contains 184 names of the most common fallacies, and it provides brief
explanations and examples of each of them. Fallacies should not be
persuasive, but they often are. Fallacies may be created
unintentionally, or they may be created intentionally in order to
deceive other people. The vast majority of the commonly identified
fallacies involve arguments, although some involve explanations, or
definitions, or other products of reasoning. Sometimes the term
"fallacy" is used even more broadly to indicate any false belief or
cause of a false belief. The list below includes some fallacies of
these sorts, but most are fallacies that involve kinds of errors made
while arguing informally in natural language.
The discussion that precedes the list begins with an account of the
ways in which the term "fallacy" is vague. Attention then turns to the
number of competing and overlapping ways to classify fallacies of
argumentation. For pedagogical purposes, researchers in the field of
fallacies disagree about the following topics: which name of a fallacy
is more helpful to students' understanding; whether some fallacies
should be de-emphasized in favor of others; and which is the best
taxonomy of the fallacies. Researchers in the field are also deeply
divided about how to define the term "fallacy" itself, how to define
certain fallacies, and whether any theory of fallacies at all should
be pursued if that theory's goal is to provide necessary and
sufficient conditions for distinguishing between fallacious and
non-fallacious reasoning generally. Analogously, there is doubt in the
field of ethics regarding whether researchers should pursue the goal
of providing necessary and sufficient conditions for distinguishing
moral actions from immoral ones.
1. Introduction
The first known systematic study of fallacies was due to Aristotle in
his De Sophisticis Elenchis (Sophistical Refutations), an appendix to
the Topics. He listed thirteen types. After the Dark Ages, fallacies
were again studied systematically in Medieval Europe. This is why so
many fallacies have Latin names. The third major period of study of
the fallacies began in the later twentieth century due to renewed
interest from the disciplines of philosophy, logic, communication
studies, rhetoric, psychology, and artificial intelligence.
The more frequent the error within public discussion and debate the
more likely it is to have a name. That is one reason why there is no
specific name for the fallacy of subtracting five from thirteen and
concluding that the answer is seven, though the error is common among
elementary school children.
The term "fallacy" is not a precise term. One reason is that it is
ambiguous. It can refer either to (a) a kind of error in an argument,
(b) a kind of error in reasoning (including arguments, definitions,
explanations, and so forth), (c) a false belief, or (d) the cause of
any of the previous errors including what are normally referred to as
"rhetorical techniques." Philosophers who are researchers in fallacy
theory prefer to emphasize (a), but their lead is often not followed
in textbooks and public discussion.
Regarding (d), ill health, being a bigot, being hungry, being stupid,
and being hypercritical of our enemies are all sources of error in
reasoning, so they could qualify as fallacies of kind (d), but they
are not included in the list below. On the other hand, wishful
thinking, stereotyping, being superstitious, rationalizing, and having
a poor sense of proportion are sources of error and are included in
the list below, though they wouldn't be included in a list devoted
only to faulty arguments. Thus there is a certain arbitrariness to
what appears in lists such as this. What have been left off the list
below are the following persuasive techniques commonly used to
influence others and to cause errors in reasoning: apple polishing,
assigning the burden of proof inappropriately, using propaganda
techniques, ridiculing, being sarcastic, selecting terms with strong
negative or positive associations, using innuendo, and weasling. All
of the techniques are worth knowing about if one wants to avoid the
fallacies.
In describing the fallacies below, the custom is followed of not
distinguishing between a reasoner committing a fallacy and the
reasoning itself committing the fallacy, though it would be more
accurate to say that a reasoner commits the fallacy and the reasoning
contains the fallacy.
In the list below, the examples are very short. If they were long, the
article would be too long. Nevertheless real arguments are often
embedded within a very long discussion. Richard Whately, one of the
greatest of the 19th century researchers into informal logic, wisely
said, "A very long discussion is one of the most effective veils of
Fallacy; …a Fallacy, which when stated barely…would not deceive a
child, may deceive half the world if diluted in a quarto volume."
2. Taxonomy of Fallacies
There are a number of competing and overlapping ways to classify
fallacies of argumentation. For example, they can be classified as
either formal or informal. A formal fallacy can be detected by
examining the logical form of the reasoning, whereas an informal
fallacy depends upon the content of the reasoning and possibly the
purpose of the reasoning. The list below contains very few formal
fallacies. Fallacious arguments also can be classified as deductive or
inductive, depending upon whether the fallacious argument is most
properly assessed by deductive standards or instead by inductive
standards. Deductive standards demand deductive validity, but
inductive standards require inductive strength such as making the
conclusion more likely. Fallacies can be divided into categories
according to the psychological factors that lead people to commit
them, and they can also be divided into categories according to the
epistemological or logical factors that cause the error. In the latter
division there are three categories: (1) the reasoning is invalid but
is presented as if it were a valid argument, or else it is inductively
much weaker than it is presented as being, (2) the argument has an
unjustified premise, or (3) some relevant evidence has been ignored or
suppressed. Regarding (2), a premise can be justified or warranted at
a time even if we later learn that the premise was false, and it can
be justified if we are reasoning about what would have happened even
when we know it didn't happen.
Similar fallacies are often grouped together under a common name
intended to bring out how the fallacies are similar. Here are three
examples. Fallacies of relevance include fallacies that occur due to
reliance on an irrelevant reason. In addition, ad hominem, appeal to
pity, and affirming the consequent are some other fallacies of
relevance. Accent, amphiboly and equivocation are examples of
fallacies of ambiguity. The fallacies of illegitimate presumption
include begging the question, false dilemma, no true Scotsman, complex
question and suppressed evidence. Notice how these categories don't
fall neatly into just one of the categories (1), (2), and (3) above.
3. Pedagogy
It is commonly claimed that giving a fallacy a name and studying it
will help the student identify the fallacy in the future and will
steer them away from committing the fallacy in their own reasoning. As
Steven Pinker says in The Stuff of Thought (p. 129),
If a language provides a label for a complex concept, that could
make it easier to think about the concept, because the mind can handle
it as a single package when juggling a set of ideas, rather than
having to keep each of its components in the air separately. It can
also give a concept an additional label in long-term memory, making it
more easily retrivable than ineffable concepts or those with more
roundabout verbal descriptions.
For pedagogical purposes, researchers in the field of fallacies
disagree about the following topics: which name of a fallacy is more
helpful to students' understanding; whether some fallacies should be
de-emphasized in favor of others; and which is the best taxonomy of
the fallacies. Fallacy theory is criticized by some teachers of
informal reasoning for its over-emphasis on poor reasoning rather than
good reasoning. Do colleges teach the Calculus by emphasizing all the
ways one can make mathematical mistakes? The critics want more
emphasis on the forms of good arguments and on the implicit rules that
govern proper discussion designed to resolve a difference of opinion.
But there has been little systematic study of which emphasis is more
successful.
4. What is a fallacy?
Researchers disagree about how to define the very term "fallacy."
Focusing just on fallacies in sense (a) above, namely fallacies of
argumentation, some researchers define a fallacy as an argument that
is deductively invalid or that has very little inductive strength.
Because examples of false dilemma, inconsistent premises, and begging
the question are valid arguments in this sense, this definition misses
some standard fallacies. Other researchers say a fallacy is a mistake
in an argument that arises from something other than merely false
premises. But the false dilemma fallacy is due to false premises.
Still other researchers define a fallacy as an argument that is not
good. Good arguments are then defined as those that are deductively
valid or inductively strong, and that contain only true,
well-established premises, but are not question-begging. A complaint
with this definition is that its requirement of truth would improperly
lead to calling too much scientific reasoning fallacious; every time a
new scientific discovery caused scientists to label a previously
well-established claim as false, all the scientists who used that
claim as a premise would become fallacious reasoners. This consequence
of the definition is acceptable to some researchers but not to others.
Because informal reasoning regularly deals with hypothetical reasoning
and with premises for which there is great disagreement about whether
they are true or false, many researchers would relax the requirement
that every premise must be true. One widely accepted definition
defines a fallacious argument as one that either is deductively
invalid or is inductively very weak or contains an unjustified premise
or that ignores relevant evidence that is available and that should be
known by the arguer. Finally, yet another theory of fallacy says a
fallacy is a failure to provide adequate proof for a belief, the
failure being disguised to make the proof look adequate.
Other researchers recommend characterizing a fallacy as a violation of
the norms of good reasoning, the rules of critical discussion, dispute
resolution, and adequate communication. The difficulty with this
approach is that there is so much disagreement about how to
characterize these norms.
In addition, all the above definitions are often augmented with some
remark to the effect that the fallacies are likely to persuade many
reasoners. It is notoriously difficult to be very precise about this
vague and subjective notion of being likely to persuade, and some
researchers in fallacy theory have therefore recommended dropping the
notion in favor of "can be used to persuade."
Some researchers complain that all the above definitions of fallacy
are too broad and do not distinguish between mere blunders and actual
fallacies, the more serious errors.
Researchers in the field are deeply divided, not only about how to
define the term "fallacy" and how to define some of the individual
fallacies, but also about whether any general theory of fallacies at
all should be pursued if that theory's goal is to provide necessary
and sufficient conditions for distinguishing between fallacious and
non-fallacious reasoning generally. Analogously, there is doubt in the
field of ethics whether researchers should pursue the goal of
providing necessary and sufficient conditions for distinguishing moral
actions from immoral ones.
5. Other Controversies
In the field of rhetoric, the primary goal is to persuade the
audience. The audience is not going to be persuaded by an otherwise
good argument with true premises unless they believe those premises
are true. Philosophers tend to de-emphasize this difference between
rhetoric and informal logic, and they concentrate on arguments that
should fail to convince the ideally rational reasoner rather than on
arguments that are likely not to convince audiences who hold certain
background beliefs.
Advertising in magazines and on television is designed to achieve
visual persuasion. And a hug or the fanning of fumes from freshly
baked donuts out onto the sidewalk are occasionally used for visceral
persuasion. There is some controversy among researchers in informal
logic as to whether the reasoning involved in this nonverbal
persuasion can always be assessed properly by the same standards that
are used for verbal reasoning.
6. Partial List of Fallacies
Consulting the list below will give a general idea of the kind of
error involved in passages to which the fallacy name is applied.
However, simply applying the fallacy name to a passage cannot
substitute for a detailed examination of the passage and its context
or circumstances because there are many instances of reasoning to
which a fallacy name might seem to apply, yet, on further examination,
it is found that in these circumstances the reasoning is really not
fallacious.
