批判性思维 (1).pdf

If you attend a university,we d bet you hear a lot about critical thinking.Perhaps you will hear your professors telling you how important it is,or how dismayed they are there isn t more of it in today s world.Unfortunately,you may not be entirely sure what exactly it is they think is lacking.If you listen for a while you may get the idea that whatever it is,all your professors are certain they empha-size it in their courses.You may even get the idea that for many of them“critical thinking”is mainly just whatever it is they happen to teachsociology,history,business,com-munications,or whatever.Is there any common ground among educators about what critical thinking is?Yes!Most educators probably agree that a person who jumps to conclusions or makes ill-formed,indefensible,knee-jerk decisions has not thought critically.A while back we read about a teenager who was spotted shoplifting;the police were called and arrested the young man.While they were reading him his rights,he shook out of their grasp and made a run for it.Unfortunately,as he made his break his huge trousers tripped him,and that was the end of his getaway.*Everyone will agree that trying*The lad had not been handcuffed,the police perhaps assuming his trousers would serve the same purpose.Students will learn to.1.Define critical thinking2.Distinguish objective claims from subjective claims3.Understand subjectivism as it relates to moral claims4.Identify issues5.Define and identify premises and conclusions6.Recognize an argument7.Define and identify twelve common cognitive biases8.Understand the terms truth and knowledge as used in this book1WHAT IS CRITICAL THINKING,ANYWAY?1moo38286_ch01_001-036.indd 1moo38286_ch01_001-036.indd 112/9/10 1:05 PM12/9/10 1:05 PM2 CHAPTER 1:WHAT IS CRITICAL THINKING,ANYWAY?to run from the police,especially when your pants are on the ground,is not thinking well,let alone thinking critically.This may seem like an unimport-ant or frivolous example,but it really is not much different in principle from signing on for mortgage payments that are more than you earn,orif you are a mortgage broker or an insurance companybetting that people who do that will be able to manage the trick.What,then,is critical thinking?Clearly it involves more than just blindly acting or reacting.Every educator will concede that critical thinking aims at making wise decisions and coming to correct conclusions,and not being way-laid by temptation,emotion,greed,irrelevant considerations,stupidity,bias,or other similar things.To refi ne this a bit,on the one hand there is good,old-fashioned think-ing.That s what we do when we form opinions or judgments,make decisions,arrive at conclusions,and the like.On the other hand,there s critical think-ing.That s what we do when we critique the fi rst kind of thinkingsubject it to rational evaluation.You might say that critical thinking involves thinking about thinking;we engage in it when we consider whether our thinking(or someone else s)abides by the criteria of good sense and logic.Possibly you ve taken courses where all you have to do is remember stuff.But in other coursesand in the workplace or in the militaryyou will per-haps have been asked to do moremaybe to design or evaluate something,to make a proposal or diagnose a situation,to explain or comment on something,or to do any number of other things that involve coming to conclusions.Pos-sibly it worked this way:your instructor or colleagues or friends or supervisors read or listened to your fi ndings,then they offered critical commentary.They gave you feedback(usually,we hope,positive).They evaluated your reason-ing.If you are brilliant,you may not have needed their feedback.If you are brilliant,perhaps you never err in your thinking or leave room for other criti-cism.But most of us do occasionally make mistakes in reasoning.We overlook important considerations and ignore viewpoints that confl ict with our own,and in other ways we don t think as clearly as we might.Most of us can ben-efi t from a little critical commentaryeven when it comes from ourselves.Our chances of producing a good essay or offering a sound proposal or making a wise decision improve if we don t simply write or propose or decide willy-nilly,but refl ect on our reasoning and try to make it better.Our chances of thinking well improve,in other words,if we think critically:if we critique our own thinking as a thinking coach might.This is a book in critical thinking because it offers guidance about cri-tiquing thinking.The book,and the course you are using it in,if you are,explain the minimum criteria of good reasoningthe requirements a piece of reasoning must meet,no matter what the context,if it is worth paying attention to.Along the way we will explore the most common and important impediments to good reasoning,as well as some of the most common mis-takes people make when coming to conclusions.Other courses you take at the university offer refi nements.In them you will learn