We are constantly told that “everyone has a right to their opinion” and “there are two sides to every story.” Our entire news system is predicated on the notion that we need to give fair time to both sides of every situation. The problem with this type of thinking is that it leads to the misconception that both sides are equally valid, or, at the very least, that there must be some truth to both sides, but in many cases, only one side has any merit. In other words, it’s often not opinion #1 vs. opinion #2, rather, it is fact vs. fiction. One “side” is reality, while the other “side” is a fairy tale. For example, if you want to say that the island of Jamaica is being carried around on the back of giant sea turtle, that’s not your opinion, you’re just wrong. There wouldn’t be two legitimate sides to that story. Rather, there would be the fact that Jamaica is not being carried by a sea turtle, and there would be the crazy person who thinks it is.
This problem is never more relevant than in “debated” scientific concepts. For example, we have all probably heard creationists insist that we need to “teach the controversy,” and if there actually was a controversy about evolution, I would agree with them. The problem is that from a scientific standpoint, there is no controversy. Similarly, the “debate” about climate change only exists in the minds of climate change deniers. There aren’t two sides to that story. Rather, there is the fact that we are causing the climate to change, and there are people who are wrong. Nevertheless, the media and anti-scientists do a marvelous job of creating the illusion of conflict where none exists. In technical terms, this is what is known as an inflation of conflict fallacy, and it is what I will devote this post to. I want to first explain what we mean when we say that something is settled in science, then (in a second post) I want to look at some of the tactics that are used to fabricate a debate.
The topic of settled science is a complicated one. You see, science doesn’t deal in proofs (with the exception of mathematical proofs in certain areas of physics). Rather, it deals in probabilities. In other words, it tells us what is most likely true, but it does not tell us what is absolutely true. It is inherently incapable of proving anything with 100% certainty because we are inherently incapable of knowing everything, which means that we always have to acknowledge the possibility that there is some other piece of evidence which eludes us. Another way to think about this is that science tells us what is correct given the current evidence, but it cannot completely eliminate the possibility of unknown evidence. So in the strictest sense, there is no such thing as “settled science.” It is always possible that some new discovery will overturn previous ideas, but, and this is the really important part, that doesn’t give you the right the assume that other evidence is out there. In other words, the fact that something technically might be wrong, doesn’t mean that you can assume it is wrong (that would be logical blunder known as an argument from ignorance fallacy). Many things in science have been so thoroughly tested and so consistently make accurate predictions that it is almost inconceivable that they could be wrong. So even though we cannot be 100% certain that they are correct, we can be 99.9999999% sure, and that is good enough to consider them essentially “settled” (note: the argument that “scientists have been wrong in the past” is flawed for numerous reasons which are explained here).
Laws and theories are good illustrations of this concept. Consider cell theory, for example. It tells us that all living things are made of cells. It is accepted by essentially everyone everywhere because it has been tested over and over again (i.e., every time we stick a living thing under a microscope, it is made of cells), and it makes consistently accurate predictions (i.e., it predicts that when we stick something under a microscope, it should be made of cells). So it is, by any reasonable definition, “settled,” but we can never be 100% sure that it is correct, because that level of certainty would require examining every single living thing in the entire universe.
Now, let’s say that for one reason or another, you think the there are organisms that aren’t made of cells (perhaps your religion says so), it would be utterly absurd of you to argue that because cell theory can never be proved, we don’t have to accept it. This all comes back to a topic that I discuss frequently: the burden of proof. According to the rules of logic, the one making the claim is required to provide the evidence. In other words, if you are going to claim that cell theory is wrong, the burden is on you to provide strong evidence that it is wrong. In the absence of that evidence, it would be absurd to claim that there is debate about the issue. The fact that you disagree does not mean that there is debate. Further, you don’t get to be offended when people make fun of you for your ridiculous belief, because that belief is clearly wrong. You have a right to believe whatever you want, but that doesn’t mean that everyone else has to take you seriously and respect your delusions.
Cell theory is obviously an extreme example because virtually everyone accepts it, but I wanted to start with it to demonstrate the concept that science gives reliable answers even though it doesn’t provide proofs. Now, let’s turn to topics like vaccines, evolution, GMOs, climate change, etc. There is no significant scientific debate on these issues. There just isn’t. Yes, there are a handful of scientists who disagree with the mainstream view, but that doesn’t mean that there is a significant debate. As I often like to say, no matter what crackpot notion you believe, you can find someone somewhere with an advanced degree who thinks that you are right. Becoming a scientist doesn’t guarantee that you are smart and it doesn’t guarantee that you know what the crap you’re talking about. So for almost any position (including things like heliocentrism and the germ theory of disease) you can find a handful of scientists who disagree with the consensus, but that clearly doesn’t mean that these issues aren’t settled or that there is debate about them.
So if we are never going to get 100% of scientists to agree, then how do we define a debate? One quick and easy approach is to look at the number of scientists who hold a position. For example, roughly 97% of climatologists agree that climate change is happening and it’s our fault. That is an extremely strong agreement. There actually aren’t many topics on which 97% of scientists agree, so by that point it is fairly safe to say that there isn’t a debate. Nevertheless, some topics don’t have quite that strong of a consensus, and relying on a consensus is inherently problematic because science isn’t a democracy. It’s decided by facts, not what people think.
Therefore, a better approach is to look at the recent literature. If there is still significant debate about an issue, then you should find lots of high quality, peer-reviewed studies which supply evidence in support of the minority view. If, however, the only studies that you find are of low quality and are published in minor or questionable journals, then you can fairly safely conclude that there isn’t a significant debate. For example, good luck finding high-quality, peer-reviewed articles supporting creationism. They are essentially non-existent. Why? Quite simply, because there is no evidence to support creationism, and, as a result, there is no scientific debate about it. Anthropogenic climate change is a similar story, with virtually no papers denying it. Vaccines and GMOs are a bit trickier because there are papers that disagree, but those papers are still in the extreme minority, and the vast majority of them are of low quality and are published in less than reputable journals (for example, see my recent post debunking several anti-GMO studies or this post about a peer-reviewed study showing that most anti-GMO studies are seriously flawed or this post explaining the problems with Tenpenny’s “Vaccine Research Library), so they still do not constitute evidence that there is significant disagreement among scientists.
Invariably, someone is going to say either that the publications are all about the money (debunked here) or that it is peer-pressure and it’s just not possible to publish anything that goes against the mainstream view (debunked here). In short, the fundamental problem with these claims is that scientists absolutely love to publish papers that defeat common views. Discoveries like that are what we live for. No one becomes a great scientist by agreeing with everyone else. You become a great scientist by discovering new things and discrediting old ideas. If you actually had solid evidence that climate change wasn’t happening, evolution wasn’t true, etc. you would have just guaranteed yourself a Nobel Prize.
In conclusion, for all of these topics (and many others) the science really is settled. Yes, there are still a few scientists who disagree, and yes, it is technically possible that we are wrong, but so many studies have confirmed the “mainstream” views and so little evidence is available against them that it is not logically valid to assume that the consensus is wrong. For all intents and purposes, the topic is “settled” and scientists should spend their time studying other topics.