* Abusive Ad Hominem
* Accent
* Accident
* Ad Baculum
* Ad Consequentiam
* Ad Crumenum
* Ad Hoc Rescue
* Ad Hominem
* Ad Hominem, Circumstantial
* Ad Ignorantiam
* Ad Misericordiam
* Ad Novitatem
* Ad Numerum
* Ad Populum
* Ad Verecundiam
* Affirming the Consequent
* Against the Person
* All-or-Nothing
* Ambiguity
* Amphiboly
* Anecdotal Evidence
* Anthropomorphism
* Appeal to Authority
* Appeal to Consequence
* Appeal to Emotions
* Appeal to Force
* Appeal to Ignorance
* Appeal to the Masses
* Appeal to Money
* Appeal to the People
* Appeal to Pity
* Appeal to Snobbery
* Appeal to Vanity
* Appeal to Unqualified Authority
* Argument from Ignorance
* Argument from Outrage
* Argument from Popularity
* Argumentum Ad ….
* Avoiding the Issue
* Avoiding the Question
* Bald Man
* Bandwagon
* Begging the Question
* Biased Sample
* Biased Statistics
* Bifurcation
* Black-or-White
* Cherry-Picking the Evidence
* Circular Reasoning
* Circumstantial Ad Hominem
* Clouding the Issue
* Common Belief
* Common Cause.
* Common Practice
* Complex Question
* Composition
* Confirmation Bias
* Consensus Gentium
* Consequence
* Converse Accident
* Cover-up
* Cum Hoc, Ergo Propter Hoc
* Definist
* Denying the Antecedent
* Digression
* Distraction
* Division
* Domino
* Double Standard
* Either/Or
* Equivocation
* Etymological
* Every and All
* Exaggeration
* Excluded Middle
* False Analogy
* False Cause
* False Dichotomy
* False Dilemma
* Far-Fetched Hypothesis
* Faulty Comparison
* Faulty Generalization
* Formal
* Four Terms
* Gambler's
* Genetic
* Group Think
* Guilt by Association
* Hasty Conclusion
* Hasty Generalization
* Heap
* Hedging
* Hooded Man
* Ignoratio Elenchi
* Ignoring a Common Cause
* Incomplete Evidence
* Inconsistency
* Insufficient Statistics
* Intensional
* Invalid Reasoning
* Irrelevant Conclusion
* Irrelevant Reason
* Is-Ought
* Jumping to Conclusions
* Lack of Proportion
* Line-Drawing
* Loaded Language
* Logical
* Lying
* Maldistributed Middle
* Many Questions
* Misconditionalization
* Misleading Vividness
* Misplaced Concreteness
* Misrepresentation
* Missing the Point
* Modal
* Monte Carlo
* Name Calling
* Naturalistic
* Neglecting a Common Cause
* No Middle Ground
* No True Scotsman
* Non Causa Pro Causa
* Non Sequitur
* One-Sidedness
* Outrage, Argument from
* Oversimplification
* Past Practice
* Pathetic
* Perfectionist
* Persuasive Definition
* Petitio Principii
* Poisoning the Well
* Popularity, Argument from
* Post Hoc
* Prejudicial Language
* Proof Surrogate
* Questionable Analogy
* Questionable Cause
* Questionable Premise
* Quibbling
* Quoting out of Context
* Rationalization
* Red Herring
* Refutation by Caricature
* Regression
* Reversing Causation
* Scapegoating
* Scare Tactic
* Scope
* Secundum Quid
* Selective Attention
* Self-Fulfilling Prophecy
* Sharpshooter's
* Slanting
* Slippery Slope
* Small Sample
* Smear Tactic
* Smokescreen
* Sorites
* Special Pleading
* Specificity
* Stacking the Deck
* Stereotyping
* Straw Man
* Style Over Substance
* Subjectivist
* Superstitious Thinking
* Suppressed Evidence
* Sweeping Generalization
* Syllogistic
* Tokenism
* Traditional Wisdom
* Tu Quoque
* Two Wrongs Make a Right
* Undistributed Middle
* Unfalsifiability
* Unrepresentative Sample
* Unrepresentative Generalization
* Untestability
* Weak Analogy
* Willed ignorance
* Wishful Thinking
Abusive Ad Hominem
See Ad Hominem.
Accent
The accent fallacy is a fallacy of ambiguity due to the different ways
a word is emphasized or accented.
Example:
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. And by using neither emphasis,
she can later claim that her response was on either side of the issue.
Aristotle's version of the fallacy of accent allowed only a shift in
which syllable is accented within a word.
Accident
We often arrive at a generalization but don't or can't list all the
exceptions. When we reason with the generalization as if it has no
exceptions, we commit the fallacy of accident. This fallacy is
sometimes called the "fallacy of sweeping generalization."
Example:
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' families. Dwayne
isn't doing right by me.
People should keep their promises, but there are exceptions as in this
case of the psychopath who wants Dwayne to keep his promise to return
the knife, but reasons by using the fallacy of accident.
Ad Baculum
See Scare Tactic and Appeal to Emotions (Fear).
Ad Consequentiam
See Appeal to Consequence.
Ad Crumenum
See Appeal to Money.
Ad Hoc Rescue
Psychologically, it is understandable that you would try to rescue a
cherished belief from trouble. When faced with conflicting data, you
are likely to mention how the conflict will disappear if some new
assumption is taken into account. However, if there is no good reason
to accept this saving assumption other than that it works to save your
cherished belief, your rescue is an ad hoc rescue.
Example:
Yolanda: If you take four of these tablets of vitamin C every day,
you will never get a cold.
Juanita: I tried that last year for several months, and still got a cold.
Yolanda: Did you take the tablets every day?
Juanita: Yes.
Yolanda: Well, I'll bet you bought some bad tablets.
The burden of proof is definitely on Yolanda's shoulders to prove that
Juanita's vitamin C tablets were probably "bad" — that is, not really
vitamin C. If Yolanda can't do so, her attempt to rescue her
hypothesis (that vitamin C prevents colds) is simply a dogmatic
refusal to face up to the possibility of being wrong.
Ad Hominem
You commit this fallacy if you make an irrelevant attack on the arguer
and suggest that this attack undermines the argument itself. It is a
form of the Genetic Fallacy.
Example:
What she says about Johannes Kepler's astronomy of the 1600's must
be just so much garbage. Do you realize she's only fourteen years old?
This attack may undermine the arguer's credibility as a scientific
authority, but it does not undermine her reasoning. That reasoning
should stand or fall on the scientific evidence, not on the arguer's
age or anything else about her personally.
If the fallacious reasoner points out irrelevant circumstances that
the reasoner is in, the fallacy is a circumstantial ad hominem. Tu
Quoque and Two Wrongs Make a Right are other types of the ad hominem
fallacy.
The major difficulty with labeling a piece of reasoning as an ad
hominem fallacy is deciding whether the personal attack is relevant.
For example, attacks on a person for their actually immoral sexual
conduct are irrelevant to the quality of their mathematical reasoning,
but they are relevant to arguments promoting the person for a
leadership position in the church. Unfortunately, many attacks are not
so easy to classify, such as an attack pointing out that the candidate
for church leadership, while in the tenth grade, intentionally tripped
a fellow student and broke his collar bone.
Ad Hominem, Circumstantial
See Guilt by Association.
Ad Ignorantiam
See Appeal to Ignorance.
Ad Misericordiam
See Appeal to Emotions.
Ad Novitatem
See Bandwagon.
Ad Numerum
See Appeal to the People.
Ad Populum
See Appeal to the People.
Ad Verecundiam
See Appeal to Authority.
Affirming the Consequent
If you have enough evidence to affirm the consequent of a conditional
and then suppose that as a result you have sufficient reason for
affirming the antecedent, you commit the fallacy of affirming the
consequent. This formal fallacy is often mistaken for modus ponens,
which is a valid form of reasoning also using a conditional. A
conditional is an if-then statement; the if-part is the antecedent,
and the then-part is the consequent. The following argument affirms
the consequent that she does speaks Portuguese.
Example:
If she's Brazilian, then she speaks Portuguese. Hey, she does
speak Portuguese. So, she is Brazilian.
If the arguer believes or suggests that the premises definitely
establish that she is Brazilian, then the arguer is committing the
fallacy. See the non sequitur fallacy for more discussion of this
point.
Against the Person
See Ad Hominem.
All-or-Nothing
See Black-or-White Fallacy.
Ambiguity
Any fallacy that turns on ambiguity. See the fallacies of Amphiboly,
Accent, and Equivocation.
Amphiboly
This is an error due to taking a grammatically ambiguous phrase in two
different ways during the reasoning.
Example:
In a cartoon, two elephants are driving their car down the road in
India. They say, "We'd better not get out here," as they pass a sign
saying:
ELEPHANTS
PLEASE STAY IN YOUR CAR
Upon one interpretation of the grammar, the pronoun "YOUR" refers to
the elephants in the car, but on another it refers to those humans who
are driving cars in the vicinity. Unlike equivocation, which is due to
multiple meanings of a phrase, amphiboly is due to syntactic
ambiguity, ambiguity caused by alternative ways of taking the grammar.
Anecdotal Evidence
If you discount evidence arrived at by systematic search or by testing
in favor of a few firsthand stories, you are committing the fallacy of
overemphasizing anecdotal evidence.
Example:
Yeah, I've read the health warnings on those cigarette packs and I
know about all that health research, but my brother smokes, and he
says he's never been sick a day in his life, so I know smoking can't
really hurt you.
Anthropomorphism
This is the error of projecting uniquely human qualities onto
something that isn't human. Usually this occurs with projecting the
human qualities onto animals, but when it is done to nonliving things,
as in calling the storm cruel, the pathetic fallacy is created. There
is also, but less commonly, called the Disney Fallacy or the Walt
Disney Fallacy.
Example:
My dog is wagging his tail and running around me. Therefore, he
knows that I love him.
The fallacy would be averted if the speaker had said "My dog is
wagging his tail and running around me. Therefore, he is happy to see
me." Animals are likely to have some human emotions, but not the
ability to ascribe knowledge to other beings. Your dog knows where it
buried its bone, but not that you also know where the bone is.
Appeal to Authority
You appeal to authority if you back up your reasoning by saying that
it is supported by what some authority says on the subject. Most
reasoning of this kind is not fallacious. However, it is fallacious
whenever the authority appealed to is not really an authority in this
subject, when the authority cannot be trusted to tell the truth, when
authorities disagree on this subject (except for the occasional lone
wolf), when the reasoner misquotes the authority, and so forth.
Although spotting a fallacious appeal to authority often requires some
background knowledge about the subject or the authority, in brief it
can be said that it is fallacious to accept the word of a supposed
authority when we should be suspicious.
