on.
For example, argument by condescension: "Support the ERA ? Sure,
when the women start paying for the drinks! Hah! Hah!"
Americans who don't like the Canadian medical system have
referred to it as "socialist", but I'm not quite sure if this is
intended to mean "foreign", or "expensive", or simply guilty by
Cliche Thinking and Argument By Slogan are useful
adjuncts, particularly if you can get the audience to chant the
slogan. People who rely on this argument may seed the audience
with supporters or "shills", who laugh, applaud or chant at
proper moments. This is the live-audience equivalent of adding a
laugh track or music track. Now that many venues have video
equipment, some speakers give part of their speech by playing a
prepared video. These videos are an opportunity to show a
supportive audience, use emotional music, show emotionally
charged images, and the like. The idea is old: there used to be
professional cheering sections. (Monsieur Zig-Zag, pictured on
the cigarette rolling papers, acquired his fame by applauding
for money at the Paris Opera.)
If the emotion in question isn't harsh, Argument By Poetic
Language helps the effect. Flattering the audience doesn't hurt
Argument By Personal Charm:
getting the audience to cut you slack. Example: Ronald Reagan.
It helps if you have an opponent with much less personal charm.
Charm may create trust, or
the desire to "join the winning team", or the desire to please
the speaker. This last is greatest if the audience feels sex
Reportedly George W. Bush lost a debate when he was young, and
said later that he would never be "out-bubba'd" again.
Appeal To Pity (Appeal to Sympathy, The Galileo Argument):
"I did not murder my mother and father with an axe! Please don't
find me guilty; I'm suffering enough through being an orphan."
Some authors want you to
know they're suffering for their beliefs. For example,
"Scientists scoffed at Copernicus and Galileo; they laughed at
Edison, Tesla and Marconi; they won't give my ideas a fair
hearing either. But time will be the judge. I can wait; I am
patient; sooner or later science will be forced to admit that
all matter is built, not of atoms, but of tiny capsules of
There is a strange variant which shows up on internet discussion
forums. Somebody refuses to answer questions about their claims,
on the grounds that the asker is mean and has hurt their
feelings. Or, that the question is personal.
Appeal To Force:
threats, or even violence. On the Net, the usual threat is of a
lawsuit. The traditional religious threat is that one will burn
in Hell. However, history is full of instances where expressing
an unpopular idea could you get you beaten up on the spot, or
"The clinching proof of my
reasoning is that I will cut anyone who argues further into
-- Attributed to Sir Geoffery de Tourneville, ca 1350 A.D.
Argument By Vehemence:
Being loud. It has been said that trial lawyers sometimes follow this rule:
If you have the facts, pound on the facts.
If you have the law, pound on the law.
If you don't have either, pound on the table.
The above rule paints vehemence as an act of desperation. But it
can also be a way to seize control of the agenda, use up the
opponent's time, or just intimidate the easily cowed. And it's
not necessarily aimed at winning the day. A tantrum or a fit is
also a way to get a reputation, so that in the future, no one
will mess with you.
Depending on what you're loud about, this may also be an Appeal
To Force, Argument By Emotive Language, Needling, or Changing
Using what you are trying to disprove. That is, requiring the
truth of something for your proof that it is false. For example,
using science to show that science is wrong. Or, arguing that
you do not exist, when your existence is clearly required for
you to be making the argument.
This is a relative of Begging The Question, except that the
circularity there is in what you are trying to prove, instead of
what you are trying to disprove.
It is also a relative of Reductio Ad Absurdum, where you
temporarily assume the truth of something.
Argument From Authority:
the claim that the speaker is an expert, and so should be
There are degrees and areas of expertise. The speaker is
actually claiming to be more expert, in the relevant subject
area, than anyone else in the room. There is also an implied
claim that expertise in the area is worth having. For example,
claiming expertise in something hopelessly quack (like
iridology) is actually an admission that the speaker is
Argument From False Authority:
A strange variation on Argument From Authority. For example, the
TV commercial which starts "I'm not a doctor, but I play one on
TV." Just what are we supposed to conclude ?
