Fourth, we should ask, “Is there agreement among appropriate experts on this issue?” Of course, there cannot be agreement among appropriate experts if there are no appropriate experts. Some issues cannot be settled by expert opinion. No group of experts now can settle whether there is life on Mars. They need more evidence than we have at present. No group of experts could ever be able to settle which kind of fish tastes best. That is not the right kind of issue to settle conclusively. We can identify such gaps in expertise by asking whether this is the kind of question that can now be settled by expert consensus.
If so, we can next ask whether experts have reached agreement. Of course, unanimity is not required. There will always be a few dissenters, but the evidence can still be strong when almost all experts agree. Doctors have reached a consensus that smoking tobacco causes cancer. Of course, the experts have evidence for this claim, but few non-experts know any or many details of the studies that convinced the experts that smoking tobacco causes cancer. That is why we need to rely on expert authorities. When non-experts argue, “Doctors agree that smoking causes cancer, so that’s good enough for me to believe that it does,” it would not make much sense to insist that they tell us how doctors reached that consensus. It is enough for non-experts to know that experts did reach a consensus.
In some cases, the appropriate kind of expert is simply a witness. The experts on whether a government official communicated with a foreign spy include witnesses who saw them meet or heard them talk. To get agreement between experts then is simply to have one witness confirm what the other said. As long as their shared story is not denied by other reliable sources, such confirmation can reduce the chance of error and justify belief. That is why most good news reporters wait to deliver stories only after they are confirmed by multiple independent sources.
A fifth question asks about the motives of the person who appeals to an authority: “Why is an appeal to authority being made at all?” When a claim is obvious, we can simply assert it and maybe also call it obvious. Then we do not need to add an appeal to any authority. It would be pointless to argue, “Most mathematicians agree that 2 + 2 = 4, so it must be true.” Thus, when someone does appeal to an authority, they usually make that appeal because they know that their claim is not obvious, at least to non-experts. Their appeal signals that they know their audience could reasonably raise questions, so they cite the authority in order to head off those questions. The best response, then, is to ask the very questions that they are trying to get you not to ask.
To see how these five questions work together, let’s apply the series to science. Many people assume that science does not depend on any authority. In their view, religion and law depend on authorities, but science works purely by observation and experimentation. That is incorrect. Almost every scientific paper cites many authorities who have previously settled other issues so that this paper can build on those predecessors to address a new issue. Sir Isaac Newton, one of the greatest scientists of all time, said that he stood on the shoulders of giants, and he meant previous authorities.
What justifies scientists in trusting other scientists as authorities? After all, scientists are human, so they are fallible like the rest of us. The difference is that individual scientists work within larger groups and institutions that are structured to foster reliability. One virtue of science that is conducive to reliability is the insistence on replication by independent scientists or laboratories. Independent attempts at replication are unlikely to succeed when results are distorted by personal motives and mistakes. Another feature of science that breeds reliability is competition. When one scientist reports a new finding, other scientists have strong incentives to refute it. With so many smart people trying so hard to find mistakes, only the best theories survive. We have reason to trust any view that survives such a process.7 Of course, many scientific theories have been overturned, and most scientific theories today will probably be overturned in the future. Nonetheless, we can still have reason to trust the best theories and data that we have now.
One important recent example is the Intergovernmental Panel on Climate Change (IPCC), which includes hundreds of top climate scientists from around the world.8 This large and diverse group has worked long and hard to reach consensus about many, though far from all, aspects of climate change. Suppose that someone appeals to the IPCC as an authority to argue that human activities that emit greenhouse gases are causing at least some climate change. Is this appeal to authority a strong argument? To assess it, we need to ask our questions.
First, did the arguer cite the authority correctly? Some environmentalists fail to cite qualifications in the IPCC reports. This omission might distort their arguments, so we need to check carefully. Still, many passages in their reports do show that the IPCC really does conclude that human emissions are causing some climate change.
Second, can the cited authority be trusted to tell the truth? This question asks whether the scientists in the IPCC have motives to exaggerate the extent of climate change. If so, we have some reason to distrust them. In fact, the members of the IPCC have incentives to uncover mistakes, because their reputations will suffer if they mess up. It would be too farfetched to imagine a conspiracy among so many disparate scientists.
Third, is the cited authority in fact an authority in the appropriate area? Here we need to check the credentials and areas of expertise of the members of the IPCC. We find that they were chosen because their expertise was relevant.
Fourth, is there agreement among the appropriate experts on this issue? The IPCC does not agree on every issue, and a few dissenters remain outside the mainstream. Nonetheless, the goal of bringing together so many diverse experts in the IPCC is to determine which claims they do agree on and then to get them to sign their joint report on the points of agreement.
Fifth, why is an appeal to authority being made at all? Because the future and the causes of climate change are unclear without extensive research and also because proposals to reduce climate change are likely to impose serious costs on many people. This issue matters, so we need to be careful.
