Critical thinking by moore and parker 12th edition

Critical Reasoning

Consider the terms vague, ambiguity and generality as they relate to our textbook reading for this week.

How are vagueness, ambiguity and generality used in politics or in law in order to achieve a desired outcome?
What are some examples of how this might be applied in your future career?
Include an example or two from current events that demonstrates the use of vagueness, ambiguity and generality.
Feel free to share an article, a screenshot of a social media post, a video, etc
Please use the textbook as reference and also cite the reference at the end

CRITICAL THINKING, TWELFTH EDITION

Published by McGraw-Hill Education, 2 Penn Plaza, New York, NY 10121. Copyright © 2017 by McGraw-Hill Education. All rights reserved. Printed in the United States of America. Previous editions © 2015, 2012, and 2009. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of McGraw-Hill Education, including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning.

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Library of Congress Cataloging-in-Publication Data

Names: Moore, Brooke Noel, author. | Parker, Richard (Richard B.), author. Title: Critical thinking / Brooke Noel Moore, Richard Parker, California

State University, Chico; with help in chapter 12 from Nina Rosenstand and

Anita Silvers. Description: Twelfth Edition. | Dubuque, IA : McGraw-Hill Education, 2016. Identifiers: LCCN 2016021518 | ISBN 9781259690877 (alk. paper) | ISBN

1259690873 (alk. paper)

Subjects: LCSH: Critical thinking. Classification: LCC B105.T54 M66 2016 | DDC 160—dc23 LC record available at https://lccn.loc.gov/2016021518

The Internet addresses listed in the text were accurate at the time of publication. The inclusion of a website does not indicate an endorsement by the authors or McGraw-Hill Education, and McGraw-Hill Education does not guarantee the accuracy of the information presented at these sites.

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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12

Brief Contents

Don’t Believe Everything You Think 1 Two Kinds of Reasoning 32 Clear Thinking, Critical Thinking, and Clear Writing 64 Credibility 93 Rhetoric, the Art of Persuasion 132 Relevance (Red Herring) Fallacies 173 Induction Fallacies 195 Formal Fallacies and Fallacies of Language 220 Deductive Arguments I: Categorical Logic 242 Deductive Arguments II: Truth-Functional Logic 284 Inductive Reasoning 338 Moral, Legal, and Aesthetic Reasoning 390

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Chapter 1

Chapter 2

Contents Preface xiv

Acknowledgments xx

About the Authors xxiv

Don’t Believe Everything You Think 1

Beliefs and Claims 4

Objective Claims and Subjective Claims 4

Fact and Opinion 5

Relativism 6

Moral Subjectivism 6

Issues 6

Arguments 7

Cognitive Biases 14

Truth and Knowledge 20

What Critical Thinking Can and Can’t Do 20

A Word About the Exercises 21

Recap 21

Additional Exercises 23

Two Kinds of Reasoning 32

Arguments: General Features 32

Conclusions Used as Premises 33

Unstated Premises and Conclusions 33

Two Kinds of Arguments 34

Deductive Arguments 34

Inductive Arguments 36

Chapter 3

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Beyond a Reasonable Doubt 37

Telling the Difference Between Deductive and Inductive Arguments 37

Deduction, Induction, and Unstated Premises 38

Balance of Considerations 40

Inference to the Best Explanation (IBE) 41

What Are Not Premises, Conclusions, or Arguments 41

Pictures 42

If . . . then . . . Sentences 42

Lists of Facts 42

“A because B” 43

Ethos, Pathos, and Logos 43

Techniques for Understanding Arguments 48

Clarifying an Argument’s Structure 49

Distinguishing Arguments from Window Dressing 51

Evaluating Arguments 52

Recap 52

Additional Exercises 53

Clear Thinking, Critical Thinking, and Clear

Writing 64

Vagueness 65

Ambiguity 67

Semantic Ambiguity 68

Grouping Ambiguity 68

Syntactic Ambiguity 68

Generality 70

Defining Terms 75

Purposes of Definitions 75

Kinds of Definitions 76

Tips on Definitions 77

Writing Argumentative Essays 79

Good Writing Practices 80

Essay Types to Avoid 81

Chapter 4

Chapter 5

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Persuasive Writing 82

Writing in a Diverse Society 82

Recap 83

Additional Exercises 84

Credibility 93

The Claim and Its Source 95

Assessing the Content of the Claim 96

Does the Claim Conflict with Our Personal Observations? 96

Does the Claim Conflict with Our Background Information? 99

The Credibility of Sources 102

Interested Parties 102

Physical and Other Characteristics 103

Expertise 105

Credibility and the News Media 109

Consolidation of Media Ownership 109

Government Management of the News 109

Bias Within the Media 111

Talk Radio 113

Advocacy Television 113

The Internet, Generally 114

Blogs 117

Advertising 118

Three Kinds of Ads 118

Recap 121

Additional Exercises 122

Rhetoric, the Art of Persuasion 132

Rhetorical Force 133

Rhetorical Devices I 134

Euphemisms and Dysphemisms 134

Weaselers 134

Downplayers 135

Chapter 6

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Rhetorical Devices II 137

Stereotypes 137

Innuendo 138

Loaded Questions 139

Rhetorical Devices III 141

Ridicule/Sarcasm 141

Hyperbole 141

Rhetorical Devices IV 142

Rhetorical Definitions and Rhetorical Explanations 142

Rhetorical Analogies and Misleading Comparisons 143

Proof Surrogates and Repetition 147

Proof Surrogates 147

Repetition 148

Persuasion Through Visual Imagery 150

The Extreme Rhetoric of Demagoguery 152

Recap 155

Additional Exercises 156

Relevance (Red Herring) Fallacies 173

Argumentum Ad Hominem 174

Poisoning the Well 175

Guilt by Association 175

Genetic Fallacy 175

Straw Man 176

False Dilemma (Ignoring Other Alternatives) 177

The Perfectionist Fallacy 178

The Line-Drawing Fallacy 178

Misplacing the Burden of Proof 179

Begging the Question (Assuming What You are Trying to Prove) 181

Appeal To Emotion 182

Argument from Outrage 182

Scare Tactics 182

Appeal to Pity 184

Chapter 7

Chapter 8

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Other Appeals to Emotion 184

Irrelevant Conclusion 186

Recap 188

Exercises 188

Induction Fallacies 195

Generalizations 195

Generalizing from Too Few Cases (Hasty Generalization) 196

Generalizing from Exceptional Cases 198

Accident 199

Weak Analogy 200

Mistaken Appeal to Authority 202

Mistaken Appeal to Popularity (Mistaken Appeal to Common Belief) 202

Mistaken Appeal to Common Practice 203

Bandwagon Fallacy 203

Fallacies Related to Cause and Effect 205

Post Hoc, Ergo Propter Hoc 205

Cum Hoc, Ergo Propter Hoc 209

Slippery Slope 211

Untestable Explanation 212

Line-Drawing Again 212

Recap 213

Exercises 213

Formal Fallacies and Fallacies of Language 220

Three Formal Fallacies: Affirming the Consequent, Denying the Antecedent,

and Undistributed Middle 220

Affirming the Consequent 220

Denying the Antecedent 221

The Undistributed Middle 222

The Fallacies of Equivocation and Amphiboly 224

The Fallacies of Composition and Division 225

Confusing Explanations with Excuses 227

Chapter 9

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Confusing Contraries and Contradictories 229

