Critical
Thinking:
Chapter 7
More Fallacies
The Ad Hominem
Fallacy
• The ad hominem fallacy rests
on a confusion between the
qualities of the person making
a claim and the qualities of the
claim itself. It is a rhetorical
device that attacks the arguer
instead of the argument.
The Ad Hominem
Fallacy
A proposal made by an
oddball is an oddball’s
proposal, but it does not follow
that it is an oddball proposal.
Personal Attack Ad
Hominem
• A pattern of fallacious
reasoning in which we refuse
to accept another’s argument
because there is something
about the person we don’t like
or of which we disapprove.
Personal Attack Ad
Hominem
• Example: Are you really going
to believe her about librarians’
salaries not being excessive?
I’ll have you know she herself
is a librarian, or don’t you think
that matters?
The Inconsistency Ad
Hominem
• A pattern of fallacious
reasoning of the sort, “I reject
your claim because you act
inconsistently with it yourself,”
or “You can’t make that claim
now because you have in the
past rejected it.”
The Inconsistency Ad
Hominem
• The double standard argument
is actually the inconsistency
ad hominem.
The Inconsistency Ad
Hominem
• Example: Did you ever notice
how the people who favor
abortion on demand are the
same people who are against
the death penalty?
The Inconsistency Ad
Hominem
• Example: It really gripes me to
see Bill Clinton talking about
how cigarette smoking is a big
contributor to public health
costs. How can we trust him?
Even he himself admits to
smoking cigars!
Circumstantial Ad
Hominem
• Attempting to discredit a
person’s claim by referring to
the person’s circumstances.
Circumstantial Ad
Hominem
• Example: Of course the Task
Force on Crime is going to
conclude that crime is on the
way up. If they conclude it’s on
the way down, they’d have to
disband the task force,
wouldn’t they?
Circumstantial Ad
Hominem
• Example: Of course that can’t
be a legitimate proposal.
They’re just trying to get the
city council to pass a
regulation that will stir up
some business for them.
Poisoning the Well
• Poisoning the well can be
thought of as an ad hominem
in advance.
Poisoning the Well
• Example: I wouldn’t take a
course from anyone in the
Poly Sci department, if I were
you. They are all anti-U.S.,
ultraliberal types, at least that’s
what I hear.
Poisoning the Well
• Example:The next speaker is
going to speak in favor of the
idea. But she works for the
gun lobby Don’t even bother
listening to what she says.
Genetic Fallacy
• The genetic fallacy occurs
when we try to refute a claim
on the basis of its origin or
history. Rejecting a proposition
because it is supported by a
group you don’t like is a
genetic fallacy.
Genetic Fallacy
• Example: You can’t trust the
arguments you find in that
magazine. It’s well known as a
right-wing apologist for the
wealthy.
Genetic Fallacy
• Example: I don’t think
postmodern expressionism is
decent art. It’s another style
spawned by the East Coast art
establishment, and, frankly, I’m
tired of that group’s dictating to
the rest of the art world.
Positive Ad Hominem
Fallacies
• If we automatically transfer the
positive or favorable attributes
of a person to what he or she
says, that is a mistake in
reasoning, as well.
Positive Ad Hominem
Fallacies
• Example: The fact that in your
view the NRA represents all
that is good and proper does
not enable you to infer that any
specific proposal from the
NRA is good and proper.
Positive Ad Hominem
Fallacies
• Example: The fact that you
think your mom is clever does
not logically entitle you to
conclude that any specific
opinion of your mom’s is
clever.
The Straw Man Fallacy
• The straw man fallacy
happens when you refute a
position or claim by distorting
or oversimplifying or
misrepresenting it, all the while
ignoring the person’s actual
position.
The Straw Man Fallacy
• Example: Gays in the military?
Yes. Maybe you favor
excluding everyone except for
white Anglo-Saxon males with
adolescent personalities, but
not me.
The Straw Man Fallacy
• Example: Do I want the police
department to take charge of
writing parking tickets? You
mean, do I want to get shot if I
pull up next to a fire hydrant?
What do you think?
The False Dilemma
Fallacy
• The false dilemma fallacy
occurs when you limit
considerations to only two
alternatives although other
alternatives may be available.
