Transcript Fallacious Reasoning

Faulty Reasoning
What is a fallacy?
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“fallacy is a generic term that
indicates an error or weakness in an
argument or thought process.”
(Ziegmuller and Kay)
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The source of a fallacy may be found
in the data, the reasoning process,
the language, or the strategic or
psychological basis of the argument.
Common fallacies:
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Red Herring: introduces an
irrelevant issue in order to divert
attention from the subject under
discussion.
Example:
– “The real problem is not eliminating
handguns; the real problem is that
pawnshops that sell guns are
controlled by the Mafia.”
More:
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Ad Hominem (mudslinging):
substitutes an attack on the person
for discussion of the real subject
under discussion.
Example:
– “Tony is an awful musician and is not
sensitive enough to chair such an
important committee.”
More:
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False dilemma (either-or): forces
listeners to choose between two
alternatives when more than two
exist.
Example:
– “Either more people should start
volunteering their time to work for their
community, or your taxes will increase.”
More:
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Bandwagon: assumes that because
something is popular, it is therefore
good, correct, or desirable.
Example:
– “Most people agree with me that we
spend too much time worrying about
Medicare.”
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Slippery slope: assumes that taking
a first step will lead inevitably to a
second step and so on down the
slope to disaster.
Example:
– “Passing federal laws to control the
amount of violence on television is the
first step in a process that will result in
absolute government control of the
media and total censorship over all
forms of artistic expression.”
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Hasty generalization: A person who
reaches a conclusion from too little
evidence or nonexistent evidence.
Example:
– “It’s clear that our schools can’t educate
children well, because my niece went to
school for six years and she still can’t
read at her grade level.”
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Post Hoc, Ergo Propter Hoc (“After
this, therefore because of this” or
false cause): assume that because
one event comes after another, the
first event must necessarily be the
cause of the second.
Example:
– “The decline of morals in this country is
caused by excessive government
spending.”
Let’s test your knowledge!
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“I don’t see any reason to wear a
helmet when I ride a bike. Everyone
bikes without a helmet.”
Answer-bandwagon fallacy
“It’s ridiculous to worry about
protecting America’s national parks
against pollution and overuse when
innocent people are being
endangered by domestic terrorists.”
Answer-red herring fallacy
More:
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“There can be no doubt that the Great
Depression was caused by Herbert
Hoover. He became President in March
1929, and the stock market crashed just
seven months later.”
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Answer-Post Hoc, Ergo Propter Hoc or
false cause.
More:
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“If we follow the school board to
spend money remodeling the
gymnasium, next they will want to
build a new school and give all the
teachers a huge raise. Taxes will
soar so high that businesses will
leave and then there will be no jobs
for anyone in this town.”
Answer-Slippery slope fallacy
More:
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“ I can’t support Representative Frey’s
proposal for campaign finance reform.
After all, he was kicked out of law
school for cheating on an exam.”
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Answer-ad hominen fallacy.
More:
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“One nonsmoker, interviewed at a
restaurant, said, “I can eat dinner just fine
even though people around me are
smoking.” Another, responding to a Los
Angeles Times survey, said, “I don’t see
what all the fuss is about. My wife has
smoked for years and it has never
bothered me.” We can see that
secondhand smoke does not cause a
problem for most nonsmokers.”
Answer-hasty generalization.
More:
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“Our school must either increase
tuition or cut back on library services
for students.”
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Answer-False dilemma or either-or
fallacy.
Conclusion:
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Use fallacies as a way to identify fault
in other’s arguments as well as our
own.
By exposing fallacies in arguments it
helps build strong sound reasoning.