Consistency and Inconsistency 230

Miscalculating Probabilities 231

Incorrectly Combining the Probability of Independent Events 231

Gambler’s Fallacy 232

Overlooking Prior Probabilities 233

Faulty Inductive Conversion 233

Recap 235

Additional Exercises 236

Deductive Arguments I: Categorical Logic 242

Categorical Claims 244

Venn Diagrams 245

Translation into Standard Form (Introduction) 246

Translating Claims in Which the Word “Only” or the Phrase “The

Only” Occurs 246

Translating Claims About Times and Places 247

Translating Claims About Specific Individuals 249

Translating Claims that Use Mass Nouns 250

The Square of Opposition 252

Existential Assumption and the Square of Opposition 252

Inferences Across the Square 253

Three Categorical Relations 254

Conversion 254

Obversion 254

Contraposition 255

Categorical Syllogisms 262

The Venn Diagram Method of Testing for Validity 264

Existential Assumption in Categorical Syllogisms 267

Categorical Syllogisms with Unstated Premises 267

Real-Life Syllogisms 268

The Rules Method of Testing for Validity 272

Recap 274

Chapter 10

Chapter 11

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Additional Exercises 274

Deductive Arguments II: Truth-Functional Logic

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Truth Tables and Logical Symbols 285

Claim Variables 285

Truth Tables 285

Symbolizing Compound Claims 291

“If” and “Only If” 292

Necessary and Sufficient Conditions 294

“Unless” 295

“Either . . . Or” 295

Truth-Functional Argument Patterns (Brief Version) 298

Three Common Valid Argument Patterns 298

Three Mistakes: Invalid Argument Forms 302

Truth-Functional Arguments (Full Version) 305

The Truth-Table Method 305

The Short Truth-Table Method 308

Deductions 313

Group I Rules: Elementary Valid Argument Patterns 314

Group II Rules: Truth-Functional Equivalences 319

Conditional Proof 327

Recap 330

Additional Exercises 330

Inductive Reasoning 338

Argument from Analogy 338

Evaluation of Arguments from Analogy 339

Three Arguments from Analogy 341

Other Uses of Analogy 342

Generalizing from a Sample 347

Evaluation of Arguments That Generalize from a Sample 348

Three Arguments That Generalize from a Sample 349

Chapter 12

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Scientific Generalizing from a Sample 350

The Statistical Syllogism 351

Causal Statements And Their Support 359

Forming Causal Hypotheses 359

Weighing Evidence 361

Confirming Causal Hypotheses 372

Calculating Statistical Probabilities 377

Joint Occurrence of Independent Events 377

Alternative Occurrences 377

Expectation Value 378

Calculating Conditional Probabilities 379

Causation in the Law 380

Recap 381

Additional Exercises 382

Moral, Legal, and Aesthetic Reasoning 390

Value Judgments 391

Moral Versus Nonmoral 392

Two Principles of Moral Reasoning 392

Moral Principles 394

Deriving Specific Moral Value Judgments 394

Major Perspectives in Moral Reasoning 397

Consequentialism 397

Duty Theory/Deontologism 398

Moral Relativism 400

Religious Relativism 402

Religious Absolutism 402

Virtue Ethics 402

Moral Deliberation 405

Legal Reasoning 410

Justifying Laws: Four Perspectives 411

Aesthetic Reasoning 414

Eight Aesthetic Principles 414

Using Aesthetic Principles to Judge Aesthetic Value 417

Evaluating Aesthetic Criticism: Relevance and Truth 419

Why Reason Aesthetically? 420

Recap 422

Additional Exercises 423

Appendix: Exercises from Previous Editions 426

Glossary 450

Answers, Suggestions, and Tips for Triangle Exercises 459

Credits 482

Index 483

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Critical Thinking . . . Skills for the course. Skills for life.

More Engaging

Moore & Parker are known for fresh and lively writing. They rely on their own classroom experience and on feedback from instructors in getting the correct balance between explication and example.

Examples and exercises are drawn from today’s headlines. Students learn to apply critical thinking skills to situations in a wide variety of areas: advertising, politics, the media, popular culture. I love the sense of humor of the authors, the very clear and elegant way they

make critical thinking come alive with visuals, exercises and stories. —Gary John, Richland College

[Before reading this chapter] most students don’t realize the extent of product

placement and other similar attempts at subtle manipulation. —Christian Blum, Bryant & Stratton, Buffalo

More Relevant

Moore & Parker spark student interest in skills that will serve them throughout their lives, making the study of critical thinking a meaningful endeavor.

Boxes show students how critical thinking skills are relevant to their day-to-day lives. Striking visuals in every chapter show students how images affect our judgment and shape our thinking.

The variety [in the exercises] was outstanding. [They] will provide ample opportunity for the students to put into practice the various

logical principles being discussed. —Ray Darr, Southern Illinois University

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More Student Success

Moore & Parker provide a path to student success, making students active participants in their own learning while teaching skills they can apply in all their courses.

Learning objectives link to chapter sections and in turn to print and online activities, so that students can immediately assess their mastery of the learning objective.

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Exercises are dispersed throughout most chapters, so that they link tightly with the concepts as they are presented. Students have access to over 2,000 exercises that provide practice in applying their skills.

Hands-on, practical, and one might say, even “patient” with the students’ learning as it emphatically repeats concepts and slowly progresses them step by

step through the process. —Patricia Baldwin, Pitt Community College

There are a lot of exercises, which provides nice flexibility. The . . . mix of

relatively easy and more challenging pieces . . . is useful in providing some flexibility for

working in class. —Dennis Weiss, York College of Pennsylvania

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Changes to the 12th Edition

aving arrived at an even dozen editions, we still have our original goal constantly in mind: helping teach students to think and reason critically and make better decisions and making life a bit easier for instructors of critical

thinking courses. We invite both students and instructors to get in touch with us with any ideas they have that might help us pursue these goals.

As usual, this edition updates names and events in examples and exercises in the hope that they will be familiar to the current crop of students. As we’ve mentioned before, what to many of us instructors are recent events are obscure history to many new freshmen. Other changes are as follows.

CHAPTER-SPECIFIC CHANGES

Chapter 1 begins with a fuller accounting of what we take critical thinking to be. It also goes into a bit more depth regarding cognitive biases that affect our thinking. Chapter 2 contains a revised section on inference to the best explanation (IBE). Chapter 3 is somewhat leaner, but still makes a wealth of points about the important concepts of vagueness and generality and it contains a revised account of several types of definitions. Chapter 4 gets the usual updating here and there plus a new section on credibility in social media.

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Chapter 5 gets updating, new photos, and a subsection on significant mention under the innuendo heading. Chapter 6 is left largely unchanged aside from some new examples and photos. Chapter 7 is also much the same as the previous version, although “fallacious” appeals have been changed to “mistaken” appeals; why use a word students have trouble spelling when there is one they don’t? Chapter 8 was new in the previous edition. It gets updated this time around, including a replacement of the section entitled “Overlooking False Positives” with an easier to understand “Faulty Inductive Conversion” section. Chapter 9 gets a bit of reformatting to make examples stand out more easily. Also, existential assumption gets its own subsection so it will be more difficult to miss.

