Introduction to Critical Thinking and Creativity (PDF)

This page intentionally left blank AN INTRODUCTION TO CRITICAL THINKING AND CREATIVITY This page intentionally left blank AN INTRODUCTION TO CRITICAL THINKING AND CREATIVITY Think More, Think Better Joe Y. F. Lau ® WILEY A JOHN WILEY & SONS, INC., PUBLICATION Copyright © 2011 by John Wiley &...

This page intentionally left blank AN INTRODUCTION TO CRITICAL THINKING AND CREATIVITY This page intentionally left blank AN INTRODUCTION TO CRITICAL THINKING AND CREATIVITY Think More, Think Better Joe Y. F. Lau ® WILEY A JOHN WILEY & SONS, INC., PUBLICATION Copyright © 2011 by John Wiley & Sons, Inc. All rights reserved Published by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permission. Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com. Library of Congress Cataloging-in-Publication Data: Lau, Joe Y. F., 1968- An introduction to critical thinking and creativity : think more, think better / Joe Y.F. Lau. p. cm. Includes bibliographical references and index. ISBN 978-0-470-19509-3 (pbk.) 1. Critical thinking. 2. Creative ability. I. Title. B809.2.L38 2011 153.4'2—dc22 2010048204 Printed in the United States of America. 10 9 8 7 6 5 4 3 2 1 To Amie and Lusina tian xingjian This page intentionally left blank CONTENTS Preface ix 1 Introduction 1 2 Thinking and writing clearly 11 3 Definitions 21 4 Necessary and sufficient conditions 33 5 Linguistic pitfalls 41 6 Truth 53 7 Basic logic 59 8 Identifying arguments 69 vii VIII CONTENTS 9 Valid and sound arguments 75 10 Inductive reasoning 87 11 Argument mapping 95 12 Argument analysis 107 13 Scientific reasoning 113 14 Mill's methods 125 15 Reasoning about causation 133 16 Diagrams of causal processes 141 17 Statistics and probability 145 18 Thinking about values 159 19 Fallacies 173 20 Cognitive biases 185 21 Analogical reasoning 195 22 Making rational decisions 201 23 What is creativity? 215 24 Creative thinking habits 223 Solutions to exercises 233 Bibliography 256 Index 261 PREFACE This is a textbook on critical and creative thinking. It can be used as a course text or a self-contained study guide. Since there are many similar textbooks in the market, let me describe some special features of this book: Unlike most textbooks, I discuss both critical and creative thinking because they are equally important for problem solving and they are not indepen- dent of each other. We need creativity in critical thinking to come up with arguments, counterexamples, and alternative explanations. And creativity needs critical thinking in evaluating and improving new ideas. They are both part of the essential thinking toolkit. Good thinking requires not just knowledge of the principles of good reason- ing. We discuss them of course, but personality and other psychological fac- tors matter as well. This book emphasizes the importance of attitudes and practice for good thinking. We also discuss findings in cognitive science and psychology, such as cognitive biases in reasoning and decision making. Our thinking directly affects our life through the choices we make. These choices depend in part on our values and moral outlook. It is of utmost importance that we can think about these issues critically and impartially. I therefore include a chapter on decision making and another one on the foundation of moral reasoning. IX X PREFACE This book has a companion website: Critical Thinking Web. It is located at http: / /philosophy.hku.hk/think, and hosted by the Philosophy Department of the University of Hong Kong. The website includes many online tuto- rials that are used in schools and universities around the world. A special section is devoted to this book, which includes errata, additional notes and exercises, and further readings. This book is not an encyclopedia on thinking skills. It aims to be a short and readable text, providing the reader with a practical and sound foundation. I deliberately leave out a complete treatment of Venn diagrams and standard formal logic. Interested readers and teachers can consult the companion website for online tutorials on these topics. Useful facts and rules are often presented in bullet points to make them clearer. I also include many examples from finance and business to show how critical thinking is relevant to a variety of careers. A note of warning: To make the text more readable and the sentences shorter, sometimes I simplify and leave out minor qualifications. I am also less strict with the use of quotations marks than I would otherwise be as an academic philoso- pher. Finally, many of the ideas in the book are not original. They come from other philosophers, psychologists, and experts in other areas. Thanks to Tim van Gelder for his comments on my earlier book proposal. I also want to thank Lee Tien Ming and Jonathan Chan. I have learned a lot about critical thinking from all of them. I would also like to thank Executive Editor Stephen Quigley at John Wiley & Sons, Inc., and Assistant Editor Jacqueline Palmieri. They have been most patient even though I kept missing one deadline after another. On a more technical matter, this book was typeset with ETÈX- It has made the whole project so much more efficient and enjoyable. Thanks to Donald Knuth, Leslie Lamport, and other contributors to the system. Finally, this book is the result of over ten years of teaching in critical thinking. My heartfelt thanks to the many generations of students who endured my classes and smiled politely at my jokes. JoeY.F.Lau Hong Kong January, 2011 CHAPTER 1 INTRODUCTION 1.1 THINKING SKILLS IN THE AGE OF GLOBALIZATION Whether we like it or not, globalization is changing the way we work and live. First of all, we are increasingly faced with complex problems that affect the whole world, whether it is global warming, pollution, financial crises, or new epidemics. We need good thinking and creative ideas to coordinate efforts to solve these prob- lems. At the personal level, globalization brings about an ever-quickening pace of life. We have a huge amount of information available, but what we learn today might easily become obsolete tomorrow. Although fast changes also bring new opportunities, we now have to compete with talented people across the world. To be successful in this environment, we need good thinking skills that can help us make reliable decisions and acquire new knowledge quickly. But what do we mean by good thinking skills? Basically, it comes down to two things—critical thinking and creativity. Critical thinking is thinking clearly and rationally. It involves thinking precisely and systematically, and following the rules of logic and scientific reasoning, among other things. As for creativity, it is a matter of coming up with new and useful ideas, generating alternative possibilities. This book is about these two sets of thinking skills, but at this point, you might ask, An Introduction to Critical Thinking and Creativity: Think More, Think Better. By Joe Y.E Lau 1 Copyright © 2011 John Wiley & Sons, Inc. 2 INTRODUCTION Which is more important, critical thinking or creativity? The short answer is that they are equally important. We need creativity to come up with ideas to solve problems, but we also need critical thinking to evaluate and improve these ideas. They complement each other, and we need both to survive and to prosper. In this book we shall discuss critical thinking first, and come back to creativity near the end. As we shall see, there is a lot more we can say systematically about critical thinking. A critical thinker is someone who is able to do the following: Understand the logical connections between ideas. Formulate ideas succinctly and precisely. Identify, construct, and evaluate arguments. Evaluate the pros and cons of a decision. Evaluate the evidence for and against a hypothesis. Detect inconsistencies and common mistakes in reasoning. Analyze problems systematically. Identify the relevance and importance of ideas. Justify one's beliefs and values. Reflect and evaluate one's thinking skills. As we can see from the list, critical thinking skills are essential for all sorts of careers in which we have to communicate ideas, make decisions, analyze, and solve problems. This is why critical thinking is called a domain-general thinking skill. But critical thinking is not just for the workplace. To live a meaningful life and plan for the future, we need to think about ourselves honestly and carefully. The Greek philosopher Socrates (469-399 B.C.E.) once said, "the unexamined life is not worth living." One big difference between human beings and other animals is our capacity for self-reflection. We can examine the purpose and meaning of our life and change ourselves accordingly. Critical thinking contributes to this process of self-evaluation and transformation. Good critical thinking is also the foundation of science and democracy. Science requires rationality in designing experiments and testing theories. A vibrant and progressive democracy requires citizens who can think objectively about social and political issues and are able to avoid biases and prejudices. So obviously the cultivation of critical thinking should be a central aim of education. 1.2 SOME MISCONCEPTIONS ABOUT CRITICAL THINKING However, critical thinking is sometimes thought to be too confrontational. Some people think critical thinking means criticizing others all the time, which is not constructive. But this is a misunderstanding. Critical thinking is not a purely  IMPROVING OUR THINKING 3 destructive force. First, by rejecting bad ideas, we become better at finding the truth. Second, thinking critically does not mean we criticize people all the time. When other people are right, we don't have to disagree. And when other people are wrong, critical thinking helps us recognize the mistakes being made, but it does not follow we have to publicly denounce them. Sometimes mistakes do not mat- ter. Sometimes we have to be polite, and sometimes we can help people reason better not by criticizing them but by other indirect means—for example, by giv- ing hints and suggestions. A critical thinker can be sympathetic and constructive rather than confrontational. Another objection to critical thinking is that it is not practically useful because people in real life do not listen to reason. They act on the basis of self-interest, emotion, or personal relationships. The first problem with this objection is that it confuses rational thinking with talking about reasons. It might be true that many people are irrational, and to influence them we need to appeal to authority, emo- tions, or anything other than reason. But we can still use critical thinking to think strategically about the best means to achieve our objectives. The objection is also wrong in assuming that critical thinking is opposed to emotions, relationships, and so on. Consider for example love and friendship. They are certainly valuable, but critical thinking can help us cultivate them. For example, thinking carefully about what is good or bad about a relationship can help us improve it and make it more fulfilling. Besides, it is not always wise to act solely on the basis of emotions. They can be biased by ego, fear, and greed. Thinking more about our decisions can counteract this problem. 