1. CS 4001Mary Jean Harrold 1 Logical Structure of Arguments

2. CS 4001Mary Jean Harrold2 Overview ŸReal-world argument not formal logic ŸDifference between formal logic and real-world argument ŸReal-world argument Ÿgrounded in beliefs, assumptions, or values granted by the audience Ÿthese beliefs, assumptions, and values often unstated

3. CS 4001Mary Jean Harrold3 Overview ŸWhat are examples of arguments in which beliefs, assumptions, and values are shared by audience and can remain unstated?

4. CS 4001Mary Jean Harrold4 Overview ŸConsider argument “ ” ŸWhat is underlying assumption of this argument? ŸWhat is an enthymeme? ŸComplete it by stating unstated assumption ŸInitial enthymeme: ŸClaim: ŸStated reason: ŸUnstated reason:

5. CS 4001Mary Jean Harrold5 Overview ŸConsider argument “Rabbits make good pets because they are gentle” ŸWhat is underlying assumption of this argument? ŸWhat is an enthymeme? ŸComplete it by stating unstated assumption ŸInitial enthymeme: “Rabbits make …gentle” ŸClaim: “Rabbits make good pets” ŸStated reason: “Because they are gentle” ŸUnstated reason: “Gentle animals make good pets.”

6. CS 4001Mary Jean Harrold6 Overview ŸConsider argument “Rabbits make good pets because they are gentle” ŸWhat is underlying assumption of this argument? ŸWhat is an enthymeme? ŸComplete it by stating unstated assumption ŸInitial enthymeme: “Rabbits make …gentle” ŸClaim: “Rabbits make good pets” ŸStated reason: “Because they are gentle” ŸUnstated reason: “Gentle animals make good pets.”

7. CS 4001Mary Jean Harrold7 The Toulmin System Enthymeme An incomplete logical structure Toulmin’s model All assertions and assumptions are contestable by “opposing counsel” 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

8. CS 4001Mary Jean Harrold8 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 ŸMust anticipate counter arguments and question assumptions ŸMust be fair in representing the other side ŸMust make sure our argument is not constructed just for those who already agree with us

9. CS 4001Mary Jean Harrold9 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 ŸMust anticipate counter arguments and question assumptions ŸMust be fair in representing the other side ŸMust make sure our argument is not constructed just for those who already agree with us

10. CS 4001Mary Jean Harrold10 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 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

11. CS 4001Mary Jean Harrold11 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?

12. CS 4001Mary Jean Harrold12 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…)

13. CS 4001Mary Jean Harrold13 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:

14. CS 4001Mary Jean Harrold14 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: ŸRebutting reasons and grounds ŸRebutting the warrant and backing Qualifier since cannot usually prove your argument, qualify it

15. CS 4001Mary Jean Harrold15 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

16. CS 4001Mary Jean Harrold16 Audience-based Reasons

17. CS 4001Mary Jean Harrold17 ISSUE QUESTION: Should it be legal for drivers to talk on cell phones while driving? Audience: Your state political representatives Claim: Cell phones should be illegal to use while driving. Reason 1: because holding a cell phone in one hand diminishes drivers’ capacity to control their cars physically Grounds: Find statistics showing how many drivers have had trouble making turns or staying in their lanes when talking on ca cell phone; statistics of number of accidents caused by cell phone users Warrant: Anything that interferes with drivers’ ability to handle their cars is bad Backing: Conditions of Rebuttal for Reason 1: Cell phones have been shown to be valuable in road emergencies; many business people need cell phones to make contact with clients and need to save time by talking while they are driving; drivers use their hands to do a lot of other equally or more distracting things while driving, such as drinking coffee, reading, fiddling with CDs and tapes, shaving, putting on make-up; should these activities be banned too? Qualifier: Except with a headset of speaker-phone, cell phones should be illegal to use while driving

18. CS 4001Mary Jean Harrold18 Audience: Your state political representatives Claim: Cell phones should be illegal to use while driving. Reason 2: Grounds: Warrant: Backing: Conditions of Rebuttal for Reason 2 Qualifier: ISSUE QUESTION: Should it be legal for drivers to talk on cell phones while driving?

19. CS 4001Mary Jean Harrold19 Audience-based Reasons ŸAudience-based VS writer-based ŸDiscussion: ŸWhat is the warrant ŸWill 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

20. CS 4001Mary Jean Harrold20 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

21. CS 4001Mary Jean Harrold21 What Will Be Your Audiences in the Next Five Years? In each case, for what are you trying to argue?

22. CS 4001Mary Jean Harrold22 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