Chapter 10 now makes the electrical circuit box a bit less distracting and adds a couple of new exercises to aid in learning to symbolize claims. But the biggest change from the previous edition is the reinsertion of a section that gives a briefer version of truth-functional arguments. This allows an instructor (like Moore) to deal quickly with this subject or (like Parker) to deal with it in much more detail by going on to the longer treatment that completes the chapter. Chapter 11 has the sections on analogies and generalizations fine-tuned, while the section on causal hypotheses remains in its previous pristine form. Chapter 12 has been left alone aside from a bit of updating of examples.

■ Vladimir Putin asks Hillary Clinton if she can get him a copy of Moore/Parker.

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W Acknowledgments

e, Moore and Parker, feel about this textbook the way people usually feel about their children. It has been a wonderful thing to watch it grow up through these (now) dozen editions, although it has caused us the occasional

pain in the backside along the way. Those pains—often in the form of criticism in reviews and correspondence from adopters—have usually been growing pains, however, and they have contributed to the improvement of the book. We are pretty pleased with the book, as proud parents are wont to be, but we realize that there are always things—smaller and smaller things, we hope—that can be changed for the better. We hope this edition incorporates changes of just that sort. Many of them are listed below.

The online accompaniment to the text continues to expand and, we trust, become more and more useful to adopters and their students. The preceding pages briefly describe LearnSmart and Connect, the principal components of the online material. These programs promise help for the student and an easier and more productive time for the instructor. We hope you find they live up to this promise.

Having escaped from the mysterious clutches of Mark Georgiev, former KGB operative and our editor a couple of editions ago, we have been blessed by guidance this time around from the gentle hands of Penina Braffman, Brand Manager; Anthony McHugh, Product Developer; Jane Mohr, Content Project Manager; as well as Erin Guendelsberger, Reshmi Rajeesh, and the ansrsource team, Development Editors, who encourage us even when we don’t quite toe the McGraw-Hill line.

The guidance of the following reviewers of current and previous editions and others who have written to us has been invaluable:

Keith Abney, California Polytechnic State University, San Luis Obispo James Anderson, San Diego State University Benjamin Arah, Bowie State University Sheldon Bachus Patricia Baldwin, Pitt Community College Monique Bindra Tim Black, California State University, Northridge Charles Blatz, University of Toledo

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Christian Blum, Bryant & Stratton, Buffalo K. D. Borcoman, Coastline College/CSUDH Keith Brown, California State University, East Bay Rosalie Brown Lee Carter, Glendale Community College Jennifer Caseldine-Bracht, Indiana University-Purdue University, Fort Wayne Lynne Chandler-Garcia, Pikes Peak Community College David Connelly Anne D’Arcy, California State University, Chico Michelle Darnelle, Fayetteville State University Ray Darr, Southern Illinois University, Edwardsville William J. Devlin, Bridgewater State University Paul Dickey, Metropolitan Community College Sandra Dwyer, Georgia State University Jeffrey Easlick, Saginaw Valley State University Aaron Edlin, University of California, Berkeley Dorothy Edlin Noel Edlin Ellery Eells, University of Wisconsin–Madison Ben Eggleston, University of Kansas Geoffrey B. Frasz, Community College of Southern Nevada Josh Fulcher Rory Goggins Geoffrey Gorham, University of Wisconsin–Eau Claire Joseph Graves, North Carolina A&T University Dabney Gray, Stillman College Patricia Hammer, Delta College Anthony Hanson, De Anza College Rebecca Hendricks Judith M. Hill, Saginaw Valley State University Steven Hoeltzel, James Madison University Steven R. Huizenga, Central Ohio Technical College J. F. Humphrey, North Carolina A&T University Amro Jayousi Gary John, Richland College Sunghyun Jung Allyn Kahn, Champlain College David Kelsey, Coastline Community College David Keyt, University of Washington

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Paulina Kohan William Krieger, California State University–Pomona Michael LaBossiere, Florida A&M University Sunita Lanka, Hartnell College Bill Lawson Marisha Lecea, Western Michigan University Marion Ledwig, University of Nevada–Las Vegas Vern Lee, University of Phoenix Terrance MacMullon, Eastern Washington University Andrew Magrath, Kent State University Alistair Moles, Sierra College Ralph J. Moore, Jr. Jeffry Norby, Northcentral Technical College Eric Parkinson, Syracuse University Steven Patterson, Marygrove College Carmel Phelan, College of Southern Nevada Jamie L. Phillips, Clarion University Domenick Pinto, Sacred Heart University Ayaz Pirani, Hartnell College Ed Pluth, California State University, Chico Scott Rappold, Our Lady of Holy Cross College N. Mark Rauls, College of Southern Nevada Victor Reppert, Glendale Community College Matthew E. Roberts, Patrick Henry College Greg Sadler, Fayetteville State University Matt Schulte, Montgomery College Richard Scott, Glendale Community College Laurel Severino, Santa Fe Community College Mehul Shah, Bergen Community College Robert Shanab, University of Nevada at Las Vegas Steven Silveria Robert Skipper, St. Mary’s University Aeon J. Skoble, Bridgewater State University Taggart Smith, Purdue University–Calumet Richard Sneed, University of Central Oklahoma Alan Soble, Drexel University Chris Soutter James Stump, Bethel College Lou Suarez

Susan Vineberg, Wayne State University Michael Ventimiglia, Sacred Heart University Helmut Wautischer, Sonoma State University Dennis Weiss, York College of Pennsylvania Linda L. Williams, Kent State University Amy Goodman Wilson, Webster University Christine Wolf Wayne Yuen, Ohlone College Marie G. Zaccaria, Georgia Perimeter College

Over the years, our Chico State colleague Anne Morrissey has given us more usable material than anybody else. She’s also given us more unusable material, but never mind. We’ve also had fine suggestions and examples from Curtis Peldo of Chico State and Butte College; Dan Barnett, also of Butte College, has helped in many ways over the years.

We thank colleagues at Chico State, who are ever ready with a suggestion, idea, or constructive criticism; in particular, Marcel Daguerre, Randy Larsen, Becky White, Wai-hung Wong, Zanja Yudell, and Greg Tropea, whose death in 2010 left us saddened beyond words. Greg was a dear friend whose deep wisdom and quiet insight contributed significantly to our thinking over the course of many years. We are also grateful to Bangs Tapscott, Linda Kaye Bomstad, Ann Bykerk-Kauffman, Sue Patterson, and Jeffrey Ridenour for contributions both archival and recent.

Last, and especially, we give thanks to two people who put up with us with patience, encouragement, and grace, Leah Blum and Marianne Moore.

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N A Note to Our Colleagues

o surprise, reading a book (or taking a course) in critical thinking won’t make anyone a genius. It won’t tell you who to vote for or whether to believe in God or whether to contribute to the Humane Society, But it can, we hope, help

students tell whether a given reason for doing or not doing one of those things is a good reason. It can help them spot irrelevancies in a discussion, emotional appeals, empty rhetoric, and bogus argument. Other courses can do these things too, of course. But speaking generally, other courses are probably not focused so intensely on those things.