what considerations are important from the perspective of individual disciplines.But in no course any-where,at least in no course that involves arriving at conclusions,will thinking that violates the standards set forth in this book be accepted.If it does nothing else,what you read here and learn in your critical thinking course should help you avoid at least a few of the more egregious common errors people make when they reason.If you would have otherwise made these mistakes,you will moo38286_ch01_001-036.indd 2moo38286_ch01_001-036.indd 212/9/10 1:05 PM12/9/10 1:05 PMWHAT IS CRITICAL THINKING,ANYWAY?3have become smarter.Not smarter in some particular subject,mind you,but smarter in general.The things you learn from this book(and from the course you may be reading it for)apply to nearly any subject people can talk or think or write about.To a certain extent,questions we should ask when critiquing our ownor someone else sthinking depend on what is at issue.Deciding whom to vote for,whether to buy a house,whether a mathematical proof is sound,which toothpaste to buy,or what kind of dog to get involve different considerations.In all cases,however,we should want to avoid making or accepting weak and invalid arguments.We should also avoid being distracted by irrelevancies or In DepthCritical Thinking,the Long VersionIn the text,we give a couple of brief characterizations of critical thinking,and as shorthand they will serve well enough.But the Collegiate Learning Assessment(CLA)Project of the Coun-cil for Aid to Education has come up with a list of skills that covers almost everything your authors believe is important in critical thinking.If you achieve mastery over all these or even a significant majority of them,youll be well ahead of most of your peersand your fellow citi-zens.In question form,here is what the council came up with:How well does the student determine what information is or is not pertinent;distinguish between rational claims and emotional ones;separate fact from opinion;recognize the ways in which evidence might be limited or compromised;spot deception and holes in the arguments of others;present his/her own analysis of the data or information;recognize logical flaws in arguments;draw connections between discrete sources of data and information;attend to contradictory,inadequate,or ambiguous information;construct cogent arguments rooted in data rather than opinion;select the strongest set of supporting data;avoid overstated conclusions;identify holes in the evidence and suggest additional information to collect;recognize that a problem may have no clear answer or single solution;propose other options and weigh them in the decision;consider all stakeholders or affected parties in suggesting a course of action;articulate the argument and the context for that argument;correctly and precisely use evidence to defend the argument;logically and cohesively organize the argument;avoid extraneous elements in an arguments development;present evidence in an order that contributes to a persuasive argument?moo38286_ch01_001-036.indd 3moo38286_ch01_001-036.indd 312/9/10 1:05 PM12/9/10 1:05 PM4 CHAPTER 1:WHAT IS CRITICAL THINKING,ANYWAY?being ruled by emotion,succumbing to fallacies or bias,and being infl uenced by dubious authority or half-baked speculation.These are not the only criteria by which reasoning might be evaluated,but they are central and important,and they provide the main focus of this book.BELIEFS AND CLAIMSWhy bother thinking critically?As we just said,the ultimate objective in thinking critically is to come to conclusions that are correct and to make deci-sions that are wise.Because our decisions refl ect our conclusions,we can sim-plify things by saying that the purpose of thinking critically is to come to correct conclusions;the method used to achieve this objective is to evaluate our thinking by the standards of rationality.Of course,we can also evaluate someone else s thinking,though the objective there might simply be to help the person.When we come to a conclusion,we have a belief.Concluding involves believing.If you conclude the battery is dead,you believe the battery is dead.Keeping this in mind,let s defi ne a few key terms.A belief is,obviously,something you believe.It is important to under-stand that a belief is propositional,which means it can be expressed in a declarative sentencea sentence that is either true or false.A good bit of mud-dleheaded thinking can be avoided if you understand that beliefs are proposi-tional entities,but more on this later.As we use these words,beliefs are the same as judgments and opinions.When we express a belief(or judgment or opinion)in a declarative sentence,the result is a statement or claim,and for our purposes these are the same thing.Claims can be used for other purposes than to state beliefs,but this is the use we re primarily concerned with.The judges critique dancers on Dancing With The Stars,but that doesnt automatically qualify as thinking critically.moo38286_ch01_001-036.indd 4moo38286_ch01_001-036.indd 412/9/10 1:05 PM12/9/10 1:05 PM BELIEFS AND CLAIMS5Objective Claims and Subjective ClaimsBefore we say something more about conclusions,we should make a distinction between claims that are objective and those that are subjective.An objective claimhas this characteristic:whether it is true or false is independent of whether people think it is true or false.