After asking these questions, an accurate appeal to the authority of the IPCC ends up looking very good, so we do have strong reasons to believe that climate change is being increased by human activities that emit greenhouse gases. This assessment does not mean that there are no problems in the IPCC. Nothing is perfect. The point is only that this institution is self-correcting, like science as a whole. The IPCC still might be wrong, and future evidence might undermine its claims. That is a risk with all inductive arguments. But inductive arguments can be strong without certainty, so the IPCC reports can give us strong reason to believe that at least some climate change results from human activities.
Nonetheless, this scientific conclusion by itself cannot solve the policy issues regarding what to do about climate change or global warming. The IPCC is often cited as an authority not only on the future and causes of climate change but also on what the government should do about it. To assess this different appeal to authority, we should focus on the question, “Is the cited authority in fact an authority in the appropriate area?” A negative answer is suggested because climate scientists are experts on science rather than on government policy. A climate scientist who knows that reducing greenhouse gas emissions will slow global warming still might not have the expertise to know whether or how much carbon taxes or cap-and-trade systems will succeed in reducing greenhouse gas emissions, whether or how much these policies will slow economic growth, and whether these policies are politically feasible or would violate standing laws. To settle those separate issues, we need experts from outside of science. Thus, our questions can illuminate not only the strengths but also the limits of science.
These questions are not foolproof, of course. Opponents will often give very different answers when they ask whether there is agreement among experts and whether a certain source is an authority in the appropriate area and can be trusted to tell the truth. The
se continuing controversies show that we should not merely ask these questions by ourselves. We should ask other people to ask these questions. We should also not simply ask allies who agree with us. Instead, we should ask our opponents. And we should ask them not only who is an authority to be trusted but also why they trust those authorities. We need to ask for reasons to back up any appeal to authority, at least in controversial areas. This example shows again why we need to learn to ask the right questions, including questions about reasons.
HAVE WE GOTTEN ANYWHERE YET?
The third kind of fallacy makes no progress beyond its premises. More technically, an argument begs the question when its premises need to be justified but cannot be justified without assuming or depending on its conclusion. This meaning is not far from common parlance, such as “My blood sugar levels are very high, which begs the question of why I am eating cake.” Here “begs the question” means “raises the question.” Similarly, an argument begs the question when it raises the question of why we should believe its premises if we doubt its conclusion.
Here’s a common example: “The death penalty is immoral, because it is always wrong to kill.” The death penalty by definition involves killing, so this argument is valid in our technical sense. It is not possible for its premise to be true when its conclusion is false, because the death penalty must be immoral if all forms of killing are immoral. Despite its validity, this argument fails to justify anything, because there is no way to justify its premise that killing is always wrong without already assuming its conclusion that killing is wrong in the particular case of the death penalty. The death penalty might be the one exception that shows why not all killing is wrong, because what is really wrong is killing innocent people. Defenders of the argument need to justify its premise without assuming its conclusion, but they have not done that yet in the simple argument as stated, and it is hard to see how they would justify its premise independently of its conclusion.9 In this way, the argument assumes its conclusion from the start, so it gets nowhere.
The same fallacy can be committed on the other side by arguing like this: “The death penalty is moral, because we should repay a life for a life.” Again, the premise that we should repay a life for a life already assumes that the death penalty is moral, since the death penalty for murder is repaying a life for a life. Thus, this argument cannot justify its conclusion, because its premise needs to be justified and cannot be justified without already assuming its conclusion.
Here’s another infamous example: “The Bible says that God exists. The Bible is the word of God (as it says in II Timothy 3:16). God would not speak words that are not true. Therefore, God truly exists.” The premise that the Bible is the word of God begs the question in two ways. First, a being cannot speak any word without existing, so this premise already assumes the conclusion that God exists. Second, II Timothy 3:16 is part of the Bible, so it also begs the question to cite that verse as evidence that the Bible is the word of God. What argument gives us reason to believe what the Bible says about itself?
The same kind of fallacy is committed by some opponents of religion when they argue like this: “This evolutionary biologist says that the theory of evolution is true. Evolutionary biologists would not say anything untrue about evolution. Therefore, the theory of evolution is true.” The second premise begs the question, because it assumes the conclusion that the theory of evolution is true. If the theory of evolution were not true, then evolutionary biologists would say something untrue about evolution (contrary to premise 2) when they say that the theory of evolution is true (as reported in premise 1). As a result, this simple appeal to evolutionary biologists cannot justify its conclusion any more than the preceding religious appeal to the Bible can justify its conclusion. Scientists need independent justification for their theories just as much as theologians do. The crucial question is who has such justification.