There are differences about how best to go about teaching critical thinking. One of us, Parker likes to emphasize formal logic. Moore, not quite so much. One thing Moore and Parker both agree on, and possibly so do many instructors, is that drill and practice are essential to improving students’ critical thinking ability. And one thing we have found is that technology can be helpful in this regard. The personalized digital reading experience of this text (called SmartBook) questions students as they read, and the credit they get depends on the proportion of the questions they answer correctly. (We instructors can also see how long they spent on a reading assignment.) Additionally, Connect, McGraw-Hill’s assignment and assessment platform through which SmartBook is accessed, gives us the means to put a whole lot of exercises online. And these two things enable us to do even more drilling in class.

If you don’t use Connect or LearnSmart, this text contains hundreds and hundreds and hundreds of exercises of the sort (we think) that can be applied directly to the world at large. And they are all answered in the Instructor’s Manual. The explanatory material found in the text is (we hope) both concise and fairly readable for even first-year university students.

If you use this text or the online peripherals, we would appreciate hearing from you. We both can be contacted through McGraw-Hill Education, or via the philosophy department at Chico State.

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B About the Authors

rooke Moore and Richard Parker have taught philosophy at California State University, Chico, for almost as long as they can remember. Moore has been that university’s Outstanding Professor, and both he and Parker have received

top academic honors on their campus. Moore has seen several terms as department chair, and Parker has served as chair of the academic senate and dean of undergraduate education.

Moore has a bachelor’s degree in music from Antioch College and a PhD in philosophy from the University of Cincinnati; Parker did his undergraduate degree at the University of Arkansas and his PhD at the University of Washington, both in philosophy.

Moore has finally given up being the world’s most serious amateur volleyball player. He and Marianne share their house and life with Sparky, as cute a pup as you’ll ever see. He has never sold an automobile.

Parker gets around in a 1962 MG or on a Harley softail. He plays golf for fun, shoots pool for money, and plays guitar for a semiprofessional flamenco troupe. He lives with Djobi, a hundred-pound Doberman.

Moore and Parker have remained steadfast friends through it all. They are never mistaken for one another.

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To: Sherry and Bill; and Sydney, Darby, Alexander and Levi Peyton Elizabeth, and Griffin From Richard From Brooke

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This is not entirely a work of nonfiction.         

1. 2. 3. 4. 5.

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1 Don’t Believe Everything You Think

Students will learn to . . .

Define critical thinking Explain the role of beliefs and claims in critical thinking Identify issues in real-world situations Recognize an argument Define and identify the common cognitive biases that affect critical thinking Understand the terms “truth” and “knowledge” as used in this book

little before noon on December 14, 2015, a man wearing a black stocking cap, black gloves, and a green sweat shirt with a four-leaf clover and the words “Get Lucky” printed on the front entered the Sterling State Bank in

Rochester, Minnesota.* He demanded cash and gave the teller a note saying he was armed. Police officers arrived and followed the man’s tracks in the snow to the parking lot of a Comfort Inn nearby, but by then the man had driven off in a car.

The next day, a reporter from KIMT-TV had set up in front of the bank to

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update the story, and right then and there the same man tried to rob the same bank again. When the teller saw the man he yelled out, “That’s the robber!” and the reporter called the police. This time when the police followed the suspect’s footprints they spotted his vehicle and apprehended him.

Now, educators will disagree about what exactly critical thinking is, but there will be no disputing that, whatever it is, “Get Lucky” wasn’t doing it. First of all, robbing banks isn’t necessarily the best way to make a living. But if you insist on robbing a bank, then probably you don’t want to leave footprints to your car, and probably you don’t want to try to rob the bank when a TV crew is filming it. Among other things, critical thinking involves considering the possible outcomes of an action.

Among what other things? Speaking generally, if we just think or do stuff, that’s not thinking critically. Critical thinking kicks in when we evaluate beliefs and actions—when we critique them. On the one hand, there is good, old- fashioned thinking. That’s what we do when we form opinions, make judgments, arrive at decisions, develop plans, come to conclusions, offer hypotheses, and the like. On the other hand, there is critical thinking. That’s what we do when we rationally evaluate the first kind of thinking. Critical thinking is thinking that critiques. It involves critiquing opinions, judgments, decisions, plans, conclusions, and reasoning in general. We engage in it when we consider whether our thinking (or someone else’s) abides by the criteria of good sense and logic.

If you are taking other courses, chances are your instructor will think critically about the work you turn in. He or she will offer critical commentary on what you submit. If you want to think critically, you have to do this yourself to your own work. Try to leave your instructor with nothing to say except, “Good job!”

It can be the same in the workplace or in the military. You might perhaps be asked to solve a problem or troubleshoot a situation or come up with a recommendation, or any number of other things that involve arriving at conclusions. Your colleagues or friends or supervisors may give you feedback or commentary. They are thinking critically about your reasoning.

Of course, if you are so brilliant that you never err in your thinking, then you may not need feedback from others. Unfortunately, there is evidence that people who think they are experts are more likely to believe they know things they don’t really know.* Anyway, almost everyone makes mistakes. We overlook important considerations, ignore viewpoints that conflict with our own, or in other ways don’t think as clearly as we might. Most of us benefit from a little critical commentary, and this includes commentary that comes from ourselves. The chances of reaching defensible conclusions improve if we don’t simply conclude willy-nilly, but reflect on our

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reasoning and try to make certain it is sound. Being able to think critically can be useful in another way. Others try to influence

what we think and do. There is much to be said for being able to critically evaluate a sales pitch, whether it comes from a stranger or a friend, or is about kitchen gadgets or for whom to vote for president. Critical thinking helps us recognize a scam when we see it.

Some educators equate critical thinking with problem solving or innovative thinking (“thinking outside the box”). This is fine, though at a certain point proposed solutions and possible innovations have to be tested. That’s where critical thinking comes in.

This is a book in critical thinking because it offers guidance about critiquing thinking. The book and the course you are using it in, if you are, explain the minimum criteria of good reasoning—the requirements a piece of reasoning must meet if it is worth paying attention to, no matter what the context. Along the way we will explore the most common and important obstacles to good reasoning, as well as some of the most common mistakes people make when coming to conclusions. Other courses you take offer refinements. In them you will learn what considerations are important from the perspective of individual disciplines. But in no course anywhere, at least in no course that involves arriving at conclusions, will thinking that violates the standards set forth in this book be accepted.

If it does nothing else, what you read here and learn in your critical thinking course should help you avoid at least a few of the more egregious common errors people make when they reason. If you would have otherwise made these mistakes, you will have become smarter. Not smarter in some particular subject, mind you, but smarter in general. The things you learn from this book (and from the course you may be reading it for) apply to nearly any subject people can talk or think or write about.

To a certain extent, questions we should ask when critiquing our own—or someone else’s—thinking depend on what is at issue. Deciding whom to vote for, whether to buy a house, whether a mathematical proof is sound, which toothpaste to buy, or what kind of dog to get involve different considerations. In all cases, however, we should want to avoid making or accepting weak and invalid arguments. We should also avoid being distracted by irrelevancies or ruled by emotion, succumbing to fallacies or bias, and being influenced by dubious authority or half-baked speculation. These are not the only criteria by which reasoning might be evaluated, but they are central and important, and they provide the main focus of this book.

