CRITICAL THINKING REASONS FOR BELIEF AND DOUBT (VAUGHN CH. 4)

Transcription

1 CRITICAL THINKING REASONS FOR BELIEF AND DOUBT (VAUGHN CH. 4) LECTURE PROFESSOR JULIE YOO Claims Without Arguments When Claims Conflict Conflicting Claims Conflict With Your Background Information Experts and Evidence Signs of Expertise Illegitimate Uses of Experts Bias Among Experts Signs of Dubious Authority Limits of Expertise Personal Experience As Source of Evidence Impairment Expectation Innumeracy Fooling Ourselves Resisting Contrary Evidence Looking for Confirming Evidence Preferring Available Evidence Claims In the News Importance of Critical Thinking Inside the News Sorting Out the News Advertising and Persuasion Reasons for Belief and Doubt Page 1 of 7

2 CLAIMS AND EVIDENCE Believing or doubting a claim is usually not an all or nothing affair. There are degrees of belief and disbelief, where some claims merit a high degree of believability, some merit a low degree of believability, and many somewhere in between. This is because much of the time, the evidence for a claim is not as complete or as supportive to fully determine its credibility. The good critical thinker will always proportion his or her belief to the evidence. This is a principle that can be understood in terms of how much of your hard-earned money you would bet on backing up the claim. If you would bet your entire bank account on a claim, then you have a high degree of belief in its truth; if you would only bet a few nickels, then you have a fairly low degree of belief in its truth. Many of your beliefs will be somewhere in between. And many other claims call for a complete suspension of belief. What are the acceptable forms of evidence? All claims need evidential support in one form or another. One form of evidence is the giving of reason in the form of a deductive or inductive argument. But often these are not explicitly stated or not available. This can happen when someone makes a claim without argument, or when a premise of an argument is itself not backed up by another argument. Nonetheless, there are ways of gathering evidence that do not come in the form of deductive or inductive arguments. In this chapter, we will consider some principles concerning some forms of non-argumentative evidence. These principles are not strict rules; they are rough rules of thumb, because there are contexts and circumstances that call for disregarding the principle. However, they can be good things to keep in mind. (My wording of the principles is slightly different from Vaughn s.) WHEN CLAIMS CONFLICT Conflicting Claims Suppose there is a new product that promises to repel mosquitoes. There is a claim that the product is effective, but there is also a conflicting claim that it does nothing at all. Suppose also that you have no other information to help you decide between the two conflicting claims. What do you do? Here is the principle: Principle: If there is no evidence supporting either one of two conflicting claims, then you cannot believe either. Until you have evidence to favor one claim over the other, you cannot believe either claim. You must suspend your belief regarding both claims until further evidence, either in the form of personal experience or a reliable source. Conflict With Your Background Information A claim is always evaluated in light of many other things you believe. These other things that you believe are what we may call your background information. Much of this background Reasons for Belief and Doubt Page 2 of 7

3 information is made up of common sense or common knowledge, which we amass as we go through life. Principle: If a claim conflicts with other claims you have good reason to believe, supported by common sense or common knowledge, then you have good reason to doubt the claim. Sometimes, this principle cannot be followed. If example, there was a time when it was common sense to believe that the earth was flat or that the earth was at the center of the solar system. Common knowledge itself had to change to accommodate new scientific findings. This means that we must always remain open to changing our background information, relying on personal experience or experts, depending on what is available. EXPERTS AND EVIDENCE Experts are a very big source of evidence. An expert is someone who is more knowledgeable about an area than others, and therefore deserves more credibility in their area of expertise than nonexperts. Principle: When experts disagree about a claim, then we have good reason to doubt it. This is not to say that experts are always right. Even experts change their views about their own areas of expertise. Also, an expert in one field is not necessarily an expert in another. Sometimes, this can be tricky to assess. As Vaughn explains in his discussion of whether doctors are experts, they are experts in diagnosing and sometimes treating disease and injury. However, they are not always experts in the effectiveness of a drug or a treatment, even though they administer them. Doctors rely upon the expert advice of medical scientists (who may also be doctors), who spend their time researching issues of drug or treatment effectiveness. Signs of Expertise There are usually two necessary prerequisites for gauging whether someone is an expert in a certain field. 1. Education and training from reputable institutions or programs in the relevant field. 2. A track record of making good judgments in the field. 3. Reputation among peers. 4. Professional accomplishments. Illegitimate Uses of Experts When we believe the claims of experts outside of their specialized area or when simply believe the claims of non-experts because of their celebrity, then we misuse the appeal to authority and commit what is known as the fallacy of the appeal to authority. Reasons for Belief and Doubt Page 3 of 7

