One of my favorite quotes from classic literature comes from Lewis Carroll’s Through the Looking Glass, when Alice encounters a rather strange character named Humpty Dumpty. Humpty Dumpty, as you will likely recall, was a giant egg with whom Alice got into an argument about the meaning of words:
And only ONE for birthday presents, you know. There’s glory for you!’
‘I don’t know what you mean by “glory,”‘ Alice said.
Humpty Dumpty smiled contemptuously. ‘Of course you don’t—till I tell you. I meant “there’s a nice knock-down argument for you!”‘
‘But “glory” doesn’t mean “a nice knock-down argument,”‘ Alice objected.
‘When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean—neither more nor less.’
‘The question is,’ said Alice, ‘whether you CAN make words mean so many different things.’
‘The question is,’ said Humpty Dumpty, ‘which is to be master—that’s all.’
This passage has a tendency to come to mind when I come across antivaccine activists (or, for that matter, quacks and cranks of almost any sort) on Twitter. For example, just yesterday, I came across these Tweets:
— Superabimus (@superabimus) July 7, 2015
Ah, yes. Who doesn’t want “safe vaccines” Who doesn’t want “uncorrupted studies”? Certainly I want those things! The devil, of course, is in the details. Here’s where Humpty Dumpty comes in. What does Superabimus mean by “safe vaccines”? What does she mean by “uncorrupted studies”? Words have meaning, but, more importantly, in science, you have to be able to define your terms. If you’re an antivaccine activist, we will certainly disagree over what constitutes as “safe vaccine.” However, if you define what you mean by “safe vaccine,” listing verifiable exact criteria that you would use to determine if a vaccine is “safe” or not, we could at least have a conversation over whether a given vaccine meets those criteria. Similarly, we might disagree over what constitutes an “uncorrupted study,” but if you at least can list the criteria by which you judge if a study is “uncorrupted” or not, again, we can have a conversation.
We can’t have a conversation if you won’t define your terms and list your criteria, at least not one that is meaningful.
This is also the difference between those who understand science and those who do not. Those who understand science know how critical it is to precisely define one’s terms. How did Superabimus do on this score? Sadly, not very well. She was asked by more than one person to define what she meant by a “safe vaccine,” with the premise being that they can’t all be dangerous. Of course, this is one of my favorite ways of identifying an antivaccine zealot, to ask those railing against vaccines which vaccines they consider sufficiently safe to recommend and which they do not. Someone who has concerns about vaccine safety not rooted in pseudoscience, ideology, or emotion would be reasonably expected to be able to answer that question based on, as I discussed above, specific criteria they can enumerate.
Of course, that’s almost never what happens when I ask that question. What usually happens is one of two things. The antivaccine activist will dance around the question, often with a mighty Gish Gallop of changing the topic, trotting out studies that they don’t understand and/or that don’t show what they think they show, and in general avoiding saying anything specific. Alternatively, she will list criteria for vaccine safety that are not achievable in the real world, such as being absolutely, 100% safe, without a chance for an adverse reaction, while also being 100% effective, which no vaccine is. Whether such unrealistic criteria for vaccine safety are a result of ignorance about how medicine in general—and vaccines in particular—work is often impossible to say. Often it’s both. It’s also often a matter of motivated reasoning, in which evidence is marshalled to support a predefined viewpoint, rather than to arrive at the truth. I also can’t help but think that, somewhere, somehow, at some level, they must know that such criteria are unattainable and unreasonable to expect.
So how did our friendly neighborhood antivaccine Twitter denizen do? Not very well. She assiduously avoided direct answers about vaccine safety. it was so bad that fellow antivaccine activists tried to come to her rescue. For example:
— Robyn Chittister (@rredhead926) July 7, 2015
This sort of comment reveals a shocking ignorance of how clinical trials are done and the ethics of clinical trials. Such a clinical trial would be completely unethical, as I have described many times in the past. Even doing epidemiological studies of vaccinated versus unvaccinated populations is not a simple matter and require far more human subjects and money to do than antivaccinationists can possibly imagine.
Of course, this brings us to the question of what antivaccine activists mean when they demand an “uncorrupted” study. When a physician or scientist says he wants an “uncorrupted” study, he usually means a study not run by big pharma. However, as we know from Humpty Dumpty, words can be tortured to mean whatever Humpty Dumpty wants them to mean, and in the antivaccine world an “uncorrupted study” goes far, far beyond no big pharma involvement. For instance, because the central conspiracy theory of the antivaccine movement posits that the CDC is at the heart of a great conspiracy to “cover up” data and studies showing that vaccines cause autism, no study with any CDC—or even government—involvement can be considered “uncorrupted.” By extension, no study with the involvement of any government, not just the U.S. government, can be considered “uncorrupted.” Any study in which a scientist they don’t trust (as in Paul Offit) cannot be considered “uncorrupted.”
Truly, the word “uncorrupted” and, by extension, the word “corrupted” can mean whatever Humpty Dumpty wants it to mean. Basically, through the power of motivated reasoning and the Dunning-Kruger effect, antivaccinationists will believe only studies that support their bias and disbelieve studies that don’t, finding a convenient reason to label them as somehow tainted or corrupt.
Similarly, when cornered on the question of how they define a “safe” vaccine, they will always find a way not to answer the question while maintaining “plausible deniability” of the contention that they find all vaccines dangerous and are, in fact, antivaccine. Indeed, here’s the ultimate:
— Maria Rossi (@vixenvalentino) July 6, 2015
And our friend Ginger Taylor chimed in:
@gorskon detailed med history/biomarkers fed into risk algorithm for asd/devdisorder/vaxinjury/autoimmunity/neuro based on current research.
— Ginger Taylor (@GingerTaylor) July 6, 2015
When it was pointed out how that sounds all very impressive to a nonscientist, it is scientifically unvalidated rubbish, as others pointed out:
— Doug Boudreau (@db247365) July 8, 2015
— Doug Boudreau (@db247365) July 8, 2015
You get the idea. “Predictive algorithm,” too, is a term that can mean whatever antivaccinationists want it to mean. As Todd W. points out, the same is true for “injected directly into the bloodstream,” a claim frequently made by antivaccinationists about vaccines. It’s not just vaccines, either. It’s any area of pseudoscience and conspiracy theories that you can imagine.
What distinguishes cranks, quacks, and pseudoscientists from real scientists and physicians is that the latter have precise definitions and criteria for what they mean and how they determine whether, for instance, a medicine or vaccine is safe and effective. In contrast, antivaccinationists, supporters of alternative medicine, creationists, denialists of human-induced global climate change, anti-GMO cranks, and the like are almost always very vague about what the terms they use mean. They are truly Humpty Dumpty, and to them words mean what they want them to mean, no more, no less. Just try to pin them down about what they mean when they use terms like “safe,” “uncorrupt,” or “unbiased,” and you’ll see what I mean.
Words matter. Definitions matter. In science, criteria for determining whether a conclusion is justified matter enormously. To cranks, they matter, too, but not in the same way. Rather, they matter as rhetorical tools to obfuscate and apply a patina of reason to massive unreason in order to disguise it as seemingly reasonable to those who don’t have the core knowledge to recognize the quackeyr and pseudoscience they are arguing. That’s why debating a denialist is, as Deborah Lipstadt so famously put it, “like trying to nail a blob of Jello to the wall.” It might be fun to try for a little while, but the end result will always be frustration and the denialist’s mind won’t be changed.