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Patrick Denehy Drexel University Critical Reasoning Updated: April 18, 2014 Informal Logic: A Pragmatic Approach (2nd Edition) Douglas Walton I recommend reading as much of the text as possible. Walton will occasionally repeat examples in subsequent chapters in order to make new points or provide a different angle on the same topic. Nevertheless, there is too much information contained within the book for us to go over each point in detail. Here’s a guide for concepts and examples I intend to discuss broken down by chapter. Chapter 1: Argument as reasoned dialogue

• Logical pragmatics and logical semantics • Basic types of reasoning

• Deductive • Inductive • Defeasible (plausible)

• Roughly 8 dialogue types • Emphasis: persuasion dialogue (critical discussion)

• Symmetrical and asymmetrical dialogues • Internal and external proofs • The nature of commitments

• Fallacy: Straw Man • Silencing technique: example 1.14

Chapter 2: Questions and answers in dialogue

• Presuppositions • Complex, Loaded, Black/White Questions • Strategies to respond to certain questions • Questions in polls and their effects

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Chapter 3: Criticisms of irrelevance

• Relevance and irrelevance • Four notions of relevance • Fallacies:

• Ignoratio Elenchi • Red Herring • Wrong Conclusion

• Fallacy work and review Chapter 4: Appeals to emotion

• Fallacies: • Ad Populum • Ad Baculum • Ad Misericordiam

• Fallacies compared and contrasted with: • Appeals in advertising • Silencing techniques • Warnings • Appeals to sympathy and compassion

Chapter 5: Valid arguments

• Working on deduction (LSAT example) • Logical semantics versus logical pragmatics • Common deductive forms:

• Modus ponens • Modus tollens • Disjunctive syllogism • Hypothetical syllogism

• Fallacies: • Composition • Division

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Chapter 6: Personal attack in argumentation

• Fallacies: • Ad Hominem abusive • Ad Hominem circumstantial & tu quoque • Ad Hominem poisoning the well

• Connections and impact: • Negative political campaigns (p. 173) • The bias paradox (p. 188) • 12 Angry Men examples • Plutocracy and the greed objection (including Sandel)

Chapter 7: Appeals to authority

• Lesson from Milgram experiments • Cognitive and administrative authority • Appeal to authority as a problem of modern history • Rational structure of the appeal to authority

• Reasonable appeals to authority • Fallacious appeals to authority • Middle cases • Criteria & tools for evaluating appeals to authority

§ See especially p. 218 • Senator Al Franken example (anti-gay study) [outside book]

Chapter 8: Inductive errors, bias, and fallacies

• Reminder: internal and external proof (ch. 1, p. 4-5) • Foci: inductive generalizations, statistical arguments, causal arguments • Statistical arguments

• Meaningless stats • Unknowable stats • Simple random samples • Stratified random samples • Insufficient stats • Biased stats

• Causal arguments • Variety of post hoc errors • Gambler’s fallacy [outside book]

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Chapter 9: Natural language argumentation

• Common linguistic problems • Ambiguity • Vagueness

• Fallacies • Slippery slope • Assessing slippery slopes

• Connections • Gay marriage example [outside book] • Connection to Sandel on morally robust aims