Most science deniers are conspiracy theorists. Many of them don’t like to think of themselves as conspiracy theorists and would even ardently deny that they deserve that label, yet when you present them with peer-reviewed evidence for anthropogenic climate change, the safety of vaccines, the safety of GMOs, etc. they almost invariably respond by asserting that those studies aren’t valid evidence because vast corporations, governments, etc. have bought off all of the scientists, doctors, regulatory bodies, etc. That claim has no evidence to support it and is a textbook example of a conspiracy theory.

As a result of the conspiratorial nature of science-deniers, conspiracy theories are a frequent target of my blog/Facebook page, but almost any time that I post about the illogical nature of conspiracy theories, I get irate responses from people who insist that conspiracy theories are not inherently illogical, and they do this based on one of two lines of logic. Either they bring up the fact that real conspiracies do exist and have been discovered, or they cite agencies like the FBI that investigate criminal conspiracies and they incorrectly assert that I am suggesting that those agencies are inherently irrational (i.e., that FBI agents are conspiracy theorists). Both of these arguments are wrong and rely on infuriating semantic games rather than actual facts or logic, but I encounter them frequently enough that I want to spend a few minutes explaining the problems with them.

Both of these lines of reasoning rely on conflating real conspiracies with conspiracy theories, but that is semantic tomfoolery. The term “conspiracy theory” generally refers to self-reinforcing ideas that rely on inserting assumptions into gaps in our knowledge, have little or no actual evidence, and conveniently excuse any evidence that is presented against them. That is a very different thing from the type of investigation that an organization like the FBI does, and we don’t use the term “conspiracy theory” to refer to that type of investigation.

Let me give an example to illustrate this. On many occasions, I have showed a science-denier a peer-reviewed paper that discredits their view, only to have them claim that the authors were paid off. Then, I showed them the conflicts of interest section of the paper which clearly showed that no conflicts of interest existed. At that point, they, of course, said that the payment was secret and, therefore, not reported. When I asked them for evidence to support that claim, however, they couldn’t provide it. It was an assumption that they were making simply because the evidence did not fit their view. This is how conspiracy theories operate. Any evidence that conflicts with the theory is explained away as part of the conspiracy, and a lack of evidence to support claims is also justified as simply being part of the conspiracy (e.g., claiming that large corporations are silencing scientists and preventing them from publishing).

Now, let’s contrast that with actual investigations of actual conspiracies. Imagine, for example, that the FBI was investigating corruption, found no evidence of it existing (i.e., no conflicts of interest) but they ignored that lack of evidence and assumed that it was simply part of the conspiracy. Obviously, that would be a really bad investigation, and they could never get a conviction out of it. If they failed to find evidence to support what they thought was true, they would have to move on. They couldn’t just ignore any evidence that disagreed with them. To put that another way, agencies like the FBI rely on evidence, not conjecture when conducting their investigations, and their hypotheses change as new evidence arises.

Do you see the difference? Conspiracy theories conveniently excuse contrary evidence by writing it off as part of the conspiracy; whereas real investigations are based on the available evidence and don’t blindly ignore any evidence that disagrees with them. Having said that, real conspiracies certainly do exist, and multiple of them have been uncovered, but the fact that real conspiracies exist does not mean that your conspiracy theory is logical or justified.

To give an example of why the existence of real conspiracies doesn’t justify conspiracy theories, imagine that I have a friend named Bob, and for one reason or another, I decided that Bob was a murderer. I didn’t have any real evidence, but I “just knew” that I was right. Now, imagine that you confronted me about this and demanded evidence for my claims, and I responded by saying, “lots of real murderers have been caught, it happens all the time; therefore, it is rational for me to think that Bob is a murderer.” Would my reasoning be correct? Obviously not. The fact that there are murderers does not in any way shape or form make it rational to think that Bob is a murderer. I need actual evidence specifically showing that Bob murdered someone. The same thing is true with conspiracies. The fact that real ones exist doesn’t mean that your theory is justified. You need actual evidence for your view to be rational.

Now, at this point, conspiracy theorists will inevitably protest and claim that they do, in fact, have evidence. However, every time that I have ever asked to see that evidence, I have been sorely disappointed. Inevitably, the “evidence” takes the form of blogs, youtube videos, and baseless conjecture, often espousing ideas that have been thoroughly investigated and debunked. For example, I still encounter people who cite “climategate” as evidence that climatologists are involved in a conspiracy, despite the fact that multiple independent and well-respected scientific bodies examined the situation and concluded that no wrong-doing or data-manipulation had occurred. Of course, the conspiracy theorists inevitably respond by asserting that those scientific bodies are also part of the conspiracy, but that just illustrates my point. Conspiracy theories are irrational precisely because they twist any evidence to fit the conspiracy. Think about it, what could you possibly show a conspiracy theorist to convince them that the theory was wrong? Nothing, because no matter what evidence you show them, they will argue that the evidence is also part of the conspiracy.

My point in all of this is really simple. The term “conspiracy theory” specifically refers to imagined conspiracies that have no real evidence to support them and inherently rely on making assumptions to fill gaps in knowledge, rather than actually basing views on the available evidence. The existence of real conspiracies does not justify these conspiracy theories, nor should you play semantic games to try to equate conspiracy theorists with evidence-based investigative bodies like the FBI. So please, if you see a post about conspiracy theories, spare us all from your pedantry.

Note: I want to be clear that the use of the word “theory” in the term “conspiracy theory” is very different from its use in science (it is far more similar to its use in the term “movie theory”). In science, a theory is an explanatory framework that has been rigorously tested and shown to have a high predictive power. It is not simply a guess nor does it indicated that we are unsure of its veracity.