Mysteries are fun. Without being regularly presented with the novel, the unknown and the unpredictable, our brains grow bored. And there are many who feel it important that the world retain some permanently insoluble mysteries in order for it, and their lives, to remain interesting and meaningful at all. I don't refer only to problems that are (likely) practically insoluble, such as the Goldbach Conjecture, but real, everyday mysteries that occur before all of our eyes. Mysteries that would require ghosts or souls or magic or gods to explain.
It doesn't take a highly educated, super intelligent person to recognize that science has explained a lot over the past few centuries. Many things that once seemed mysterious have been laid bare. The origins of the universe, the origins of life, how both of these things have evolved since their origins, and many other less colossal questions have been answered to a degree that would have been unimaginable even 200 years ago. But still, some people insist, there are things that science, empiricism and humanity simply can't explain. Things like consciousness, they say. Things like why there is something rather than nothing in the first place.
These are just the most reasonable examples, though you can hear many less reasonable ones from lots of people, depending on the degree to which they need mystery to maintain a sense of "specialness" or "uniqueness" for their own particular existence. Any kind of spiritual or alternative healing, or anything invoking magic, "energies," ghosts, spirits or gods as the only possible explanation for something that happens in the real world would be such an example.
"Only possible" is very important here. Because, as is often the case with something such as, say, acupuncture, which has been shown to have some beneficial effects, one only starts to go off the deep end when one digs their heels in and insists that only an invisible, unmeasurable, untestable magical energy called "chi" can explain these effects. On the other hand, a more reasonable, and far more likely explanation would be that a long time ago some ancient people stumbled across a beneficial practice that they couldn't explain, so they gave it an explanation which turned out to be off-base. This doesn't change the fact that they had hit on something useful. But is "chi" real? Very probably not.
As a matter of fact, this is a recurring pattern. People living in the less-knowledgeable past of our planet were able to establish a causal relationship between an event and a result. Take, for example, the relationship between sexual intercourse and child birth. It has been documented (I have no source at the moment, though I will look for it) that there are people living in hunter-gatherer societies among whom this relationship is not understood. In the example I am recalling, this was most humorously, and tragically, demonstrated in the story of an anthropologist who took a male member of a tribe he was studying back to London for several years. When they returned, the tribesman was thrilled that he was a father, since his wife had just recently given birth in his absence. Whoops!
But among most peoples this relationship has long been understood. But how "understood?" The Greeks thought that the offspring belonged entirely to the father, and that the mother was merely an empty vessel who carried his progeny until birth. In Renaissance Europe, it was believed that inside each sperm was a "little man," a homunculus, who traveled to the womb fully formed and simply grew there. We now know, of course, that both of these theories are way off, though I am sure they made quite a bit of sense to the people who invented and perpetuated them. Nevertheless, being wrong about the "how" or "why" it worked didn't stop them from putting the right things in the right places.
Then along came empiricism and science and our modern understanding of sperm and eggs and DNA. And now there is very little left to explain about how the sexual act produces offspring. This is the part that recurs, over and over and over. Ancient explanations, relying on best-guesses and armchair assumptions, give way to reason, empiricism and evidence. This has occurred thousands, nay, millions of times in the course of human history, with the bulk of it in the last dozen generations or so.
But do you know what is really interesting? The reverse has never happened. Never ever, zero times, not even once. Never has humanity had a rational, scientific, empirical explanation for something and it turned out that was the wrong one, and we instead needed a god or magic or mystery to explain it. Never.
Think about it. Think of all the natural phenomena that people used to use magic and spirits and gods to explain. The rain. The sun. The stars. Animals living. Plants growing. Fire. The changing of the seasons. The phases of the moon. Pregnancy and childbirth... the list could go on for days. And for everything on that list, every one of those phenomena that used to require a supernatural explanation now only requires a natural one.
But never has it occurred that something we understand with a natural explanation like, say, the ways stars form, turned out to be wrong and we instead we needed an explanation such as, "they are actually put together by hordes of really industrious, really sweaty, demons with shovels."
What does this mean? Does this prove anything in the definitive, absolute certitude, once-and-for-all sense? No, because nothing can be proven with that degree of rigor, not even your own existence. But what it does allow us to talk about is probabilities. The sun has risen in the east every morning for the last 4.6 billion years. Will it rise in the east tomorrow? Well, I can't say with absolute, irrefutable certainty that it will, but it is a pretty safe bet. So can I say with absolute certainty that no observable phenomena will ever require a supernatural explanation? No, but, again, it is looking like a pretty safe bet at this point.
So when someone says, "Well, I think there are some things that science just can't explain," they are really just placing a very bad bet, like Dr. Z assuming that just because the Bills lost three Super Bowls in a row, they were certain to win number four. Actually, it is way worse a bet than that. It is a lot more like betting everything you have on the moon being made of cheese.
Sure, there are plenty of things science currently has no explanation for, and there likely always will be. But this is for the very simple fact that the more layers of existence you peel back, the more you find. We have questions that are very likely unanswerable in principle, questions about what occurs in other universes, or what existence would feel like in higher dimensional space. But this does not mean we get to pull angels and demons out of our backsides and start dancing nude around the fire again.
All it means is that we are running into the natural limitations of a very highly overrated mammal. Of course there are things we have trouble explaining. We're monkeys. Have you ever seen a monkey? They get a kick out of throwing their own feces at each other. But that doesn't automatically mean that just because we can't explain it, or can't explain it currently, that we can just make up any damn explanation we want.
It just means we need to keep looking.
(I owe some of the reasoning for this particular post to Greta Christina, who put this idea forth in a more clear and concise way than I had heard it before. Her blog is linked at the top of the page here.)