Critical Thinking, the Long Version

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The Collegiate Learning Assessment (CLA) Project of the Council for Aid to Education has come up with a list of skills that covers almost everything your authors believe is important in critical thinking. If you achieve mastery over all these or even a significant majority of them, you’ll be well ahead of most of your peers—and your fellow citizens. In question form, here is what the council came up with:

How well does the student determine what information is or is not pertinent; distinguish between rational claims and emotional ones; separate fact from opinion; recognize the ways in which evidence might be limited or compromised; spot deception and holes in the arguments of others; present his/her own analysis of the data or information; recognize logical flaws in arguments; draw connections between discrete sources of data and information; attend to contradictory, inadequate, or ambiguous information; construct cogent arguments rooted in data rather than opinion; select the strongest set of supporting data; avoid overstated conclusions; identify holes in the evidence and suggest additional information to collect; recognize that a problem may have no clear answer or single solution; propose other options and weigh them in the decision; consider all stakeholders or affected parties in suggesting a course of action; articulate the argument and the context for that argument;

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correctly and precisely use evidence to defend the argument; logically and cohesively organize the argument; avoid extraneous elements in an argument’s development; present evidence in an order that contributes to a persuasive argument?

_______________ www.aacu.org/peerreview/pr_sp07_analysis1.cfm.

BELIEFS AND CLAIMS

Why bother thinking critically? The ultimate objective in thinking critically is to come to conclusions that are correct and to make decisions that are wise. Because our decisions reflect our conclusions, we can simplify things by saying that the purpose of thinking critically is to come to correct conclusions. The method used to achieve this objective is to evaluate our thinking by the standards of rationality. Of course, we can also evaluate someone else’s thinking, though the objective there might simply be to help the person.

■ The judges on The Voice critique singers, but that doesn’t automatically qualify as thinking critically.

http://www.aacu.org/peerreview/pr_sp07_analysis1.cfm
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When we come to a conclusion, we have a belief. Concluding involves believing. If you conclude the battery is dead, you believe the battery is dead. Keeping this in mind, let’s define a few key terms.

A belief is, obviously, something you believe. It is important to understand that a belief is propositional, which means it can be expressed in a declarative sentence—a sentence that is either true or false. A good bit of muddleheaded thinking can be avoided if you understand that beliefs are propositional entities, but more on this later.

As we use these words, beliefs are the same as judgments and opinions. When we express a belief (or judgment or opinion) in a declarative sentence, the result is a statement or claim or assertion, and for our purposes these are the same thing. Claims can be used for other purposes than to state beliefs, but this is the use we’re primarily concerned with.

Beliefs and claims are propositional: they can be expressed in true-or-false declarative sentences.

Objective Claims and Subjective Claims

Before we say something more about conclusions, we should make a distinction between objective and subjective claims. An objective claim has this characteristic: whether it is true or false is independent of whether people think it is true or false. “There is life on Mars” is thus an objective claim, because whether or not life exists there doesn’t depend on whether people think it does. If everyone suddenly believed there is life on Mars, that doesn’t mean that suddenly there would be life on Mars. Likewise, “God exists” is an objective claim because whether it is true doesn’t depend on whether people think it is true.

Although objective claims are either true or false, we may not know which a given

■ That could be you under the snow if you don’t think critically.

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claim is. “Portland, Oregon, is closer to the North Pole than to the equator” is a true objective claim. “Portland, Oregon, is closer to the equator than to the North Pole” is a false objective claim. “More stamp collectors live in Portland, Oregon, than in Portland, Maine” is an objective claim whose truth or falsity is not known, at least not by us.

Not every claim is objective, of course. “Bruno Mars has swag” is not objective, for it lacks the characteristic mentioned previously. That is, whether or not someone has swag does depend on whether people think he does. If nobody thinks Bruno Mars has swag, then he doesn’t. If Parker thinks he does and Moore doesn’t, you will say that Parker and Moore are each entitled to their opinions. Whether someone has swag is in the eyes of the beholder.

Claims of this variety are subjective. Whether a subjective claim is true or false is not independent of whether people think it is true or false. Examples of subjective claims would be judgments of taste, such as “Rice vinegar is too sweet.” Is rice vinegar too sweet? It depends on what you think. Some kinds of comparisons also are subjective. Is snowboarding more fun than skiing? Again, it depends on what you think, and there is no further “truth” to consider. However, many statements contain both objective and nonobjective elements, as in “Somebody stole our nifty concrete lawn duck.” Whether the lawn duck is concrete is an objective question; whether it is our lawn duck is an objective question; and whether it was stolen is an objective question. But whether the stolen concrete lawn duck is nifty is a subjective question.

Fact and Opinion

Sometimes people talk about the difference between “fact” and “opinion,” having in mind the notion that all opinions are subjective. But some opinions are not subjective, because their truth or falsity is independent of what people think. Again, in this book “opinion” is just another word for “belief.” If you believe that Portland, Oregon, is closer to the North Pole than to the equator, that opinion happens to be true, and would continue to be true even if you change your mind. You can refer to objective opinions as factual opinions or beliefs, if you want—but that doesn’t mean factual opinions are all true. “Portland, Oregon, is closer to the equator than to the North Pole” is a factual opinion that is false.

Factual opinion/belief/claim = objective opinion/belief/claim = opinion/belief/claim whose truth is independent of whether anyone thinks it is true.

Thinking About Thinking

Remember, an objective statement is not made true by someone thinking it is true. “Wait a minute,” you might say. “Isn’t the statement ‘Joanie is thinking about Frank’ made true by her thinking that it is true?” The answer is no! It is made true by her thinking about Frank.

Relativism

Relativism is the idea that truth is relative to the standards of a given culture. More precisely, relativism holds that if your culture and some other culture have different standards of truth or evidence, there is no independent “God’s-eye view” by which one culture’s standards can be seen to be more correct than the others’.

Whatever may be said of this as an abstract philosophical doctrine, it cannot possibly mean that an objective statement could be made true by a culture’s thinking that it is true. If it is universally believed in some culture that “water” is not H2O, then either the people in that culture are mistaken or their word “water” does not refer to water.

Moral Subjectivism

Moral subjectivism is the idea that moral opinions, such as “Bullfighting is morally wrong” or “Jason shouldn’t lie to his parents,” are subjective. It is the idea, in other words, that if you think bullfighting is morally wrong, then it is morally wrong for you and you don’t need to consider any further truth. It is the idea expressed by Hamlet in the famous passage, “There is nothing either good or bad, but that thinking makes it so.”

You should be wary of Hamlet’s dictum. Ask yourself this: If someone actually believed there is nothing wrong with torturing donkeys or stoning women to death for adultery, would you say, well, if that’s what he thinks, then it’s fine for him to torture donkeys or stone women to death? Of course you wouldn’t. Those ideas can’t be made true by thinking they are true anymore than drinking battery acid can be made good for you by thinking it is.