Appeal To Anonymous Authority:
An Appeal To Authority is made, but the authority is not named.
For example, "Experts agree that ..", "scientists say .." or
even "they say ..". This makes the information impossible to
verify, and brings up the very real possibility that the arguer
himself doesn't know who the experts are. In that case, he may
just be spreading a rumor.
The situation is even worse if the arguer admits it's a rumor.
Appeal To Authority:
"Albert Einstein was extremely impressed with this theory." (But
a statement made by someone long-dead could be out of date. Or
perhaps Einstein was just being polite. Or perhaps he made his
statement in some specific context. And so on.)
To justify an appeal, the arguer should at least present an
exact quote. It's more convincing if the quote contains context,
and if the arguer can say where the quote comes from.
A variation is to appeal to unnamed authorities .
There was a New Yorker cartoon, showing a doctor and patient.
The doctor was saying: "Conventional medicine has no treatment
for your condition. Luckily for you, I'm a quack." So the joke
was that the doctor boasted of his lack of authority.
Appeal To False Authority:
A variation on Appeal To Authority, but the Authority is outside
his area of expertise.
For example, "Famous
physicist John Taylor studied Uri Geller extensively and found
no evidence of trickery or fraud in his feats." Taylor was not
qualified to detect trickery or fraud of the kind used by stage
magicians. Taylor later admitted Geller had tricked him, but he
apparently had not figured out how.
A variation is to appeal to a non-existent authority. For
example, someone reading an article by Creationist Dmitri
Kuznetsov tried to look up the referenced articles. Some of the
articles turned out to be in non-existent journals.
Another variation is to misquote a real authority. There are
several kinds of misquotation. A quote can be inexact or have
been edited. It can be taken out of context. (Chevy Chase: "Yes,
I said that, but I was singing a song written by someone else at
the time.") The quote can be separate quotes which the arguer
glued together. Or, bits might have gone missing. For example,
it's easy to prove that Mick Jagger is an assassin. In "Sympathy
For The Devil" he sang: "I shouted out, who killed the Kennedys,
When after all, it was ... me."
Statement Of Conversion:
The speaker says "I used to believe in X."
This is simply a weak form
of asserting expertise. The speaker is implying that he has
learned about the subject, and now that he is better informed,
he has rejected X. So perhaps he is now an authority, and this
is an implied Argument From Authority.
A more irritating version of this is "I used to think that way
when I was your age." The speaker hasn't said what is wrong with
your argument: he is merely claiming that his age has made him
"X" has not actually been countered unless there is agreement
that the speaker has that expertise. In general, any bald claim
always has to be buttressed.
For example, there are a number of Creationist authors who say
they "used to be evolutionists", but the scientists who have
rated their books haven't noticed any expertise about evolution.
An abstract thing is talked about as if it were concrete. (A
possibly Bad Analogy is being made between concept and reality.)
For example, "Nature abhors a vacuum."
Causal Reductionism (Complex Cause):
Trying to use one cause to explain something, when in fact it
had several causes. For example, "The accident was caused by the
taxi parking in the street." (But other drivers went around the
taxi. Only the drunk driver hit the taxi.)
Using as evidence a well-known wise saying, as if that is
proven, or as if it has no exceptions.
Exception That Proves The Rule:
A specific example of Cliche Thinking. This is used when a rule
has been asserted, and someone points out the rule doesn't
always work. The cliche rebuttal is that this is "the exception
that proves the rule". Many people think that this cliche
somehow allows you to ignore the exception, and continue using
In fact, the cliche originally did no such thing. There are two
standard explanations for the original meaning.
The first is that the word "prove" meant test. That is why the
military takes its equipment to a Proving Ground to test it. So,
the cliche originally said that an exception tests a rule. That
is, if you find an exception to a rule, the cliche is saying
that the rule is being tested, and perhaps the rule will need to
The second explanation is that the stating of an exception to a
rule, proves that the rule exists. For example, suppose it was
announced that "Over the holiday weekend, students do not need
to be in the dorms by midnight". This announcement implies that
normally students do have to be in by midnight. Here is a
discussion of that explanation.
