The movement against vaccinating kids has apparently reached critical mass, causing potentially serious outbreaks of measles and other easily preventable diseases. This is obviously terrible. And it has left many people perplexed as to why so-called anti-vaxxers decided to abandon all evidence and endanger their children and others'.

I have some useful insight into what is going on. I grew up as an intellectual Christian in the West. At some point, I had to think hard about science: what it is, how it works, what it proves and doesn't prove, and how. I also had to think about how Christianity came to decline in the secular West. And therein lie some hidden-in-plain-sight truths of the anti-vaccine movement.

Let's start with Christianity: Christians believe that God is the necessary unconditioned reality that makes the contingent Universe we live in possible, the unconditioned good that is the source of every finite good. God draws us toward Him out of love, and to His embrace we respond in love, loving our neighbor because God loves her. Classical Christianity held that because God is perfect, he can do no evil (since that is an imperfection), and that there is evil in the world because it is the necessary price of our creaturely freedom. But God will in the end bring out a greater good of that evil.

John Calvin held that God actively caused Adam's original sin, thereby making him the author of all evil and suffering in the world, "to manifest His glory" — that is, just to show everyone how powerful he is, like some B-movie villain. Thus, passages in the Bible seeming to endorse violence, which had been hitherto read allegorically, came to be seen, even by serious people, as God sometimes approving genocide when he feels like it. And indeed, the most striking thing about the "New Atheism" fad of a few years back is how those writers described Christians as believing in some superpowerful superbeing, a violent sociopath who directly influences reality out of whim, and whose followers blindly obey his arbitrary commands as revealed through literalistic readings of the Bible for fear of eternal punishment and out of desire to escape the world to some place called Heaven. Not a very attractive picture!

"Christianity" in the public mind of the West long ago became this bizarro, evil-twin, parallel-universe version of actual Christianity. (This was often the fault of Christians.) And it is this version that people understandably reject. Christianity became implausible in practice, too. Only credentialed theologians could miss the fact that burning heretics in public was not consistent with Jesus' message, let alone the enormous cultural devastation brought about by the Protestant Reformation.

What does all this have to do with science and vaccinations, you ask?

Well, just like actual Christianity became replaced by bizarro "Christianity" in the public mind, a similar thing is happening with science. In the public mind, science is increasingly being replaced with a bizarro cousin, "Science". And we're increasingly at risk that people, in rejecting the bizarro caricature, also reject the real deal. And, just like with Christianity, the blame often lies on overzealous advocates.

What is science? And what is the distinction between actual science and "Science"?

As I explained in a previous column describing this problem (and pointing to the anti-vax movement as one symptom), science is a process for making reliable, nonobvious predictions about the future through the practice of controlled experiment. What we now call the Scientific Revolution happened when scientists ditched the Aristotelian definition of science as "knowledge of the ultimate causes of things" and instead focused on investigating specific empirical claims through controlled experiment. Scientific claims, properly speaking, concern only what the philosopher of science Karl Popper called falsifiable claims, meaning empirical claims that can be proven or disproven by experiment.

By contrast, public-imagination "Science" is basically just a synonym for "magic." "Science" is complicated stuff with lots of math, and it produces absolute truths and magical things.

This has many implications.

The first is that actual science is, or ought to be, intrinsically humble work: Science works precisely because it defines its aims narrowly. Aristotelian "science" tried to explain everything, and explained nothing. Baconian science tries to explain very little — only falsifiable empirical claims — but with those very little pebbles it builds very big mountains. But it also means that when you're not dealing with a falsifiable empirical claim, you're not dealing, properly speaking, with a scientific claim. And it also means that successful scientific work is humble work.

The second is that the magic of the scientific method comes from that little word: "controlled." A controlled experiment allows you to make reliable, nonobvious predictions about the future because it isolates all possible causes from an effect but one, to see which causes cause which effect. Contrary to popular myth, when Galileo did his revolutionary experiment on the fall of heavy and light objects, he did not just drop two balls from the tower of Pisa — he designed elaborate contraptions to do experiments that would take into account, for example, the potential effect of wind resistance.

Some kinds of science are harder than others. To perform controlled experiments, you need to be able to isolate all causes but one. In extremely complex environments, that is very hard to do. And it turns out that things like the human body and human society are even more complex than the beginnings of the Universe. In medicine and social studies, it is much harder to produce good scientific knowledge — reliable, nonobvious predictions about the future validated by controlled experiment — because it is much harder to produce controlled experiments, as it is much harder to isolate one cause.

