- F- Book Two CRITICAL THINKING Problem Solving, Reasoning, Logic, and Arguments Anita Harnadek • TEACHER’S MANUAL CRITICAL THINKING BOOK TWO ANITA HARNADEK © 1981 CRITICAL THINKING BOOKS & SOFTWARE www.criticalthinking.com P.O. Box 448 • Pacific Grove • CA 93950-0448 Phone 800-458-4849 • FAX 831-393-3277 ISBN 0-89455-060-8 Printed in the United States of America Reproduction rights granted for single-classroom use only. TO THE TEACHER I believe that a student learns how to think critically not by being toki how to do it but by doing it. Consequently, neither the textbook nor this Teacher’s Guide is intended to serve either as a workbook for students or as an instrument which will help you stand in front of the class and lecture the students on what they should be learning and then read them the “correct” answers when they’ve answered a problem or question. With rare exceptions, the textbook problems and questions are designed to provoke class discussions. This Teacher’s Guide gives you many comments and suggestions about the ma terials, about teaching the class, and about stim ulating class discussions. Let the students settle their own differences of opinion and do their own arguing, for the more you step in and settle arguments, the less thinking the students will do themselves, and so the less the students will practice what you’re trying to teach them. Comments, criticisms, or suggestions you or your students may have about the text or this Teacher’s Guide will be appreciated. It is hoped that both you and your students enjoy this course. ii TABLE OF CONTENTS PART 1 GENERAL INFORMATION Content level 1 Interest level 1 Reading level 2 Teaching goal 2 General comments 2 General suggestions 3 PART 2. ANSWERS AND SUGGESTIONS Chapter 1 5 Chapter 2 15 Chapter 3 25 Chapter 4 31 Chapter 5 35 Chapter 6 40 Chapter 7 50 Chapter 8 56 Chapter 9 65 PART 3 TEST INFORMATION Cornell Test X 71 Cornell Test Z 71 Ennis Weir Test 71 Whereas the problems discussed in CTB1 were primarily of the kind to which the student could respond “I agree” or “I disagree,” many problems in CTB2 are not that simple and the student is asked instead to think of acceptable solutions to the problems. In other words, the CTB1 problems involving value judgments could PARTI. almost invariably be answered, “This is either black or white,” but many of the CTB2 problems GENERAL INFORMATION which call for value judgments involve gray areas —i.e., what may be “right” for one case may be “wrong” for another and may be neither “right” nor “wrong” for still another case. CONTENT, INTEREST, AND Finally, the problems in CTB1 were somewhat READING LEVELS compartmentalized, with some, but not a great deal of, integration of materials from earlier chap ters into later chapters. In CTB2, however, ma terials from the first chapters appear again and Content level: again in many different contexts throughout the Critical Thinking, Book 2 (CTB2) assumes that book. (This is not evident from the index, how the students have completed Critical Thinking, ever, for most of these appearances are brought Book 1 (CTB1). Brief reviews of some CTB1 out by questions such as, “What reasoning materials are given in CTB2, but these reviews errors does the writer use in the third para will not serve as a substitute for the detailed graph?”) By using such a wide variety of con explanations, examples, and class discussions texts to expose the uses of various errors and needed for a thorough understanding of the ma techniques, the students learn automatically to terials in CTB1. look for such things and to think critically when Whereas CTB1 concentrated on some of the they are not in the classroom. obvious reasoning errors and propaganda tech It can be seen, then, that the level of the con niques and asked questions about some of the tent of CTB2 will result in the development of a more obvious items in the materials studied, considerably higher level of reasoning ability CTB2 assumes that the students are now than CTB1. This assumes, of course, that the thoroughly familiar with such materials and are student has reached a level of mental maturity past the stage of needing to have the obvious where such abilities are present and are waiting pointed out. CTB2 takes looks at uses and mis only to be developed. As mentioned in the uses of words, at more subtle reasoning errors Teacher’s Guide for CTB1, we can’t teach a six- and propaganda techniques, at hidden assump months-old baby to ride a bicycle, because the tions, and atwhat is probably meant by aspeaker baby lacks the necessary muscular strength and or writer. There are more problems to illustrate coordination. Similarly, we may not be able to uses of combinations of questionable state teach some of the CTB2 materials to a pre-teen ments and reasoning, and the questions asked or to a young teenager, since the thinking are more probing and more detailed in order to abilities needed may not yet be present. (More analyze the illustrations more thoroughly. research needs to be done on this topic.) Whereas CTB1 merely asked the student to decide whether a statement following a story was true, false, or questionable, chapter 5 of Interest level: CTB2 asks the student to distinguish among In order to expose the students to a realistic seven possibilities: absolutely true (or false), sampling of the kinds of