As always, this criticism of the argument does not imply that the conclusion in any of these pairs of arguments is either true or false. The point, instead, is simply that the issue cannot be resolved with arguments like these, because they beg the question. Some other argument is needed. Whether a better argument is possible will be controversial, but it is significant progress to recognize which arguments fail.
IS THAT ALL?
Have we covered all of the fallacies that people ever commit? Of course not. There are plenty more. Some fall into patterns like those we discussed. Genetic fallacies, appeals to ignorance, and tu quoque (or appeal to hypocrisy) resemble ad hominem arguments. Appeals to emotion, to personal experience, to tradition, and to popular opinion resemble appeals to authority. False dichotomy sometimes resembles begging the question. These other arguments can be understood by comparing them to the fallacies that they resemble. Still other fallacies form new patterns, such as the gambler’s fallacy, fallacies of composition and division, false cause, and so on. Some books and websites list hundreds of fallacies.10 We will not do that here. Long lists are boring.
So-called fallacies on standard lists are not always fallacious. We saw that slippery slope arguments and appeals to authority sometimes provide strong reasons. This potential makes it misleading to refer to the general type of argument simply as a fallacy.
The same point applies to appeals to emotion, which are often seen as fallacious and opposed to reason. When someone describes the anguish and weariness of refugees as well as their empathy for refugees and revulsion at the ways they are treated, these emotions can provide good reasons to help refugees, because the emotions point to suffering and injustice. These emotions show nothing if they are irrational, but normal emotions can sometimes be reliable guides, much like authorities. We can decide when to trust emotions by asking questions much like those we asked about appeals to authority: Why am I feeling this emotion now? Are my emotions distorted by self-interest or irrelevant motives? Do other people feel this same emotion in similar situations? Does this emotion reliably react to relevant facts in the world (such as suffering and injustice)? We need to be careful when we appeal to emotions, just as we need to be careful when we appeal to authorities, but some appeals to emotion are not fallacious.
More generally, we should not be too quick to accuse opponents of fallacies. They do not commit an ad hominem fallacy every time they criticize a person. They do not commit a slippery slope fallacy every time they use a word that is slightly imprecise (like all words). They do not commit a fallacy of appealing to tradition every time they point out that their views align with tradition. When making accusations of fallacies becomes a knee-jerk reaction without thought, they cease to be illuminating and instead become annoying and polarizing. Such name-calling is not much better than simply announcing, “I disagree.”
Instead of abusing opponents with names of fallacies, we need to look carefully and charitably at each argument. In particular, we should always ask whether what appears to be a fallacy can be fixed simply by adding a suppressed premise. For example, suppose someone argues that a government employee did not reveal classified information on her private server, because we cannot find any specific email on that server that revealed anything classified. Or suppose someone argues that a political candidate did not collude with the enemy because we cannot prove that he did. In both cases, critics could retort, “Appeal to ignorance! That’s a fallacy!” That label will not help anyone understand the issues. It would be much more constructive to ask whether the argument assumes a suppressed premise. It does: “If he or she had done it, we would know (or at least have the kind of evidence that we lack).” That suppressed premise is true in some cases: If my son had wrecked my car last night, I would probably see dents in my car. But that same suppressed premise is false in other cases: If my son had come home late, I would not know (because I was sound asleep). In every case of appeal to ignorance, then, we need to ask whether the suppressed premise is true: If an email did reveal classified information, would we find it? If the candidate did collude, would we know it? In orde
r to get beyond name-calling and figure out how strong an argument really is, we need to reconstruct the argument as charitably as possible and then ask how strong it is in its best form.
Of course, some arguments will still end up fallacious. We should not be too quick to accuse, but we should also not be too slow to point out fallacies and weaknesses in arguments. Moreover, we need to be able to find and explain flaws in arguments even when we do not have a name for those flaws. The next chapter will teach that skill.
11
HOW TO REFUTE ARGUMENTS
MANY PEOPLE TALK AS IF all you need to do to refute a position is simply deny it or say anything at all in reply to it. Such talk is too loose. Monty Python taught that “argument is not just contradiction” or denial. Even if you go beyond denial and say something in reply, not every response is a refutation.
For example, suppose a theist argues, “God exists, because nothing else could explain the existence of the Universe.” An atheist cannot refute that argument simply by saying “No, God does not exist” or “I do not believe in God” or “That’s stupid.” The same goes for the other side. If an atheist argues, “Evil exists, so God does not,” a theist cannot refute that argument simply by saying “God does exist” or “I believe in God” or “That’s silly.” These simple responses are not refutations.
To refute an argument, you need to give an adequate reason to doubt that argument. We saw that some arguments give reasons that justify belief in their conclusions, whereas other arguments give reasons that explain phenomena. In contrast, refutations give reasons to doubt other arguments. Thus, refutation is a new purpose of arguments in addition to justification and explanation.
Think Again: How to Reason and Argue Page 18