1.3 IMPROVING OUR THINKING So how do we enhance our critical thinking if it is so useful? Obviously, we are all able to think critically to some extent, or we will not survive very long! But there is always room for improvement. Even with a skill as natural as running, training with an expert can improve our breathing and posture and help us run even bet- ter. Thinking is something we all do and take for granted, but the fact is that even normally intelligent people can sometimes be stubborn and biased. Psychology research tells us that people make lot of mistakes in their reasoning—they over- estimate their abilities, interpret the world to confirm their prejudices, and look for causes and patterns in the wrong places. By studying critical thinking, we are more likely to avoid such errors. We can also help other people by studying criti- cal thinking. Sometimes we get the feeling that an argument is wrong but we do not know exacdy why. Critical thinking gives us the concepts and vocabulary to explain what is wrong. This promotes understanding and more effective discus- sions. Good critical thinking is a cognitive skill. In general, developing a skill requires three conditions—learning the theory, deliberate practice, and adopting the right attitudes. By theory we mean the rules and facts we have to know in order to possess the skill. For example, one cannot be a good basketball player without 4 INTRODUCTION knowing the rules of the game—for example, kicking the basketball is not allowed. Likewise, thinking critically requires knowing a certain amount of logic. However, knowing the theory is not the same as being able to apply it. You might know in theory that you should balance the bike when you are cycling, but it does not mean you can actually do it. This is where practice comes in, because it trans- lates your theoretical knowledge into actual ability. However, your attitudes make a big difference as to whether your practice is effective and sustainable. If you hate playing the piano, forcing you to practice is not productive in the long run. 1.3.1 Theory Let us now look at the theoretical knowledge required for good critical thinking. It can be divided into five main areas, and in this book we shall discuss all of them: 1. Meaning analysis: Explain ideas clearly and systematically; use definitions and other tools to clarify meaning and make ideas more precise. 2. Logic: Analyze and evaluate arguments; identify logical consequences and inconsistencies. 3. Scientific methods: Use empirical data to test a theory; identify causes and effects; probability theory and statistics. 4. Decision and values: Rational decision making; critical reflection of value frameworks and moral judgments. 5. Fallacies and biases: Typical mistakes of reasoning and the psychological traits likely to cause such mistakes. Naturally you will find some topics more interesting than others. But whether we are learning martial arts or the piano, there are basic techniques we have to master. They might be boring, but they form the foundation of more advanced techniques. The same is true of critical thinking. Some theories and principles seem rather dry and abstract, but I hope you will appreciate their power and rele- vance to everyday thinking once you understand how they can be applied. 1.3.2 Practice Psychologists have discovered a 10-year rule when it comes to acquiring a skill. It takes about 10 years of intensive and structured practice—around 10,000 hours of practice—to reach world-class level in a certain area, even for a talented in- dividual. This rule is supposed to apply to all kinds of expertise, whether it is sports, music, chess, writing, or scientific research. Even a genius prodigy such as Mozart spent years practicing musical instruments and writing lesser pieces, under great pressure from his father, who was himself an outstanding musician. Many of Mozart's childhood compositions were arrangements of works by other composers, or they were thought to be partly written by his father. His piano con-  IMPROVING OUR THINKING 5 certo No. 9 (K.271) is perhaps the earliest original work that is highly regarded by critics. But by then Mozart had already been composing for over 10 years. Years of early training and dedicated parents are two typical themes in achiev- ing world-class performance. Tiger Woods has been one of the most successful golf players of all time. His father, Earl, gave him a sawed off a golf club to play with when he was 9 months old. When Tiger was 18 months old, Earl started tak- ing his son to the golf course, and a coach was hired when Tiger was 4 years old. Earl continued to train his son, and just over 10 years later in 1991, Tiger became the youngest ever U.S. Junior Amateur Champion. Of course, it is probably unrealistic to expect all of us to put in the same amount of effort solely into improving our thinking. But what empirical research tells us is that good thinking does not come for free. If we are serious about improving our minds, we have to come up with a plan and be ready to spend a lot of time training. Just reading this book is not going to be enough. You also need to do the exercises and apply your knowledge to your daily life. Critical thinking should become a natural habit, a way of life, rather than something you do occasionally. How do we turn critical thinking into a natural habit? Here is a simple and practical method for you to try out. We call it the fourfold path to good thinking. To follow the method, we make it a habit to ask these four basic questions about the ideas we come across: Question Issues to think about What does it mean? Are the keywords and the main concepts clear? Can the ideas be made more precise? How is it related to other things? Any examples to illustrate what is meant? How many supporting List the reasons for and against the claim. reasons and objections? Count and evaluate these reasons. Think about both sides of an issue. Any counterexamples to the claim? Why is this important or relevant? What are the major consequences? How does it affect people? Is it useful? Is it surprising? Have I learned something new and interesting? Which are the other What other information might be relevant? possibilities to consider? Any similar cases to think about? These questions look simple, but they are actually quite powerful because they introduce a good structure to organize our analysis. As an example, suppose we are discussing whether it is wrong to eat (nonhuman) animals. Here is how we might apply the fourfold path: 6 INTRODUCTION 1. The first question—what does it mean?—is about clarifying the key con- cepts so that we can understand more clearly the claim under discussion. What do we mean by animals'? Dogs and chickens are obviously ani- mals. But what about fish, oysters, insects, bacteria? Is it also wrong to eat them? Where do we draw the line? If eating animals is wrong, how wrong is it? As bad as killing people? 2. To carry out the second step of the fourfold path, we list all the reasons for and against the claim under consideration. Arguments against eating meat might include: animals have rights, animal farming create a lot of suffering, and it is more efficient to use land to grow vegetables than to raise animals. Arguments on the opposite side might include: farm animals exist be- cause of us and so we can do what want with them, and humans are more intelligent than animals. It is always a good idea to be able to count the number of arguments. For example, three arguments in support and two against. Think about both sides of an issue. Even if you think eating meat is fine, you should try your best to come up with opposing arguments. You will gain a deeper understanding of your own position and be able to defend it better. Evaluate the arguments on both sides. What seems to be a good ar- gument might turn out not to be the case on further reflection—for example, why can we eat animals just because we are smarter? Does it also mean adults can eat babies and intelligent aliens can eat human beings? 3. The third step of the fourfold path is to consider whether the issue is impor- tant. Does it really matter what the correct answer is? What are the theoret- ical, social, personal, or political implications? How would the world be different if more people give up meat? How important is this question compared with other issues such as poverty and starvation? 4. The last step is to explore alternative possibilities and further issues. Does the level of intelligence of the animal make a difference? How about eating animals raised in a happy environment and killed in a painless manner? Is this also wrong? What about eating animals that die naturally? What if we can grow meat from stem cells and eat meat without killing animals?  IMPROVING OUR THINKING 7 As you can see, although the fourfold path consists of four very simple ques- tions, they help us examine an issue in depth from different perspectives. To improve your thinking, use this method often in your daily life, when you read magazines, surf the web, watch TV, or chat with others. You will become a more sophisticated, systematic, and creative thinker. Critical thinking and investment The idea that we should think critically might seem downright boring, and yet we should not underestimate the power of critical thinking. It re- quires having the discipline to reflect on the reasons for our actions, and this is very important if we want to improve ourselves and become more successful. Warren Buffet is one of the world's richest persons, widely admired for his investment record and philanthropy. The adherence to critical thinking is a crucial factor in Buffet's success. Here is what he says about the importance of being able to give reasons for our actions: You ought to be able to explain why you're taking the job you're taking, why you're making the investment you're mak- ing, or whatever it may be. And if it can't stand applying pen- cil to paper, you'd better think it through some more. And if you can't write an intelligent answer to those questions, don't doit. I never buy anything unless I can fill out on a piece of pa- per my reasons. I may be wrong, but I would know the an- swer to that. "I'm paying $32 billion today for the Coca-Cola Company because..." If you can't answer that question, you shouldn't buy it. If you can answer that question, and you do it a few times, you'll make a lot of money. Making money might not be our top priority, but if we can apply the same discipline in giving reasons for our actions and think about these reasons carefully, we are more likely to achieve our goals. 