5.3: Evaluating Claims to Expertise

Appeals to experts can be thought of as arguments with the following form:

Premise: An expert on the subject says that X is true.

Conclusion: Therefore, X is true.

Or, breaking the premise up into smaller parts:

Premise 1: E is an expert on subject S.

Premise 2: Claim X involves subject S.

Premise 3: E says that X is true.

Conclusion: Therefore, X is true.

We don’t usually say this sort of thing explicitly when we cite an expert to convince others that X is true. But we usually go through this sort of reasoning (though not always consciously or explicitly) any time we rely on an expert. Such arguments are not deductively valid. Why not? Because even the best experts can be wrong. But in the case of legitimate appeals to authority, the argument will often be inductively strong. The better the authority, and the more the authorities agree about the issue in question, the stronger the argument will be.

When evaluating the claims or advice of a potential expert, we should ask ourselves the following seven questions:

1. Do we care enough about the issue to try to evaluate those who claim to be experts about it?
2. Is the field one in which there even are experts?
3. Is the source an expert on the relevant issue?
4. Has the source been quoted accurately?
5. Is the issue one in which the experts are (mostly) in agreement?
6. Is the source’s claim one that is very unusual or surprising?
7. Is there any reason to think that the source might be biased or mistaken in this case in particular?

We will consider these matters in turn.

Is the Issue Important to us?

Information is often very valuable. What you don’t know can hurt you. It can even kill you. Suppose tests show that you (or your ten-month-old daughter, or your sixty-year-old grandfather) have a serious form of cancer. Various treatments are available, each with its pluses and minuses. Here, you would want to find out what the experts thought about the merits of various treatments before you decided what to do. Indeed, it would be very sensible to get more than one opinion.

But information is not intrinsically valuable. More isn’t always better. The trick is to know when you need information and when you don’t (an even bigger trick is mustering the energy to go get it when you know you need it). Lots of information is useless. No normal person will feel the need to know the exact number of blades of grass in their front yard, at least not enough to count them. Lots of information isn’t relevant to our concerns. Moreover, even when it is, there is usually a cost to acquiring it. It takes time and effort to read the relevant things and to talk to the relevant people, and in many cases the return on this investment is not large enough to justify the effort.

Information is also not intrinsically important. What information is important to you at a given time depends on your needs and interests at that time. If Wilbur makes a claim about OU’s record in football ten years ago, you may doubt his recollection, but the topic probably doesn’t matter enough for you to check. But if you have a lot of money riding on a bet about OU’s record over the past decade, it would be important to find out if Wilbur really is reliable about such things. Whether this is so or not depends on your priorities and the situation. It is possible to spend too much time gathering information that we don’t need and too little time gathering information that we do need. But most of us err much more in the direction of obtaining less information than we need, rather than obtaining too much. So, we’ll focus on that here.

There are also cases where we need more information but there isn’t time to get it. If you are driving down a country road and find someone who is bleeding badly after a motorcycle accident, it would be very useful to know a good deal about first aid. But you don’t have time to acquire the information you need. It is useful to acquire such skill in first aid, but there will always be situations we aren’t prepared for, and here we must do the best that we can.

Are There Even Experts in the Relevant Field?

In some areas, there may not be any experts at all. Are there people we can rely on to tell us the best name to give our new cat, or if Captain America and Superman would be friends if they were real people? In extreme cases, people claim to know things that couldn’t possibly be known, at least not now. No one, for example, can now know whether there is intelligent life on other planets (though some people can make more informed estimates about such things than others). In cases where you can’t be certain who, if anyone, is an expert, it is best to keep an open mind and remain undecided or, if you feel you must have some view, to accept an opinion very tentatively and provisionally.

Is the Source an Expert on the Relevant Issue?

We can only rely on an expert on matters that fall within their field of expertise. So, it is always important to ask whether the source is likely to be reliable about the subject matter at hand. Advertisements featuring celebrity endorsements often show people who aren’t experts about the products they hawk. Lebron James probably knows a lot about nutrition, but he can’t be relied on to know whether Wheaties are more nutritious than comparable cereals.