reasoning and arguing true (or false) beyond a reasonable doubt, prob which are common in our society, a great many ably true (or false), or none of these. Further of the basic ideas for problems used in CTB2 more, the CTB2 student is expected not only to were taken from newspaper articles, editorials, be able to tell whether or not a statement letters to editors, advice columns, and commen supports a viewpoint (as distinguished from taries, and from newscasts, ads, ordinary con merely favoring the viewpoint) but, if so, to tell versations, political speeches and circulars, and whether the statement is a strong support or a government regulations, as well as from various weak support. other sources. Consequently, the material is at 1 the secondary school level of interest, with em among conclusions which are possibly true (or phasis on the high school level. false), probably true (or false), true (or false) Reading level: beyond a reasonable doubt, and absolutely true As in CTB1, it is recognized that many (or false); to recognize invalid arguments; to secondary school students have reading difficul recognize faulty reasoning; to recognize tech ties. With this in mind, the reading level of the niques of propaganda and argument; to sections preceding the problems and of most recognize strong points (and be able to refute problems and questions has been kept the same them) for both sides of a two-sided issue; to as in CTB1. However, in order to approximate analyze arguments (and statements of opinion); more closely actual newspaper articles, etc., the to be able to think of several solutions to reading level of some of the problems is higher problems which are not simply two-sided; to than in the rest of the text. distinguish between fact and opinion; to Daily newspapers are often said to be written recognize which side (if either) a statement at approximately a sixth grade reading level, and supports; to know whether a supporting yet I found many words (in newspaper articles I argument is strong or weak; to look for and wished to use as a basis for problems) which recognize unstated assumptions. were not on my reference list of words for the sixth grade level. I struggled with the decision of GENERAL COMMENTS whether or not to include such words in the In this book, the word “argument” is used problems and finally decided that if we are going in different ways at different times. It can be to teach our students to reason well when they (1) a discussion between two people who read something in a newspaper or hear it on TV, disagree on the answer to a question, with then we’d better expose them to the vocabulary each person making statements to convince such sources use. the other person to change her or his mind; The next decision was whether or not to in (2) one of the statements made in the dis clude the “newspaper” words in the glossary. cussion in (1) above; or Again, my decision was based on giving the (3) a set of premises and a conclusion (as in students a realistic exposure to such items, and chapters 2 and 6). (with a handful of exceptions) such words are In many cases, the decision of where in the not in the glossary, so you may find it helpful to book to place material was arbitrary. As ex keep a couple of dictionaries handy when your amples: most of the reasoning errors discussed class is discussing such problems. (chapter 3) are also used as propaganda tech The glossary does include about forty other niques (chapter 4), and vice versa; faulty infer words used in the text, however, and you will ences (chapter 5) are made as a result of rea want to point out to the students that the book soning errors (chapter 3); weak arguments does have a glossary. Words which are ex (chapters 2, 6, and 7) can be made to sound plained within the text are not included in the more plausible by the clever use of words glossary but are included in the index, so if a stu (chapter 1) and by use of the proper propa dent wants to find the meaning of a word, both ganda techniques (chapter 4); misuse and overly the glossary and the index can be checked. If it clever use of words (chapter 1) are generally does not appear in either place, then a dic techniques of argument and propaganda (chap tionary should be used. ter 4); deciding how well an argument is sup ported (chapters 2, 6, 7, and 8) often involves TEACHING GOAL the recognition of reasoning errors (chapter 3), techniques of propaganda and argument (chap Your teaching goal here, as in CTB1, should ter 4), unstated assumptions (chapter 7), and be to teach your students to think critically. misuse or overly clever use of words (chap Among the specific objectives included in reach ter 1). ing the goal this time are to get your students to In several problems, “Big City” is mentioned. do all of these: to know when to ask questions; Tell the students to assume that Big City is, in to know which kinds of answers are reasonable fact, a big city—say, a population of 1,000,000 and which kinds are not; to learn how choices of or more. words and phraseology can influence listeners’ The index will show that there is a wide variety attitudes; to knowwhen more evidence isneeded of problems here, which means that the students to reach a reasonable conclusion; to distinguish will be exposed to a good selection of everyday 2 life situations which require critical thinking. 