Example:
You can believe the moon is covered with dust because the
president of our neighborhood association said so, and he should know.
This is a fallacious appeal to authority because, although the
president is an authority on many neighborhood matters, he is no
authority on the composition of the moon. It would be better to appeal
to some astronomer or geologist. If you place too much trust in expert
opinion and overlook any possibility that experts talking in their own
field of expertise make mistakes, too, then you also commit the
fallacy of appeal to authority.
Example:
Of course she's guilty of the crime. The police arrested her,
didn't they? And they're experts when it comes to crime.
Appeal to Consequence
Arguing that a belief is false because it implies something you'd
rather not believe. Also called Argumentum Ad Consequentiam.
Example:
That can't be Senator Smith there in the videotape going into her
apartment. If it were, he'd be a liar about not knowing her. He's not
the kind of man who would lie. He's a member of my congregation.
Smith may or may not be the person in that videotape, but this kind of
arguing should not convince us that it's someone else in the
videotape.
Appeal to Emotions
You commit the fallacy of appeal to emotions when someone's appeal to
you to accept their claim is accepted merely because the appeal
arouses your feelings of anger, fear, grief, love, outrage, pity,
pride, sexuality, sympathy, relief, and so forth. Example of appeal to
relief from grief:
[The speaker knows he is talking to an aggrieved person whose
house is worth much more than $100,000.] You had a great job and
didn't deserve to lose it. I wish I could help somehow. I do have one
idea. Now your family needs financial security even more. You need
cash. I can help you. Here is a check for $100,000. Just sign this
standard sales agreement, and we can skip the realtors and all the
headaches they would create at this critical time in your life.
There is nothing wrong with using emotions when you argue, but it's a
mistake to use emotions as the key premises or as tools to downplay
relevant information. Regarding the fallacy of appeal to pity, it is
proper to pity people who have had misfortunes, but if as the person's
history instructor you accept Max's claim that he earned an A on the
history quiz because he broke his wrist while playing in your
college's last basketball game, then you've committed the fallacy of
appeal to pity.
Appeal to Force
See Scare Tactic.
Appeal to Ignorance
The fallacy of appeal to ignorance comes in two forms: (1) Not knowing
that a certain statement is true is taken to be a proof that it is
false. (2) Not knowing that a statement is false is taken to be a
proof that it is true. The fallacy occurs in cases where absence of
evidence is not good enough evidence of absence. The fallacy uses an
unjustified attempt to shift the burden of proof. The fallacy is also
called "Argument from Ignorance."
Example:
Nobody has ever proved to me there's a God, so I know there is no God.
This kind of reasoning is generally fallacious. It would be proper
reasoning only if the proof attempts were quite thorough, and it were
the case that if God did exist, then there would be a discoverable
proof of this.
Appeal to the Masses
See Appeal to the People.
Appeal to Money
The fallacy of appeal to money uses the error of supposing that, if
something costs a great deal of money, then it must be better, or
supposing that if someone has a great deal of money, then they're a
better person in some way unrelated to having a great deal of money.
Similarly it's a mistake to suppose that if something is cheap it must
be of inferior quality, or to suppose that if someone is poor
financially then they're poor at something unrelated to having money.
Example:
He's rich, so he should be the president of our Parents and
Teachers Organization.
Appeal to the People
If you suggest too strongly that someone's claim or argument is
correct simply because it's what most everyone believes, then you've
committed the fallacy of appeal to the people. Similarly, if you
suggest too strongly that someone's claim or argument is mistaken
simply because it's not what most everyone believes, then you've also
committed the fallacy. Agreement with popular opinion is not
necessarily a reliable sign of truth, and deviation from popular
opinion is not necessarily a reliable sign of error, but if you assume
it is and do so with enthusiasm, then you're guilty of committing this
fallacy. It is also called mob appeal, appeal to the gallery, argument
from popularity, and argumentum ad populum. The 'too strongly' is
important in the description of the fallacy because what most everyone
believes is, for that reason, somewhat likely to be true, all things
considered. However, the fallacy occurs when this degree of support is
overestimated.
Example:
You should turn to channel 6. It's the most watched channel this year.
This is fallacious because of its implicitly accepting the
questionable premise that the most watched channel this year is, for
that reason alone, the best channel for you.
Appeal to Pity
See Appeal to Emotions.
Appeal to Snobbery
See Appeal to Emotions.
Appeal to Unqualified Authority
See Appeal to Authority.
Appeal to Vanity
See Appeal to Emotions.
Argument from Ignorance
See Appeal to Ignorance.
Argument from Outrage
See Appeal to Emotions.
Argument from Popularity
See Appeal to the People.
Argumentum Ad ….
See Ad …. without the word "Argumentum."
Avoiding the Issue
A reasoner who is supposed to address an issue but instead goes off on
a tangent has committed the fallacy of avoiding the issue. Also called
missing the point, straying off the subject, digressing, and not
sticking to the issue.
Example:
A city official is charged with corruption for awarding contracts
to his wife's consulting firm. In speaking to a reporter about why he
is innocent, the city official talks only about his wife's
conservative wardrobe, the family's lovable dog, and his own
accomplishments in supporting Little League baseball.
However, the fallacy isn't committed by a reasoner who says that some
other issue must first be settled and then continues by talking about
this other issue, provided the reasoner is correct in claiming this
dependence of one issue on the other.
Avoiding the Question
The fallacy of avoiding the question is a type of fallacy of avoiding
the issue that occurs when the issue is how to answer some question.
The fallacy is committed when someone's answer doesn't really respond
to the question asked.
Example:
Question: Would the Oakland Athletics be in first place if they
were to win tomorrow's game?
Answer: What makes you think they'll ever win tomorrow's game?
Bald Man
See Line-Drawing.
Bandwagon
If you suggest that someone's claim is correct simply because it's
what most everyone is coming to believe, then you're committing the
bandwagon fallacy. Get up here with us on the wagon where the band is
playing, and go where we go, and don't think too much about the
reasons. The Latin term for this fallacy of appeal to novelty is
Argumentum ad Novitatem.
Example:
[Advertisement] More and more people are buying sports utility
vehicles. Isn't it time you bought one, too? [You commit the fallacy
if you buy the vehicle solely because of this advertisement.]
Like its close cousin, the fallacy of appeal to the people, the
bandwagon fallacy needs to be carefully distinguished from properly
defending a claim by pointing out that many people have studied the
claim and have come to a reasoned conclusion that it is correct. What
most everyone believes is likely to be true, all things considered,
and if one defends a claim on those grounds, this is not a fallacious
inference. What is fallacious is to be swept up by the excitement of a
new idea or new fad and to unquestionably give it too high a degree of
your belief solely on the grounds of its new popularity, perhaps
thinking simply that 'new is better.'
Begging the Question
A form of circular reasoning in which a conclusion is derived from
premises that presuppose the conclusion. Normally, the point of good
reasoning is to start out at one place and end up somewhere new,
namely having reached the goal of increasing the degree of reasonable
belief in the conclusion. The point is to make progress, but in cases
of begging the question there is no progress.
Example:
"Women have rights," said the Bullfighters Association president.
"But women shouldn't fight bulls because a bullfighter is and should
be a man."
The president is saying basically that women shouldn't fight bulls
because women shouldn't fight bulls. This reasoning isn't making an
progress toward determining whether women should fight bulls.
Insofar as the conclusion of a deductively valid argument is
"contained" in the premises from which it is deduced, this containing
might seem to be a case of presupposing, and thus any deductively
valid argument might seem to be begging the question. It is still an
open question among logicians as to why some deductively valid
arguments are considered to be begging the question and others are
not. Some logicians suggest that, in informal reasoning with a
deductively valid argument, if the conclusion is psychologically new
insofar as the premises are concerned, then the argument isn't an
example of the fallacy. Other logicians suggest that we need to look
instead to surrounding circumstances, not to the psychology of the
reasoner, in order to assess the quality of the argument. For example,
we need to look to the reasons that the reasoner used to accept the
premises. Was the premise justified on the basis of accepting the
conclusion? A third group of logicians say that, in deciding whether
the fallacy is committed, we need more. We must determine whether any
premise that is key to deducing the conclusion is adopted rather
blindly or instead is a reasonable assumption made by someone
accepting their burden of proof. The premise would here be termed
reasonable if the arguer could defend it independently of accepting
the conclusion that is at issue.
Biased Sample
See Unrepresentative Sample.
Biased Statistics
See Unrepresentative Sample.
Bifurcation
See Black-or-White.
Black-or-White
The black-or-white fallacy is a false dilemma fallacy that unfairly
limits you to only two choices.
Example:
Well, it's time for a decision. Will you contribute $10 to our
environmental fund, or are you on the side of environmental
destruction?
A proper challenge to this fallacy could be to say, "I do want to
prevent the destruction of our environment, but I don't want to give
$10 to your fund. You are placing me between a rock and a hard place."
The key to diagnosing the black-or-white fallacy is to determine
whether the limited menu is fair or unfair. Simply saying, "Will you
contribute $10 or won't you?" is not unfair.
Cherry-Picking the Evidence
This is another name for the Fallacy of Suppressed Evidence.
Circular Reasoning
Circular reasoning occurs when the reasoner begins with what he or she
is trying to end up with. The most well known examples are cases of
the fallacy of begging the question. However, if the circle is very
much larger, including a wide variety of claims and a large set of
related concepts, then the circular reasoning can be informative and
so is not considered to be fallacious. For example, a dictionary
contains a large circle of definitions that use words which are
defined in terms of other words that are also defined in the
dictionary. Because the dictionary is so informative, it is not
considered as a whole to be fallacious. However, a small circle of
definitions is considered to be fallacious.
Here is Steven Pinker's example:
Definition: endless loop, n. See loop, endless.
Definition: loop, endless, n. See endless loop.
In properly constructed recursive definitions, defining a term by
using that term is not fallacious. For example, here is a recursive
definition of "a stack of coins." Basis step: Two coins, with one on
top of the other, is a stack of coins. Recursion step: If p is a stack
of coins, then adding a coin on top of p produces a stack of coins.
For additional difficulties in deciding whether an argument is
deficient because it is circular, see Begging the Question.
Circumstantial Ad Hominem
See Ad Hominem, Circumstantial.
Clouding the Issue
See Smokescreen.
Common Belief
See Appeal to the People and Traditional Wisdom.
Common Cause
This fallacy occurs during causal reasoning when a causal connection
between two kinds of events is claimed when evidence is available
indicating that both are the effect of a common cause.