In most cases, though, the ad is probably not really designed to strike us as an appeal to expertise. It is so obvious that celebrities are rarely experts about the things they sell that we aren’t likely to be taken in by them. Such advertisements are probably aimed more at getting us to identify emotionally with a product because we like (or want to be like) the celebrity selling it.

The views of famous people are often cited on matters where there are not experts. Albert Einstein is one of the greatest physicists who ever lived, and he did think carefully about many things. Even so, there is little reason to think that he discovered deep truths about religion or ethics. With the knowledge explosion, there are also people who were experts in a field, but who didn’t keep up with things. If their information is sufficiently out of date, they may appear to be experts when they no longer are.

Is the Expert Quoted Accurately?

It should go without saying that the source needs to be quoted accurately, but we often fail to do this. Usually no one bothers to check, and so a misquotation or inaccurate paraphrase easily escapes notice. Misquotation is sometimes intentional; it can be useful to cite some respected person to help make our case. But human memory is very fallible, and a misquotation often results from an honest mistake. It is also possible to quote someone accurately, but to take their remark out of context or to omit various qualifications they would make. Such quotations are also of little value in constructing a good appeal to expertise.

Are the Experts in Substantial Agreement?

Experts in any area will disagree now and then, but in some areas disagreement is the typical state of affairs. For example, there is considerable disagreement among good economists on long-range economic forecasts or on the trends the stock market will take. There is little consensus among meteorologists about long-range weather forecasts. Able scientists disagree about the likelihood that there is life on other planets. When such disagreement is widespread, some of the experts are bound to be wrong, and we cannot reasonably expect that the expert we happen to rely on will be one of those who turns out to be right.

We can’t expect total agreement among all the experts, of course, so again we face a matter of degree (the more agreement among the experts the better). In cases where reasonable disagreement is inevitable, it is impossible to rely uncritically on experts, and you must obtain as much information as you can and think critically about the issues for yourself.

Is the Claim Unusually Surprising?

When someone makes a claim that almost everyone agrees is true (e.g., that United States is in North America), they don’t need to build a case for it. Life is short, and we don’t want to hear arguments to support everything anybody says. But if someone makes a surprising or controversial or implausible claim (e.g., that vaccines cause autism), then it is their responsibility to give reasons for their claim.

The more implausible the claim, the heavier their burden of proof. The basic point is that people can be wrong, and if a claim is extremely surprising, it may be far more likely that the source made a mistake (or is lying) than that the surprising claim is true (we will return to this topic when we discuss appeals to ignorance in chapter 10.)

Is the Expert Likely to be Biased or Mistaken?

Experts are only human, and they are subject to the same biases and flaws as the rest of us.

Vested Interests

In some cases, an expert may have a reason to deceive us. There is a sucker born every minute, and experts can use their credentials to take advantage of this. There will always be people with advanced degrees or years of training who offer a quick fix in exchange for a fast buck. Doctors working for tobacco companies did many studies that allegedly failed to establish the harmful effects of smoking.

If it is obvious that someone stands to gain if we follow their advice, we are likely to be suspicious. But it isn’t always clear when this is the case. For example, a skilled financial advisor often gets a cut if you invest your money in the mutual funds he recommends. The adjustor from the insurance company may well be an expert on roofs, but it can be in their interest to have the insurance company pay you as little as possible. Of course, such people are often honest and do give good advice, but it is always important to know whether others have something to gain before we follow their advice.

It is also important to keep in mind that we often have biases without even realizing it. We will talk about this in detail in chapter xx, but for now it is enough to note that a person’s vested interest may be so engrained in how they view the world that they may not even realize it is leading to biased recommendations.

Honest Mistakes

Sometimes an expert has good intentions but is still prone to error for some reason or another. A referee who is usually good at telling whether a basketball player was guilty of charging may miss a call because they didn’t see the action clearly. A conscientious psychiatrist who is adept at spotting problems in adolescents may have a blind spot when it comes to their own children.