The appeal to authority is probably one of the most common logical fallacies. You hear it and see it all the time: “The Intergovernmental Panel on Climate Change says the climate is changing. All those scientists can’t be wrong, so the climate must be changing.” It’s true that the IPCC’s research has revealed a great deal of scientific evidence that the climate is changing, and that the change is most likely caused by human activity. But simply saying it’s true because a fancy-sounding panel of scientists says so is not enough. It’s the research that supports the conclusion, so if you are going to make an argument about something, cite the research, not just the source.

Don’t get me wrong; I’m not saying that it’s a bad thing to bolster your argument by touting the credibility of your sources. I am saying that you better be prepared to cite the conclusions of your sources as well. The reason an appeal to authority by itself is not enough is because it can be extremely misleading. Just because a person, group, or study is associated or affiliated with a highly-respected institution or researcher does not mean that the conclusions themselves are sound. Linus Pauling, a Nobel laureate in chemistry, was rightfully lauded for his work in explaining complex molecular bonds (and he was also awarded a Nobel Peace Prize for his anti-war activism). Pauling is routinely listed as one of the most influential American scientists of the 20th century. However, in his later years, he did work on vitamin C, among other things, that fell short when critically analyzed by other scientists. Nevertheless, even today people will cite Pauling’s work to bolster claims about vitamin C’s efficacy in treating certain diseases, such as cancer, even though none of his claims have stood up to testing. It is simply his authority as a Nobel prize winner that seems to give credence to disproved claims.

Something similar happens with people who have the title of “doctor” (and I should know, being one of them); somehow, the Doctor is seen as an authority simply because of her title. I claim no specialized knowledge outside of my very specific research in anthropology, but when I talk, people who know I’m a PhD tend to listen… and to ask me about things I really know nothing about! Along similar lines, Dr. Laura Schlessinger, of conservative talk-show radio fame, earned the title of Dr. by virtue of her PhD in physiology… not in the psychotherapy she dispensed on her program. Yet “Dr. Laura” was able to trade on her title to enhance her credibility with her listeners: a perfect example of the appeal to authority. This is a fallacy we all have to be very careful of, not only because we use it in our arguments with others but because we fall for it ourselves when convincing ourselves of the rightness of our views. Always remember that it is not enough that somebody is “a Harvard Medical School neurosurgeon.” That by itself does not make the research credible. It is the scientific process, the peer review, the repeated testing, that gives a particular conclusion its credence. And on the flip side, reversing the appeal to authority – e.g., “how can we trust that research when it’s only from Bob State University?” – does not mean that the research is shoddy or its conclusions can’t be trusted. If it has gone through the same rigorous scientific process as the work of the Harvard neurosurgeon, then it should have equal credibility. Final flog of the dead horse: you should definitely be aware of the credentials and background of researchers, but you should not use that as the sole criterion by which to judge their work.

And now our bonus fallacy: the tu quoque fallacy. It has a fancy name but the concept itself is simple. This is the classic child’s whine that “so-and-so gets to stay up until 10, so I should get to stay up too!” Just because someone else gets to do it doesn’t mean you get to do it! Even more specifically, the tu quoque fallacy is used to try to justify wrongdoing. I’m sure cops hear it all the time in the form of “Why didn’t you get that other guy who was racing past me at 95?” You know as well as the cop does that just because somebody else was going 95 doesn’t make it ok for you to go 90. I love tu quoque because it’s really so childish when used in this classic sense. But it does get used in other ways as well, in more of an “apples to oranges” way. You tend to hear the tu quoque fallacy when people can’t really refute an argument with logic, but they remember an example of something similar turning out not to be true, so they cite that instead. I’ve been hearing it regularly in discussions of global climate change when people refer to a brief, media-hyped panic in the 1970s that the world was about to go through a global freeze. As it happens, while a few papers suggested that a cooling period might be coming, the majority of research at the time found more evidence for global warming. But the media got ahold of the cooling theory and ran with it. The conclusion is that the climate scientists who proposed a potential global cooling period turned out to be wrong; therefore, climate scientists who are predicting global warming are also wrong. It’s a variation of the child’s whine: “science was wrong about something in the past, so it must be wrong now.” This is absurd. Scientific research is based on revising conclusions based on new information. If scientists gave up every time something they predicted turned out to be wrong, no scientific field would ever advance. So being wrong in the past has little predictive value for being wrong in the future.

It’s exhausting to try to keep track of all these fallacies, committed by ourselves, the people we talk with, and the sources we rely on for information. It’s also exhausting to glean what’s important from a conversation and use care to establish credibility without tipping over into an appeal to authority, or to cite examples of previous, similar situations without falling into a tu quoque, or to refrain from the ad hominem of calling somebody a blithering idiot (or much, much worse) instead of actually deconstructing their argument. Of course, a lot of people don’t really want to try because the fallacies are so much easier… but I do hope we will all keep trying.