Example:
Noting that the auto accident rate rises and falls with the rate
of use of windshield wipers, one concludes that the use of wipers is
somehow causing auto accidents.
However, it's the rain that's the common cause of both.
Common Practice
See Appeal to the People and Traditional Wisdom.
Complex Question
You commit this fallacy when you frame a question so that some
controversial presupposition is made by the wording of the question.
Example:
[Reporter's question] Mr. President: Are you going to continue
your policy of wasting taxpayer's money on missile defense?
The question unfairly presumes the controversial claim that the policy
really is a waste of money. The fallacy of complex question is a form
of begging the question.
Composition
The composition fallacy occurs when someone mistakenly assumes that a
characteristic of some or all the individuals in a group is also a
characteristic of the group itself, the group "composed" of those
members. It is the converse of the division fallacy.
Example:
Each human cell is very lightweight, so a human being composed of
cells is also very lightweight.
Confirmation Bias
The tendency to look only for evidence in favor of one's controversial
hypothesis and not to look for disconfirming evidence, or to pay
insufficient attention to it. This is the most common kind of Fallacy
of Selective Attention.
Example:
She loves me, and there are so many ways that she has shown it.
When we signed the divorce papers in her lawyer's office, she wore my
favorite color. When she slapped me at the bar and called me a
"handsome pig," she used the word "handsome" when she didn't have to.
When I called her and she said never to call her again, she first
asked me how I was doing and whether my life had changed. When I
suggested that we should have children in order to keep our marriage
together, she laughed. If she can laugh with me, if she wants to know
how I am doing and whether my life has changed, and if she calls me
"handsome" and wears my favorite color on special occasions, then I
know she really loves me.
Committing the fallacy of confirmation bias is often a sign that one
has adopted some belief dogmatically and isn't seriously setting about
to confirm or disconfirm the belief.
Consensus Gentium
Fallacy of argumentum consensus gentium (argument from the consensus
of the nations). See Traditional Wisdom.
Consequence
See Appeal to Consequence.
Converse Accident
If we reason by paying too much attention to exceptions to the rule,
and generalize on the exceptions, we commit this fallacy. This fallacy
is the converse of the accident fallacy. It is a kind of Hasty
Generalization, by generalizing too quickly from a peculiar case.
Example:
I've heard that turtles live longer than tarantulas, but the one
turtle I bought lived only two days. I bought it at Dowden's Pet
Store. So, I think that turtles bought from pet stores do not live
longer than tarantulas.
The original generalization is "Turtles live longer than tarantulas."
There are exceptions, such as the turtle bought from the pet store.
Rather than seeing this for what it is, namely an exception, the
reasoner places too much trust in this exception and generalizes on it
to produce the faulty generalization that turtles bought from pet
stores do not live longer than tarantulas.
Cover-up
See Suppressed Evidence.
Cum Hoc, Ergo Propter Hoc
Latin for "with this, therefore because of this." This is a false
cause fallacy that doesn't depend on time order (as does the post hoc
fallacy), but on any other chance correlation of the supposed cause
being in the presence of the supposed effect.
Example:
Gypsies live near our low-yield cornfields. So, gypsies are
causing the low yield.
Definist
The definist fallacy occurs when someone unfairly defines a term so
that a controversial position is made easier to defend. Same as the
Persuasive Definition.
Example:
During a controversy about the truth or falsity of atheism, the
fallacious reasoner says, "Let's define 'atheist' as someone who
doesn't yet realize that God exists."
Denying the Antecedent
You are committing a fallacy if you deny the antecedent of a
conditional and then suppose that doing so is a sufficient reason for
denying the consequent. This formal fallacy is often mistaken for
modus tollens, a valid form of argument using the conditional. A
conditional is an if-then statement; the if-part is the antecedent,
and the then-part is the consequent.
Example:
If she were Brazilian, then she would know that Brazil's official
language is Portuguese. She isn't Brazilian; she's from London. So,
she surely doesn't know this about Brazil's language.
Digression
See Avoiding the Issue.
Distraction
See Smokescreen.
Division
Merely because a group as a whole has a characteristic, it often
doesn't follow that individuals in the group have that characteristic.
If you suppose that it does follow, when it doesn't, you commit the
fallacy of division. It is the converse of the composition fallacy.
Example:
Joshua's soccer team is the best in the division because it had an
undefeated season and shared the division title, so Joshua, who is
their goalie, must be the best goalie in the division.
Domino
See Slippery Slope.
Double Standard
There are many situations in which you should judge two things or
people by the same standard. If in one of those situations you use
different standards for the two, you commit the fallacy of using a
double standard.
Example:
I know we will hire any man who gets over a 70 percent on the
screening test for hiring Post Office employees, but women should have
to get an 80 to be hired because they often have to take care of their
children.
This example is a fallacy if it can be presumed that men and women
should have to meet the same standard for becoming a Post Office
employee.
Either/Or
See Black-or-White.
Equivocation
Equivocation is the illegitimate switching of the meaning of a term
during the reasoning.
Example:
Brad is a nobody, but since nobody is perfect, Brad must be perfect, too.
The term "nobody" changes its meaning without warning in the passage.
So does the term "political jokes" in this joke: I don't approve of
political jokes. I've seen too many of them get elected.
Etymological
The etymological fallacy occurs whenever someone falsely assumes that
the meaning of a word can be discovered from its etymology or origins.
Example:
The word "vise" comes from the Latin "that which winds," so it
means anything that winds. Since a hurricane winds around its own eye,
it is a vise.
Every and All
The fallacy of every and all turns on errors due to the order or scope
of the quantifiers "every" and "all" and "any." This is a version of
the scope fallacy.
Example:
Every action of ours has some final end. So, there is some common
final end to all our actions.
In proposing this fallacious argument, Aristotle believed the common
end is the supreme good, so he had a rather optimistic outlook on the
direction of history.
Exaggeration
When we overstate or overemphasize a point that is a crucial step in a
piece of reasoning, then we are guilty of the fallacy of exaggeration.
This is a kind of error called Lack of Proportion.
Example:
She's practically admitted that she intentionally yelled at that
student while on the playground in the fourth grade. That's assault.
Then she said nothing when the teacher asked, "Who did that?" That's
lying, plain and simple. Do you want to elect as secretary of this
society someone who is a known liar prone to assault? Doing so would
be a disgrace to the Collie Society.
When we exaggerate in order to make a joke, though, we aren't guilty
of the fallacy.
Excluded Middle
See False Dilemma or Black-or-White.
False Analogy
When reasoning by analogy, the fallacy occurs when the analogy is
irrelevant or very weak or when there is a more relevant disanalogy.
See also Faulty Comparison.
Example:
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.
False Cause
Improperly concluding that one thing is a cause of another. The
Fallacy of Non Causa Pro Causa is another name for this fallacy. Its
four principal kinds are the Post Hoc Fallacy, the Fallacy of Cum Hoc,
Ergo Propter Hoc, the Regression Fallacy, and the Fallacy of Reversing
Causation.
Example:
My psychic adviser says to expect bad things when Mars is aligned
with Jupiter. Tomorrow Mars will be aligned with Jupiter. So, if a dog
were to bite me tomorrow, it would be because of the alignment of Mars
with Jupiter.
False Dichotomy
See False Dilemma or Black-or-White.
False Dilemma
A reasoner who unfairly presents too few choices and then implies that
a choice must be made among this short menu of choices commits the
false dilemma fallacy, as does the person who accepts this faulty
reasoning.
Example:
I want to go to Scotland from London. I overheard McTaggart say
there are two roads to Scotland from London: the high road and the low
road. I expect the high road would be too risky because it's through
the hills and that means dangerous curves. But it's raining now, so
both roads are probably slippery. I don't like either choice, but I
guess I should take the low road and be safer.
This would be fine reasoning is you were limited to only two roads,
but you've falsely gotten yourself into a dilemma with such reasoning.
There are many other ways to get to Scotland. Don't limit yourself to
these two choices. You can take other roads, or go by boat or train or
airplane. The fallacy is called the "False Dichotomy Fallacy" when the
unfair menu contains only two choices. Think of the unpleasant choice
between the two as being a charging bull. By demanding other choices
beyond those on the unfairly limited menu, you thereby "go between the
horns" of the dilemma, and are not gored. For another example of the
fallacy, see Black-or-White.
Far-Fetched Hypothesis
This is the fallacy of offering a bizarre (far-fetched) hypothesis as
the correct explanation without first ruling out more mundane
explanations.
Example:
Look at that mutilated cow in the field, and see that flattened
grass. Aliens must have landed in a flying saucer and savaged the cow
to learn more about the beings on our planet.
Faulty Comparison
If you try to make a point about something by comparison, and if you
do so by comparing it with the wrong thing, you commit the fallacy of
faulty comparison or the fallacy of questionable analogy.
Example:
We gave half the members of the hiking club Durell hiking boots
and the other half good-quality tennis shoes. After three months of
hiking, you can see for yourself that Durell lasted longer. You, too,
should use Durell when you need hiking boots.
Shouldn't Durell hiking boots be compared with other hiking boots, not
with tennis shoes?
Faulty Generalization
A fallacy produced by some error in the process of generalizing. See
Hasty Generalization or Unrepresentative Generalization for examples.
Formal
Formal fallacies are all the cases or kinds of reasoning that fail to
be deductively valid. Formal fallacies are also called logical
fallacies or invalidities.
Example:
Some cats are tigers. Some tigers are animals. So, some cats are animals.
This might at first seem to be a good argument, but actually it is
fallacious because it has the same logical form as the following more
obviously invalid argument:
Some women are Americans. Some Americans are men. So, some women are men.
Nearly all the infinity of types of invalid inferences have no
specific fallacy names.
Four Terms
The fallacy of four terms (quaternio terminorum) occurs when four
rather than three categorical terms are used in a standard-form
syllogism.
Example:
All rivers have banks. All banks have vaults. So, all rivers have vaults.
The word "banks" occurs as two distinct terms, namely river bank and
financial bank, so this example also is an equivocation. Without an
equivocation, the four term fallacy is trivially invalid.
Gambler's
This fallacy occurs when the gambler falsely assumes that the history
of outcomes will affect future outcomes.
Example:
I know this is a fair coin, but it has come up heads five times in
a row now, so tails is due on the next toss.
The fallacious move was to conclude that the probability of the next
toss coming up tails must be more than a half. The assumption that
it's a fair coin is important because, if the coin comes up heads five
times in a row, one would otherwise become suspicious that it's not a
fair coin and therefore properly conclude that the probably is high
that heads is more likely on the next toss.