1.3.3 Attitude If you enjoy an activity and believe it is important, you will probably put in more effort and pay more attention to your performance. Similarly, there are positive attitudes that are more conducive to good thinking: Independence of thought: Good thinking is hard. Some people just want to know the answers rather than work it out themselves. Others have no patience for abstract or complicated ideas. A good thinker is able to think independently and go against conventional wisdom if need be. 8 INTRODUCTION Open-mindedness: A good thinker looks at the evidence objectively, and is willing to suspend judgment or change her opinion depending on the evi- dence. This is not a sign of weakness. An open-minded thinker is not dog- matic. She is willing to admit mistakes, think about new possibilities, and will not reject new ideas without good reasons. Cool-headedness and impartiality: Good thinking does not require giving up emotions. But we should avoid letting our feelings overwhelm our rea- soning. For example, it is difficult to think straight if you get angry easily when other people disagree with you. Fair and objective evaluations help us make better decisions. An analytical and reflective attitude: Do not jump to conclusions. A good thinker is one who spends time to analyze an issue systematically and care- fully and to actively search for arguments and evidence on both sides. She is interested in learning more about her own strengths and weaknesses to improve her performance. These attitudes are crucial for good thinking, but they are more a way of life than a piece of theoretical knowledge. They have to be internalized to become part of our natural habit and personality. This is easier said than done! Good thinking takes a lot of time and effort. But look at it this way: If we are willing to change ourselves when most people don't, this gives us the opportunity to excel and become better than average. EXERCISES Note: Suggested answers are at the end of the book, except questions that are marked with Kl. 1.1 This is a passage from the management best-seller In Search of Excellence (Peters and Waterman, 1982, p. 108). Can you summarize the argument against intelligence and logical thinking? Is it a good argument or not? Explain your rea- sons. If you place in a botde half a dozen bees and the same number of flies, and lay the bottle horizontally, with its base (the closed end) to the window, you will find that the bees will persist, till they die of ex- haustion or hunger, in their endeavor to discover an opening through the glass; while the flies, in less than two minutes, will all have sal- lied forth through the neck on the opposite side.... It is the bees' love of flight, it is their very intelligence, that is their undoing in this ex- periment. They evidently imagine that the issue from every prison must be where the light shines clearest; and they act in accordance, and persist in too-logical action. To bees glass is a supernatural mys- tery.... And, the greater their intelligence, the more inadmissible, more incomprehensible, will the strange obstacle appear. Whereas  EXERCISES 9 the featherbrained flies, careless of logic... flutter wildly hither and thither, and meeting here the good fortune that often waits on the simple... necessarily end up by discovering the friendly opening that restores their liberty to them. 1.2 Do you agree with these remarks? Explain your answers. a) Critical thinking is too negative because we are always trying to find fault but this is not a very healthy attitude. b) Critical thinking is not very useful because personal connections and re- lationships are more important for success. c) We often have to make decisions very quickly without a lot of time to think. So critical thinking is not really that useful. 1.3 Here is another definition of critical thinking from Scriven and Paul (1987). How would you compare this definition with the one in this book? Critical thinking is the intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action. In its exemplary form, it is based on universal in- tellectual values that transcend subject matter divisions: clarity, accu- racy, precision, consistency, relevance, sound evidence, good reasons, depth, breadth, and fairness. 1.4 E3 Apply the fourfold path to the following claims and list the issues and questions you should consider. a) It is always better to have more choices. b) Buying stocks is a good investment because the stock market always goes up in the long run. c) It is not wrong for a person to commit suicide rather than to suffer through a painful terminal illness. 1.5 Here are some questions for you to reflect on your thinking attitudes. Which of them are true of you? a) I can improve my thinking skills further. b) The purpose of thinking is not to be right all the time. c) I am not afraid to try out new ideas. d) Thinking takes time and might not be easy. e) I do not enjoy thinking about complicated ideas. f) Thinking is boring and it is better to spend time doing other things. g) Thinking is easy. I just use my gut feelings to make up my mind. h) The point of giving reasons is to show people that they are wrong. This page intentionally left blank CHAPTER 2 THINKING AND WRITING CLEARLY Do you believe in UFOs? According to a poll in 2005,34% of Americans do. In 2007, Japanese Cabinet Secretary Nobutaka Machimura caused quite a stir when he said on TV that UFOs "definitely" exist. But before you answer the question, pause and think about what UFO means. It is actually an abbreviation for "unidentified flying object." In other words, if there is something in the sky and nobody knows what it is, then it is an UFO. On this interpretation, there are certainly plenty of UFOs, but they could have been weather balloons, atmospheric reflections, and so on. Of course, UFO can also mean an alien spaceship. If this is what is meant, then it is not so clear that there are any. This example shows that when the meaning of a claim is unclear, it might be impossible to say whether it is true or false. Two people might disagree about the existence of UFOs, but the disagreement is pointless if they are using the term to mean different things. Being clear helps us avoid such verbal disputes. The UFO example also illustrates a crucial habit we should cultivate if we want to become a better thinker—before accepting a claim, pause to think about what it means and whether we understand what it says. We are bombarded with sound bites and slogans every day, and we should avoid accepting them uncritically. An Introduction to Critical Thinking and Creativity: Think More, Think Better. By Joe Y.F. Lau 11 Copyright © 2011 John Wiley & Sons, Inc. 12 THINKING AND WRITING CLEARLY Consider the popular idea that the economy should be a free market without government interference. Before deciding whether we agree or disagree, we need to clarify what a free market is and what counts as interference. For example, surely companies are not free to harm people. But then what about regulating pollution or monopolies? Would investment in education and research count as interference? What about supporting arts and culture or disadvantaged minori- ties such as the disabled? Once we start thinking about these issues, we begin to realize that a totally free market is undesirable. The real issue is not whether, but how, the government should regulate the economy. Although we should try to improve the clarity and precision of ideas, this is not an absolute rule. Sometimes there is no need to be clear. We do not need to understand the physics of microwave radiation to use a microwave oven. What is important is that we can explain things clearly when we need to. But what kind of skills do we need to be able to think and communicate ideas clearly? We are going to discuss two methods below: enhancing our sensitivity to literal meaning and making connections between ideas. 2.1 LITERAL MEANING To begin with, we ought to be able to identify the literal meaning of a statement and distinguish it from its conversational implicatures. Literal meaning is a prop- erty of linguistic expressions. The literal meaning of a sequence of words is deter- mined by its grammatical properties and the meanings that are conventionally assigned to the individual words. For example, the literal meaning of bachelor in English is "an unmarried man". The phrase I cannot be happier literally means it is impossible for the speaker to be more happy than he or she is right now. On the other hand, the conversational implicature is the information that a speaker implicitly conveys in a particular context, distinct from the literal mean- ing of what might have been said. Someone who looks at the windows and says, "It is cold here," might be suggesting that the windows be closed. But this mes- sage is distinct from the literal meaning of the statement. Similarly, the phrase / love books seems to say that the speaker likes reading, but strictly speaking that is again not part of the literal meaning. The sentence is still true if the speaker does not like to read but loves to collect books as a form of investment or to show off. Of course, good communication skills require sensitivity to conversational im- plicatures or related clues such as body language. But we should also be able to use literal meaning to convey ideas directly and explicidy. First, it helps us avoid misunderstanding. Second, the truth of what we say generally depends on literal meaning and not the conversational implicature. Suppose I tell you, "I shall try to come to the meeting." This reply is similar to "I will come," but with a significant difference. If I use the first sentence and I fail to show up, I can at least say I tried but could not make it in the end. But if I use the second sentence, I will have made a promise, and failing to show up implies that I have broken my promise and said something false. So if you care about truth and promises, you should care about  CONNECTING IDEAS 13 literal meaning. This is particularly important in law, when it comes to interpret- ing legislation and contracts. Take the following two clauses for a rental contract. They look similar, but they differ in literal meaning. Which version should you use for your lease if you were a prospective tenant? 1. You may terminate the lease after 12 months by giving 2 months' notice. 2. After 12 months, you may give 2 months' notice and terminate the lease. This example illustrates an important technique in clarifying meaning. One way to explain differences in literal meaning is to identify their different logical im- plications. The first clause implies a lease that lasts for a minimum of 12 months (if you give notice to leave the apartment at the end of the 10th month), whereas the second one implies a minimum lease of 14 months. Obviously, if you are rent- ing an apartment you want more flexibility and to have the option to move out as early as possible if you need to. So the first clause is preferable. As you can see, attention to literal meaning can clarify our rights and duties and help us avoid unnecessary disputes and nasty surprises later on. Attention to literal meaning is useful in other contexts as well. For example, as consumers we are naturally concerned about the safety and quality of our food, and to make informed choices we need to paying attention to the meaning of food labels. Nowadays lots of foods are supposed to be low-fat, but low-fat does not imply low-sugar or low-salt. Food with "no artificial flavors" can contain preser- vatives, and "hormone-free" chicken might be injected with lots of antibiotics. Interesting enough, the American food company Tyson at one point was selling chickens advertised as "raised without antibiotics" when in fact the chicken eggs were injected with plenty of antibiotics before they hatched! The company in- sisted that they had not advertised falsely, because "raised" literally applies only to the bringing up the chicks after they have hatched. Whether you agree with this definition or not, it tells us that those who are concerned about food safety have to be very careful about the meanings of food labels. 