5. Don’t feel that your students must go Furthermore, even within a given category (such through all problems and questions in the book. as “Court cases,” for example) the problems Although the problems and questions have been have been chosen to bring out different points carefully chosen to bring out different points, it from each other and so avoid being repetitious. is important to keep the students interested in the material. When you feel they have spent enough time on a particular section, feel free to go to the next section. (You can always come GENERAL SUGGESTIONS back to the previous section later and do more problems if you feel that certain points still need The suggestions in the Teacher’s Guide for to be brought out.) CTB1 apply here, too, and you may wish to read 6. Certain chapters have a great many prob them again to refresh your memory. In addition lems and questions in the Chapter Review sec to those suggestions, you might consider these: tions. It. is suggested that you have the students 1. Don’t take for granted that my answers are do as few of them as are needed to provide a infallible. Do encourage the students to think of good review, and ignore the rest of the prob and support their own answers. The fact that I lems for the time being. Then once a week or think right now that my answers are right doesn’t so, go back and choose an unused problem or mean I wouldn’t change my mind if presented two from each Chapter Review section for the with a good reason to do so. students to do. This will provide a constant 2. When a problem has several answers (such review of old material and so make it easier as, “What reasoning errors are present here?”), for the students to apply the knowledge to don’t take for granted that you’re through with it new situations. once the students come up with my answers. Do encourage the students to see if they can find 7. If a student presents a questionable line of additional answers I didn’t think of. reasoning, follow the reasoning through to its 3. Make a habit of throwing in many questions logical conclusion. Whereas we tended to be about the materials being studied. I am con rather careful about pointing out students’ rea stantly amazed at the way many of my students soning errors during CTB1 (in order to encour have to grope for answers to what I think are age the students to keep participating and in “giveaway questions”—questions whose an order not to embarrass them), we may now swers I think will be obvious to the students assume that students who have survived CTB1 and which are asked primarily to build up their are ready for some serious and objective obser confidence. For example, a student may (1) vations about their own thinking processes. This know what a proposition and its converse are, is not to suggest that you be pedantic or tactless (2) be able to state the converse of any proposi about pointing out students’ reasoning faults, but tion I state, (3) know that the converse of “All rather that the students’ reasoning processes tigers are animals” is “All animals are tigers,” should now have matured to the point were a (4) know that all tigers are animals but that not all dogged (but not dogmatic) line of questioning is animals are tigers, and yet (5) have to stop and no longer mistaken for a put-down. think a while about the answer to, “Suppose a 8. Although you will encourage class discus proposition is true. Then does its converse have sion of all answers, the discussions will be quite to be true, too?” short on some, since some problems encourage 4. Although we encouraged the students to be convergent thinking. Be especially careful, how nit-pickers and hair-splitters in most of the CTB1 ever, about suggesting that a student has a answers to problems and questions, we want to wrong answer to a question which asks an discourage this in answering most of the prob opinion—e.g., “Do you think. “What would . .?“ lems and questions in CTB2. That is, we want you do if “Do you agree “What . . .?“ . . .?“ the students to realize (and take into account) seems to be the purpose of. In cases where . .?“ that remote possibilities exist, but we also want I give answers to such questions, remember that them to recognize such possibilities for what such answers are simply my personal opinions. they are and to beable to decide what is prob Don’t think that the students are “supposed” to jy true (or false). Many students will find such arrive eventually at the answers I give. (My an decisions to be very difficult, so be prepared to swers to such problems are sometimes prefaced allow a good deal of time for class discussions with, “Answers will vary,” and sometimes are when such decisions are involved. not so prefaced.) Give a student credit for any 3 answer which is backed up well. The student may or may not have a change of mind after hearing classmates’ arguments, but either way, he or she should not feel pressured to go along with the others. 9. The kinds of questions mentioned in item 8 above are often matters of value judgments and, although it may bother you personally that a stu dent has made a “wrong”—i.e., immoral or un ethical—judgment, your job as a teacher of criti cal thinking is to get the student to be consistent. Make a mental note of a “wrong” decision and then point out the inconsistency when the stu dent makes a “right” decision in a similarcase. 