Genetic
A critic commits the genetic fallacy if the critic attempts to
discredit or support a claim or an argument because of its origin
(genesis) when such an appeal to origins is irrelevant.
Example:
Whatever your reasons are for buying that DVD they've got to be
ridiculous. You said yourself that you got the idea for buying it from
last night's fortune cookie. Cookies can't think!
Fortune cookies are not reliable sources of information about what DVD
to buy, but the reasons the person is willing to give are likely to be
quite relevant and should be listened to. The speaker is committing
the genetic fallacy by paying too much attention to the genesis of the
idea rather than to the reasons offered for it. An ad hominem fallacy
is one kind of genetic fallacy, but the genetic fallacy in our passage
isn't an ad hominem.
If I learn that your plan for building the shopping center next to the
Johnson estate originated with Johnson himself, who is likely to
profit from the deal, then my pointing out to the planning commission
the origin of the deal would be relevant in their assessing your plan.
Because not all appeals to origins are irrelevant, it sometimes can be
difficult to decide if the fallacy has been committed. For example, if
Sigmund Freud shows that the genesis of a person's belief in God is
their desire for a strong father figure, then does it follow that
their belief in God is misplaced, or does this reasoning commit the
genetic fallacy?
Group Think
A reasoner commits the group think fallacy if he or she substitutes
pride of membership in the group for reasons to support the group's
policy. If that's what our group thinks, then that's good enough for
me. It's what I think, too. "Blind" patriotism is a rather nasty
version of the fallacy.
Example:
We K-Mart employees know that K-Mart brand items are better than
Wall-Mart brand items because, well, they are from K-Mart, aren't
they?
Guilt by Association
Guilt by association is a version of the ad hominem fallacy in which a
person is said to be guilty of error because of the group he or she
associates with. The fallacy occurs when we unfairly try to change the
issue to be about the speaker's circumstances rather than about the
speaker's actual argument. Also called "Ad Hominem, Circumstantial."
Example:
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.
Has any evidence been presented here that Acheson's actions are
inappropriate in regards to communism? This sort of reasoning is an
example of McCarthyism, the technique of smearing liberal Democrats
that was so effectively used by the late Senator Joe McCarthy in the
early 1950s. In fact, Acheson was strongly anti-communist and the
architect of President Truman's firm policy of containing Soviet
power.
Hasty Conclusion
See Jumping to Conclusions.
Hasty Generalization
A hasty generalization is a fallacy of jumping to conclusions in which
the conclusion is a generalization. See also Biased Statistics.
Example:
I've met two people in Nicaragua so far, and they were both nice
to me. So, all people I will meet in Nicaragua will be nice to me.
Heap
See Line-Drawing.
Hedging
You are hedging if you refine your claim simply to avoid
counterevidence and then act as if your revised claim is the same as
the original.
Example:
Samantha: David is a totally selfish person.
Yvonne: I thought we was a boy scout leader. Don't you have to
give a lot of your time for that?
Samantha: Well, David's totally selfish about what he gives money
to. He won't spend a dime on anyone else.
Yvonne: I saw him bidding on things at the high school auction fundraiser.
Samantha: Well, except for that he's totally selfish about money.
You don't commit the fallacy if you explicitly accept the
counterevidence, admit that your original claim is incorrect, and then
revise it so that it avoids that counterevidence.
Hooded Man
This is an error in reasoning due to confusing the knowing of a thing
with the knowing of it under all its various names or descriptions.
Example:
You claim to know Socrates, but you must be lying. You admitted
you didn't know the hooded man over there in the corner, but the
hooded man is Socrates.
Ignoratio Elenchi
See Irrelevant Conclusion.
Ignoring a Common Cause
See Common Cause.
Incomplete Evidence
See Suppressed Evidence.
Inconsistency
The fallacy occurs when we accept an inconsistent set of claims, that
is, when we accept a claim that logically conflicts with other claims
we hold.
Example:
I'm not racist. Some of my best friends are white. But I just
don't think that white women love their babies as much as our women
do.
That last remark implies the speaker is a racist, although the speaker
doesn't notice the inconsistency.
Insufficient Statistics
Drawing a statistical conclusion from a set of data that is clearly too small.
Example:
A pollster interviews ten London voters in one building about
which candidate for mayor they support, and upon finding that
Churchill receives support from six of the ten, declares that
Churchill has the majority support of London voters.
This fallacy is a form of the Fallcy of Jumping to Conclusions.
Intensional
The mistake of treating different descriptions or names of the same
object as equivalent even in those contexts in which the differences
between them matter. Reporting someone's beliefs or assertions or
making claims about necessity or possibility can be such contexts. In
these contexts, replacing a description with another that refers to
the same object is not valid and may turn a true sentence into a false
one.
Example:
Michelle said she wants to meet her new neighbor Stalnaker
tonight. But I happen to know Stalnaker is a spy for North Korea, so
Michelle said she wants to meet a spy for North Korea tonight.
Michelle said no such thing. The faulty reasoner illegitimately
assumed that what is true of a person under one description will
remain true when said of that person under a second description even
in this context of indirect quotation. What was true of the person
when described as "her new neighbor Stalnaker" is that Michelle said
she wants to meet him, but it wasn't legitimate for me to assume this
is true of the same person when he is described as "a spy for North
Korea."
Extensional contexts are those in which it is legitimate to substitute
equals for equals with no worry. But any context in which this
substitution of co-referring terms is illegitimate is called an
intensional context. Intensional contexts are produced by quotation,
modality, and intentionality (propositional attitudes). Intensionality
is failure of extensionality, thus the name "intensional fallacy".
Invalid Reasoning
An invalid inference. An argument can be assessed by deductive
standards to see if the conclusion would have to be true if the
premises were to be true. If the argument cannot meet this standard,
it is invalid. An argument is invalid only if it is not an instance of
any valid argument form. The fallacy of invalid reasoning is a formal
fallacy.
Example:
If it's raining, then there are clouds in the sky. It's not
raining. Therefore, there are no clouds in the sky.
This invalid argument is an instance of denying the antecedent. Any
invalid inference that is also inductively very weak is a non
sequitur.
Irrelevant Conclusion
If an arguer argues for a certain conclusion while falsely believing
or suggesting that a different conclusion is established, one for
which the first conclusion is irrelevant, then the arguer commits the
fallacy of irrelevant conclusion. The premises miss the point.
Example:
In court, Thompson testifies that the defendant is a honorable
person, who wouldn't harm a flea. The defense attorney rises to say
that Thompson's testimony shows once again that his client was not
near the murder scene.
The testimony of Thompson may be relevant to a request for leniency,
but it is irrelevant to any claim about the defendant not being near
the murder scene. Other examples of this fallacy are Ad Hominem,
Appeal to Authority, Appeal to Emotions, and Argument from Ignorance.
==
Irrelevant Reason
This fallacy is a kind of non sequitur in which the premises are
wholly irrelevant to drawing the conclusion.
Example:
Lao Tze Beer is the top selling beer in Thailand. So, it will be
the best beer for Canadians.
Is-Ought
The is-ought fallacy occurs when a conclusion expressing what ought to
be so is inferred from premises expressing only what is so, in which
it is supposed that no implicit or explicit ought-premises are need.
There is controversy in the philosophical literature regarding whether
this type of inference is always fallacious.
Example:
He's torturing the cat.
So, he shouldn't do that.
This argument clearly would not commit the fallacy if there were an
implicit premise indicating that he is a person and persons shouldn't
torture other beings.
Jumping to Conclusions
When we draw a conclusion without taking the trouble to acquire all
the relevant evidence, we commit the fallacy of jumping to
conclusions, provided there was sufficient time to assess that extra
evidence, and that the effort to get the evidence isn't prohibitive.
Example:
This car is really cheap. I'll buy it.
Hold on. Before concluding that you should buy it, you ought to have
someone check its operating condition, or else you should make sure
you get a guarantee about the car's being in working order. And, if
you stop to think about it, there may be other factors you should
consider before making the purchase. Are size or appearance or gas
mileage relevant?
Lack of Proportion
Either exaggerating or downplaying a point that is a crucial step in a
piece of reasoning is an example of the Fallacy of Lack of Proportion.
It's a mistake of not adopting the proper perspective. An extreme form
of downplaying occurs in the Fallacy of Suppressed Evidence.
Example:
Chandra just overheard the terrorists say that they are about to
plant the bomb in the basement of the courthouse, after which they'll
drive to the airport and get away. But they won't be taking along
their cat. The poor cat. The first thing that Chandra and I should do
is to call the Humane Society and check the "Cat Wanted" section of
the local newspapers to see if we can find a proper home for the cat.
Line-Drawing
If we improperly reject a vague claim because it's not as precise as
we'd like, then we commit the line-drawing fallacy. Being vague is not
being hopelessly vague. Also called the Bald Man Fallacy, the Fallacy
of the Heap and the Sorites Fallacy.
Example:
Dwayne can never grow bald. Dwayne isn't bald now. Don't you agree
that if he loses one hair, that won't make him go from not bald to
bald? And if he loses one hair after that, then this one loss, too,
won't make him go from not bald to bald. Therefore, no matter how much
hair he loses, he can't become bald.
Loaded Language
Loaded language is emotive terminology that expresses value judgments.
When used in what appears to be an objective description, the
terminology unfortunately can cause the listener to adopt those values
when in fact no good reason has been given for doing so. Also called
Prejudicial Language.
Example:
[News broadcast] In today's top stories, Senator Smith carelessly
cast the deciding vote today to pass both the budget bill and the
trailer bill to fund yet another excessive watchdog committee over
coastal development.
This broadcast is an editorial posing as a news report.
Logical
See Formal.
Lying
A fallacy of reasoning that depends on intentionally saying something
that is known to be false. If the lying occurs in an argument's
premise, then it is an example of the fallacy of questionable premise.
Example:
Abraham Lincoln, Theodore Roosevelt, and John Kennedy were assassinated.
They were U.S. presidents.
Therefore, at least three U.S. presidents have been assassinated.
Roosevelt was never assassinated.
Maldistributed Middle
See Undistributed Middle.
Many Questions
See Complex Question.
Misconditionalization
See Modal Fallacy.
Misleading Vividness
When the fallacy of jumping to conclusions is committed due to a
special emphasis on an anecdote or other piece of evidence, then the
fallacy of misleading vividness has occurred.
Example:
Yes, I read the side of the cigarette pack about smoking being
harmful to your health. That's the Surgeon General's opinion, him and
all his statistics. But let me tell you about my uncle. Uncle Harry
has smoked cigarettes for forty years now and he's never been sick a
day in his life. He even won a ski race at Lake Tahoe in his age group
last year. You should have seen him zip down the mountain. He smoked a
cigarette during the award ceremony, and he had a broad smile on his
face. I was really proud. I can still remember the cheering. Cigarette
smoking can't be as harmful as people say.