In either case, the cliche is not about waving away objections.
Appeal To Widespread Belief (Bandwagon Argument, Peer
Pressure, Appeal to Common Practice):
The claim, as evidence for an idea, that many people believe it,
or used to believe it, or do it.
If the discussion is about social conventions, such as "good
manners", then this is a reasonable line of argument.
However, in the 1800's there was a widespread belief that
bloodletting cured sickness. All of these people were not just
wrong, but horribly wrong, because in fact it made people
sicker. Clearly, the popularity of an idea is no guarantee that
Similarly, a common justification for bribery is that "Everybody
does it". And in the past, this was a justification for slavery.
Fallacy Of Composition:
Assuming that a whole has the same simplicity as its constituent
parts. In fact, a great deal of science is the study of emergent
For example, if you put a
drop of oil on water, there are interesting optical effects. But
the effect comes from the oil/water system: it does not come
just from the oil or just from the water.
Another example: "A car makes less pollution than a bus.
Therefore, cars are less of a pollution problem than buses."
Another example: "Atoms are colorless. Cats are made of atoms,
so cats are colorless."
Fallacy Of Division:
Assuming that what is true of the whole is true of each
constituent part. For example, human beings are made of atoms,
and human beings are conscious, so atoms must be conscious.
Complex Question (Tying):
Unrelated points are treated as if they should be accepted or
rejected together. In fact, each point should be accepted or
rejected on its own merits.
For example, "Do you support freedom and the right to bear arms
Slippery Slope Fallacy (Camel's Nose)
There is an old saying about how if you allow a camel to poke
his nose into the tent, soon the whole camel will follow.
The fallacy here is the assumption that something is wrong
because it is right next to something that is wrong. Or, it is
wrong because it could slide towards something that is wrong.
For example, "Allowing abortion in the first week of pregnancy
would lead to allowing it in the ninth month." Or, "If we
legalize marijuana, then more people will try heroin." Or, "If I
make an exception for you then I'll have to make an exception
Argument By Pigheadedness (Doggedness):
Refusing to accept something after everyone else thinks it is
well enough proved. For example, there are still Flat Earthers.
Appeal To Coincidence (opposite of False Cause:
Asserting that some fact is due to chance. For example, the
arguer has had a dozen traffic accidents in six months, yet he
insists they weren't his fault. This may be Argument By
Pigheadedness. But on the other hand, coincidences do happen, so
this argument is not always fallacious.
Argument By Repetition (Argument Ad Nauseam):
if you say something often enough, some people will begin to
believe it. There are some net.kooks who keeping reposting the
same articles to Usenet, presumably in hopes it will have that
Argument By Half Truth (Suppressed Evidence; similar to
argument by lie):
This is hard to detect, of course. You have to ask questions.
For example, an amazingly accurate "prophecy" of the
assassination attempt on President Reagan was shown on TV. But
was the tape recorded before or after the event ? Many stations
did not ask this question. (It was recorded afterwards.)
A book on "sea mysteries" or the "Bermuda Triangle" might tell
us that the yacht Connemara IV was found drifting crewless,
southeast of Bermuda, on September 26, 1955. None of these books
mention that the yacht had been directly in the path of
Hurricane Iona, with 180 mph winds and 40-foot waves.
Argument By Generalization:
Drawing a broad conclusion from a small number of perhaps
unrepresentative cases. (The cases may be unrepresentative
because of Selective Observation.) For example, "They say 1 out
of every 5 people is Chinese. How is this possible ? I know
hundreds of people, and none of them is Chinese." So, by
generalization, there aren't any Chinese anywhere. This is
connected to the Fallacy Of The General Rule.
Similarly, "Because we allow terminally ill patients to use
heroin, we should allow everyone to use heroin."