2.2 CONNECTING IDEAS Albert Einstein (1879-1955) once said, "If you can't explain it simply, you don't understand it well enough." Many people are attracted to obscure ideas that they cannot explain. They think the ideas are profound, and they might well be right. But it is often just an illusion. To avoid such self-deception, we should ensure that we can explain our ideas clearly and systematically. The way to do it is to connect our ideas to other ideas. The following sections present some typical methods. 2.2.1 Give examples Understanding words and concepts through examples is central to learning—think about how children learn words like red and vegetables. Being able to give your 14 THINKING AND WRITING CLEARLY own examples is a good sign that you understand a concept well enough to apply it. Concrete examples are good for illustrating abstract concepts. The speed of light is about 300,000 kilometers per second. This number means nothing to most people. But explain that at this speed you can go round the world seven times in one second, it suddenly becomes very impressive. Choose your examples carefully in your writing and presentations. Vivid and unexpected ones create a deeper impression. Personal stories that your audience can relate to will make your message seem more relevant. Contrasting or opposite examples are also useful, as in explaining why a rule applies in one situation but not another. 2.2.2 Definitions Definitions can go further than examples in explaining the full meaning of a term. Why are human beings and cows examples of mammals, but fish and turtles are not? You need a definition of mammal to explain why. Definitions are also use- ful in removing ambiguity and making meaning more precise. (See Chapter 3 for further discussion.) 2.2.3 Identifying implications To explain theories, proposals, and rules, we can point to their distinctive conse- quences. In other words, we explain how they make a difference if they are correct or accepted. For example, utilitarianism is the moral theory that the right thing to do in any situation is to choose the action that will maximize the greatest happi- ness for the greatest number of people. What does that mean? It means we should make more people happy rather than just ourselves. But it also implies that the in- terests of a small minority can be sacrificed if this will make the majority happier. Similarly, scientists say global warming might lead to a 5°C increase in temper- ature by 2100. To explain this further, we can list the dire implications, such as rising sea levels, disappearing glaciers, global water shortages, and one third of all species being threatened with extinction. Understanding the consequences of a theory allows us to see its significance and connect it to other ideas. 2.2.4 Compare and contrast Understanding something implies knowing how it is different from other things. To explain how sentences P and Q are different in meaning, find a situation in which one is true and the other one is false, as in the rental contract example ear- lier. Similarly, you can explain the differences between concepts by showing that they apply in different situations. Take speed and acceleration. Acceleration is the rate of change of speed. Something moving at a very high speed can in fact have zero acceleration if the speed does not change. Similarly, an object can have a high acceleration if it changes speed very quickly, even if the final speed is very low. In law, there is a difference between charitable and non-profit organizations.  FIVE TIPS FOR EFFECTIVE WRITING AND PRESENTATION 15 All charitable organizations are non-profit, but non-profit organizations need not be charitable. Roughly speaking, charitable ones must be for the benefit of the general public. So a club that aims to benefit only certain private members is not charitable, even if it is not for profit. 2.2.5 Breaking things down To understand how a complex system works, we can look at its parts and how they interact with each other. A mechanic fixes a car by checking the functions of different parts and see if they fit together properly. A wine buff evaluates a wine by focusing on the different aspects of taste, color, smell, and texture and their balance. Similarly, we can explain an idea more clearly by breaking it down. For exam- ple, in this book we explain good thinking in terms of critical and creative thinking. We then define critical thinking as clear and rational thinking, and we can explain clarity and rationality further. A general idea is broken down into smaller con- cepts, and the smaller concepts are broken down even further, like a tree trunk leading up to the main branches and then smaller and smaller branches. Orga- nizing ideas like a tree has many advantages. It makes them easier to understand and remember. It also helps us adjust the level of details we want to provide in our explanations to other people. We can start with the ideas at the top level, and go down further and further depending on the audience and the time we have. Some people are incapable of explaining anything without launching into a 10-minute speech. But an intelligent person with a deep understanding is just at ease giving a 10-second explanation as a 10-minute one. 2.3 FIVE TIPS FOR EFFECTIVE WRITING AND PRESENTATION Good communication is not just about using words with the right meaning. We also need to think about how ideas are packaged in a way that is attractive and easy to understand. It would be a pity if you put in a lot of effort but still fail to convey your important ideas. The basic rule is simple enough—make sure that your ideas are simple, organized, and relevant to your readers. It is easier said than done, but improving our writing and presentation can improve our critical thinking as well. Here are five general guidelines. Tip 1 : Know your audience Focus on the points your audience will find interesting and relevant. We can com- municate more effectively and leave a better impression. Ask yourself these ques- tions: How much does the audience know about the topic? Are they professionals or lay people, or both? Provide the appropriate level of information. 16 THINKING AND WRITING CLEARLY What do they expect from you? Is your goal to entertain, to inform, or to demonstrate your knowledge? What would the audience be most interested in? Facts, diagrams, predictions, practical advice, or personal stories? Should you consider any special requirements about the format? Should you provide handouts? Use a projector? Provide a summary? Is there a word or time limit? Tip 2: What is your central message and why is it important? It is an open secret that people who listen to a talk quickly forget most of it. The same goes for students attending lectures. When people remember things, it is because they find something interesting, useful, or funny. So think carefully about the main purpose of your presentation. Is there a take-home message? Focus on it and deliver the message clearly. If everything is important, then nothing will stand out as important. You need to make a choice about which idea to emphasize. If people are going to spend part of their lives listening to you or reading your work, which is the one thing you can point to in order to show that they have not wasted their time? In particular, learn how to formulate a thesis statement for presentation and writing that is analytical in character—that is, involving analyses, arguments, or explanations. The thesis statement is a claim that summarizes the most impor- tant point you want to make. Suppose you want to write an essay explaining that people worry too much about radiation from mobile phones. Somewhere near the beginning of the essay you should write down your main point. It sets the tone of the essay and shows the reader what he or she might expect later on. For example, this can be the first sentence of your introduction: Many people believe that mobile phones emit dangerous radiation, but there is to date no convincing evidence that mobile phones cause cancer or other serious health problems. Later on in the essay you can then say more about how worried people might be about this issue and what the relevant scientific studies say. Ideally, your thesis statement should be informative and attract the attention of your reader. (See the companion website for further discussion.) Tip 3: Organize your ideas Good writing takes time to ferment. Always begin with some research and analysis before you start typing out the real thing. Read widely and collect data, diagrams, photos, arguments, articles, and web pages and whatever else might be relevant. When you have collected enough material, think about their connections and the proper order of presentation. Develop the habit of using a point-by-point outline to organize your ideas, where each point might be a concept or a short sentence. The outline helps you distill and organize your ideas.  FIVE TIPS FOR EFFECTIVE WRITING AND PRESENTATION 17 Recently declassified documents in the United States includes a handwritten outline by former President Richard Nixon (1913-1994). Whatever we might think of Nixon,1 his historic visit to China in 1972 was widely regarded as a diplomatic achievement. It was the first time a U.S. president visited the People's Republic of China, and it started the normalization of relations between the two countries. But when he was preparing for his visit, Nixon used the following simple outline to condense the most fundamental issues into a list of bullet points. It might be somewhat surprising to see that complicated diplomatic issues between two countries can be written down on half a page, but the beauty of this outline is that the fundamental issues are organized so clearly: What they want: 1. Build up their world credentials 2. Taiwan 3. Get US out of Asia What we want: 1. Indochina (?) 2. Communists — to restrain Chinese expansion in Asia 3. In Future — Reduce threat of confrontation by Chinese Super Power What we both want: 1. Reduce danger of confrontation + conflict 2. a more stable Asia 3. a restraint on U.S.S.R Organization also means being clear about the function of every part of your writing. This includes: The whole presentation or article should have different parts. An essay typ- ically starts with an introduction, followed by further background informa- tion, the supporting evidence and arguments, potential objections, and a conclusion. Each paragraph should have a clear function—for example, explaining a definition, describing some data, replying to an objection, or adding a qual- ification. 1 He was involved in the coverup of a politically motivated burglary. The so-called Watergate scandal eventually led to the imprisonment of some of his aides and his own resignation, the first and only resignation of a U.S. president. 