ISSUES

An issue, as we employ that concept in this book, is simply a question. Is Moore taller than Parker? When we ask that question, we raise the issue as to whether Moore is taller than Parker. To put it differently, we are considering whether the claim “Moore is taller than Parker” is true. Let us note in passing that as with claims, some issues are objective. Is Moore taller than Parker? Whether he is or isn’t doesn’t depend on

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whether we think he is, so this is an objective issue (question). Other issues, such as whether P. Diddy dresses well, are subjective, in the sense

explained previously. The first order of business when it comes to thinking critically about an issue is to

determine what, exactly, the issue is. Unfortunately, in many real-life situations, it is difficult to identify exactly what the issue is—meaning it is difficult to identify exactly what claim is in question. This happens for lots of reasons, from purposeful obfuscation to ambiguous terminology to plain muddleheaded thinking. In his inaugural address President Warren G. Harding said,

We have mistaken unpreparedness to embrace it to be a challenge of the reality and due concern for making all citizens fit for participation will give added strength of citizenship and magnify our achievement.

This is formidable. Do you understand what issue Harding is addressing? Neither does anyone else, because his statement is perfectly meaningless. (American satirist H. L. Mencken described it as a “sonorous nonsense driven home with gestures.”*) Understanding what is meant by a claim has so many aspects that we’ll devote a large part of Chapter 3 to the subject.

However, if you have absolutely no clue as to what an issue actually is, there isn’t much point in considering it further—you don’t know what “it” is. There also isn’t much point in considering it further if you have no idea as to what would count toward settling it. For example, suppose someone asks, “Is there an identical you in a different dimension?” What sort of evidence would support saying either there is or isn’t? Nobody has any idea. (Almost any question about different “dimensions” or “planes” or “universes” would be apt to suffer from the same problem unless, possibly, it were to be raised from someone well educated in physics who used those concepts in a technical way.) “Is everything really one?” would also qualify as something you couldn’t begin to settle, as would wondering if “the entire universe was created instantly five minutes ago with all false memories and fictitious records.”**

Obscure issues aren’t always as metaphysical as the preceding examples. Listen carefully and you may hear more than one politician say something like, “It is human nature to desire freedom.” Oh, really? This sounds good, but if you look at it closely it’s hard to know exactly what sort of data would support the remark.

This isn’t to imply that only issues that can be settled through scientific test or via the experimental method are worth considering. Moral issues cannot be settled in that way, for example. Mathematical and historical questions are not answered by experiment, and neither are important philosophical questions. Does God exist? Is there free will? What difference does it make if he does or doesn’t or there is or isn’t?

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Legal questions, questions of aesthetics—the list of important questions not subject to purely scientific resolution is very long. The point here is merely that if a question is to be taken seriously, or if you want others to take it seriously, or if you want others who can think critically to take it seriously, you must have some idea as to what considerations bear on the answer.

ARGUMENTS

In our experience, lots of college students seriously contemplate getting a dog or cat. But they are conflicted. On the one hand, it would be sweet to have a nice pet; but on the other, it would be extra work and cost money, and they aren’t sure what to do with the animal if they take a trip.

If you are such a student, you weigh the arguments pro and con. An argument presents a consideration for accepting a claim. For example, this is an argument:

A dog would keep me company; so I should get one.

Are You Good at Reasoning?

Are you the kind of person who reasons well? Some people are. Unfortunately, maybe people who aren’t very good at reasoning are the most likely to overestimate their reasoning ability.*

And so is this:

My landlord will raise my rent; so I shouldn’t get one.

The first example is an argument for getting a dog. The second is an argument for not getting one.

As you can see from these two examples, an argument consists of two parts. One part gives a reason for accepting the other part. The part that provides the reason is called the premise of the argument,* though an argument may have more than one premise. The other part is called the conclusion. The conclusion of an argument is what the premise supposedly supports or demonstrates.

You should always think of the conclusion of an argument as stating a position on an issue, and of the premise or premises as giving reasons for taking that position.

Want an example? Look at the two arguments previously shown. They both

1.

2.

▲  1.  2.  3.

▲  4.

 5.  6.

▲  7.  8.  9.

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address the issue of whether I should get a dog. The premise of the first example (“A dog would keep me company”) gives a reason for saying I should get a dog. The premise of the second example (“My landlord will raise my rent”) gives a reason for saying I should not get a dog.

What does this have to do with critical thinking? Everything. You want to make the best decision on an important issue—in this case, whether to get a dog. You evaluate the arguments pro and con. Being able to do this intelligently may not be the sum total of critical thinking, but it is an essential part of it.

A large part of this book is devoted to understanding how to evaluate arguments, and all this will begin in Chapter 2. However, right now, two minor points about arguments are worth noticing:

The two arguments given as examples are not very long or complicated. Some arguments can be very long and complicated. Einstein’s revolutionary theory that E = mc2 was based on complex mathematical reasoning, and that reasoning was his argument for saying that E = mc2. Not every issue requires an argument for resolution. Is your throat sore? You can just tell directly, and no argument is necessary.

We will now offer you a few exercises to help you understand these fundamental concepts. In the next section we will look at psychological factors that impede clear thought.

Exercise 1-1

Answer the questions based on your reading to this point, including the boxes.

▲—See the answers section at the back of the book. What is an argument?

T or F: A claim is what you use to state an opinion or a belief. T or F: Critical thinking consists in attacking other people’s ideas.

T or F: Whether a passage contains an argument depends on how long it is.

T or F: When a question has been asked, an issue has been raised. T or F: All arguments have a premise.

T or F: All arguments have a conclusion. T or F: You can reach a conclusion without believing it is true. T or F: Beliefs, judgments, and opinions are the same thing.

▲ 10. 11. 12.

▲ 13.

14. 15.

▲ 16. 17.

18. ▲ 19.

20.

T or F: All opinions are subjective. T or F: All factual claims are true. “There is nothing either good or bad but that thinking makes it so” expresses a doctrine known as _____________________.

The first order of business when it comes to thinking critically about an issue is (a) to determine whether the issue is subjective or objective, (b) to determine whether the issue can be resolved, or (c) to determine what exactly the issue is.

T or F: The conclusion of an argument states a position on an issue. T or F: Issues can be resolved only through scientific testing.

T or F: Statements, claims, and assertions are the same thing. T or F: The claim “Death Valley is an eyesore” expresses a subjective opinion. T or F: Every issue requires an argument for a resolution.

T or F: Relativism is the idea that if the standards of evidence or truth are different for two cultures, there is no independent way of saying which standards are the correct ones.

T or F: It is not possible to reason correctly if you do not think critically.

Exercise 1-2

On the basis of a distinction covered so far, divide these items into two groups of five items each such that all the items in one group have a feature that none of the

■ Can bears and other animals think critically? Find out by checking the answers section at the back of the book.

▲  1.  2.  3.

▲  4.

 5.

 6. ▲  7.

 8.

 9.

▲ 10.

▲  1.  2.

 3. ▲  4.

 5.  6.

▲  7.  8.  9.

▲ 10. 11. 12.

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items in the second group have. Describe the feature on which you based your classifications. The items that belong in one group are listed at the back of the book.

You shouldn’t buy that car because it is ugly. That car is ugly, and it costs more than $25,000, too. Rainbows have seven colors, although it’s not always easy to see them all.

