||LEO: Literacy Education Online|
When you attempt to employ logic to support claims in your papers, your
reasoning is sometimes weakened because you are presenting fallacious arguments.
It is important for you to be able to identify and eliminate fallacies
in your writing.
This handout will explain and give examples of typical fallacies as
divided into five major categories:
The argumentation methods comprising these five categories can be used
as rhetorical devices, but they must not be confused with logical thinking.
Tutors can help their students to make such a distinction.
Quite often, writers appeal to their audiences' feelings to attract
attention to and elicit agreement with their ideas. Although this
can be effective, manipulating audience feelings is not employing logic,
and it does not make a writer's argument stronger. Logical thinking
never involves feelings.
Appeal to Force: The writer threatens the audience, explicitly
or implicitly, with negative consequences if the claim is not believed.
Appeal to Pity: The writer begs for the approval of the claim;
the audience may agree because they feel sorry for the arguer.
If you do not believe in God, you will go to hell.
Appeal to Gallery: The writer uses emotive language that will
produce a desired effect on a group or "gallery" of readers. By appealing
to the fears or interests of the audience, the writer hopes to gain approval.
I cannot get a job because the public education system failed me;
I have to steal to survive. It is society's fault, not mine.
Appeal to Authority: The writer cites authorities to show
the validity of the claim, but the authority is not an expert in the field,
the authority's view is taken out of context, or other experts of that
field disagree with the authority quoted.
Same-sex marriage must be prohibited, or the family structure as we
know it will collapse.
Old is Better: The writer relies on traditional wisdom to
support the argument. This is a logical pitfall because the argument
does not consider that new ideas could apply.
I think that businesses should not have to limit the amount of pollutants
they release into the atmosphere because Rush Limbaugh says that
there is no real evidence for industrial pollutants causing the Greenhouse
New is Better: The writer claims that a new discovery has
better effects or is more applicable to a given situation simply because
it is new. However, being newer does not make an idea more correct.
People have believed that fish is "brain food" for decades, so I don't
believe the FDA when they claim that eating fish does not enhance
Word processed papers are clearer and more error-free than typed papers
because they make use of new technology.
DISTRACTION FROM THE ARGUMENT
This type of fallacy often happens when writers do not have strong support
for their claims. Distraction is also used if the opposition's view
is strong and logical; then, writers have a tendency to attack the
context instead of the argument.
Attacking the Speaker: The writer reduces the credibility
of the opposition by attacking them personally for who they are and not
for what they say. The validity of logical reasoning does not depend
on the morality of the speaker.
Irrelevant Material: The writer introduces irrelevant material
to distract the audience from the subject at hand. Then, s/he draws
conclusions based on the unrelated material presented.
Oprah Winfrey's diet advice is useless; she has had problems
with maintaining her weight for most of her life, bouncing back and forth
between being overweight and slender.
Shifted Burden of Proof: The writer challenges those with
an opposing view to defend their arguments; this puts the writer
in a position in which s/he can deny the opposition's assertions.
Education is important for the future of the American people and our
country. So, you should choose to study at St. Cloud State
Straw Man: The writer does not attack the argument that the
opposition sets forth. The arguer may attack one of the opposition's
points as if it were the whole argument, distort what the opposition is
attempting to express, or exaggerate the opposition's argument to the point
of satirizing it.
The author writes that animals shouldn't be killed because they can
feel pain, but he doesn't prove that they can. For his
argument to persuade me, he has to give me positive empirical evidence
of animals' ability to feel pain.
Al Gore's support of the discussion of sexual orientation issues on
Ellen is dangerous: he advocates the exposure of children to
sexually explicit materials, which is wrong.
Sometimes, writers present questionable or ambiguous reasons to sustain
their arguments. A logical demonstration of a belief, however, must
be conclusive and convincing to be effective; any doubtful premises
leads the audience to believe that the conclusion is weak.
From Ignorance: The writer's argument is simply that the
point has not been proven otherwise. The fact that the counterclaim
has not been proven does not make a claim correct.
False Cause: The writer points out as the cause of an event
something that is not the actual cause, or the writer has insufficient
evidence for making a causal link. If the identified cause is not
the real cause, nothing assures that the point of discussion is true.
Questionable Premises: The writer's reasons for holding a
belief are not as obvious to the audience as they are to the writer, and
the writer does not back up the claim with enough support. This fallacy
also occurs when the writer introduces an unsupported value judgment.
I believe in God because no one can prove that a god doesn't exist.
Ambiguity of Terms/Equivocation: The writer uses two different
senses of the same word in an argument, and this ambiguity allows a mistaken
conclusion to be drawn by the writer.
All judges are fair-minded individuals; therefore, Judge Ito
is fair in his decisions.
Simplifying: When restating the opposition's view, the writer
mistakenly ignores information which is relevant to the conclusion reached
by the opposition.
It is immoral to kill an innocent human being. Fetuses are innocent
human beings. Therefore, it is immoral to kill fetuses.