It is also possible to under-generalize. For example,
"A man who had killed both of his grandmothers declared himself
rehabilitated, on the grounds that he could not conceivably
repeat his offense in the absence of any further grandmothers."
-- "Ports Of Call" by Jack Vance
Argument From Small Numbers:
"I've thrown three sevens in a row. Tonight I can't lose." This
is Argument By Generalization, but it assumes that small numbers
are the same as big numbers. (Three sevens is actually a common
occurrence. Thirty three sevens is not.)
Or: "After treatment with the drug, one-third of the mice were
cured, one-third died, and the third mouse escaped." Does this
mean that if we treated a thousand mice, 333 would be cured ?
Misunderstanding The Nature Of Statistics (Innumeracy):
President Dwight Eisenhower expressed astonishment and alarm on
discovering that fully half of all Americans had below average
intelligence. Similarly, some people get fearful when they learn
that their doctor wasn't in the top half of his class. (But
that's half of them.)
"Statistics show that of those who contract the habit of eating,
very few survive." -- Wallace Irwin.
Very few people seem to understand "regression to the mean".
This is the idea that things tend to go back to normal. If you
feel normal today, does it really mean that the headache cure
you took yesterday performed wonders ? Or is it just that your
headaches are always gone the next day ?
Journalists are notoriously bad at reporting risks. For example,
in 1995 it was loudly reported that a class of contraceptive
pills would double the chance of dangerous blood clots. The news
stories mostly did not mention that "doubling" the risk only
increased it by one person in 7,000. The "cell phones cause
brain cancer" reports are even sillier, with the supposed
increase in risk being at most one or two cancers per 100,000
people per year. So, if the fearmongers are right, your
cellphone has increased your risk from "who cares" to "who
For example, the declining life expectancy in the former Soviet
Union is due to the failures of communism. But, the quite high
infant mortality rate in the United States is not a failure of
This is related to Internal Contradiction.
Something that just does not follow. For example, "Tens of
thousands of Americans have seen lights in the night sky which
they could not identify. The existence of life on other planets
is fast becoming certainty !"
Another example: arguing at length that your religion is of
great help to many people. Then, concluding that the teachings
of your religion are undoubtably true.
Or: "Bill lives in a large building, so his apartment must be
Irresistible forces meeting immovable objects, and the like.
Argument By Poetic Language:
If it sounds good, it must be right. Songs often use this effect
to create a sort of credibility - for example, "Don't Fear The
Reaper" by Blue Oyster Cult. Politically oriented songs should
be taken with a grain of salt, precisely because they sound
Argument By Slogan:
If it's short, and connects to an argument, it must be an
argument. (But slogans risk the Reductive Fallacy.)
Being short, a slogan increases the effectiveness of Argument By
Repetition. It also helps Argument By Emotive Language (Appeal
To The People), since emotional appeals need to be punchy.
(Also, the gallery can chant a short slogan.) Using an old
slogan is Cliche Thinking.
Argument By Prestigious Jargon:
Using big complicated words so that you will seem to be an
expert. Why do people use "utilize" when they could utilize
For example, crackpots
used to claim they had a Unified Field Theory (after Einstein).
Then the word Quantum was popular. Lately it seems to be Zero
Argument By Gibberish (Bafflement):
This is the extreme version of Argument By Prestigious Jargon.
An invented vocabulary helps the effect, and some net.kooks use
lots of CAPitaLIZation. However, perfectly ordinary words can be
used to baffle. For example, "Omniscience is greater than
omnipotence, and the difference is two. Omnipotence plus two
equals omniscience. META = 2." [From R. Buckminster Fuller's No
More Secondhand God.]
Gibberish may come from people who can't find meaning in
technical jargon, so they think they should copy style instead
of meaning. It can also be a "snow job", AKA "baffle them with
BS", by someone actually familiar with the jargon. Or it could
be Argument By Poetic Language.
