Logical Structure of Arguments CS 4001 Mary Jean

Logical Structure of Arguments CS 4001 Mary Jean Harrold 1

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 CS 4001 Mary Jean Harrold 2

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 CS 4001 Mary Jean Harrold 3

Quick Quiz Name 1. Write three questions that would be appropriate from today’s reading assignment: Writing Arguments, Chapter 5 2. Answer these questions CS 4001 Mary Jean Harrold 4

Overview Real-world argument not formal logic Differences between formal logic and real-world argument CS 4001 Mary Jean Harrold 5

Overview What are examples of arguments in which beliefs, assumptions, and values are shared by audience and can remain unstated? CS 4001 Mary Jean Harrold 7

Overview What is an enthymeme? CS 4001 Mary Jean Harrold 8

Overview Consider argument “ ” What is underlying assumption of this argument? Complete it by stating unstated assumption CS 4001 Initial enthymeme: Claim: Stated reason: Unstated reason: Mary Jean Harrold 9

Overview Consider argument “Rabbits make good pets because they are gentle” What is underlying assumption of this argument? Complete it by stating unstated assumption CS 4001 Initial enthymeme: “Rabbits make …gentle” Claim: “Rabbits make good pets” Stated reason: “Because they are gentle” Unstated reason: “Gentle animals make good pets. ” Mary Jean Harrold 10

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 CS 4001 Initial enthymeme: Claim: Stated reason: Unstated reason: Mary Jean Harrold 12

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? CS 4001 Mary Jean Harrold 13

The Toulmin System Enthymeme An incomplete logical structure Toulmin’s model 1. 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 CS 4001 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 14

The Toulmin System Enthymeme An incomplete logical structure Toulmin’s model 1. 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 CS 4001 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

The Toulmin System (cont’d) Example Initial enthymeme: We should buy this used Volvo because it is extremely safe Claim: We should buy this used Volvo Stated Reason: because it is is extremely safe Unstated Reason: because we should buy the car that is the safest In Toulmin’s system, the unstated reasons are warrants Warrant: The safest car is the best car CS 4001 Mary Jean Harrold 16

The Toulmin System (cont’d) Example Initial enthymeme: We should buy this used Volvo because it is extremely safe Claim: We should buy this used Volvo Stated Reason: It is extremely safe Warrant: The safest car is the best car How do we support the reason and warrant? CS 4001 Mary Jean Harrold 17

The Toulmin System (cont’d) Example Initial enthymeme: We should buy this used Volvo because it is extremely safe Claim: We should buy this used Volvo Stated Reason: It is extremely safe Warrant: 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…) CS 4001 Mary Jean Harrold 18

The Toulmin System (cont’d) Example Initial enthymeme: We should buy this used Volvo because it is extremely safe Claim: We should buy this used Volvo Stated Reason: It is extremely safe Grounds: Warrant: The safest car is the best car Backing: CS 4001 Mary Jean Harrold 19

The Toulmin System (cont’d) Example Initial enthymeme: We should buy this used Volvo because it is extremely safe Claim: We should buy this used Volvo Stated Reason: It is extremely safe Grounds: Warrant: The safest car is the best car Backing: How do we address the resistant audience Conditions of Rebuttal: Rebutting reasons and grounds Rebutting the warrant and backing Qualifier since cannot usually prove your argument, qualify it CS 4001 Mary Jean Harrold 20

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 CS 4001 Mary Jean Harrold 21

Audience-based Reasons Audience-based VS writer-based Discussion: What is the warrant Will audience grant it? 1. Audience: a beleaguered parent a. 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 CS 4001 Mary Jean Harrold 22

Who is Your Audience 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? CS 4001 Mary Jean Harrold 23

What Will Be Your Audiences in the Next Five Years? In each case, for what are you trying to argue? CS 4001 Mary Jean Harrold 24

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 CS 4001 Mary Jean Harrold 25