10. You may find it helpful to read the ma terials listed in the bibliography. Some items listed are good primarily for background on thinking skills, but most will supply you with many more examples and problems you can give your class for discussion. I particularly enjoyed the writing and the examples given by Engel and Potter in their books. In the Arendt books, I found a great many statements whose truth I questioned. If your class is unusually sharp, you might like to choose some of Arendt’s state ments for the class to discuss. And, although I based many problems and questions on items found in Detroit’s two major daily newspapers, your own local paper(s) should supply you with many additional possibilities for class discussion. 4 words per se, they are used in problems PART 2. ANSWERS throughout the text. As you go from section to section and chapter to chapter,keep pointing AND SUGGESTIONS out that emotional words are being used so that the students learn to recognize automatically the CHAPTER1 bias such words introduce into sentences. Emphasize that we are not saying it is wrong to use emotional words or to express opinions General Comments: instead of facts. But we do want the students to We can hear things and be influenced without recognize emotional words for what they are, even realizing it. Or if we do realize we are being and we do want the students to be able to tell influenced, we may not quite know why. Under the difference between a fact and an opinion. lying this influence may be any of a number of Section 7.4 discusses the difference between a the topics discussed in this chapter. As you go fact and an opinion in more detail. from section to section, it would be a good idea to keep pointing out to the class how we can be Sec. 1.2 answers: influenced without being aware of it. 1. Answers may vary. My answers are these: An excellent source of examples ofthe misuse Pleasant: true, dependable, honor, paramedic, of words is “The Public Doublespeak News tidy, interesting, champion, physician, talent, letter,” published by the Committee on Public friendship. Unpleasant: boring, sloppy, awkward, Doublespeak of the National Council of Teachers nasty, disorganized, disloyal, clumsy, misman of English. As of this time, subscriptions are age, failure, messy. (If your students’ lists $2.50 a year (payable to NCTE) and may be sent disagree, ask them to discuss how come. to The Committee on Public Doublespeak, Remember, the lists were to be made according NCTE, 1111 Kenyon Road, Urbana, Illinois to the t reaction to the word, not to whether 61801. or not the word “should” sound pleasant or unpleasant to us.) 2. a. Pleasant: steadfast, Sec. 1.1 comments: leader, organized, pal, physician, honesty. Un At this stage of the students’ critical thinking pleasant: counterfeit, bungling, enemy, false, development, we would like to discourage nit- hatred, unreliable b. Other answers are picking except in parts of the book which spe possible. Answers could be: steadfast enemy, cifically call for it. The students are informed of false honesty, organized hatred, counterfeit pal, this in this section. As implied in the second bungling physician, unreliable leader. (Watch for paragraph of the section, it will sometimes be a answers which seem not to make sense, such battle to teach the students the difference as “enemy pal” or “false steadfast.” Ask between nit-picking and a good possibility. students who have such answers to use them in Although we will go into this in some detail later a clear context. For example, clear contexts for in the book, we start out by giving situations my answers are: (1) He was a steadfast enemy. where nit-picking exceptions are (we hope) He never let up. He twisted meanings, assumed obviously not the probable answers. At the same the worst, and pounced on the smallest errors. time, in section 1 .5 (Vague Sentences) and (2) She claimed she was being honest, but it was section 1 .8 (Meaningless Words.. .), we want a false honesty. She told the truth all right, but the students to distinguish between nit-picking she didn’t tell the whole truth. She said she saw and honestly not having enough information to the big kid take away the little kid’s toy and slap draw an intelligent conclusion. the little kid and make him cry. But she didn’t Althoughthere are no exercisesforthissection, mention that the little kid’s toy was a loaded BB you will want to discuss this section with your gun which the little kid was using to try to force students so that they will know what they will be the big kid into giving him money in order not to studying and why they will be studying it. be shot. (3) In Nazi Germany, it was a campaign Sec. 1.2 comments: of organized hatred against the Jews: Jews This section points out that we automatically were inferior; Jews were pushy; Jews observed react to many words with a value judgment of strange rituals; Jews were the cause of all the “pleasant” or “unpleasant.” It follows that such money problems; once Jews were eliminated, words influence us one way or the other when Germany would be.a great country. (4) He was a they are used to describe something. Although counterfeit pal. His apparent affection was part the text refers only occasionally to emotional of a calculated plan to be accepted into the 5