An example of poetic gibberish: "Each autonomous individual
emerges holographically within egoless ontological consciousness
as a non-dimensional geometric point within the transcendental
Equivocation (a form of non sequitur):
Using a word to mean one thing, and then later using it to mean
something different. For example, sometimes "Free software"
costs nothing, and sometimes it is without restrictions. Some
"The sign said 'fine for parking here', and since it was fine, I
All trees have bark.
All dogs bark.
Therefore, all dogs are trees.
"Consider that two wrongs never make a right, but that three
- "Deteriorata", National Lampoon
The use of words that sound better. The lab rat wasn't killed,
it was sacrificed. Mass murder wasn't genocide, it was ethnic
cleansing. The death of innocent bystanders is collateral
damage. Microsoft doesn't find bugs, or problems, or security
vulnerabilities: they just discover an issue with a piece of
This is related to Argument By Emotive Language, since the
effect is to make a concept emotionally palatable.
This is very much like Euphemism, except that the word changes
are done to claim a new, different concept rather than soften
the old concept. For example, an American President may not
legally conduct a war without a declaration of Congress. So,
various Presidents have conducted "police actions", "armed
incursions", "protective reaction strikes," "pacification,"
"safeguarding American interests," and a wide variety of
"operations". Similarly, War Departments have become Departments
of Defense, and untested medicines have become alternative
medicines. The book "1984" has some particularly good examples.
Error Of Fact:
For example, "No one knows how old the Pyramids of Egypt are."
(Except, of course, for the historians who've read records and
letters written by the ancient Egyptians themselves.)
Typically, the presence of one error means that there are other
errors to be uncovered.
Intentional Errors of Fact.
If the speaker thinks that lying serves a moral end, this would
be a Pious Fraud.
Hypothesis Contrary To Fact:
Arguing from something that might have happened, but didn't.
Saying two contradictory things in the same argument. For
example, claiming that Archaeopteryx is a dinosaur with hoaxed
feathers, and also saying in the same book that it is a "true
bird". Or another author who said on page 59, "Sir Arthur Conan
Doyle writes in his autobiography that he never saw a ghost."
But on page 200 we find "Sir Arthur's first encounter with a
ghost came when he was 25, surgeon of a whaling ship in the
This is much like saying
"I never borrowed his car, and it already had that dent when I
This is related to Inconsistency.
Changing The Subject (Digression, Red Herring, Misdirection,
This is sometimes used to avoid having to defend a claim, or to
avoid making good on a promise. In general, there is something
you are not supposed to notice.
For example, I got a bill which had a big announcement about how
some tax had gone up by 5%, and the costs would have to be
passed on to me. But a quick calculation showed that the
increased tax was only costing me a dime, while a different part
of the the bill had silently gone up by $10.
This is connected to various diversionary tactics, which may be
obstructive, obtuse, or needling. For example, if you quibble
about the meaning of some word a person used, they may be quite
happy about being corrected, since that means they've derailed
you, or changed the subject. They may pick nits in your wording,
perhaps asking you to define "is". They may deliberately
"You said this happened five years before Hitler came to power.
Why are you so fascinated with Hitler ? Are you anti-Semitic ?"
It is also connected to various rhetorical tricks, such as
announcing that there cannot be a question period because the
speaker must leave. (But then he doesn't leave.)
Argument By Fast Talking:
If you go from one idea to the next quickly enough, the audience
won't have time to think. This is connected to Changing The
Subject and (to some audiences) Argument By Personal Charm.
However, some psychologists say that to understand what you
hear, you must for a brief moment believe it. If this is true,
then rapid delivery does not leave people time to reject what
Having Your Cake (Failure To Assert, or Diminished Claim):
Almost claiming something, but backing out. For example, "It may
be, as some suppose, that ghosts can only be seen by certain
so-called sensitives, who are possibly special mutations with,
perhaps, abnormally extended ranges of vision and hearing. Yet
some claim we are all sensitives."
Another example: "I don't
necessarily agree with the liquefaction theory, nor do I endorse
all of Walter Brown's other material, but the geological
statements are informative." The strange thing here is that
liquefaction theory (the idea that the world's rocks formed in
flood waters) was demolished in 1788. To "not necessarily agree"
with it, today, is in the category of "not necessarily agreeing"
with 2+2=3. But notice that writer implies some study of the
matter, and only partial rejection.