Walking is the best exercise. It places the least stress on your joints.

The ocean on the central coast is the most beautiful shade of sky blue, but it gets greener as you go north. Her favorite color is yellow because it is the color of the sun.

Pooh is my favorite cartoon character because he has lots of personality. You must turn off the lights when you leave the room. They cost a lot of money to run, and you don’t need them during the day. Television programs have too much violence and immoral behavior. Hundreds of killings are portrayed every month.

You’ll be able to find a calendar on sale after the first of the year, so it is a good idea to wait until then to buy one.

Exercise 1-3

Which of the following claims are objective? Nicki Minaj can fake a great English accent.

On a baseball field, the center of the pitcher’s mound is 59 feet from home plate. Staring at the sun will damage your eyes.

Green is the most pleasant color to look at. Yellow is Jennifer’s favorite color. With enough experience, a person who doesn’t like opera can come to appreciate it.

Opera would be easier to listen to if they’d leave out the singing. Sailing is much more soothing than sputtering about in a motorboat. Driving while drowsy is dangerous.

Pit vipers can strike a warm-blooded animal even when it is pitch dark. P. Diddy is totally bink. P. Diddy is totally bink to me.

▲  1.  2.  3.

▲  4.  5.  6.

▲  7.  8.  9.

▲ 10.

▲  1.

 2.

 3. ▲  4.

 5.

 6.

▲  7.

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Exercise 1-4

Which of the following are subjective? Fallon tells better jokes than Colbert.

In 2013 Miguel Cabrera hit the most home runs on a 3–0 count. Your teacher will complain if you text in class.

Your teacher would be crazy not to complain if you text in class. There is life on Mars. Golf wastes time.

Warcraft scared the you-know-what out of my sister. Warcraft is lousy. A total letdown. Movies like Warcraft lack redeeming social value. [Hint: An assertion might have more than one subjective element.]

Donald Trump has unusual hair.

Exercise 1-5

Some of these items are arguments, and some are not. Which are which? Tipsarevic is unlikely to win the U.S. Open this year. He has a nagging leg injury, plus he doesn’t have the drive he once had.

Hey there, Marco! Don’t go giving that cat top sirloin. What’s the matter with you? You got no brains? If you’ve ever met a pet bird, you know they are busy creatures.

Everybody is saying the president earned the Nobel Prize. What a stupid idea! She hasn’t earned it at all. There’s not a lick of truth in that notion.

“Is the author really entitled to assert that there is a degree of unity among these essays which makes this a book rather than a congeries? I am inclined to say that he is justified in this claim, but articulating this justification is a somewhat complex task.”

—From a book review by Stanley Bates

As a long-time customer, you’re already taking advantage of our money management expertise and variety of investment choices. That’s a good reason for consolidating your other eligible assets into an IRA with us.

PROFESSOR X: Well, I see where the new chancellor wants to increase class sizes. PROFESSOR Y: Yeah, another of his bright ideas.

 8.

 9.

▲ 10.

▲  1.

 2.

 3.

▲  4.

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PROFESSOR X: Actually, I don’t think it hurts to have one or two extra people in class. PROFESSOR Y: What? Of course it hurts. Whatever are you thinking? PROFESSOR X: Well, I just think there are good reasons for increasing the class size a bit.

Yes, I charge a little more than other dentists. But I feel I give better service. So my billing practices are justified. Since you want to purchase the house, you should exercise your option before June 30, 2018. Otherwise, you will forfeit the option price.

John Montgomery has been the Eastern Baseball League’s best closer this season. Unfortunately, when a closer gets shelled, as Montgomery did last night, it takes him a while to recover. Nobody will say he is the best closer after that performance.

Exercise 1-6

Determine which of the following passages contain arguments. For any that do, identify the argument’s conclusion. There aren’t hard-and-fast rules for identifying arguments, so you’ll have to read closely and think carefully about some of these.

The Directory of Intentional Communities lists more than 200 groups across the country organized around a variety of purposes, including environmentally aware living.

Carl would like to help out, but he won’t be in town. We’ll have to find someone else who owns a truck. Once upon a time Washington, DC, passed an ordinance prohibiting private ownership of firearms. After that, Washington’s murder rate shot up 121 percent. Bans on firearms are clearly counterproductive.

Computers will never be able to converse intelligently through speech. A simple example proves this. The sentences “How do you recognize speech?” and “How do you wreck a nice beach?” have different meanings, but they sound similar enough that a computer could not distinguish between the two.

 5.

 6.

▲  7.

 8.

 9.

▲ 10.

The Carrie Diaries isn’t very good. It’s just a repackage of Sex and the City. “Like short-term memory, long-term memory retains information that is encoded in terms of sense modality and in terms of links with information that was learned earlier (that is, meaning).”

—Neil R. Carlson

Fears that chemicals in teething rings and soft plastic toys may cause cancer may be justified. Last week, the Consumer Product Safety Commission issued a report confirming that low amounts of DEHP, known to cause liver cancer in lab animals, may be absorbed from certain infant products.

“It may be true that people, not guns, kill people. But people with guns kill more people than people without guns. As long as the number of lethal weapons in the hands of the American people continues to grow, so will the murder rate.”

—Susan Mish’alani

Then: A Miami man gets thirty days in the stockade for wearing a flag patch on the seat of his trousers. Now: Miami department stores sell boxer trunks made up to look like an American flag. Times have changed.

Dockers are still in style, but skinny legs are no longer trending.

Exercise 1-7

■ Think you are welcome? Think again and think critically.

▲  1.

a. b. c. d.

 2.

a. b.

 3.

a.

b.

c.

d.

▲  4.

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For each numbered passage, identify which lettered item best states the primary issue discussed in the passage. Be prepared to say why you think your choice is the correct one.

Let me tell you why Hank ought not to take that math course. First, it’s too hard, and he’ll probably flunk it. Second, he’s going to spend the whole term in a state of frustration. Third, he’ll probably get depressed and do poorly in all the rest of his courses.

whether Hank ought to take the math course whether Hank would flunk the math course whether Hank will spend the whole term in a state of frustration whether Hank will get depressed and do poorly in all the rest of his courses

The county has cut the library budget for salaried library workers, and there will not be enough volunteers to make up for the lack of paid workers. Therefore, the library will have to be open fewer hours next year.

whether the library will have to be open fewer hours next year whether there will be enough volunteers to make up for the lack of paid workers

Pollution of the waters of the Everglades and of Florida Bay is due to multiple causes. These include cattle farming, dairy farming, industry, tourism, and urban development. So it is simply not true that the sugar industry is completely responsible for the pollution of these waters.

whether pollution of the waters of the Everglades and Florida Bay is due to multiple causes whether pollution is caused by cattle farming, dairy farming, industry, tourism, and urban development whether the sugar industry is partly responsible for the pollution of these waters whether the sugar industry is completely responsible for the pollution of these waters

It’s clear that the mainstream media have lost interest in classical music. For example, the NBC network used to have its own classical orchestra conducted by Arturo Toscanini, but no such orchestra exists now. One newspaper, the no-longer-existent Washington Star, used to have thirteen classical music reviewers; that’s more than twice as many as

a. b.

c.

