Transcript Argument Analysis

Argument Analysis
Understanding the structure of an
argument
All propaganda is dangerous. Therefore,
network news is dangerous, because
network news is propaganda.
All arguments have two main
parts:
Premise
Conclusion
What is a premise?
Any claim used to prove the truth of another
claim in an argument.
May be factual or opinion
What is a conclusion?
Any claim you are trying to prove in an
argument
Must be an opinion
The author will sometimes use signal words to help the reader
distinguish between the premise and the conclusion
Premise Signal Words
Any word or phrase,
that if you have an
argument, tells you
that what follows may
be some type of
premise
Conclusion Signal
Words
Any word or phrase,
that if you have an
argument, tells you
that what follows may
be some type of
conclusion
Memorize the signal words on
your handout!!!!!!!!!!
If you do not memorize them...
You will be very
sorry!
______ sent me an autographed
photo. (premise)
He/she wants my body. (conclusion)
Harriet should divorce Harry
because he will not work, he
hasn’t bathed since 1988 and he
is seeing her grandmother.
Important Terms:
Final/Main Conclusion: The main point
that the author is trying to prove in an
argument. It is never used to prove anything
else in the argument. What all the evidence
is either directly or indirectly proving.
Rule: Can be introduced only by
conclusion signal words.
Unsupported Premise/Basic Premise
Any premise in an argument for which there
is no evidence offered. May be factual or
may be an opinion. Rule: Unsupported
premises may be introduced only by
premise signal words.
Supported Premise/Subconclusion/Intermediate
Conclusion
Any premise in an argument for which there
is evidence given. It is a premise and a
conclusion at the same time. It is used to
prove another claim, and at the same time, a
claim is being used to prove it. Rule: May
be introduced by premise or conclusion
signal words.
Sometimes, the author of an
argument will offer support for
some of the premises he or she is
using in the argument. When
support or evidence is offered for
a premise, that premise is called a
supported premise or
subconclusion.
Example
Harriet should divorce Harry because he
refuses to work, as shown by the many job
offers that he has refused, hasn’t bathed
since 1998, and is dating her grandmother.
When no evidence is offered to
prove a premise, that premise is
called an unsupported or basic
premise.
Example
Harry will surely get an A+ in this class. He
attends regularly and has submitted every
assignment on time. He has also received
‘A’s’ on all of his tests.
Your examples:
Harry will surely get an A+ in this class.
he attends regularly. he has also submitted
every assignment. He has also received
‘A’s’ on all of his tests, as shown by the
tests in his folder.
Another Example:
He got an A+, so he probably cheated.
Consequently, he should be suspended.
The next concept we need to
discuss is the difference between
dependent and independent
premises. The best way to get at
this difference is to look at some
examples.
Example One
All students who study hard will pass their
courses, and you are a student who is studying
hard. It follows that you will pass your
courses.
Now we must ask a question:
Does each premise in this
example have enough
information in it to get you to the
conclusion: ‘you will pass your
courses?’
‘You are a student who is
studying hard,’ it follows that
you will pass your courses.
O.K. that seems to make sense
and pass our test. What about the
first premise?
All student who study hard will pass
their courses, it follows that you will
pass your courses.
Is there something missing here?
Something that we need to get to the
conclusion? Yes. In order to get to
the information in the conclusion,
we need to know that you are a
student who is studying hard.
Since at least one of the premises
does not have enough
information in it to get you to the
information in the conclusion,
these premises must be taken as
dependent.
One method you can use to
determine if the premises under
question are dependent is this.
Cover up one of the premises.
Can you determine what is
implied? If so, then the premises
are dependent.
Example
All cats have fleas and Fluffy is
a cat, so Fluffy must have fleas.
Can you determine what is
implied with certainty?
Yes, therefore the premises are
dependent.
Your Examples:
All men are dogs. John is a man; therefore, John
is a dog.
All bad students have to sit in front of the class.
Stork is sitting in front of the class, so he must be
a bad student.
All kids eat junk food; Lin is a kid, therefore, he
eats junkfood.
I wear hats, and hats make you go bald.
Therefore, I will be bald.
Your examples:
Joan is in better shape. She works out at
Bally’s, and working out at Bally’s helps
one to get in better shape.
All cats like warm places. Oreo is a cat, so
she likes warm places.
Kate eats salads and salads are healthy
foods, so Kate eats healthy foods.
How about an example of an
argument with independent
premises?
What are independent premises?
Premises are independent when each
premise has in it enough information to get
you to the information in the conclusion.
Example:
Smoking in the workplace should be
banned. Smoke damages computer
hardware and software; second hand smoke
causes many health problems, including
cancer, and finally, smoking on the job
presents a poor impression to potential
clients.
Are these premises dependent or
independent? Does each one
have enough information in it to
get you to the information in the
conclusion? Yes. They are
independent. But let’s use our
test to check.
Smoking in the workplace should be banned.
Smoke damages computer hardware and
software; second hand smoke causes many
health problems, including cancer, and finally,
smoking on the job presents a poor impression
to potential clients.
Can we determine what is
implied here? No, so the
premises are independent.
Your examples:
Ashley loves me as much as I love her, so we
moved in together. Our love is so deep we go to
the same school. Therefore, we belong together.
Rain can cause you to wreck your car. Rain also
can make you slip. So rain causes a lot of
problems for people.
In spring the flowers bloom and all the animals
fall in love. Therefore, Spring is the best season.
The desks in this classroom are extremely small.
Harris-Stowe should purchase new desks, so tall
students can sit more comfortably.
Your Examples:
Drinking and driving is not safe. Drinking
slows down a body’s natural reflexes, and it
affects judgment.
Men can be a pain in the rear end. They can
also make you cry. Men, therefore, cause a
lot of stress to women.
Puppies can cause problems. They chew on
furniture and pee on stuff.
How about an example that sums
this all up?
All men are slobs, as indicated by
the many wives unhappy with the
housekeeping habits of their
husbands. Harry is a man, so it
necessarily follows that Harry is
a slob.
Do we have any supported
premises here?
Yes, the premise ‘All men are
slobs.’
Are the premises dependent or
independent?
Let’s check
Does ‘Harry is a man’ have enough
information in it to get you to ‘Harry is a
slob’?
No, we need to know ‘all men are slobs.’
Let’s use our test to check.
All men are slobs, as indicated by
the many wives unhappy with the
housekeeping habits of their
husbands. Harry is a man, so it
necessarily follows that Harry is
a slob.
Can we determine what is
implied?
Yes, we can determine that ‘all men are
slobs’ is what is implied. The premises,
then, in this argument are dependent.
What does the diagram look like?
2
U.P.
S.P.
1
U.P.
+
3
____________________
4
F.C.
Another Example:
The Constitution guarantees the separation
of religion and the state. Seeing that prayer
is part of religion, and in view of the fact
that public schools are supported by the
state, prayer must be banned in public
schools. You should vote, then, for Senator
Smith, since she supports the banning of
prayer in public schools, as indicated by her
statements of October 29, 2003.
The next concept we must cover
is the concept of an
‘enthymeme.’
What is an enthymeme?
An enthymeme is an argument with a part missing
or implied. That is, it is an argument with either a
missing conclusion or a missing premise.
When you have an enthymeme, you must supply
the missing part (write it down last, so it will be
numbered last) and include it on your diagram.
Example:
All children who go to Josie’s preschool are
smart, so little Joey must be smart.
Go ahead and determine what is missing,
write it last, and following the steps we
went over in class, diagram this argument.
Another Example:
All students who study hard will pass this
class, and Harry has studied very hard in
this class.