4 Bias Among Experts Sometimes, experts are biased even in their own field of expertise. They can be driven by their personal religious convictions, or by financial rewards, or just their own inflated egos. When this happens, the claims they make are not always reliable. Unfortunately, it is not always easy to detect bias among experts. We thus have to do some of our own research in gauging the reliability of an expert. Signs of a Dubious Authority When an expert does the following things, that is a signal that we should not give them as much authority: Make simple factual or formal errors. Does not support their claims, even when given the opportunity. Commit logical contradictions or inconsistencies in their speech or writing. Does not treat opposing views fairly. Is biased, emotion, or dismissive. Relies on information that you know is out of date. Most other experts in the same field disagree. Again, none of these things are hard and fast rules. It depends on the amount, the extent, and the context. And just as belief can come in degrees, so does doubt about the reliability of an expert. Limits of Expertise The kinds of areas to which re reply for expert opinion are things like science, medicine, engineering, history, and current affairs. For these areas, we have people who excel in the body of knowledge that goes with these fields: scientists, doctors, engineers, historians, and journalists. But there are some areas that cannot be decided by experts. These involve problems that arise in morality, politics, and religion. Although there are people who are experts in the scholarship of these areas, they are not necessarily the people who know what is right for an individual when specific problems arise. PERSONAL EXPERIENCE AS SOURCE OF EVIDENCE Much of the evidence for a claim comes from one s own personal experience. Evidence gained from personal experience includes the things you discover from your senses, the events you remember, and our judgment involving the faculties of sensory observation and memory. But personal experience is not always perfect. Thus, we have the following principle: Reasons for Belief and Doubt Page 4 of 7

5 Principle: We should accept the evidence of personal experience unless there are good reasons to doubt the personal experience. A number of things can impede the reliability of the evidence gained from personal memory. It is fairly easy to identify these when these impediments occur in other people. It is much harder when we try to identify when they occur in ourselves. Let us see what they are. Impairment Our sense can be debilitated in several ways: illness, injury, stress, intoxication, distraction, disorientation, and others. Information from the senses can also be poor when conditions for perception are not optimal: poor lighting, noisy environment, we are too far away from the object of perception, and so on. Memory is also not always reliable, since we often forget things or simply misremember events. Part of the reason for this is that our faculties of sensory perception and memory function constructively. They do not just passively record an event the way cameras or tape recorders do. Instead, they construct perceptions from partial data, shaped in large part by a person s expectations and background information. Expectation We need to be aware of how influential someone s expectations may be. We often perceive what we want to perceive, or what we expect to perceive, even when there is no input that justifies the perception. Expectation can also distort memories. Innumeracy When it comes to judging the probability of an event, we need to be extra careful. This is because human brains are very bad at figuring out probabilities. Our gut feelings about the probability of an event are often wrong. Even doctors, who have had years of math and science training, routinely make errors about probabilities. (There are several basic laws of probability that we will be introduced to at the end of the semester.) FOOLING OURSELVES Human weakness is not only a problem for morality. It is also a problem for critical thinking. There are three common forms of human weakness in the area of crucial thinking, all of which lead us to mishandle evidence. Reasons for Belief and Doubt Page 5 of 7

6 Resisting Contrary Evidence When something challenges a cherished belief, we tend to deny evidence, ignore it, or reinterpret it so that it fits better with our prejudices. This often happens when one is emotionally tied to believing something. The emotional tie make you blind to the relevant evidence. Looking for Confirming Evidence In chapter 2, we went over the problems of self-interested thinking (pp ). We discussed the problems of what is known as confirmation bias, which is the tendency to believe things that already conform to our opinions. Preferring Available Evidence Another mistake is what is known as availability error. This is when we rely on evidence because it is memorable or striking, not because it is trustworthy. This may underlie airplane phobia, where the phobic flyer avoids taking airplanes because of vivid pictures of airplane crashes. Such sensational pictures are more psychologically available than numbers and statistics about car and air travel and accidents. CLAIMS IN THE NEWS Importance of Critical Thinking The news is supposed to be in the business of updating us on the facts, not in rationally justifying what they believe are the facts. This is why critical reasoning is so important. Without justifying one s beliefs about the facts, one cannot really claim to have knowledge, since knowledge is more than mere belief. Knowledge requires justification, and journalists are not always good about justifying their claims. Inside the News We need to remember that news organizations are businesses that aim to make a profit. This may compromise the quality of the reporting, since valuable stories do not always sell. There are several ways in which an accurate account of the world gets distorted: passive reporting versus hard investigative journalism selective, non-offensive, reporting inaccurate coloring and emphasis Reasons for Belief and Doubt Page 6 of 7

7 Sorting Out the News Here are some things you can look out for to assess whether a news report is trustworthy. As always, it is easier harder to identify the biases in real life cases. look for reporter slanting consider the source check for missing information look for false emphasis check alternative news sources ADVERTISING AND PERSUASION Ads make all sorts of claims favoring their products. Since their purpose is to get you to buy their things, there is an undeniable bias about their products that discredit their credibility. The following principle is: Principle: We generally have good reason to doubt advertising claims and to be wary of advertising s persuasive powers. In other words, we should always approach claims made by ads with suspicion. This is for several reasons. First, advertisements are not always interested in promoting the welfare of the consumer; it is much more interested in getting you to buy. Second, there is a poor track record of truth and accuracy. There are certain things to be wary of: celebrity endorsements slogans misleading comparisons weasel words Reasons for Belief and Doubt Page 7 of 7