“There is life on Mars”is thus an objective claim,because whether or not life exists there doesn t depend on whether people think it does.If everyone suddenly believed there is life on Mars,that doesn t mean that suddenly there would be life on Mars.Likewise,“God exists”is an objective claim because whether it is true doesn t depend on whether people think it is true.Although objective claims are either true or false,we may not know which a given claim is.“Portland,Oregon,is closer to the North Pole than to the Equa-tor”is a true objective claim.“Portland,Oregon,is closer to the Equator than to the North Pole”is a false objective claim.“More stamp collectors live in Portland,Oregon,than in Portland,Maine”is an objective claim whose truth or falsity is not known,at least not by us.Not every claim is objective,of course.“Barack Obama is one cool daddy”is not objective,for it lacks the characteristic mentioned previously.That is,whether or not some-one is one cool daddy does depend on whether people think he is.If nobody thinks Barack Obama is one cool daddy,then he isn t.If Parker thinks Barack Obama is one cool daddy and Moore doesn t,you will say that Parker and Moore are each entitled to his opinion.That s because whether someone is one cool daddy is in the eyes of the beholder.Claims of this variety are subjective claims.Whether a subjective claim is true or false is not independent of whether people think it is true or false.Examples of subjective claims would be judgments of taste,such as“Rice vin-egar is too sweet.”Is rice vinegar too sweet?It depends on what you think.Some kinds of comparisons also are subjective.Is snow boarding more fun than A rescue team in action.Not thinking critically about your decision to ski in avalanche conditions can have grave consequences.moo38286_ch01_001-036.indd 5moo38286_ch01_001-036.indd 512/9/10 1:05 PM12/9/10 1:05 PM6 CHAPTER 1:WHAT IS CRITICAL THINKING,ANYWAY?skiing?Again,it depends on what you think,and there is no further“truth”to consider.However,many statements contain both objective and non-objective elements,as in“Somebody stole our nifty concrete lawn duck.”Whether the lawn duck is concrete is an objective question;whether it is our lawn duck is an objective question;and whether it was stolen is an objective question.But whether the stolen concrete lawn duck is nifty is a subjective question.Fact and OpinionSometimes people talk about the difference between“fact”and“opinion,”having in mind the notion that all opinions are subjective.But some opinions are not subjective,because their truth or falsity is independent of what people think.Again,in this book“opinion”is just another word for“belief.”If you believe that Portland,Oregon,is closer to the North Pole than to the Equa-tor,your opinion happens to be true,and would continue to be true even if you change your mind.You can refer to objective opinions as factual opinions or beliefs,if you wantbut that doesnt mean factual opinions are all true.“Portland,Oregon,is closer to the Equator than to the North Pole”is a factual opinion that is false.So:factual opinion/belief/claim=objective opinion/belief/claim=opinion/belief/claim whose truth/falsity is independent of what anyone thinks.Moral Subjectivism“There is nothing either good or bad,but that thinking makes it so,”said Hamlet,nicely expressing a point of view known as moral subjectivism.Some beginning critical thinking students,like Hamlet,assume that when you ascribe a moral property to something,your claim is purely subjective:whether something is good or bad or right or wrong depends entirely on what you think.Is bullfi ghting wrong?Well,as moral subjectivists say,it s a matter of opinion,and one opinion is as correct as the next.You should be wary of the notion that all moral opinions are subjective or that one moral opinion is as correct as the rest.Consider the following real-life event.(We must warn you the example is very unpleasant.Unfortu-nately,it often takes an example of this sort to get the point across.)In Kelsey In DepthThinking About ThinkingA subjective statement is made true by someones thinking it is true.Does this mean that statements about what someone is thinking are subjective?The answer is no,though it may take a second to see this.Take the statement“Joanie is thinking of moving.”What makes that statement true,if it is,is not Joanies thinking that the statement is true.What makes it true is that Joanie is thinking of moving.A statement about what someone is thinking is an objective statement about what is going on in the pe