cs 4001mary jean harrold1 logical structure of arguments

Mary Jean Harrold 1 CS 4001

Logical Structure of Arguments

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Argument

Core of an argument Logos—internal consistency, logical, best reasons,

supporting evidence Pathos—make reader open to message, appeal to

their values, engage them emotionally Ethos—enhance my credibility, present myself

effectively

Mary Jean Harrold 3 CS 4001

Argument

Core of an argument Logos—internal consistency, logical, best reasons,

supporting evidence Pathos—make reader open to message, appeal to

their values, engage them emotionally Ethos—enhance my credibility, present myself

effectively

Mary Jean Harrold 4 CS 4001

Quick Quiz Name

1. Write three questions that would be appropriate from today’s reading assignment: Writing Arguments, Chapter 5

2. Answer these questions

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Overview

Real-world argument not formal logic Differences between formal logic and real-world

argument

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Overview

What are examples of arguments in which beliefs, assumptions, and values are shared by audience and can remain unstated?

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Overview

What is an enthymeme?

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Overview

Consider argument “<complete> ” What is underlying assumption of this argument? Complete it by stating unstated assumption

Initial enthymeme: Claim: Stated reason: Unstated reason:

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Overview

Consider argument “Rabbits make good pets because they are gentle” What is underlying assumption of this argument? Complete it by stating unstated assumption

Initial enthymeme: “Rabbits make …gentle” Claim: “Rabbits make good pets” Stated reason: “Because they are gentle” Unstated reason: “Gentle animals make good pets.”

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Overview

Consider argument “Practicing piano is good for kids because it teaches good discipline” What is underlying assumption of this argument? Complete it by stating unstated assumption

Initial enthymeme: Claim: Stated reason: Unstated reason:

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Overview

What car should we buy?1. We should buy a Geo Metro because it is extremely

economical.

2. We should buy a used Volvo because it is very safe.

3. We should buy this Ford Escort because it is red.

How would we support these arguments?

Mary Jean Harrold 14 CS 4001

The Toulmin System

EnthymemeAn incomplete logical structure

Toulmin’s model1. All assertions and assumptions are contestable by “opposing

counsel”2. All final “verdicts” about the persuasiveness of alternative

arguments will be rendered by a neutral third party, a judge or jury.

Implications of Toulmin’s model for argument Must anticipate counter arguments and question assumptions Must be fair in representing the other side Must make sure our argument is not constructed just for those

who already agree with us

Mary Jean Harrold 15 CS 4001

The Toulmin System

EnthymemeAn incomplete logical structure

Toulmin’s model1. All assertions and assumptions are contestable by “opposing

counsel”2. All final “verdicts” about the persuasiveness of alternative

arguments will be rendered by a neutral third party, a judge or jury.

Implications of Toulmin’s model for argument Must anticipate counter arguments and question assumptions Must be fair in representing the other side Must make sure our argument is not constructed just for those

who already agree with us

Mary Jean Harrold 16 CS 4001

The Toulmin System (cont’d)

ExampleInitial enthymeme: We should buy this used Volvo because it is extremely safeClaim: We should buy this used VolvoStated Reason: because it is is extremely safeUnstated Reason: because we should buy the car that is the safest

In Toulmin’s system, the unstated reasons are warrantsWarrant: The safest car is the best car

Mary Jean Harrold 17 CS 4001

The Toulmin System (cont’d)

ExampleInitial enthymeme: We should buy this used Volvo because it is extremely safeClaim: We should buy this used VolvoStated Reason: It is extremely safeWarrant: The safest car is the best car

How do we support the reason and warrant?

Mary Jean Harrold 18 CS 4001

The Toulmin System (cont’d)

ExampleInitial enthymeme: We should buy this used Volvo because it is extremely safeClaim: We should buy this used VolvoStated Reason: It is extremely safeWarrant: The safest car is the best car

How do we support the reason and warrant?Support stated reason with grounds (evidence, what you have to go on---facts, statistics, data, testimony, interviews, surveys, …)Support warrant with backing (for audience who may not share the unstated claim, why do you believe this, how do you know this…)

Mary Jean Harrold 19 CS 4001

The Toulmin System (cont’d)

ExampleInitial enthymeme: We should buy this used Volvo because it is extremely safeClaim: We should buy this used VolvoStated Reason: It is extremely safe

Grounds: Warrant: The safest car is the best car

Backing:

Mary Jean Harrold 20 CS 4001

The Toulmin System (cont’d)

ExampleInitial enthymeme: We should buy this used Volvo because it is extremely safeClaim: We should buy this used VolvoStated Reason: It is extremely safe

Grounds: Warrant: The safest car is the best car

Backing:

How do we address the resistant audienceConditions of Rebuttal:

Rebutting reasons and grounds Rebutting the warrant and backing

Qualifiersince cannot usually prove your argument, qualify it

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Exercise

Use Toulmin’s scheme to help determine what you have to consider in developing the following enthymeme

Practicing Piano is good for kids because it teaches discipline

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Audience-based Reasons

Audience-based VS writer-based Discussion:

What is the warrant Will audience grant it?

1. Audience: a beleaguered parenta. I should be allowed to stay out until 2 A.M. because all my

friends do

b. I should be allowed to stay out until 2 A.M. because only if I’m free to make my own decisions will I mature

Mary Jean Harrold 23 CS 4001

1. Who is your audience?

2. How much do they care about your issue?

3. What is your audience’s current attitude toward your issue?

4. What will be your audience’s likely objections to your argument?

5. What values, beliefs, or assumptions about the work do you and your audience share?

Who is Your Audience

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What Will Be Your Audiences in the Next Five Years?

In each case, for what are you trying to argue?

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What Will Be Your Audiences in the Next Five Years?

In each case, for what are you trying to argue?

1. A company where you want to get a job

2. A boss whom you want to convince about your project.

3. A project leader whom you want to convince about your design.

4. A customer whom you want to convince about your plan for developing their software.

5. A graduate school where you want to enroll.

6. A teacher whom you want to convince to pass you