The vivid anecdote is the story about Uncle Harry. Too much emphasis
is placed on it and not enough on the statistics from the Surgeon
General.
Misplaced Concreteness
Mistakenly supposing that something is a concrete object with
independent existence, when it's not.
Example:
There are two footballs lying on the floor of an otherwise empty
room. When asked to count all the objects in the room, John says there
are three: the two balls plus the group of two.
John mistakenly supposed a group or set of concrete objects is also a
concrete object.
Misrepresentation
If the misrepresentation occurs on purpose, then it is an example of
lying. If the misrepresentation occurs during a debate in which there
is misrepresentation of the opponent's claim, then it would be the
cause of a straw man fallacy.
Missing the Point
See Irrelevant Conclusion.
Modal
This is the error of treating modal conditionals as if the modality
applies only to the consequent of the conditional. "The" modal fallacy
is the most well known of the infinitely many errors involving modal
concepts, concepts such as necessity, possibility and so forth. A
conditional is an if-then proposition. The consequent is the
then-part, and the antecedent is the if-part.
Example:
If a proposition is true, then it can not be false. But if a
proposition can not be false, then it is not only true but necessarily
true. Therefore, if a proposition is true, then it's necessarily true.
The acceptable interpretation of the first premise, requires the
modality to apply to the entire conditional in the sense that it
really means "It's not possible that if a proposition is true, then
it's false." However, the entire inference works only if the first
premise is miscontrued as saying "If a proposition is true, then it is
necessary that it's not false."
To see that the misconstrual is unacceptable, pick a proposition such
as "It's raining in Detroit." Let's suppose it actually is raining in
Detroit. So, the antecedent of the misconstrual is true, but the
consequent isn't, because it says "It is necessary that 'it's raining
in Detroit' is not false." This isn't necessary, is it?
Monte Carlo
See Gambler's Fallacy.
Name Calling
See Ad Hominem.
Naturalistic
On a broad interpretation of the fallacy, it is said to apply to any
attempt to argue from an "is" to an "ought," that is, to argue
directly from a list of facts to a claim about what ought to be done.
Example:
Owners of financially successful companies are more successful
than poor people in the competition for wealth, power and social
status. Therefore, these owners are morally better than poor people,
and the poor deserve to be poor.
The fallacy would also occur if one argued from the natural to the
moral as follows: since women are naturally capable of bearing and
nursing children, they ought to be the primary caregivers of children.
There is considerable disagreement among philosophers regarding what
sorts of arguments the term "Naturalistic Fallacy" applies to, and
even whether it is a fallacy at all.
Neglecting a Common Cause
See Common Cause.
No Middle Ground
See False Dilemma.
No True Scotsman
This error is a kind of ad hoc rescue of one's generalization in which
the reasoner re-characterizes the situation solely in order to escape
refutation of the generalization.
Example:
Smith: All Scotsmen are loyal and brave.
Jones: But McDougal over there is a Scotsman, and he was arrested
by his commanding officer for running from the enemy.
Smith: Well, if that's right, it just shows that McDougal wasn't a
TRUE Scotsman.
Non Causa Pro Causa
This label is Latin for mistaking the "non-cause for the cause." See
False Cause.
Non Sequitur
When a conclusion is supported only by extremely weak reasons or by
irrelevant reasons, the argument is fallacious and is said to be a non
sequitur. However, we usually apply the term only when we cannot think
of how to label the argument with a more specific fallacy name. Any
deductively invalid inference is a non sequitur if it also very weak
when assessed by inductive standards.
Example:
Nuclear disarmament is a risk, but everything in life involves a
risk. Every time you drive in a car you are taking a risk. If you're
willing to drive in a car, you should be willing to have disarmament.
The following is not an example: "If she committed the murder, then
there'd be his blood stains on her hands. His blood stains are on her
hands. So, she committed the murder." This deductively invalid
argument commits the fallacy of affirming the consequent, but it isn't
a non sequitur because it has significant inductive strength.
One-Sidedness
See Slanting and Suppressed Evidence.
Oversimplification
You oversimplify when you cover up relevant complexities or make a
complicated problem appear to be too much simpler than it really is.
Example:
President Bush wants our country to trade with Fidel Castro's
Communist Cuba. I say there should be a trade embargo against Cuba.
The issue in our election is Cuban trade, and if you are against it,
then you should vote for me for president.
Whom to vote for should be decided by considering quite a number of
issues in addition to Cuban trade. When an oversimplification results
in falsely implying that a minor causal factor is the major one, then
the reasoning also commits the false cause fallacy.
Past Practice
See Traditional Wisdom.
Pathetic
The pathetic fallacy is a mistaken belief due to attributing
peculiarly human qualities to inanimate objects (but not to animals).
The fallacy is caused by anthropomorphism.
Example:
Aargh, it won't start again. This old car always breaks down on
days when I have a job interview. It must be afraid that if I get a
new job, then I'll be able to afford a replacement, so it doesn't want
me to get to my interview on time.
Persuasive Definition
Some people try to win their arguments by getting you to accept their
faulty definition. If you buy into their definition, they've
practically persuaded you already. Same as the Definist Fallacy.
Poisoning the Well when presenting a definition would be an example of
a using persuasive definition.
Example:
Let's define a Democrat as a leftist who desires to overtax the
corporations and abolish freedom in the economic sphere.
Perfectionist
If you remark that a proposal or claim should be rejected solely
because it doesn't solve the problem perfectly, in cases where
perfection isn't really required, then you've committed the
perfectionist fallacy.
Example:
You said hiring a house cleaner would solve our cleaning problems
because we both have full-time jobs. Now, look what happened. Every
week she unplugs the toaster oven and leaves it that way. I should
never have listened to you about hiring a house cleaner.
Petitio Principii
See Begging the Question.
Poisoning the Well
Poisoning the well is a preemptive attack on a person in order to
discredit their testimony or argument in advance of their giving it. A
person who thereby becomes unreceptive to the testimony reasons
fallaciously and has become a victim of the poisoner. This is a kind
of ad hominem, circumstantial fallacy.
Example:
[Prosecuting attorney in court] When is the defense attorney
planning to call that twice-convicted child molester, David
Barnington, to the stand? OK, I'll rephrase that. When is the defense
attorney planning to call David Barnington to the stand?
Post Hoc
Suppose we notice that an event of kind A is followed in time by an
event of kind B, and then hastily leap to the conclusion that A caused
B. If so, we commit the post hoc fallacy. Correlations are often good
evidence of causal connection, so the fallacy occurs only when the
leap to the causal conclusion is done "hastily." The Latin term for
the fallacy is post hoc, ergo propter hoc ("After this, therefore
because of this"). It is a kind of false cause fallacy.
Example:
I ate in that Ethiopian restaurant three days ago and now I've
just gotten food poisoning. The only other time I've eaten in an
Ethiopian restaurant I also got food poisoning, but that time I got
sick a week later. My eating in those kinds of restaurants is causing
my food poisoning.
Your background knowledge should tell you this is unlikely because the
effects of food poisoning are felt soon after the food is eaten.
Before believing your illness was caused by eating in an Ethiopian
restaurant, you'd need to rule out other possibilities, such as your
illness being caused by what you ate a few hours before the onset of
the illness.
Prejudicial Language
See Loaded Language.
Proof Surrogate
Substituting a distracting comment for a real proof.
Example:
I don't need to tell a smart person like you that you should vote
Republican.
This comment is trying to avoid a serious disagreement about whether
one should vote Republican.
Questionable Analogy
See False Analogy.
Questionable Cause
See False Cause.
Questionable Premise
If you have sufficient background information to know that a premise
is questionable or unlikely to be acceptable, then you commit this
fallacy if you accept an argument based on that premise. This broad
category of fallacies of argumentation includes appeal to authority,
false dilemma, inconsistency, lying, stacking the deck, straw man,
suppressed evidence, and many others.
Quibbling
We quibble when we complain about a minor point and falsely believe
that this complaint somehow undermines the main point. To avoid this
error, the logical reasoner will not make a mountain out of a mole
hill nor take people too literally.
Example:
I've found typographical errors in your poem, so the poem is
neither inspired nor perceptive.
Quoting out of Context
If you quote someone, but select the quotation so that essential
context is not available and therefore the person's views are
distorted, then you've quoted "out of context." Quoting out of context
in an argument creates a straw man fallacy.
Example:
Smith: I've been reading about a peculiar game in this article
about vegetarianism. When we play this game, we lean out from a
fourth-story window and drop down strings containing "Free food" signs
on the end in order to hook unsuspecting passers-by. It's really
outrageous, isn't it? Yet isn't that precisely what sports fishermen
do for entertainment from their fishing boats? The article says it's
time we put an end to sport fishing.
Jones: Let me quote Smith for you. He says "We…hook unsuspecting
passers-by." What sort of moral monster is this man Smith?
Jones's selective quotation is fallacious because it makes Smith
appear to advocate this immoral activity when the context makes it
clear that he doesn't.
Rationalization
We rationalize when we inauthentically offer reasons to support our
claim. We are rationalizing when we give someone a reason to justify
our action even though we know this reason is not really our own
reason for our action, usually because the offered reason will sound
better to the audience than our actual reason.
Example:
"I bought the matzo bread from Kroger's Supermarket because it is
the cheapest brand and I wanted to save money," says Alex [who knows
he bought the bread from Kroger's Supermarket only because his
girlfriend works there].
Red Herring
A red herring is a smelly fish that would distract even a bloodhound.
It is also a digression that leads the reasoner off the track of
considering only relevant information.
Example:
Will the new tax in Senate Bill 47 unfairly hurt business? One of
the provisions of the bill is that the tax is higher for large
employers (fifty or more employees) as opposed to small employers (six
to forty-nine employees). To decide on the fairness of the bill, we
must first determine whether employees who work for large employers
have better working conditions than employees who work for small
employers.
Bringing up the issue of working conditions is the red herring.
Refutation by Caricature
See Ad Hominem.
Regression
This fallacy occurs when regression to the mean is mistaken for a sign
of a causal connection. Also called the Regressive Fallacy. It is a
kind of false cause fallacy.
Example:
You are investigating the average heights of groups of Americans.
You sample some people from Chicago and determine their average
height. You have the figure for the mean height of Americans and
notice that your Chicagoans have an average height that differs from
this mean. Your second sample of the same size is from people from
Miami. When you find that this group's average height is closer to the
American 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 Miamians rather than Chicagoans be more like
the average American.
