CS 4001Mary Jean Harrold 1 Logical Structure of Arguments
CS 4001Mary Jean Harrold2 Overview Real-world argument not formal logic Difference between formal logic and real-world argument Real-world argument grounded in beliefs, assumptions, or values granted by the audience these beliefs, assumptions, and values often unstated
CS 4001Mary Jean Harrold3 Overview What are examples of arguments in which beliefs, assumptions, and values are shared by audience and can remain unstated?
CS 4001Mary Jean Harrold4 Overview Consider argument “ ” What is underlying assumption of this argument? What is an enthymeme? Complete it by stating unstated assumption Initial enthymeme: Claim: Stated reason: Unstated reason:
CS 4001Mary Jean Harrold5 Overview Consider argument “Rabbits make good pets because they are gentle” What is underlying assumption of this argument? What is an enthymeme? 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.”
CS 4001Mary Jean Harrold6 Overview Consider argument “Rabbits make good pets because they are gentle” What is underlying assumption of this argument? What is an enthymeme? 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.”
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
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 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
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 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
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
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?
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…)
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:
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: Rebutting reasons and grounds Rebutting the warrant and backing Qualifier since cannot usually prove your argument, qualify it
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
CS 4001Mary Jean Harrold16 Audience-based Reasons
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
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?
CS 4001Mary Jean Harrold19 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 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
CS 4001Mary Jean Harrold21 What Will Be Your Audiences in the Next Five Years? In each case, for what are you trying to argue?
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