18 THINKING AND WRITING CLEARLY Tip 4: Be simple and direct Leonardo da Vinci (1452-1519) is supposed to have said: "Simplicity is the ulti- mate sophistication." Many people think profound writing must be difficult and long. So they use complicated sentences and long words to impress people. This is a mistake. Simple writing conveys ideas more clearly. Convoluted writing gives the impression that we are bad at explaining things. In a recent study, people who used plain language were judged to be more clever than those who used long words needlessly (Oppenheimer, 2006). Sometimes people fail to write in a simple way because they want to give as much information as possible. Paradoxically, this can have the opposite effect. People switch off their attention and forget things quickly unless they come across something really interesting. Information overload can therefore bury your main message. So be ruthless and cut out irrelevant material. Go through every word and sentence you have written and see if they can be simplified. Consider this example: If there are any points on which you require explanation or further particulars we shall be glad to furnish such additional details as may be required by telephone. Our telephone number is 555-5555. This sentence is typical of many company brochures, but it is awkward and un- necessarily long. The folllowing is much simpler: For enquiries, please call 555-5555. Some writers are also accustomed to long phrases when in fact simpler ones will do. Here are some common phrases that can be shortened: Phrases -» Shorten to in order to to in the event that if whether or not whether is in agreement with agree with provide a description of describe come to the decision decide Below are some other rules for simple and direct writing. But remember that they are just guidelines with plenty of exceptions. Break up long sentences (for example, more than 30 words) into shorter ones. Avoid linking sentences with and. Use the active voice instead of the passive voice. "The customer filed a com- plaint" rather than "A complaint was filed by the customer."  EXERCISES 19 Use positive rather than negative terms. "The room was clean" rather than "The room was not dirty." A good test is to read a passage aloud and see if it sounds clumsy. Easy-to- read text has a higher chance of being understood. Tip 5: Rewrite, rewrite, rewrite Good writing does not finish with your first draft. A good author will reread every word and sentence and think about how to make the text even better. Hemingway, who won the Nobel Prize in literature in 1954, said he rewrote the ending to A Farewell to Arms thirty-nine times, just to "get the words right."2 Leonardo da Vinci used a mirror to look at his own painting in reverse so it would look less familiar and he could criticize his work better. This is why it is a good idea to leave your finished writing aside for a while. Read it aloud again later with a fresh eye, and it will be easier to spot problems. Of course, you can also get someone else to read it and give some advice. But try as hard as you can to find something that can be improved, even if it is just deleting a word or changing the order of a few sentences. Good writing is often like a great performance—beautiful to behold and seeming to be without effort, but in reality it is the product of intense labor and love. Rereading what we have written sounds obvious, but it is surprising how few people do it, even when mistakes are costly. A survey of UK recruitment firms found that more than half of the application CVs they have received contain gram- matical and spelling errors, leaving a bad impression on prospective employers. Furthermore, applicants aged between 21 and 25 years made the most mistakes. Most firms also said applicants were wasting their time by including details about their hobbies and interests (BBC, 2010). EXERCISES 2.1 For each pair of sentences below, explain whether they differ in literal mean- ing. a) Do not be evil. Be good. b) I like lobsters. I like eating lobsters. c) We do not add preservatives to our food. Our food contains no preserva- tives. d) Do not say anything if the police are here. Do not say anything in case the police are here. e) You may kiss the bride. You must kiss the bride. f) Everyone is not sick. Not everyone is sick. 2 He also has this to say about his experience working at a newspaper: "On the Star you were forced to learn to write a simple declarative sentence. This is useful to anyone." He also told F. Scott Fitzgerald, "I write one page of masterpiece to ninety-one pages of shit.... I try to put the shit in the wastebasket." 20 THINKING AND WRITING CLEARLY g) Nothing that is good is cheap. Nothing that is cheap is good. h) There are many restaurants and the best one is The French Laundry. There is no restaurant better than The French Laundry. 2.2 Kl Howwould you explain the differences in meaning of the following terms? a) eternity, infinity b) ideal, paradigm 2.3 Imagine that following paragraph is taken from a reference letter for a stu- dent named Harry. Read each sentence carefully, and explain why the paragraph does not literally say anything positive about Harry. Harry's abilities must be seen to be believed. The amount of mate- rial he knows will surprise you. It would be very hard to find someone as capable as he is. He has left a deep impression on all the teachers in the department. You would be fortunate if he works for you. 2.4 How would you rewrite these sentences to make them simpler? a) When the teacher gave the explanation to the class, the explanation was delivered in such a way that it was rather lengthy and could not be easily understood by the students. b) The current situation in this place, which is already tense, turned ex- plosive earlier this month when the international administration, which was put in place after the 1995 peace accord that put an end to the war in Bosnia, gave an order to execute a raid on Herzegovacka Bank. c) In the basement there are four baskets made of bamboo that have got absolutely nothing in them whatever and that might perhaps be given away by us to charitable organizations and societies. d) Anai's used money to purchase a large-type minivan produced by Toyota that is red in color. e) Apple has designed a laptop that is quite special—the case of the laptop is made from the material aluminum and is not composed of any smaller parts. 2.5 M Take something you have written a few years ago, and read it again to see how it can be improved in light of the suggestions here. CHAPTER 3 DEFINITIONS Definitions are very useful in explaining and clarifying meaning. A typical defini- tion has two parts: The definiendum: the term being defined ^ bachelor = unmarrie man d The definiens: // the words that define the definiendum-^ People often use is instead of the equality sign in giving definitions—for exam- ple, a bachelor is an unmarried man. A bit more terminology: A term is a referring expression in a language made up of one or more words, such as The United Nations, Beethoven, mammals, purple. An Introduction to Critical Thinking and Creativity: Think More, Think Better. By Joe Y.F. Lau 21 Copyright © 2011 John Wiley & Sons, Inc. 22 DEFINITIONS The referent of a term is what the term refers to. So the terms listed in the last paragraph refer respectively to an organization, a person, a class of ani- mals, and a particular shade of color. A term such as Mount Everestrefers to a real physical thing in the world, but other terms such as truth and 13467 refer to more abstract things. The set of things a term refers to is known as the extension of the term. So dolphins, humans, donkeys, gorillas are all within the extension of mammals. The concept associated with a term is an idea that encapsulates our under- standing of the term. Although a term is made up of words, a concept is not. Agua is a Spanish word distinct from the English word water. They have different spelling and pronunciation, but they have the same meaning and express the same concept. In this book we shall take definitions to be primarily definitions of terms, al- though we can loosely speak of defining a concept (that is, defining the term that expresses the concept). We can divide definitions into three kinds according to their purpose: stipulative, reportive, and precising. A definition worth US$7 billion On September 11,2001, terrorists destroyed the twin towers of the World Trade Center in New York City by crashing two planes into them. At the time, Larry Silverstein was holding a 99-year lease for the buildings. The buildings were covered by insurance which would pay US$3.55 billion for an "occurrence" of a terrorist attack. But Silverstein argued that he should get double the amount, because there were two occurrences of attacks, as there were two planes that hit the buildings about 15 minutes apart. Obviously, the insurers claimed this was just one occurrence of a coordinated attack. So here is a definition that is worth a few billion dollars! This is a good example about the importance of definitions in contracts and official documents. (The trial was a long and complicated affair. In the end a jury decided that there were two occurrences, even though Silverstein did not get the full amount he wanted.) 3.1 REPORTIVE DEFINITION A reportive definition is also known as a lexical definition. It reports the existing meaning of a term. Here are some examples: Prime number = any integer greater than 1 and divisible only by 1 and itself. WTO stands for "The World Trade Organization".  REPORTIVE DEFINITION 23 Sushi is a kind of food made with vinegared rice with some meat or veg- etable topping. Obviously, reportive definitions are useful for learning new words in a language. The main criterion for evaluating a reportive definition is that the meaning of the definiens should match the meaning of the definiendum exactly. This means the definition should not be inconsistent with the existing usage of the term in ques- tion. Suppose someone consults a very old dictionary that defines computer as "a person whose job is to carry out mathematical calculations." This definition was before modern electronic computers were invented. It is inconsistent with how we actually use the word computer today, and so it is no longer a good reportive definition. A correct reportive definition should not be too wide or too narrow. A definition is too wide if the definiens applies to things that the definiendum does not apply to. In other words, the definition includes things that it should not. For example, defining an airplane as a flying machine is too wide, since helicopters are also flying machines but they are not airplanes. The situation is indicated by the Venn diagram below. The thick circle represents the set of all airplanes, and the bigger circle represents all flying machines. Since all airplanes are flying machines, the thicker circle is inside the other one. But there are plenty of flying machines within the larger circle that are not airplanes, such as helicopters, rockets, and airships. helicopter -jetfighter flying machines A definition is too narrow if the definiens fails to include things to which the definiendum applies. In other words, the definition fails to include things that it should. Consider the definition of religion as any belief system that includes worshiping a god who created the universe. This definition is too narrow since it excludes religions that do not postulate a creator, such as Jainism and certain versions of Buddhism and Daoism. Daoism -^. f /-—-s"\ ^ ^ f \ \ ^ ^ _ ^ belief