 5.

a.

b.

c.

 6.

a.

b. c.

▲  7.

a.

b.

c.

The New York Times has now. H. L. Mencken and other columnists used to devote considerable space to classical music; nowadays, you almost never see it mentioned in a major column.

whether popular taste has turned away from classical music whether newspapers are employing fewer writers on classical music whether the mainstream media have lost interest in classical music

This year’s National Football League draft lists a large number of quarterbacks among its highest-ranking candidates. Furthermore, quite a number of teams do not have first-class quarterbacks. It’s therefore likely that an unusually large number of quarterbacks will be drafted early in this year’s draft.

whether teams without first-class quarterbacks will choose quarterbacks in the draft whether this year’s NFL draft includes a large number of quarterbacks whether an unusually large number of quarterbacks will be drafted early in this year’s draft

An animal that will walk out into a rainstorm and stare up at the clouds until water runs into its nostrils and it drowns—well, that’s what I call the world’s dumbest animal. And that’s exactly what young domestic turkeys do.

whether young domestic turkeys will drown themselves in the rain whether any animal is dumb enough to drown itself in the rain whether young domestic turkeys are the world’s dumbest animal

The defeat of the school voucher initiative was a bad thing for the country because now public schools won’t have any incentive to clean up their act. Furthermore, the defeat perpetuates the private-school-for-the- rich, public-school-for-the-poor syndrome.

whether public schools now have any incentive to clean up their act whether the defeat of the school voucher initiative was bad for the country whether public schools now have any incentive to clean up their act and whether the private-school-for-the-rich, public-school-for-

 8.

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a.

b.

c.

 9.

a.

b. c. d.

▲ 10.

the-poor syndrome will be perpetuated (issues are equally stressed)

From an editorial in a newspaper outside Southern California: “The people in Southern California who lost a fortune in the wildfires last year could have bought insurance that would have covered their houses and practically everything in them. And anybody with any foresight would have made sure there were no brush and no trees near the houses so that there would be a buffer zone between the house and any fire, as the Forest Service recommends. Finally, anybody living in a fire danger zone ought to know enough to have a fireproof or fire-resistant roof on the house. So, you see, most of the losses those people suffered were simply their own fault.”

whether fire victims could have done anything to prevent their losses whether insurance, fire buffer zones, and fire-resistant roofs could have prevented much of the loss whether the losses people suffered in the fires were their own fault

“Whatever we believe, we think agreeable to reason, and, on that account, yield our assent to it. Whatever we disbelieve, we think contrary to reason, and, on that account, dissent from it. Reason, therefore, is allowed to be the principle by which our belief and opinions ought to be regulated.”

—Thomas Reid, Essays on the Active Powers of Man

whether reason is the principle by which our beliefs and opinions ought to be regulated whether what we believe is agreeable to reason whether what we disbelieve is contrary to reason both b and c

Most people you find on university faculties are people who are interested in ideas. And the most interesting ideas are usually new ideas. So most people you find on university faculties are interested in new ideas. Therefore, you are not going to find many conservatives on university faculties, because conservatives are not usually interested in new ideas.

a. b. c.

d.

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whether conservatives are interested in new ideas whether you’ll find many conservatives on university faculties whether people on university faculties are interested more in new ideas than in older ideas whether most people are correct

When a poll is really, really out of whack with what I want to happen, I do have a tendency to disregard it. —Rush Limbaugh, recognizing his own confirmation bias

COGNITIVE BIASES

Unconscious features of psychology can affect human mental processes, sometimes in unexpected ways. Recent research suggests that donning formal business attire or a physician’s white lab coat might improve a person’s performance on a cognitive test.* Seeing a fast food logo (e.g., McDonald’s golden arches) may make some individuals attempt to process information more hastily.** In one experiment, subjects being told that the expensive sunglasses they were asked to wear were fake increased their propensity to cheat on tests that involved cash payments for correct answers.† In another experiment, male subjects, if dressed in sweats, made less profitable deals in simulated negotiations than did subjects dressed in suits.

Were we entirely rational, our conclusions would be grounded in logic and based on evidence objectively weighed. The unconscious features of human psychology affecting belief formation that have been reasonably well established include several that are widely referred to as cognitive biases.* They skew our apprehension of reality and interfere with our ability to think clearly, process information accurately, and reason objectively.

People will generally accept facts as truth only if the facts agree with what they already believe. —Andy Rooney, nicely explaining belief bias

For example, we tend to evaluate an argument based on whether we agree with it rather than on the criteria of logic. Is the following specimen good reasoning?

All pit bulls are dogs. Some dogs bite.

Therefore some pit bulls bite.

It isn’t. You might as well conclude some pit bulls are fox terriers. After all, all pit bulls are dogs and some dogs are fox terriers. If it took you a moment to see that the first argument is illogical, it’s because its conclusion is something you know is true.

The tendency to evaluate reasoning by the believability of its conclusion is known as belief bias. A closely related cognitive bias is confirmation bias, which refers to the tendency to attach more weight to evidence that supports our viewpoint. If you are a Democrat, you may view evidence that Fox News is biased as overwhelming; if you are a Republican you may regard the same evidence as weak and unconvincing. In science, good experiments are designed to ensure that experimenters can’t “cherry- pick” evidence, that is, search for evidence that supports the hypothesis they think is true while ignoring evidence to the contrary.

There isn’t any hard-and-fast difference between confirmation bias and belief bias; they are both unconscious expressions of the human tendency to think our side of an issue must be the correct side. Thinking critically means being especially critical of arguments that support our own points of view.

Some cognitive biases involve heuristics, general rules we unconsciously follow in estimating probabilities. An example is the availability heuristic, which involves unconsciously assigning a probability to a type of event on the basis of how often one thinks of events of that type. After watching multiple news reports of an earthquake or an airplane crash or a case of child abuse, thoughts of earthquakes and airplane crashes and child abuse will be in the front of one’s mind. Accordingly, one may overestimate their probability. True, if the probability of airplane crashes were to increase, then one might well think about airplane crashes more often; but it does not follow that if one thinks about them more often, their probability has increased.

■ Bad-mouthing someone is not the same as thinking critically about what he or she says.

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The availability heuristic may explain how easy it is to make the mistake known as generalizing from anecdote, a logical fallacy we discuss later in the book. Generalizing from anecdote happens when one accepts a sweeping generalization based on a single vivid report. The availability heuristic is also probably related to the false consensus effect, which refers to the inclination we may have to assume that our attitudes and those held by people around us are shared by society at large.*

Another source of skewed belief is the bandwagon effect, which refers to an unconscious tendency to align one’s thinking with that of other people. The bandwagon effect is potentially a powerful source of cognitive distortion. In famous experiments, psychologist Solomon Asch found that what other people say they see may actually alter what we think we see.** We—the authors—have students take tests and quizzes using smartphones and clickers, with software that instantly displays the opinion of the class in a bar graph projected on a screen. Not infrequently it happens that, if opinion begins to build for one answer, almost everyone switches to that option —even if it is incorrect or illogical.

If you have wondered why consumer products are routinely advertised as best- sellers, you now know the answer. Marketers understand the bandwagon effect. They know that getting people to believe that a product is popular generates further sales.