There is most probably nothing causing Miamians to be more like the
average American; but rather what is happening is that averages are
regressing to the mean.
Reversing Causation
Drawing an improper conclusion about causation due to a causal
assumption that reverses cause and effect. A kind of false cause
fallacy.
Example:
All the corporate officers of Miami Electronics and Power have big
boats. If you're ever going to become an officer of MEP, you'd better
get a bigger boat.
The false assumption here is that having a big boat helps cause you to
be an officer in MEP, whereas the reverse is true. Being an officer
causes you to have the high income that enables you to purchase a big
boat.
Scapegoating
If you unfairly blame an unpopular person or group of people for a
problem, then you are scapegoating. This is a kind of fallacy of
appeal to emotions.
Example:
Augurs were official diviners of ancient Rome. During the
pre-Christian period, when Christians were unpopular, an augur would
make a prediction for the emperor about, say, whether a military
attack would have a successful outcome. If the prediction failed to
come true, the augur would not admit failure but instead would blame
nearby Christians for their evil influence on his divining powers. The
elimination of these Christians, the augur would claim, could restore
his divining powers and help the emperor. By using this reasoning
tactic, the augur was scapegoating the Christians.
Scare Tactic
If you suppose that terrorizing your opponent is giving him a reason
for believing that you are correct, then you are using a scare tactic
and reasoning fallaciously.
Example:
David: My father owns the department store that gives your
newspaper fifteen percent of all its advertising revenue, so I'm sure
you won't want to publish any story of my arrest for spray painting
the college.
Newspaper editor: Yes, David, I see your point. The story really
isn't newsworthy.
David has given the editor a financial reason not to publish, but he
has not given a relevant reason why the story is not newsworthy.
David's tactics are scaring the editor, but it's the editor who
commits the scare tactic fallacy, not David. David has merely used a
scare tactic. This fallacy's name emphasizes the cause of the fallacy
rather than the error itself. See also the related fallacy of appeal
to emotions.
Scope
The scope fallacy is caused by improperly changing or misrepresenting
the scope of a phrase.
Example:
Every concerned citizen who believes that someone living in the US
is a terrorist should make a report to the authorities. But Shelley
told me herself that she believes there are terrorists living in the
US, yet she hasn't made any reports. So, she must not be a concerned
citizen.
The first sentence has ambiguous scope. It was probably originally
meant in this sense: Every concerned citizen who believes (of someone
that this person is living in the US and is a terrorist) should make a
report to the authorities. But the speaker is clearly taking the
sentence in its other, less plausible sense: Every concerned citizen
who believes (that there is someone or other living in the US who is a
terrorist) should make a report to the authorities. Scope fallacies
usually are amphibolies.
Secundum Quid
See Accident and Converse Accident, two versions of the fallacy.
Selective Attention
Improperly focusing attention on certain things and ignoring others.
Example:
Father: Justine, how was your school day today? Another C on the
history test like last time?
Justine: Dad, I got an A- on my history test today. Isn't that
great? Only one student got an A.
Father: I see you weren't the one with the A. And what about the math quiz?
Justine: I think I did OK, better than last time.
Father: If you really did well, you'd be sure. What I'm sure of is
that today was a pretty bad day for you.
The pessimist who pays attention to all the bad news and ignores the
good news thereby commits the fallacy of selective attention. The
remedy for this fallacy is to pay attention to all the relevant
evidence. The most common examples of selective attention are the
fallacy of Suppressed Evidence and the fallacy of Confirmation Bias.
See also the Sharpshooter's Fallacy.
Self-Fulfilling Prophecy
The fallacy occurs when the act of prophesying will itself produce the
effect that is prophesied, but the reasoner doesn't recognize this and
believes the prophesy is a significant insight.
Example:
A group of students are selected to be interviewed individually by
the teacher. Each selected student is told that the teacher has
predicted they will do significantly better in their future school
work. Actually, though, the teacher has no special information about
the students and has picked the group at random. If the students
believe this prediction about themselves, then, given human
psychology, it is likely that they will do better merely because of
the teacher's making the prediction.
The prediction will fulfill itself, so to speak, and the students
commit the fallacy.
This fallacy can be dangerous in an atmosphere of potential war
between nations when the leader of a nation predicts that their nation
will go to war against their enemy. This prediction could very well
precipitate an enemy attack because the enemy calculates that if war
is inevitable then it is to their military advantage not to get caught
by surprise.
Sharpshooter's
The sharpshooter's fallacy gets its name from someone shooting a rifle
at the side of the barn and then going over and drawing a target and
bulls eye concentrically around the bullet hole. The fallacy is caused
by overemphasizing random results or making selective use of
coincidence. See the Fallacy of Selective Attention.
Example:
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."
Slanting
This error occurs when the issue is not treated fairly because of
misrepresenting the evidence by, say, suppressing part of it, or
misconstruing some of it, or simply lying. See the following
fallacies: Lying, Misrepresentation, Questionable Premise, Quoting out
of Context, Straw Man, Suppressed Evidence.
Slippery Slope
Suppose someone claims that a first step (in a chain of causes and
effects, or a chain of reasoning) will probably lead to a second step
that in turn will probably lead to another step and so on until a
final step ends in trouble. If the likelihood of the trouble occurring
is exaggerated, the slippery slope fallacy is committed.
Example:
Mom: Those look like bags under your eyes. Are you getting enough sleep?
Jeff: I had a test and stayed up late studying.
Mom: You didn't take any drugs, did you?
Jeff: Just caffeine in my coffee, like I always do.
Mom: Jeff! 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.
The form of a slippery slope fallacy looks like this:
A leads to B.
B leads to C.
C leads to D.
…
Z leads to HELL.
We don't want to go to HELL.
So, don't take that first step A.
Think of the sequence A, B, C, D, …, Z as a sequence of closely
stacked dominoes. The key claim in the fallacy is that pushing over
the first one will start a chain reaction of falling dominoes, each
one triggering the next. But the analyst asks how likely is it really
that pushing the first will lead to the fall of the last? For example,
if A leads to B with a probability of 80 percent, and B leads to C
with a probability of 80 percent, and C leads to D with a probability
of 80 percent, is it likely that A will eventually lead to D? No, not
at all; there is about a 50- 50 chance. The proper analysis of a
slippery slope argument depends on sensitivity to such probabilistic
calculations. Regarding terminology, if the chain of reasoning A, B,
C, D, …, Z is about causes, then the fallacy is called the Domino
Fallacy.
Small Sample
This is the fallacy of using too small a sample. If the sample is too
small to provide a representative sample of the population, and if we
have the background information to know that there is this problem
with sample size, yet we still accept the generalization upon the
sample results, then we commit the fallacy. This fallacy is the
fallacy of hasty generalization, but it emphasizes statistical
sampling techniques.
Example:
I've eaten in restaurants twice in my life, and both times I've
gotten sick. I've learned one thing from these experiences:
restaurants make me sick.
How big a sample do you need to avoid the fallacy? Relying on
background knowledge about a population's lack of diversity can reduce
the sample size needed for the generalization. With a completely
homogeneous population, a sample of one is large enough to be
representative of the population; if we've seen one electron, we've
seen them all. However, eating in one restaurant is not like eating in
any restaurant, so far as getting sick is concerned. We cannot place a
specific number on sample size below which the fallacy is produced
unless we know about homogeneity of the population and the margin of
error and the confidence level.
Smear Tactic
A smear tactic is an unfair characterization either of the opponent or
the opponent's position or argument. Smearing the opponent causes an
ad hominem fallacy. Smearing the opponent's argument causes a straw
man fallacy.
Smokescreen
This fallacy occurs by offering too many details in order either to
obscure the point or to cover-up counter-evidence. In the latter case
it would be an example of the fallacy of suppressed evidence. If you
produce a smokescreen by bringing up an irrelevant issue, then you
produce a red herring fallacy. Sometimes called clouding the issue.
Example:
Senator, wait before you vote on Senate Bill 88. Do you realize
that Delaware passed a bill on the same subject in 1932, but it was
ruled unconstitutional for these twenty reasons. Let me list them
here…. Also, before you vote on SB 88 you need to know that …. And so
on.
There is no recipe to follow in distinguishing smokescreens from
reasonable appeals to caution and care.
Sorites
See Line-Drawing.
Special Pleading
Special pleading is a form of inconsistency in which the reasoner
doesn't apply his or her principles consistently. It is the fallacy of
applying a general principle to various situations but not applying it
to a special situation that interests the arguer even though the
general principle properly applies to that special situation, too.
Example:
Everyone has a duty to help the police do their job, no matter who
the suspect is. That is why we must support investigations into
corruption in the police department. No person is above the law. Of
course, if the police come knocking on my door to ask about my
neighbors and the robberies in our building, I know nothing. I'm not
about to rat on anybody.
In our example, the principle of helping the police is applied to
investigations of police officers but not to one's neighbors.
Specificity
Drawing an overly specific conclusion from the evidence. A kind of
jumping to conclusions.
Example:
The trigonometry calculation came out to 35,005.6833 feet, so
that's how wide the cloud is up there.
Stacking the Deck
See Suppressed Evidence and Slanting.
Stereotyping
Using stereotypes as if they are accurate generalizations for the
whole group is an error in reasoning. Stereotypes are general beliefs
we use to categorize people, objects, and events; but these beliefs
are overstatements that shouldn't be taken literally. For example,
consider the stereotype "She's Mexican, so she's going to be late."
This conveys a mistaken impression of all Mexicans. On the other hand,
even though most Mexicans are punctual, a German is more apt to be
punctual than a Mexican, and this fact is said to be the "kernel of
truth" in the stereotype. The danger in our using stereotypes is that
speakers or listeners will not realize that even the best stereotypes
are accurate only when taken probabilistically. As a consequence, the
use of stereotypes can breed racism, sexism, and other forms of
bigotry.
Example:
German people aren't good at dancing our sambas. She's German. So,
she's not going to be any good at dancing our sambas.
This argument is deductively valid, but it's unsound because it rests
on a false, stereotypical premise. The grain of truth in the
stereotype is that the average German doesn't dance sambas as well as
the average South American, but to overgeneralize and presume that ALL
Germans are poor samba dancers compared to South Americans is a
mistake called "stereotyping."
Straw Man
You commit the straw man fallacy whenever you attribute an easily
refuted position to your opponent, one that the opponent wouldn't
endorse, and then proceed to attack the easily refuted position
believing you have undermined the opponent's actual position. If the
misrepresentation is on purpose, then the straw man fallacy is caused
by lying.
