analyzing and evaluating arguments

GXEX1406

Thinking and Communication Skills

Analyzing and Evaluating Arguments

2GXEX1406 Thinking and Communication Skills – Week 9 Analyzing and Evaluating Arguments

What is an argument ?

Forms of discourse that attempt to persuade readers or listeners to accept a claim, whether acceptance is based on logical or emotional appeals or, is usually a case, on both.

Statement or statements offering support for a claim.


Components of argument

Claim

Statement that is either true or false. Must always have a

truth value, i.e. it must be true or false.

Support / Premise

Consists of materials used by arguer to

convince the claim. Include evidence &

motivational appeals.

Warrant / ConclusionAn inference / assumption, a belief / principlethat is taken for granted. Allow to make the

connection between support & claim.


Example

Claim or not? Student in FSKTM like PBL class. Please shut the door behind you.

Support / Premise 98% of the students in PBL class passed the

exam. Warrant / Conclusion

Most of the student in FSKTM like PBL class.


The Claim

FactAssert that a condition has existed, exists or will exist

based on facts or data that objectively verifiable.

ValueAttempt to prove that

some things are more or

less desirable than others.

Policy

Assert that specific policies

should be instituted as solutions to problems.

E.g. should, must, ought to,

etc.


Evaluating Argument

Should be able to : Identify assumptions Recognize contradictions Distinguish between fact & opinion Recognize bias Distinguish between fact & inference


Examples

Teaching is rewarding occupation & you only work until 2.00p.m. It is a suitable profession for anyone who wants their afternoon free

MyKad has been produced with the most secure technology. It has been cloned once

(assumptions).

(contradiction).


Cont..

Mount Kinabalu is a beautiful mountain

Mount Kinabalu is the highest peak in Southeast Asia

I don’t think teaching in English is good and practical because my son is not able to understand what the teacher is talking about

(opinion).

(fact).

(bias).


Cont..

You noticed that your friend is loosing weight, quieter than usual & her face is sunken. When you asked ‘Are you OK?’, the replies ‘Oh, I’m fine’. It would be reasonable to conclude: She is on diet Suffering from some disease On hallucinatory drugs

The conclusions is reasonable but not factual reports. It is called inferences.


Reasons for using arguments

Persuading others

E.g.

She should marry you

because you are so good

looking.

Making decisions

E.g.

Being a carpenter, because you are good at working

with your hands & like building

things.

Explaining things

E.g.

You are late for an important

meeting, and the boss wants to know why.


How to detect an argument1. Search for

premise & conclusion indicator

words.

E.g. Since, because, for, follows from,

therefore, thus, so, it follows

that, accordingly, etc.

2. Determine if the purpose of the words is to

persuade someone.

3. Make an effort to understand the

context of the passage in question.


Examples (1)

1) All Malaysians like badminton. Hafiz is a Malaysian. So, Hafiz likes badminton.

2) April 28 is when federal income taxes are due. So, Malaysians take April 28 seriously.

So (1) conclusion indicator. So (2) X conclusion indicator.


Common Premise indicators

As shown by Because Follows from For For the reason that Given that Since


Common conclusion indicators Accordingly Consequently Hence In conclusion It follows that So Then Therefore Thus We can conclude that


Examples (2)

1) I was late for an appointment because my car broke down & an accident slowed down the traffic.

2) I think Bush was the worst person in the 21st century because he was responsible for the death of millions of people & because he promoted hate & violence.

(1) explanation (2) arguments


Examples (3)

Suppose abortion is being discussed & someone says, “I disagree with you, let me tell you why.” means that an argument will be forthcoming.

Suppose you & a friend are trying to figure out why the economy is doing so well. You ask, “Why is it doing so well?” & she responds, “How about the following reasons?” although she is offering reasons, she is not trying to persuade you anything (not arguments).


Other kinds of Non-Arguments

Descriptions

E.g.

•Dr. Mahathir is a Prime Minister.

•Winters are cold in Alaska.

•My old brother is 45 years old

•Ajai was a composer

Reports

E.g.

•The dropping of atomic bombs on the Japanese cities of Hiroshima and Nagasaki

(1945)

•The formation of United Nations (1945)

•The first human on the moon (1969)


Characteristics of Arguments

Elements of an arguments.

Premise(s) + Conclusion

Standard form for an argument.

1. Premise (1)

2. Premise (2)

:. Conclusion

One important principle

Principle of charity : when more than one reading of an argument is

possible, interpret the

argument in the way most

flattering to its presenter


Inductive vs. Deductive arguments

Deductive – premises guarantees the truth of the conclusion

Inductive – strong argument: truth of the premises conclusion probably true. Weak argument: truth of premises conclusion

probably not true.

Characteristics of Arguments (Cont.)


Examples

Jorge: Everyone should be a vegetarian. That’s a claim but not argument. For it to be

argument, make a claim & give some support or reasons for it.

Jorge: Everyone should be a vegetarian because my grandmother says so.

That’s an argument. Made a claim – everyone should be a vegetarian & offered reason – grandmother says so – in support of it.


Cont..

1. Anyone who is out of food should buy some more.

2. Lili is out of food.

____________________________

:. Lili should buy some food


Cont..

1. Most (80%) of the people from Singapore has been infected with SARS.

2. Joe is from Singapore.

_____________________________

:.Joe has been infected with SARS.

Inductively strong, conclusions contradictory; they cannot both be true.


7 Good argument patterns

1. Modus Ponens1. If A, then B.2. A.:. B.e.g.1. If I study, then I will pass.2. I will study.

:. I will pass.


Modus Tollens

1. If A, then B.

2. Not B.

:. Not A.

e.g.

1. If Tamika is healthy, then she’s happy.

2. Tamika is not happy.

:. Tamika is not healthy.


Disjunctive argument

1. Either A or B.

2. Not A

:. B

e.g.

1. Either I sleep or eat

2. I am not sleeping

:. I am eating.


Hypothetical Syllogism

1. If A, then B.

2. If B, then C.

:. If A, then C.

e.g.

1. If I work, then I’ll get paid.

2. If I get paid, then I’ll be happy.

:. If I work, then I’ll be happy.


Chain argument1. A

2. If A, then B.

3. If B, then C.

:. C.

e.g.

1. Antoine is short.

2. If Antoine is short, then Camille won’t date him.

3. If Camille won’t date him, then Antoine will ask Donna out.

:. Antoinne will ask Donna out.


Predicate Instantiation

1. All A’s are B’s.

2. M is an A.

:. M is a B.

e.g.

1. All carpenters are good at building.

2. Mahmud is a carpenter.

:. Mahmud is good at building.


Universal Syllogism

1. All A’s are B’s.

2. All B’s are C’s.

:. All A’s are C’s.

e.g.

1. All whales are mammals.

2. All mammals nurse their young.

:. All whales nurse their young.


Missing parts of argumentsImplicit conclusions

E.g.

1. If Brian is late, then Gail will be angry.

2. Brian is late.____

:. Gail will be angry.

1. If A, then B.

2. A.____________

:. B. (implicit)

Implicit Premises

E.g.

1. If Lukes loves Laura, then he will treat her well.

2. He often does not treat her well._____________

:. ?

1. If A, then B.

2. Not B._____

:. ?


Distinguishing Good Arguments from Bad Ones.

Validity

1. All whales are mammals

2. All mammals nurse their young.________

:. All whales nurse their young.

Conclusion follows from the premises. Premises true + conclusion true = valid.

Soundness

If and only if

-It is valid

-All premise are reasonable or rationally acceptable.

analyzing and evaluating arguments

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