Transcript File logical fallacies pptx

Logical Fallacies
Oct. 6th
• Finish the work from yesterday. Use this time
wisely.
• If you are having trouble, focus on the following:
–
–
–
–
Ad Hominem: Personal attack
Bandwagon: Go with the crowd
Either-Or Fallacy: Only two options
Hasty Generalization: Jumps to a conclusion from not
enough evidence
– Slippery Slope: Relies on fear. “If we allow X to
happen, Y will surely follow.”
Oct. 4th, 2016
Warm-up
• “Once you hear the details of victory, it is hard
to distinguish it from a defeat.”
– Jean-Paul Sartre
Propaganda/Manipulation
Persuasion vs. Manipulation
Rhetoric/Persuasion
Valid Arguments
Propaganda/Logical
Fallacies/Manipulation
Invalid Arguments/tricks to
manipulate and control
What is a logical fallacy?
• A fallacy is an error of reasoning. These are
flawed statements that often sound true
1. Used to persuade with manipulation tactics
Origins
• The word “fallacy” may derive from the Latin
word fallere meaning, “to deceive, to trip, to
lead into error or to trick.” The word may also
derive from the Greek phelos, meaning
“deceitful.”
www.sun-design.com/talitha/fallacies.htm
Why study logical fallacies?
•
It is important to develop logical fallacy detection skills in your own writing, as well as others’.
Think of this as “intellectual kung-fu: the art of intellectual self defense.” (Logical Fallacies Handlist)
Ad Hominem –
“to the man”
Ad Hominem
(name calling)
• A person’s character is attacked instead of his
argument.
Ad populum –
“to the crowd”
Ad Populum
• A misconception that a widespread
occurrence of something is assumed to make
it right or wrong.
Either/or or False
Dilemma Fallacy
Either/Or
• Tendency to see an issue as having only two
sides
Lesser of Two Evils
• Tries to convince us of an idea by presenting it as
the least offensive option.
Often used during wartime to convince people of
the need for sacrifices or to justify difficult
decisions.
Ex. During Cold War it was used to remind
Americans why it was important to stick to
rations during war, since it was better than living
with Communism.
Faulty Analogy
• Making a misleading comparison between
logically unconnected ideas. The assumption
that because two things are alike in some
respects, they are alike in others.
– If we put humans on the moon, we should be able
to find a cure for the common cold!
– If adults can legally drink alcohol, teenagers
should be able to also!
Post Hoc Ergo Propter Hoc
“after this, therefore because of this”
• Assuming that an incident that precedes
another is the cause of the second incident.
• Every time I wear my blue sweater, it snows. OMG,
MY BLUE SWEATER CAUSES SNOW!!!
Red Herring
• An argument that focuses on an
irrelevant issue to detract attention from
the real issue.
• A Red Herring is literally a SMELLY FISH.
You basically say, “My back is against the
wall. I cannot win this argument. HERE IS
AN AWFUL SMELLY FISH TO DISTRACT
YOU!
– Mom, I know I have ISS for tardies but at
least I am not doing drugs like all those other
kids up there!
Circular Reasoning/ Begging the
Question
• An argument in which the writer, instead
of applying evidence simply restates the
point in other language.
Chicken nuggets are good. Why are they good?
Because they are tasty. Why are they tasty?
Because they are good!
FALSE AUTHORITY
The person presenting the argument is an
authority, but not on the subject at hand.
I have a degree in Medicine and I am here to
Three types:
tell you the economy is about to FAIL!
Self Proof—”Because I said so”
Spokes Person—”Because famous person says
I have a degree in
so”
Medicine and I am
here to tell you the
economy is about to they are good at
Too much Credit—”Because
FAIL!
one thing, they know all things”
• “Everyone has it”
Bandwagon
• Threat of rejection is substituted for evidence,
desire to conform to beliefs of a group.
Non Sequitur (Does Not Follow)
• A conclusion that does not follow logically
from preceding statements. Or the train of
thought jumps the tracks at some point.
– Mary loves children, so she will make an excellent
school teacher. (This support alone does not
follow or is Non-Sequitor—If Mary is a murderer,
or has a 50 IQ, she will not make a good teacher
no matter how much she loves kids.)
– No one should grill their steaks. Cows don’t like
smoke. (This does not follow because it does not
make sense. The cows are dead. They are steaks.)
SLIPPERY SLOPE
• Like a muddy hill, if we go down this slope we will
fall
• If we allow one thing a whole slew of other,
negative events will occur as a result
Ex. If we allow students to have ipods, pretty soon
they will have entire systems out in class bumping
bass all over the school.
Ex. If we pass this health care bill eventually the
government will take over the decision-making
from patients and doctors
STRAW MAN
• The person attacks an argument which is different
from, and usually weaker than, the opposition's best
argument. Ignores a person’s actual position and
substitutes an exaggerated or distorted version.
– Setting up a fake version of something or someone that is
easy for others to not like.
– Ex. Katie, my shih-tzu, isn’t really hungry; she just wants
us to get up all the time and cater to her every whim!
– People who think abortion should be banned have no
respect for the rights of women. They treat them as
nothing but baby-making machines. That's wrong.
Women must have the right to choose.
• Discrediting what a person might later claim
by presenting unfavorable information in
advance.
• Senator Creavey was once arrested for tax
evasion.
Oversimplification
• Tendency to provide simple solutions to
complex problems.
Ex.
To avoid drunk driving accidents restaurants
should just stop selling alcohol.
Card Stacking
(Selective Omission)
• Presenting positive information only and
omitting negative information.
Pinpointing the Enemy
• Attempt to simplify a complex situation by
presenting one specific group or person as the
enemy (clear-cut right and wrong).
Plain Folks
• Convince their audience that they and their
ideas are “of the people.”
Ex. Jimmy Carter presented himself as a humble
peanut farmer from Georgia during his
election term.
Transfer
Attempt to make
the subject view
a certain item
the same way
they view
another item to
link the 2 in the
subjects mind.
Hasty Generalization
• essentially making a hasty conclusion without
considering all of the variables (similar to
stereotypes)
Ex. All women are bad drivers.
Oct. 5th, 2016
• Warm-up:
– Watch the video clip and determine what logical
fallacies are being used. All you need to do is
make a list of the ones that are being used.
End of Class Quiz
• Explain the logical fallacy in each of the following statements:
1. Unless you can close your eyes to abuse, write a check to
save this puppy.
2. Both of my parents smoked all their lives, and they lived into
their eighties, so cigarettes can’t really be that bad for you.
3. Don’t ever gamble! Once you start, you won’t be able to
stop, and you’ll end up bankrupt.
4. People from big cities are not as friendly as those from small
towns.
5. He can’t be a great athlete; he cheated on his wife.
6. If you’re not part of the solution, then you’re part of the
problem.
Assignment Due at The End of Class
• Read the Argument against Senate
Constitution Amendment No. 8
• On a separate sheet of paper, write down the
logical fallacies (with evidence) that oppose
granting voting rights (called suffrage) to
women.
Advisory
• DEAR, SSR, Something silent.
• Give me a summary of what you read today.
At least 5 sentences long.