systems that I \^ * N < | worship a creator religions X ^ ^S Christianity Notice that a definition can be too wide and too narrow at the same time. Sup- pose someone defines bravery as "not running away from danger". The definition 24 DEFINITIONS is too wide because even a coward might fail to run away from danger. Perhaps he is immobilized by fear, or perhaps he does not even realize that he is in dan- ger. But the definition is also too narrow because a person can be brave even if he avoids dangerous situations. Bravery does not require stupidity. There is no reason why a fireman who escapes from a burning building cannot be brave. c j * /-x. \ / frozen with fear escaping from danger without panicking ~ ^ ^ not running bravery " ^ ' away from danger 3.2 STIPULATIVE DEFINITION A stipulative definition is used to assign a new meaning to a term, whether or not the term has an existing meaning. If the stipulative definition is accepted, then the term is used in the new way that is prescribed. Suppose we agree to define IBM to mean "incredibly boring movie". Once this is accepted, we can then say things like "Cable TV is showing another IBM right now." Stipulative definitions are not just for secret codes and acronyms. They are also used to introduce new technical terms—for example, quark (physics), priori (biology), risk premium (economics). Notice that a stipulative definition does not have to be faithful to the old meaning of the term being defined, if it has any. In physics, a strange quark is just one type of elementary particle, and it is not particularly strange. In a stipulative definition, the meaning of the definiendum is completely determined by the meaning of the definiens, whatever it is, so the question of whether it is too wide or too narrow simply does not apply. One more point to bear in mind about stipulative definitions: If you define a term more than once, make sure that the definitions are equivalent. Otherwise confusion might arise due to the inconsistent definitions. 3.3 PRECISING DEFINITION A precising dennition is something in between reportive and stipulative defini- tions. The function of a precising definition is to make the meaning of a term more precise. Suppose a bus company wants to give discounts to old people. If the company simply declares, "old people pay only 50% of the full fare," this would be too vague because it is not clear when a person becomes old. Some people might say that being 60 is old, but others might disagree. To avoid disputes and uncertainty, the company might define old person to mean "any person of age 65 or older." This definition is in part stipulative because there is no special reason why age 65 should be chosen as the cut-off point, as opposed to say 64 or 66. But  PRECISING DEFINITION 25 it is not entirely arbitrary because given the purpose of the definition, it would be inappropriate to adopt a definition that classifies children as "old." As we can see, one major function of precising definitions is to make laws and regulations more precise, so there is less uncertainty regarding their application. Precising definition are also useful in resolving verbal disputes. A verbal dis- pute is a disagreement that is due solely to the ambiguity of a term. The American philosopher William James (1842-1910) once told this story about some hunters in a forest. One of the hunters was standing on one side of a tree and there was a squirrel climbing on the other side of the tree trunk. The hunter tried to look at the squirrel by walking around the tree, but the squirrel kept moving around the tree as well and always stayed on the opposite side of the tree trunk. Now the hunter certainly circled the tree, and the squirrel was on the tree. But did the hunter go round the squirrel or not7. The hunters entered into a heated debate about this, and it was left to James to adjudicate. He explained that it all depends on what go round means: If you mean passing from the north of him to the east, then to the south, then to the west, and then to the north of him again, obviously the man does go round him, for he occupies these successive posi- tions. But if on the contrary you mean being first in front of him, then on the right of him, then behind him, then on his left, and finally in front again, it is quite as obvious that the man fails to go round him, for by the compensating movements the squirrel makes, he keeps his belly turned towards the man all the time, and his back turned away. Make the distinction, and there is no occasion for any farther dispute. (James, 1995, p. 17) This is a dispute that a precising definition can resolve. The ordinary mean- ing of go round is not precise, and a more fine-grained distinction accurately pin- points the source of disagreement. Verbal disputes are contrasted with factual disputes, which are disagreements about facts rather than meaning. If someone thinks Sydney is the capital of Australia and others disagree, then this is a factual dispute that can be resolved by checking the facts. Many disputes are a mixture of verbal and factual disputes, and we should sep- arate them out to advance the discussion. Often, the first step is to use precis- ing definitions to clarify the issue. Take the question of whether nonhuman an- imals have language. To answer this question, we should be more precise about what language means. If it refers to any system of communication, then obvi- ously birds and other animals have languages, since they do communicate with each other. On the other hand, language might also be used in a different sense, requiring the use of words to form sentences according to a system of grammar or being able to communicate about arbitrary objects and situations, including those that might be far away and distant in time. Given this definition, many an- imal communication systems do not qualify as languages. It is of course possible that some mammals such as chimpanzees might possess language in this more 26 DEFINITIONS sophisticated sense. Precising definitions allow us to refine questions, so we can gain a better understanding of how to answer them. 3.4 CRITERIA FOR GOOD DEFINITIONS We have said that a reportive definition should not be too wide or too narrow. Here are more criteria for evaluating all kinds of definitions, not just reportive ones. 3.4.1 Use intensional definitions if possible Philosophers very often draw a distinction between the extension and intension of a term (or concept). The extension of a term is the set of things to which the term applies. So for example, the extension of prime number is set of numbers {2, 3, 5, 7, 11, 13,...}. On the other hand, the intension of a term is its meaning. The intension of prime number would be "any integer larger than one which is completely divisible only by one and itself." When we define a term, should we define it by extension or intension? It de- pends, but we should use intensional definition where possible. A term such as human beinghas a very large extension. It is impossible to define the term by list- ing all the human beings there are. Furthermore, even if we are able to list all the items in the extension of a term, this might not explain the criterion for including them. Defining prime numbers as 2, 3, 5, 7, 11,... fails to explain how the num- bers are selected and how the list should continue. An intensional definition is better. However, in some situations, an intensional definition might not be avail- able. The seven deadly sins, for example, is understood as referring to pride, greed, envy, anger, lust, gluttony, and sloth. There is of course a long story about the his- tory of the term and why it is these seven sins that appear on the list. However, this history is not relevant to the definition of the list. 3.4.2 Avoid circularity A good definition should avoid circularity. A circular definition is one where the definiens cannot be understood without knowing the meaning of the definien- dum. Consider the definition of time as "a quantity measured by clocks or watches." This definition is circular because we cannot fully explain what clocks and watches are without taking them as instruments that measure time. Similarly, sometimes people say "the meaning of life is to search for the meaning of life." This sounds profound, but taken as a definition, it is hopelessly circular and does not make much sense. If the meaning of life is to search for the meaning of life, then it fol- lows that the meaning of life is to search for a search for the meaning of life, which is to search for a search for a search of the meaning of life, and so on. Of course, on a more charitable interpretation, perhaps the suggestion is that the mere process of searching for the meaning of life is itself sufficient to make one's life meaning- ful. But this does not seem very plausible. Imagine a selfish and bitter person who  DEFINITION TECHNIQUES 27 contributes nothing to the world, who spends his entire life doing nothing except being obsessed with the question of what the meaning of life is. This does not seem like a very meaningful life at all. 3.4.3 Avoid obscurity Definitions should avoid obscure and metaphorical language as far as possible. "Science is searching for a black cat in a dark room" might convey an amusing image of the difficulty of scientific research, but as a definition it is too obscure to tell us much about the nature of science. However, a reportive definition should not be more precise than the term that is being defined. A ship might be defined as a vessel of considerable size for nav- igating on water. This definition is vague because it is unclear what considerable size means. But this is in itself not a good objection to the definition, because our concept of a ship is vague in exactly the same way. Defining a ship as a vessel longer than 30 meters will make the definition too precise and end up distorting the ordinary meaning of the word. 3.4.4 Avoid persuasive definitions Finally, definitions should also avoid inappropriate emotional connotations. A persuasive definition is a definition that attaches a positive or negative emotional meaning to a term when there is in fact no such association. For example, if someone defines democracy as "dictatorship by the poor and the uneducated," obviously such a person does not think very highly of democracy. But whether democracy is a good or bad thing should depend on further arguments and not be decided solely by a definition. Similarly, consider the definition "abortion is the termination of pregnancy by murdering an unborn child." This definition as- sumes that abortion is wrong because it classifies abortion as murder. But it is surely possible to understand abortion in a more neutral way. The biased defini- tion that is proposed distorts the ordinary meaning of the term. (Another problem with the definition is that it assumes without argument that the aborted fetus is already a child—that is, a person.) This is not to deny that a persuasive defini- tion can be a useful rhetorical tool. They are often used in debates and political speeches, but we should avoid them in a rational and fair-minded discussion. 3.5 DEFINITION TECHNIQUES Here are some of the different ways of formulating a definition. 