A straw man is often used as
part of a false dilemma.
The False Dilemma
Fallacy
• Example: Overheard: “I don’t
know why Barbara won’t go
out with me. She must think
I’m too intense for her.”
The False Dilemma
Fallacy
• Example: Gays in the military?
Either let them in, or keep out
all minorities; take your choice.
I’m for letting them in. the
alternative is ridiculous.
The Perfectionist Fallacy
• The perfectionist fallacy is a
subspecies of false dilemma
and a common rhetorical ploy.
This principle downgrades
policy X simply because it isn’t
perfect.
The Perfectionist Fallacy
• Example: No, I don’t believe
we ought to reinstate the death
penalty in this state. Doing it
isn’t going to prevent all crime,
and you know it.
The Perfectionist Fallacy
• Example:Don’t stay in the
army. You were ROTC instead
of going to one of the
academies, and that means
they might promote you for a
while, but you’ll never get
above lieutenant colonel.
The Line-Drawing
Fallacy
• Another version of the false
dilemma is called the linedrawing fallacy, the fallacy of
insisting that a line must be
drawn at some point when in
fact it is not necessary that
such a line be drawn.
The Line-Drawing
Fallacy
• Example: All this talk about
secondhand smoke causing
cancer, I just don’t get it. How
does it happen? WHEN does it
happen? The first time you
take a breath in a smoky
room? The second time? You
can never pin it down exactly.
The Line-Drawing
Fallacy
• Example:What do you mean, I
broke my curfew? All I did was
walk to the curb. You wouldn’t
cite me if I stood on the porch,
would you? And if I’d just
stepped off the porch, that
wouldn’t be any different. So
what’s so magical about the
curb?
Slippery Slope
• A form of fallacious reasoning
in which it is assumed that
some event must inevitably
follow from some other, but in
which no argument is made for
the inevitability.
Slippery Slope
• Example: No, I don’t believe in
“three strikes and you’re out”
for convicted felons. Next thing
it will be two strikes, then one
strike. Then we will be sticking
people in jail for life for
misdemeanors. It’s not good
policy.
Slippery Slope
• Example:Gays in the military?
If we allow that, then next time
we’ll be letting women into the
men’s barracks. And the next
thing you know, women, men,
gays, everyone--they’ll all be
showering together and
sleeping in the same bunks.
Get real.
Misplacing the Burden
of Proof
• Misplacing the burden of proof
occurs when the burden of
proof is placed on the wrong
side of an issue.
Misplacing the Burden
of Proof
• 1. The less initial plausibility a
claim has, the greater the
burden of proof we place on
someone who asserts that
claim.
Misplacing the Burden
of Proof
• 2. Other things being equal,
the burden of proof falls
automatically on those
supporting the affirmative side
of an issue rather than on
those supporting the negative
side.
Misplacing the Burden
of Proof
• When someone claims that we
should believe in such-andsuch because nobody has
proved it isn’t so, we have a
subtype known as appeal to
ignorance.
Misplacing the Burden
of Proof
• 3. Special circumstances
like court or contracts will
specify where the burden
of proof lies so there are no
doubts or confusion about
who needs to prove what.
Misplacing the Burden
of Proof
• Example: I beg to differ, Officer, but
sometimes you people go
overboard talking about the
dangers of fast driving. If you can
prove that there’s actually a child
near the street right now, and that
the child would have stepped out in
front of my car, then I’ll grant you
that going fifty-five was dangerous.
Misplacing the Burden
of Proof
• Example: Preferential
treatment in hiring is
something we must support;
after all, can you think of a
reason why we shouldn’t?
Begging the Question
• We are guilty of begging the
question when we ask our
audience to accept premises
that are as controversial as the
conclusion we’re arguing for
and are controversial on the
same grounds.
Begging the Question
• Example: The ACLU? Yeah, I
know about them, and I don’t
like them very much. They’re
the ones who furnish free
lawyers for criminals.
Begging the Question
• Example: No, I don NOT
believe that a murderer ought
to be allowed to live. No way!
Murderers have forfeited the
right to live because anyone
who murders another person
has lost that right.