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  Fallacies in Making a Case

• Fallacies of Relevance
• Fallacies of Inadequate Evidence
• Fallacies of Illegitimate Assumption
   Fallacies of Relevance

Irrelevant evidence is give to
 support the argument
     Fallacies of Relevance

          Appeal to Ignorance

 Of course I believe in ESP. No one has
 ever demonstrated that it doesn’t exist.
     Fallacies of Relevance

   Appeal to Inappropriate Authority

 Aldous Huxley, renowned author, wrote a
 book advocating that nearsightedness
 could be cured with eye exercises.
     Fallacies of Relevance
        Appeal to General Belief

 We all know most people on welfare are
 just too lazy to work. We should start a
 program requiring those on welfare to
 provide community service to earn their
      Fallacies of Relevance
Appeal to Popular Attitudes & Emotions

 I’ll tell you why I believe we were right to
 go into Iraq. It’s because I love my
 country. If you love America, then you’d
     Fallacies of Relevance

            Gambler’s Fallacy

 The last ten flips have been tails, so heads
 should come up soon. We’d better bet all
 we have on heads.
Fallacies of Inadequate Evidence

 Arguments with premises that present
  relevant, but inadequate evidence to
  support a conclusion
Fallacies of Inadequate Evidence

         False Cause (Post Hoc)

 I wore this pair of socks for the last game,
 and we won, so the socks must have
 given me good luck.
Fallacies of Inadequate Evidence

          Hasty Generalization

 An accountant opens her own business.
 The first two clients lie about their income
 and she finds out. She concludes that
 most clients lie about their income.
Fallacies of Relevance
 Inadequate Evidence
After death experiences are a reality.
Despite years of attempts at
debunking, no one has ever been
able to show that reports from beyond
the grave are all due to error,
deception, or simply wishful thinking.
I’ve been feeding this slot
machine for 20 minutes, and the
person before me pumped in
$200 with no payout. I’m due a
hit any minute.
Nobody wants to say so in public,
but we all know that immigrants
don’t have as strong a
commitment to this country as
those of us who were born here.
The Dallas group held a rain dance at
the Turtle Creek fountain Sunday
night, and the group leader, Debra
Denton, claimed it got results. “It
rained, didn’t it?” she asked.
Dr. R.J. Palmer, one of New York’s
leading oral surgeons, has pointed
out that evolution theory requires us
to say that a species of reptile
changed into a birdlike creature, so
the whole absurd theory is mistaken.
Dr. Palmer’s scientific assessment
shows why it is that no reasonable
person can be an evolutionist.
You don’t have to be of noble birth
to appreciate Cutty Sark Scotch
Whiskey. All that is required is
noble taste.
Americans reject gun control. A
2003 survey conducted at the
National Hunting Association
revealed that 71% of the 50
people interviewed are opposed
to legal regulation, including the
restriction of assault rifles.
Fallacies of Illegitimate Assumption

Arguments that rely on some sort of
 illegitimate premise
Fallacies of Illegitimate Assumption

            False Dilemma

 Either you’re for us or against us. It is
 obvious that you aren’t for us, so you must
 be against us.
Fallacies of Illegitimate Assumption

            Loaded Question

 Are you still beating your wife?
Fallacies of Illegitimate Assumption

          Begging the Question

 James is a murderer because he wrongfully
 killed someone.
Fallacies of Illegitimate Assumption

             Slippery Slope

 If we legalize marijuana, then next thing
 people will be shooting up heroine in every
 public bathroom.
Fallacies of Illegitimate Assumption
Are women still discouraged from
excelling in sports by a lack of
financial or emotional support?
Once we adopt a policy of failing
to enforce laws prohibiting
littering, loitering, and
panhandling, we might as well
give up on enforcing the laws on
assault, rape, and murder.
Adultery cannot be justified. The
reason it can’t is simply that it is
never acceptable for a married
person to have sex with someone
who is not his or her spouse.
When can I make up the exam I
We can achieve peace in the
Middle East either by negotiations
or by war. Negotiations have led
nowhere, so what is there left to
do but send in troops?
If we recognize Cuba
diplomatically, then we will have
to grant the same status to every
country run by an anti-American
The reason you can’t trust Roth is
that he’s a liar, a fraud, and a
deliberate deceiver.
Senator Anson voted against the
proposed constitutional amendment
prohibiting burning the America flag
as a form of protest. A legislator must
either support the amendment or
support flag burners. Senator Anson
has made his choice, and next
November the voters will make theirs.
Why do the Democrats always
want to raise taxes?
      Fallacies of Criticism

Misdirection away from the main point, so
 the respondent doesn’t have to consider
 the legitimacy of the claim
      Fallacies of Criticism
   Against the Person (Ad Hominem)

   As a gay conservative, Andrew Sullivan
   can’t possibly have anything constructive
   to offer the right.
      Fallacies of Criticism
                You Too

• Brown: You are a cheat. You left half your
  income off your tax return last year.
• Smith: Big deal. You lied about
  deductions and had the nerve to claim
  your dog as a dependent.
      Fallacies of Criticism

 Mr. Paulson would basically pooh-pooh
 the subprime problems until major Wall
 Street powers got in trouble and then—
 presto—swing into action.
      Fallacies of Criticism
                Straw Man

 The theory of evolution boils down to the
 idea that human beings are descended
 from apes.
      Fallacies of Criticism
            Loaded Words

 Medical research on animals simply must
 be stopped at once. This torture of
 innocent creatures is morally indecent.
       Fallacy of Response
            Definitional Dodge
You’re not real fan of the Bengals because
 you don’t finish watching the games when
 they’re losing.
Yeah, well, only a real fan has season
 tickets. And since I have season tickets
 and you don’t, I’m the true fan.
Fallacies of Criticism
Jimmy Carter: The survival of the world
  depends on ending the cycle of nuclear
  arms development. That’s why it’s crucial
  for us to join with other nuclear states and
  sign the SALT II Treaty.

Ronald Reagan: Jimmy Carter says we
 should sign the SALT II Treaty because
 nobody will like us if we don’t.
If you can’t come up with
something besides the feminist
cliché that our ad demeans
women, I don’t see any reason to
answer you.
Gloria Grag’s views on fighting
terrorism are wrong. Is she an
intelligence expert? No. Someone
with police experience? No. I tell you
what she is, she’s a commercial
baker. That’s right, a cookie maker!
So I don’t want to see gays in
public office, but you’ve got no
room to object. You don’t want to
see women get elected.
Senator Clemens says we should
spend less on giving tax rebates to
the rich and more on improving
education. But this is just the same
tired liberal cliché we’ve heard
before—nothing worth taking
Bob is as morally bankrupt as
he is financially.
You’ve never had a taste of
beer because beer can’t be
tasted in a sip.

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