Example (a debate before the city council):
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. I say we should continue to
observe Columbus Day, and vote down this resolution that will make the
City of Berkeley the laughing stock of the nation.
The speaker has twisted what his opponent said; the opponent never
said, nor even indirectly suggested, that everybody who ever came to
America from another country somehow oppressed the Indians.
Style Over Substance
Unfortunately the style with which an argument is presented is
sometimes taken as adding to the substance or strength of the
argument.
Example:
You've just been told by the salesperson that the new Maytag is an
excellent washing machine because it has a double washing cycle. If
you were to notice that the salesperson smiled at you and was well
dressed, this wouldn't add to the quality of the original argument,
but unfortunately it does for those who are influenced by style over
substance, as most of us are.
Subjectivist
The subjectivist fallacy occurs when it is mistakenly supposed that a
good reason to reject a claim is that truth on the matter is relative
to the person or group.
Example:
Justine has just given Jake her reasons for believing that the
Devil is an imaginary evil person. Jake, not wanting to accept her
conclusion, responds with, "That's perhaps true for you, but it's not
true for me."
Superstitious Thinking
Reasoning deserves to be called superstitious if it is based on
reasons that are well known to be unacceptable, usually due to
unreasonable fear of the unknown, trust in magic, or an obviously
false idea of what can cause what. A belief produced by superstitious
reasoning is called a superstition. The fallacy is an instance of the
False Cause Fallacy.
Example:
I never walk under ladders; it's bad luck.
It may be a good idea not to walk under ladders, but a proper reason
to believe this is that workers on ladders occasionally drop things,
and that ladders might have dripping wet paint that could damage your
clothes. An improper reason for not walking under ladders is that it
is bad luck to do so.
Suppressed Evidence
Intentionally failing to use information suspected of being relevant
and significant is committing the fallacy of suppressed evidence. This
fallacy usually occurs when the information counts against one's own
conclusion. Perhaps the arguer is not mentioning that experts have
recently objected to one of his premises. The fallacy is a kind of
fallacy of Selective Attention.
Example:
Buying the Cray Mac 11 computer for our company was the right
thing to do. It meets our company's needs; it runs the programs we
want it to run; it will be delivered quickly; and it costs much less
than what we had budgeted.
This appears to be a good argument, but you'd change your assessment
of the argument if you learned the speaker has intentionally
suppressed the relevant evidence that the company's Cray Mac 11 was
purchased from his brother-in-law at a 30 percent higher price than it
could have been purchased elsewhere, and if you learned that a recent
unbiased analysis of ten comparable computers placed the Cray Mac 11
near the bottom of the list.
If the relevant information is not intentionally suppressed by rather
inadvertently overlooked, the fallacy of suppressed evidence also is
said to occur, although the fallacy's name is misleading in this case.
The fallacy is also called the Fallacy of Incomplete Evidence and
Cherry-Picking the Evidence. See also Slanting.
Sweeping Generalization
See Fallacy of Accident.
Syllogistic
Syllogistic fallacies are kinds of invalid categorical syllogisms.
This list contains the fallacy of undistributed middle and the fallacy
of four terms, and a few others though there are a great many such
formal fallacies.
Tokenism
If you interpret a merely token gesture as an adequate substitute for
the real thing, you've been taken in by tokenism.
Example:
How can you call our organization racist? After all, our
receptionist is African American.
If you accept this line of reasoning, you have been taken in by tokenism.
Traditional Wisdom
If you say or imply that a practice must be OK today simply because it
has been the apparently wise practice in the past, you commit the
fallacy of traditional wisdom. Procedures that are being practiced and
that have a tradition of being practiced might or might not be able to
be given a good justification, but merely saying that they have been
practiced in the past is not always good enough, in which case the
fallacy is committed. Also called argumentum consensus gentium when
the traditional wisdom is that of nations.
Example:
Of course we should buy IBM's computer whenever we need new
computers. We have been buying IBM as far back as anyone can remember.
The "of course" is the problem. The traditional wisdom of IBM being
the right buy is some reason to buy IBM next time, but it's not a good
enough reason in a climate of changing products, so the "of course"
indicates that the fallacy of traditional wisdom has occurred.
Tu Quoque
The fallacy of tu quoque is committed if we conclude that someone's
argument not to perform some act must be faulty because the arguer
himself or herself has performed it. Similarly, when we point out that
the arguer doesn't practice what he preaches, we may be therefore
suppose that there must be an error in the preaching, but we are
reasoning fallaciously and creating a tu quoque. This is a kind of ad
hominem circumstantial fallacy.
Example:
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.
Discovering that a speaker is a hypocrite is a reason to be suspicious
of the speaker's reasoning, but it is not a sufficient reason to
discount it.
Two Wrongs Make a Right
When you defend your wrong action as being right because someone
previously has acted wrongly, you commit the fallacy called "two
wrongs make a right." This is a kind of ad hominem fallacy.
Example:
Oops, no paper this morning. Somebody in our apartment building
probably stole my newspaper. So, that makes it OK for me to steal one
from my neighbor's doormat while nobody else is out here in the
hallway.
Undistributed Middle
In syllogistic logic, failing to distribute the middle term over at
least one of the other terms is the fallacy of undistributed middle.
Also called the fallacy of maldistributed middle.
Example:
All collies are animals.
All dogs are animals.
Therefore, all collies are dogs.
The middle term ("animals") is in the predicate of both universal
affirmative premises and therefore is undistributed. This formal
fallacy has the logical form: All C are A. All D are A. Therefore, all
C are D.
Unfalsifiability
This error in explanation occurs when the explanation contains a claim
that is not falsifiable, because there is no way to check on the
claim. That is, there would be no way to show the claim to be false if
it were false.
Example:
He lied because he's possessed by demons.
This could be the correct explanation of his lying, but there's no way
to check on whether it's correct. You can check whether he's twitching
and moaning, but this won't be evidence about whether a supernatural
force is controlling his body. The claim that he's possessed can't be
verified if it's true, and it can't be falsified if it's false. So,
the claim is too odd to be relied upon for an explanation of his
lying. Relying on the claim is an instance of fallacious reasoning.
Unrepresentative Generalization
If the plants on my plate are not representative of all plants, then
the following generalization should not be trusted.
Example:
Each plant on my plate is edible.
So, all plants are edible.
The set of plants on my plate is called "the sample" in the technical
vocabulary of statistics, and the set of all plants is called "the
target population." If you are going to generalize on a sample, then
you want your sample to be representative of the target population,
that is, to be like it in the relevant respects. This fallacy is the
same as the Fallacy of Unrepresentative Sample.
Unrepresentative Sample
If the means of collecting the sample from the population are likely
to produce a sample that is unrepresentative of the population, then a
generalization upon the sample data is an inference committing the
fallacy of unrepresentative sample. A kind of hasty generalization.
When some of the statistical evidence is expected to be relevant to
the results but is hidden or overlooked, the fallacy is called
suppressed evidence.
Example:
The two men in the matching green suits that I met at the Star
Trek Convention in Las Vegas had a terrible fear of cats. I remember
their saying they were from Delaware. I've never met anyone else from
Delaware, so I suppose everyone there has a terrible fear of cats.
Most people's background information is sufficient to tell them that
people at this sort of convention are unlikely to be representative,
that is, typical members of society.
Large samples can be unrepresentative, too.
Example:
We've polled over 400,000 Southern Baptists and asked them whether
the best religion in the world is Southern Baptist. We have over 99%
agreement, which proves our point about which religion is best.
Getting a larger sample size does not overcome sampling bias.
Untestability
See Unfalsifiability.
Weak Analogy
See False Analogy.
Willed ignorance
I've got my mind made up, so don't confuse me with the facts. This is
usually a case of the Traditional Wisdom Fallacy.
Example:
Of course she's made a mistake. We've always had meat and potatoes
for dinner, and our ancestors have always had meat and potatoes for
dinner, and so nobody knows what they're talking about when they start
saying meat and potatoes are bad for us.
Wishful Thinking
A reasoner who suggests that a claim is true, or false, merely because
he or she strongly hopes it is, is committing the fallacy of wishful
thinking. Wishing something is true is not a relevant reason for
claiming that it is actually true.
Example:
There's got to be an error here in the history book. It says
Thomas Jefferson had slaves. He was our best president, and a good
president would never do such a thing. That would be awful.
7. References and Further Reading
* Eemeren, Frans H. van, R. F. Grootendorst, F. S. Henkemans, J.
A. Blair, R. H. Johnson, E. C. W. Krabbe, C. W. Plantin, D. N. Walton,
C. A. Willard, J. A. Woods, and D. F. Zarefsky, 1996. Fundamentals of
Argumentation Theory: A Handbook of Historical Backgrounds and
Contemporary Developments. Mahwah, New Jersey, Lawrence Erlbaum
Associates, Publishers.
* Fearnside, W. Ward and William B. Holther, 1959. Fallacy: The
Counterfeit of Argument. Prentice-Hall, Inc. Englewood Cliffs, New
Jersey.
* Fischer, David Hackett., 1970. Historian's Fallacies: Toward
Logic of Historical Thought. New York, Harper & Row, New York, N.Y.
o This book contains additional fallacies to those in this
article, but they are much less common, and many have obscure names.
* Groarke, Leo and C. Tindale, 2003. Good Reasoning Matters! 3rd
edition, Toronto, Oxford University Press.
* Hamblin, Charles L., 1970. Fallacies. London, Methuen.
* Hansen, Has V. and R. C. Pinto., 1995. Fallacies: Classical and
Contemporary Readings. University Park, Pennsylvania State University
Press.
* Huff, Darrell, 1954. How to Lie with Statistics. New York, W. W. Norton.
* Levi, D. S., 1994. "Begging What is at Issue in the Argument,"
Argumentation, 8, 265-282.
* Walton, Douglas N., 1989. Informal Logic: A Handbook for
Critical Argumentation. Cambridge, Cambridge University Press.
* Walton, Douglas N., 1995. A Pragmatic Theory of Fallacy.
Tuscaloosa, University of Alabama Press.
* Walton, Douglas N., 1997. Appeal to Expert Opinion: Arguments
from Authority. University Park, Pennsylvania State University Press.
* Whately, Richard, 1836. Elements of Logic. New York, Jackson.
* Woods, John and D. N. Walton, 1989. Fallacies: Selected Papers
1972-1982. Dordrecht, Holland, Foris.
Research on the fallacies of informal logic is regularly published in
the following journals: Argumentation, Argumentation and Advocacy,
Informal Logic, Philosophy and Rhetoric, and Teaching Philosophy.
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