A similar thing is the failure to rebut. Suppose I raise an
issue. The response that "Woodmorappe's book talks about that"
could possibly be a reference to a resounding rebuttal. Or
perhaps the responder hasn't even read the book yet. How can we
tell ? [I later discovered it was the latter.]
A statement is made, but it is sufficiently unclear that it
leaves some sort of leeway. For example, a book about Washington
politics did not place quotation marks around quotes. This left
ambiguity about which parts of the book were first-hand reports
and which parts were second-hand reports, assumptions, or
Of course, lack of clarity is not always intentional. Sometimes
a statement is just vague.
If the statement has two different meanings, this is Amphiboly.
For example, "Last night I shot a burglar in my pyjamas."
Failure To State:
If you make enough attacks, and ask enough questions, you may
never have to actually define your own position on the topic.
Information is given, but it is not the latest information on
the subject. For example, some creationist articles about the
amount of dust on the moon quote a measurement made in the
1950's. But many much better measurements have been done since
The speaker seems to have information that there is no possible
way for him to get, on the basis of his own statements. For
example: "The first man on deck, seaman Don Smithers, yawned
lazily and fingered his good luck charm, a dried seahorse. To no
avail ! At noon, the Sea Ranger was found drifting aimlessly,
with every man of its crew missing without a trace !"
Ignoring all of the most reasonable explanations. This makes the
desired explanation into the only one. For example: "I left a
saucer of milk outside overnight. In the morning, the milk was
gone. Clearly, my yard was visited by fairies."
There is an old rule for deciding which explanation is the most
plausible. It is most often called "Occam's Razor", and it
basically says that the simplest is the best. The current phrase
among scientists is that an explanation should be "the most
parsimonious", meaning that it should not introduce new concepts
(like fairies) when old concepts (like neighborhood cats) will
On ward rounds, medical students love to come up with the most
obscure explanations for common problems. A traditional response
is to tell them "If you hear hoof beats, don't automatically
think of zebras".
Argument By Scenario:
Telling a story which ties together unrelated material, and then
using the story as proof they are related.
Affirming The Consequent (a form of non sequitur): :
Logic reversal. A correct statement of the form "if P then Q"
gets turned into "Q therefore P."
For example, "All cats
die; Socrates died; therefore Socrates was a cat."
Another example: "If the earth orbits the sun, then the nearer
stars will show an apparent annual shift in position relative to
more distant stars (stellar parallax). Observations show
conclusively that this parallax shift does occur. This proves
that the earth orbits the sun." In reality, it proves that Q
[the parallax] is consistent with P [orbiting the sun]. But it
might also be consistent with some other theory. (Other theories
did exist. They are now dead, because although they were
consistent with a few facts, they were not consistent with all
Another example: "If space creatures were kidnapping people and
examining them, the space creatures would probably hypnotically
erase the memories of the people they examined. These people
would thus suffer from amnesia. But in fact many people do
suffer from amnesia. This tends to prove they were kidnapped and
examined by space creatures." This is also a Least Plausible
Moving The Goalposts (Raising The Bar, Argument By Demanding
If your opponent successfully addresses some point, then say he
must also address some further point. If you can make these
points more and more difficult (or diverse) then eventually your
opponent must fail. If nothing else, you will eventually find a
subject that your opponent isn't up on.
This is related to Argument By Question. Asking questions is
easy: it's answering them that's hard.
If each new goal causes a new question, this may get to be
It is also possible to lower the bar, reducing the burden on an
argument. For example, a person who takes Vitamin C might claim
that it prevents colds. When they do get a cold, then they move
the goalposts, by saying that the cold would have been much
worse if not for the Vitamin C.
Appeal To Complexity:
If the arguer doesn't understand the topic, he concludes that
nobody understands it. So, his opinions are as good as
Disproof By Fallacy:
If a conclusion can be reached in an obviously fallacious way,
then the conclusion is incorrectly declared wrong.