3.5.1 Definition by synonym In a definition by synonym, a word (or a short term) is defined by giving an- other term that has exactly the same meaning—for example, physicians = doctors, lawyer = attorney, ameliorate = improve, and prognosticate = predict. 28 DEFINITIONS 3.5.2 Definition by ostension An ostensive definition explains the meaning of a term by giving examples, as when we explain the meaning of red to children by pointing to examples of red things. Or someone might explain a professional as "people like doctors, lawyers, and accountants." Ostensive definitions are useful when it is difficult to explain the meaning of a term precisely. But an ostensive definition is a form of definition by extension, and intensional definitions can explain meaning better if they are available. 3.5.3 Definition by genus-differentia The genus-differentia method is a very useful tool for constructing definitions. According to this approach, when we want to define a term, first we identify the broad category that the term is supposed to apply to. This category is known as genus. To define mule, we note first of all that a mule is an animal. Of course, there are many kinds of animals other than mules. So the next step is to identify the differentia. This is the property that separates the items in the genus into two groups—those that fall within the extension of the definiendum, and those that do not. In the case of mule, this would be the property of being the offspring of a male donkey and a female horse. Putting the two parts together, we arrive at the full definition: A mule is an animal that is the offspring of a male donkey and a female horse. This type of definition is useful because it informs the audience about the kind of thing the definiendum applies to, even if the complete definition is difficult to remember and understand. Here are more examples of this kind of definition, with the genus part underlined: Ice = frozen water. Witness = a person who testifies under oath at a trial or deposition. Vitamin = a low molecular weight organic compound required in trace amounts for normal growth and metabolic processes. Bear market = a prolonged condition of the financial market in which invest- ment prices fall and accompanied by widespread pessimism. Phoneme = the smallest unit of sound in a language. 3.6 THREE MISCONCEPTIONS ABOUT DEFINITIONS Definitions are no doubt useful, and this has led some people to claim that we should define all the words we use. But this is far too extreme. First of all, we do  EXERCISES 29 not have to be precise and clear all the time. Otherwise we have to throw away lots of jokes, poems, and ordinary conversations. Also, many words are difficult to define. We learn words like green, warm and cold through examples and not complete definitions. Other words like time and existence seem so basic and hard to define even though we understand them well enough in everyday life. In any case, it is surely impossible to define all the words we use without circularity, since our language contains only a finite number of words. A second misconception about definitions is to think that dictionaries provide the most accurate and authoritative definitions. Dictionaries are of course useful in learning a language, but dictionary entries often describe only the main usage of a term, leaving out its more subtle aspects. An entry might also include extra factual information that is not part of the meaning of the term. According to The Pocket Oxford Dictionary of Current English, a cat is a small soft-furred four-legged domesticated animal. As a definition it is both too wide and too narrow, because a small furry dog is not a cat, and a cat that has become large as a result of hormonal injection does not thereby cease to be a cat. Another point to remember is that a lot of terms have technical meanings, such as inflation in economics and mass in physics. A general dictionary might not give you the correct explanation. You need to consult a more specialized dictionary for that particular discipline. Finally, the definitions of many abstract concepts can be controversial. Think of art, justice, knowledge, rationality. A short dictionary entry might be a good start to help us think more deeply about these concepts, but we should not expect a dictionary to give us the final word on their proper understanding. A third misconception about definition is the belief that to know the real mean- ing of a term, we have to find its original definition or meaning. Many people like to explain X by beginning with the history of the word X. The etymological fal- lacy is the mistaken idea that we always need to look at the history and original usage of a term to decide what its current meaning is. For instance, the word passion derives from a Latin root that means "suffering." But it would be a bad argument to judge that a certain relationship is not really passionate because the parties involved are not suffering. The current meaning of a word depends on how it is actually used, and there is no reason why meaning and usage cannot change drastically over a long period of time. EXERCISES 3.1 Classify these definitions as reportive, precising, stipulative or persuasive: a) Above average intelligence means "having an IQ of more than 100." b) A camera is an instrument for taking photos. c) Animal rights activists are people who love animals more than human beings. d) An atheist is a person who does not believe in the existence of God. e) X is harder than Y = X can make a scratch on Y but not the other way round. 30 DEFINITIONS 3.2 Evaluate these definitions and see if they have any problems. a) Hatred = the wish to harm other people or to ruin something that is im- portant to them. b) Biology is when you study living organisms. c) What is Yin? Not Yang. What is Yang? Not Yin. d) Love is the master key that opens the gates of happiness. (Oliver Wendell Holmes) e) Love is the affinity experienced between two people who are naturally able and willing to tune into one another's emotional, intellectual, and physical states—and respond to them in a nurturing and a stimulating way. (biomatch.com) f) Furious = being angry at someone. g) A bomb is a device designed to explode so as to hurt people. 3.3 E3 How would you define vegetable! a) What do you think of the definition of vegetable as an edible plant or part of an edible plant that is not a seed or a sweet fruit? b) Would the following items count as vegetables under this definition: rice, avocado, mushroom, ginko nut, peanut, lemon, lotus seed, tomato juice? 3.4 What is wrong with these arguments, if anything? a) Philosophy originally meant "love of wisdom" in Greek. If you are a philoso- pher, you must be very wise. b) Art originally meant "to make." So art is created whenever someone makes something. 3.5 Insider trading is a crime in most countries. Suppose you are a legislator trying to draft regulation prohibiting insider trading. How would you define it? What about this definition: Insider trading is any sale or purchase of the shares or bonds of a com- pany that relies on information about the internal operations of the company. 3.6 Consider this definition of domestic violence from a 2004 UK crime survey: Any violence between current or former partners in an intimate rela- tionship, wherever and whenever the violence occurs. The violence may include physical, sexual, emotional or financial abuse. a) Is it possible to simply it further? Which is the most important part? b) Compare the survey definition with the following one from a women's self-help group. Identify the main differences and their respective strengths and weaknesses: Domestic violence is physical, psychological, sexual or financial vio- lence that takes place within an intimate or family-type relationship and forms a pattern of coercive and controlling behavior.  EXERCISES 31 3.7 Evaluate these definitions. Come up with as many objections as you can. a) Sexual harassment is any action related to sex that makes someone dis- tressed or unhappy. b) Harassment means being told that a raise, promotion, or other benefit is dependent on you going on a date with your boss or some other similar activity. 3.8 A lawyer suggests defining the word container as "a receptacle having at least one exterior surface and a plurality of walls defining a discrete object receiv- ing volume." What is your opinion? 3.9 K Give definitions of these terms using the genus-differentia method: or- phan, portrait, ballpoint pen, square, even number. This page intentionally left blank CHAPTER 4 NECESSARY AND SUFFICIENT CONDITIONS Necessary and sufficient conditions help us understand and explain the connec- tions between concepts, and how different situations are related to each other. 4.1 NECESSARY CONDITIONS To say that X is a necessary condition for Y is to say that the occurrence of X is required for the occurrence of Y (sometimes also called an essential condition). In other words, if there is no X, Y would not exist. Examples: Having four sides is necessary for being a square. Infection by HIV is necessary for developing AIDS. Having die intention to kill someone or to cause grievous bodily harm is necessary for murder. To show that X is not a necessary condition for Y, we simply find a situation where Y is present but X is not. Examples: An Introduction to Critical Thinking and Creativity: Think More, Think Better. By Joe Y.F. Lau 33 Copyright © 2011 John Wiley & Sons, Inc. 34 NECESSARY AND SUFFICIENT CONDITIONS Eating meat is not necessary for living a healthy life. There are plenty of healthy vegetarians. Being a land animal is not necessary for being a mammal. Whales are mam- mals, but they live in the sea. In daily life, we often talk about necessary conditions, maybe not explicitly. When we say combustion requires oxygen, this is equivalent to saying that the presence of oxygen is a necessary condition for combustion. Note that a single situation can have more than one necessary condition. To be a good pianist, it is necessary to have good finger technique. But this is not enough. Another necessary condition is being good at interpreting piano pieces. 4.2 SUFFICIENT CONDITIONS If X is a sufficient condition for Y, this means the occurrence of X guarantees the occurrence of Y. In other words, it is impossible to have X without Y. If X is present, then Y must also be present. Some examples: Being a square is sufficient for having four sides. Being a grandfather is sufficient for being a father. To show that X is not sufficient for Y, we list cases where X occurs but not Y: Being infected by HIV is not sufficient for developing AIDS because there are many people who have the virus but have not developed AIDS. Loyalty is not sufficient for honesty because one might have to act in a dis- honest manner to protect the person one is loyal to. Note that a single state of affairs can have more than one sufficient condition. Being red and being green are different conditions, but they are both sufficient for something being colored. 4.3 DESCRIBING HOW TWO THINGS ARE CONNECTED Given any two conditions X and Y, there are four ways in which they might be related to each other: 1. X is both (jointly) necessary and sufficient for Y. 2. X is necessary but not sufficient for Y. 3. X is sufficient but not necessary for Y. 4. X is neither necessary nor sufficient for Y.  