Note: In the first sentence, the writer uses "human being"
in the sense of a morally considerable being. In the second,
the writer could be using the term "human being" to make the less
controversial claim that a fetus is a genetically human creature.
Presuppositions: The writer presupposes some information that
supports his/her claim; the writer does not confirm the assumed material.
Freud argued that women have penis envy because they want to be men.
Hiding Information/Half Truth: The writer, consciously or
unconsciously, establishes conclusions without stating all of the facts
relevant to the situation.
All students who study on this campus want more computers available
for their use, so computer fees should be raised 50% to cover the
costs of the expansion.
The Geo Metro is a superior car because it averages 43 miles per gallon.
Note: The writer neglects to mention that this figure was
derived in tests where the car was driven with 30 mile per hour tailwinds.
Some writers stereotype and generalize their ideas to make a powerful
statement. To construct effective logical arguments, writers must
avoid generalizations; once an exception to a generalization is found,
the argument that the generalization supports is discredited.
Popularity: The writer bases the argument on the belief
that if an idea is held by a large group of people, it is true.
Exception: The writer applies a general rule to a case where
the rule is inapplicable.
Millions of people are Marxists, so Marxist economic and political
theories are correct.
Particular Experiences: The writer makes a rule out of particular
experiences to support the claim. As soon as an exception to the
derived rule is found, the rule fails to support the argument.
A year is 365 days long, so I celebrate my birthday every 365 days.
Property in the Whole: The writer makes a claim based on the
belief that a whole always possesses the characteristics of its parts,
which is often untrue. Although this belief is sometimes acceptable,
it is not universally applicable, so the appropriateness of using this
idea must be determined on a case by case basis.
All Greek food causes illness; when I traveled through Greece,
I got food poisoning.
Property in the Parts: Often, a writer who makes the above
fallacy will also commit this one. The writer erroneously assumes
that because a whole has a particular property, the parts forming the whole
have the same property.
Since many of the students at St. Cloud State University get A's, St.
Cloud State must be a top-rated school.
False Alternative: The writer only presents some of the alternatives
for solving a problem when more possibilities exist because the writer
assumes that the list of alternatives created is exhaustive.
IBM is a reputable organization, so all of its employees must be reputable.
In the United States, one can vote for either Democrats or Republicans.
Some writers' arguments fail not because of the information given, but
because of the type of connections established between the parts of the
argument. If the logical structures are not valid, the argument will
fail, even if all of the premises are true and correct.
Consecutive Relation: The writer assumes that because two
events occur consecutively or concurrently, they are causally related.
Slippery Slope: The writer bases the claim on the assumption
that if a particular event occurs, so will other undesirable events.
However, there are no reasons to believe that the subsequent events will
occur. This fallacy is usually caused by fear.
I believe in supernatural beings because every time I drive past the
cemetery where my grandmother is buried, a light on my dashboard
flashes. Her spirit causes this because it never happens otherwise.
Two Wrongs Make a Right: The writer defends an action on the
grounds that someone else has done something similar.
If we put limits on the right to bear arms, soon all of our Constitutionally-given
rights will be taken away.
Wrong Analogy: The writer reasons by analogy, using a similar,
known situation as the basis for the argument. Extended analogies
tend to lose their direct connection with the actual topic of discussion,
leading to erroneous conclusions.
Residents of St. Cloud should not have to recycle plastics because
those who live in Waite Park are not required to.
Circular Reasoning: The writer defends the claim by using
the conclusion as one of the premises to support the conclusion.
Having a television rating system is like being in prison. Both
infringe on one's rights.
Affirmation of the Consequent: The writer uses an If...then
statement in the argument's reasoning. Then, the writer confirms
the then part of the statement and derives the If part, thereby committing
a serious logical flaw.
God exists because the Bible says so. The Bible is a reliable
source because it is the word of God.
Denial of the Antecedent: Again, the writer employs an If...then
statement, but in this case, the writer denies the If part so that the
negation of the then part can be concluded. However, just because
the If part does not happen, it does not follow that the then part will
not happen. The then part could result for some other reason.
If one is 16 years old or older, one can drive an automobile in Wisconsin.
I saw your niece driving through Wausau yesterday. She must
be at least 16.
If the ozone layer is destroyed, many people will get cancer and suffer
from other illnesses. The ozone layer is being protected, not destroyed.
So, many people will be spared the pain of cancer and other illnesses.
Kahane, Howard. Logic and Contemporary Rhetoric: The
Use of Reason in Everyday Life. 7th ed. Belmont, CA:
Pitt, Jack. Logic for Argument. New York: Random
Woodhouse, Mark B. A Preface to Philosophy. 5th ed.
Belmont, CA: Wadsworth, 1994.
© 1998 The Write Place
This page was created by Maggie Escalas, Julie Feia, and
Carrie Jean Schroeder, St. Cloud State University, St. Cloud, MN;
it may be copied for educational purposes only. If you copy this document,
please include our copyright notice and the names of the writers; if you
revise it, please add your name(s) to the list of writers.
Last update: 20 August 1998