"Take the division 64/16.
Now, canceling a 6 on top and a six on the bottom, we get that
64/16 = 4/1 = 4."
"Wait a second ! You can't just cancel the six !"
"Oh, so you're telling us 64/16 is not equal to 4, are you ?"
Note that this is
different from Reductio Ad Absurdum, where your opponent's
argument can lead to an absurd conclusion. In this case, an
absurd argument leads to a normal conclusion.
Reductio Ad Absurdum:
Showing that your opponent's argument leads to some absurd
conclusion. This is in general a reasonable and non-fallacious
way to argue. If the issues are razor-sharp, it is a good way to
completely destroy his argument. However, if the waters are a
bit muddy, perhaps you will only succeed in showing that your
opponent's argument does not apply in all cases, That is, using Reductio Ad Absurdum is sometimes using the Fallacy Of The
General Rule. However, if you are faced with an argument that is
poorly worded, or only lightly sketched, Reductio Ad Absurdum
may be a good way of pointing out the holes.
An example of why absurd
conclusions are bad things:
Bertrand Russell, in a
lecture on logic, mentioned that in the sense of material
implication, a false proposition implies any proposition. A
student raised his hand and said "In that case, given that 1 =
0, prove that you are the Pope". Russell immediately replied,
"Add 1 to both sides of the equation: then we have 2 = 1. The
set containing just me and the Pope has 2 members. But 2 = 1, so
it has only 1 member; therefore, I am the Pope."
If one does not understand a debate, it must be "fair" to split
the difference, and agree on a compromise between the opinions.
(But one side is very possibly wrong, and in any case one could
simply suspend judgment.) Journalists often invoke this fallacy
in the name of "balanced" coverage.
"Some say the sun rises in the east, some say it rises in the
west; the truth lies probably somewhere in between."
Television reporters like balanced coverage so much that they
may give half of their report to a view held by a small minority
of the people in question. There are many possible reasons for
this, some of them good. However, viewers need to be aware of
Fallacy Of The Crucial Experiment:
Claiming that some idea has been proved (or disproved) by a
pivotal discovery. This is the "smoking gun" version of history.
Scientific progress is often reported in such terms. This is
inevitable when a complex story is reduced to a soundbite, but
it's almost always a distortion. In reality, a lot of background
happens first, and a lot of buttressing (or retraction) happens
afterwards. And in natural history, most of the theories are
about how often certain things happen (relative to some other
thing). For those theories, no one experiment could ever be
Two Wrongs Make A Right (Tu Quoque, You Too, What's sauce for
the goose is sauce for the gander):
A charge of wrongdoing is answered by a rationalization that
others have sinned, or might have sinned. For example, Bill
borrows Jane's expensive pen, and later finds he hasn't returned
it. He tells himself that it is okay to keep it, since she would
have taken his.
War atrocities and terrorism are often defended in this way.
Similarly, some people defend capital punishment on the grounds
that the state is killing people who have killed.
This is related to Ad Hominem (Argument To The Man).
A fraud done to accomplish some good end, on the theory that the
end justifies the means.
For example, a church in Canada had a statue of Christ which
started to weep tears of blood. When analyzed, the blood turned
out to be beef blood. We can reasonably assume that someone with
access to the building thought that bringing souls to Christ
would justify his small deception.
In the context of debates, a Pious Fraud could be a lie. More
generally, it would be when an emotionally committed speaker
makes an assertion that is shaded, distorted or even fabricated.
For example, British Prime Minister Tony Blair was accused in
2003 of "sexing up" his evidence that Iraq had Weapons of Mass
Around the year 400, Saint Augustine wrote two books, De
Mendacio[On Lying] and Contra Medacium[Against Lying], on this
subject. He argued that the sin isn't in what you do (or don't)
say, but in your intent to leave a false impression. He strongly
opposed Pious Fraud. We believe that Martin Luther also wrote on
return to the brief introduction to unintentional obstacles to
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