This is typically done through randomized controlled experiment: split a group randomly into two groups; give one of them a treatment, another a placebo; because the groups are randomly split, all causes except the treatment should cancel each other out. This is a great approach, and it has produced a lot of progress. But to truly validate a claim, you don't need just one experiment, you need replication over many experiments, because the human body is so complex that there's still a risk some other, unobserved cause might be at work. If physical science is like blitzkrieg, medical science is more like trench warfare. Galileo overturned 2,000 years of physics with one experiment; it took decades to prove the link between smoking and cancer.

So, what does this have to do with the anti-vaxxers?

Well, here it is. If, like a Grand Inquisitor or a creationist Christian, scientists start to drink their own Kool-Aid and confuse actual science with "Science," they begin to saw off the branch they're sitting on. And people get mad.

As wrong as the anti-vaxxers are about vaccines, one thing that's most definitely not wrong about their outlook is that the medical establishment has a heck of a record of using its authority to promote junk "Science" as science.

Take pediatrics, for example. How about that time the American Academy of Pediatrics realized that an infant sleeping in your bed is actually totally fine and their shrieking about it was totally unjustified, and probably actually led to preventable deaths of children? (Not that the fact that billions of people have been doing it for millennia could have been a hint, or anything.) Or how about the fact that the AAP still recommends circumcision for infant males (which originally became prevalent in America because of a demented Christian fundamentalist crusade against masturbation), unlike practically every other international pediatrics body?

Or consider another domain where there's a lot of "Science" and not a lot of science: diet and fitness. As Scott Adams points out, over the lifespan of the average American, "Science" has been saying — each time very loudly, and each time with all the authority of divine command — black one day, and white the next.

The media also fuels our science-"Science" confusion, publishing studies showing a statistically insignificant link between, say, eating kale and being eaten by bears with a headline trumpeting "according to science." Blame our education system, too, where basic epistemology is devalued.

Is it any wonder that there are a lot of people who have stopped trusting men in white coats talking about "Science"?

Our politics also turn science into "Science." For decades, we have had politicians pretending that middle-school science about when life begins is a big mystery. They also warn that Armageddon awaits if carbon taxes aren't implemented, even though the IPCC emphatically does not say that.

There are problems with science on the right as well as the left, but perhaps the best symbol of how bad the politicization of science — and its transformation from science into "Science" — is can be seen in this: Even though the anti-vax movement is a product of the loony left, liberal media outlets are trying as hard as possible to paint it as a product of the loony right. The lens of politics corrupts everything and turns science into "Science."

The incentive to politicize science is really attractive. And when academia becomes dominated by one sort of person, it becomes nearly irresistible. But if scientists want to maintain their credibility (not to mention do the right thing), they need to resist it.

Finally, one last tip from a Christian: Be empathetic. In January, I predicted a new year of online outrage, because the internet favors the phenomenon of scapegoating, in which a group of people picks a lone person to project their sins onto and destroy them to protect the strength of the community. Scapegoating is always an evil impulse, and we should be wary of it, especially if the victim "has it coming" as the anti-vaxxers do, since it only increases the impetus. As I've tried to show above, the anti-vax movement might not have even taken root if the medical establishment had been a little more careful with their credibility, if we took time to think about what science actually is, and if we weren't in such a rush to always turn everything into a political football.

Here's a thought experiment: Imagine you have a lively, outgoing, wonderful toddler, slowly becoming withdrawn, locked into their own world. As the parent of a 3-year-old, the thought turns my stomach into knots. And the simple fact of the matter is, we don't understand what causes autism, at all (it might not even be a disease!). And in our culture, the one thing we won't accept is that something doesn't have a solution. The urge to try to come up with an alternative explanation, while seriously misguided, is also deeply human and, ultimately, understandable.

There is some evidence that beating people over the head with arguments only makes them dig in more. I see all the anti-anti-vax tweets, and I wonder: "You do realize that probably no anti-vaxxer reads you? Are you just tweeting to signal to your peers how science-y you are?"

Righteously unloading on some poor person on the internet feels really good — trust me, I know — but are you trying to make yourself feel good, or do you want to actually change someone's mind?