THE WRITE-OFF FALLACY 35 Some examples: 1. Being an unmarried man is necessary and sufficient for being a bachelor. 2. Oxygen is necessary but not sufficient for our survival. 3. Having a son is sufficient but not necessary for being a parent. 4. Being rich is neither necessary nor sufficient for a happy life. This fourfold classification is useful because it provides the starting point for analyzing how things are related. When we think about the relationship between two things X and Y, we can begin by asking whether one is necessary or sufficient for the other. For example, what is the connection between democracy and the rule of law? First, we might say that the rule of law is necessary for democracy. A democracy is impossible if people do not follow legal procedures to elect leaders or resolve disputes. But we might also add that the rule of law is not sufficient for democracy, because the legal rules that people follow might not be fair or demo- cratic. As this example shows, the concepts of necessary and sufficient conditions can be very useful in studying and teaching. When you understand a subject more deeply, you do not just memorize individual pieces of information. You should also be able to understand the connections between the basic concepts, and this includes relationships of necessity and sufficiency. Necessary and sufficient conditions are also related to the topic of definition. In effect, a definition of X provides conditions that are both necessary and sufficient for X. When we define a bachelor as an married man, this implies that being an unmarried man is both necessary and sufficient for being a bachelor. 4.3.1 Using necessary and sufficient conditions to resolve disputes The concepts of necessary and sufficient conditions are quite simple, but they are very useful and fundamental concepts. Sometimes when people disagree with each other, especially about some theoretical issue, we can use these concepts to identify more clearly the differences between the parties. For example, suppose someone claims that computers cannot think because they can never fall in love or be sad. To understand this argument better, we can ask whether this person is assuming that having emotions is necessary for thinking, and if so why? If something is capable of reasoning and deduction, then presumably it can think. But emotions seem to be a different category of mental states. We can imagine a person who is able to think and reason, but who cannot feel any emotion, perhaps due to brain injuries. If this is possible, it shows that emotions are not necessary for thinking. 4.4 THE WRITE-OFF FALLACY Although the concepts of necessary and sufficient conditions are very important, they are also used in some bad arguments. One such fallacy, which we might call 36 NECESSARY AND SUFFICIENT CONDITIONS the write-off fallacy, is to argue that something is not important, because it is not necessary or not sufficient for something else that is good or valuable. For example, some people argue that democracy is not really that important because it is not necessary for having a good government. It is possible for a non- democratic government to work efficiently for the interests of the people, and this might be correct. Furthermore, democracy is not sufficient for good governance either, since citizens can make bad choices and end up electing a bad government. This is also possible. However, it might still be the case that a democratic political system is more likely to produce a good government than other alternatives.1 In principle, a benevolent dictator can be a wise and competent ruler, but the fact is that this is extremely rare, and dictators are more likely to abuse their power. The general lesson here is that a condition C can be an important factor that makes an effect E more likely to happen, even if C is neither necessary nor sufficient for E. It is not enough to write off C as unimportant simply by pointing to isolated cases where there is C but no E, or where there is E but no C. 4.5 DIFFERENT KINDS OF POSSIBILITY Necessary and sufficient conditions are related to the concept of possibility. To say that X is necessary for Y is to say that it is not possible for Y to occur without X. To say that X is sufficient for Y is to say that it is not possible for X to occur without Y. There are, however, different senses of possibility, and corresponding to these different sense there are different kinds of necessary and sufficient conditions. Let us consider these statements: It is impossible to draw a red square without drawing a square. It is impossible to dissolve gold in pure water. It is impossible to travel from India to France in less than one hour. It is impossible to vote in Australia if you are under 18. The word impossible does not have the same meaning in these statements. In the first statement, what is being referred to is logical impossibility. Something is logically impossible if it is contradictory or against the laws of logic. Thus a round square is a logical impossibility, and it is logically impossible for there to be a red square without there being a square. But it is not logically impossible to dissolve gold in water. Logic itself does not tell us that this cannot happen. Rather, the impossibility is due to the laws of physics and chemistry that happen to hold in our universe. If our universe had 'Here is a famous quote from Winston Churchill (1874-1965): "No one pretends that democracy is perfect or all-wise. Indeed it has been said that democracy is the worst form of government except all those other forms that have been tried from time to time." (Speech in the House on the Parliament Bill, Novemberll, 1947)  EXCLUSIVE AND EXHAUSTIVE POSSIBILITIES 37 operated differently, then perhaps gold would dissolve in water. Dissolving gold in water is therefore logically possible but empirically impossible. Empirical pos- sibility is sometimes also known as causal or nomological possibility. The sense in which the third statement is true is again different. The laws of physics probably do not stop us from traveling from India to France within an hour. Perhaps such a short trip is possible with some future airplane, but it is cer- tainly not possible at this point in time. When current technology does not permit a situation to happen, we say that it is technologically impossible, even though it might be both logically and empirically possible. Of course, what is currently technologically impossible might well turn out to be technologically possible in the future. Finally, voting under the age of 18 is certainly not prohibited by logic, the laws of nature, or current technology. What is meant by impossible in the fourth state- ment is thus something else—namely legal impossibility. To say that X is not possible in this sense is to say that X is incompatible with the relevant legislation. Note that what we have just said about the different senses of possibility applies to necessary and must as well. "A square must have four sides" and "it is necessary that a square has four sides" express logical necessity. Whereas "you must be 18 to vote in Australia" is obviously about legal rather than logical necessity. 4.6 EXCLUSIVE AND EXHAUSTIVE POSSIBILITIES Apart from talking about the ways in which something is or is not possible, there are also some useful terms for talking about the connections between different possibilities. First, we can speak of a possibility including another. There being rain tomor- row includes the possibility of a heavy rainstorm, and the possibility of just a light drizzle. Second, one possibility can exclude another. If Cinta is in Spain right now, that excludes the possibility that she is in Brazil. Finally, two possibilities can also be independent of each other. Whether it will rain tomorrow presumably does not depend on what you ate for breakfast this morning. The word exclusive is sometimes used to talk about one possibility excluding another, and it is important not to confuse exclusive with exhaustive. A set of possibilities is exhaustive when at least one of them obtains in any logically possible situation (they do not leave out any situation). A set of possibilities is exclusive when there is no logically possible situation in which more than one of them obtains (the truth of one excludes the truth of the others). In other words, if a set of possibilities is both exhaustive and exclusive, then in any logically possible situation, exacüy one of them obtains. This explanation might be a bit too abstract, so here is an illustration. Suppose x is an integer: 38 NECESSARY AND SUFFICIENT CONDITIONS Two possibilities that are neither exhaustive nor exclusive: x > 3, x > 4. They are not exhaustive because the possibility that x = 2 is not included. They are not exclusive because both of them can be correct, as when x > 5. Exhaustive but not exclusive: x > 4, x < 10 Exclusive but not exhaustive: x> 4, x = 1 Exclusive and exhaustive: x > 0 , x = 0, x < 0 EXERCISES 4.1 Suppose we have a definition X=Y. Are the following statements correct about this definition? Why or why not? a) If the definition is too wide, then X is not necessary for Y. b) If the definition is too wide, then Y is not necessary for X. c) If the definition is too narrow, then X is not sufficient for Y. d) If the definition is too narrow, then Y is not sufficient for X. e) If X is not necessary for Y, then the definition is too wide. 4.2 Are these statements true or false? a) If X is logically sufficient for Y, and Y is logically sufficient for Z, then X is logically sufficient for Z. b) If X is logically necessary for Y, and Y is logically necessary for Z, then X is logically necessary for Z. c) If X is not necessary for Y, then Y is not necessary for X. d) Being an intelligent student in the class is necessary for being the most intelligent student in the class. e) If something is not logically impossible, then it is logically possible. f) If something is empirically impossible, then it does not actually happen in the world. g) If something is empirically possible, then it actually happens in the world. h) If something actually happens in the world, then it is empirically possi- ble. i) If something is logically possible, then it is empirically possible. j) If something is empirically possible, then it is logically possible. k) If something is empirically possible, then it is technologically possible. 4.3 A definition of X provides necessary and sufficient condition for X. See if you canfillin the blanks below correctly with necessary condition or sufficient con- dition: a) If the definition is too wide, this means the definition fails to provide the correct for X. b) If the definition is too narrow, this means the definition fails to provide the correct for X.  EXERCISES 39 4.4 Determine whether these possibilities are exhaustive and/or exclusive. a) Inflation goes up. Inflation comes down. b) P and Q. Neither P nor Q. c) Sadie and Rita are happy. Sadie and Rita are sad. 4.5 Many management and law school admission tests include questions known as "data sufficiency questions." There are also similar questions in many recruit- ment exams. So do try out the following questions. You will be given some infor- mation, and then you have to pick the correct answer out of