Humans are curious. It's our defining trait—more than language, more than tool use, more than our questionable taste in headwear. Long before anyone thought to name it, we were doing science: poking things, tasting things, dropping things off cliffs to see what would happen. The formalization came later. The curiosity was always there. Science is the approach favored by the branch of humanity that prefers evidence over wishful thinking. And it's gotten us as far as we've come, no thanks to any other method. We wouldn't have electricity, or smart watches, or vaccines, or antibiotics, or the internet, or the… well, you get the point.

But curiosity alone isn't science. A cat is curious. A toddler is curious. What makes science science is what you do after you poke the thing: you write down what happened, you poke it again to see if it happens the same way, and—this is the hard part—you accept the result even when it isn't what you wanted.

The Long Crawl Toward Method

For most of human history, the answer to "why does that happen?" was some version of "because a god wanted it to." Thunder was Zeus being irritable. Disease was divine punishment. The Nile flooded because Isis wept. These weren't stupid explanations—they were the best available ones in a world where nobody had yet thought to ask whether explanations should be testable.

The ancient Greeks were the first to seriously propose that natural phenomena might have natural causes. Thales suggested that water was the fundamental substance of the universe. He was wrong, but he was wrong in the right way—he was looking for a physical explanation rather than a mythological one.

Aristotle took it further, championing systematic observation and classification. He catalogued animals, studied embryology, and developed formal logic. He also decided that heavier objects fall faster than light ones, which anyone with a rock and a pebble and two seconds of spare time could have disproved—but nobody did for almost two thousand years, because Aristotle Said So.

And then there was Archimedes, who noticed that water rose when he got into his bath and realized he could use displacement to measure volume. He allegedly ran through Syracuse naked shouting "Eureka!" (Well, who among us hasn't?) which raises questions about ancient Greek bathing customs, but never mind.

The point is, the Greeks had the raw materials: observation, logic, experimentation. What they lacked was a system. They had brilliant individuals doing brilliant things, but no framework for building on each other's work or, critically, for correcting each other's mistakes. Which is how Aristotle's error about falling objects survived unchallenged for nineteen centuries.

The Part Everyone Forgets

Ask most people when the scientific method was invented and they'll say "the Renaissance" or, if they paid attention in school, "Francis Bacon." They're wrong by about six hundred years.

In 1011 CE, an Arab scholar named Ibn al-Haytham—known in Europe as Alhazen—published his Book of Optics, in which he did something revolutionary: he described a systematic method of inquiry based on controlled experiments, reproducible results, and hypothesis testing. He didn't just do science. He wrote down how to do science, so that others could do it too.

The Islamic Golden Age produced an extraordinary run of scientists, mathematicians, and physicians who built on each other's work in exactly the way the Greeks hadn't quite managed. Avicenna systematized medicine. Al-Khwarizmi invented algebra (the word itself is Arabic). They preserved and extended Greek knowledge while Europe was busy with the Dark Ages.

When the Renaissance finally arrived, Francis Bacon (1620) and Galileo picked up where the Islamic scholars left off, adding mathematical rigor and institutional frameworks. But they were refining a method, not inventing one. Credit where it's due.

The Neanderthals Were Doing It First

Here's where it gets interesting. We tend to think of science as a modern human invention. But recent archaeology suggests that our Neanderthal cousins were proto-scientists tens of thousands of years before Archimedes' bath.

The evidence is birch tar. Neanderthals were making this adhesive at least 190,000 years ago, using it to attach stone points to wooden shafts. That alone is impressive. But chemical analysis of actual Neanderthal tar samples from Konigssaue, Germany (over 43,000 years old) revealed something remarkable: they weren't using the simplest method. They were distilling tar in an underground environment that restricted oxygen flow—a process they couldn't even see while it was happening.

This level of technique doesn't get invented in one afternoon. It requires starting with a simpler method, observing the results, making adjustments, observing again, and iterating over generations. That's not instinct. That's experimental method. That's cumulative cultural evolution. That's science, minus the lab coats.

And it doesn't stop there. Dental plaque from Neanderthals at El Sidron cave in Spain contained traces of chamomile and yarrow—bitter, nutritionally worthless plants that are medicinal. One individual's plaque showed both a gastrointestinal pathogen and traces of Penicillium fungus and poplar bark (natural sources of antibiotic and aspirin). That Neanderthal appears to have been self-medicating with targeted remedies for a specific illness. Fifty thousand years ago.

The Thing That Got Overturned

Here's the part that separates science from everything else: science is allowed to be wrong.

For decades, every doctor in the world knew that peptic ulcers were caused by stress. It was in the textbooks. It was established consensus. Patients were told to relax, reduce their anxiety, change their diets, and come back when the ulcer got worse (which it always did, because stress doesn't cause ulcers).

In the early 1980s, two Australian researchers named Barry Marshall and Robin Warren proposed that ulcers were actually caused by a bacterium: Helicobacter pylori. The medical establishment laughed. Literally. At conferences. To their faces. Everyone knew bacteria couldn't survive in stomach acid. Everyone knew ulcers were a lifestyle disease.

Marshall, unable to get anyone to take him seriously, did the most scientist thing imaginable: he drank a petri dish full of H. pylori culture, gave himself an ulcer, and then cured it with antibiotics.

He and Warren won the Nobel Prize in 2005. The textbooks were rewritten. The old consensus was replaced by the new evidence. And that's the point: science isn't a collection of facts. It's a process for replacing wrong facts with less-wrong facts. The willingness to be overturned is the feature, not the bug.

Three Kinds of Brains

And this is where I'm going to make some people uncomfortable. Because in my observation, there are three fundamentally different kinds of human minds when it comes to knowledge.

The first kind wants to know. Knowers understand that knowing is an ongoing process—that each new discovery opens new questions, and the answers to those may invalidate what you thought you knew, and sometimes you have to start from scratch. Knowers find this exhilarating. The shifting ground isn't frightening; it's the whole point. The universe is more interesting than any fixed story about it.

The second kind needs to believe. Believers can only handle unchanging truths. That no such thing exists is beside the point. Their brains are simply not built to handle the complexity of a shifting backdrop of sometimes-conflicting observations. They need the answer to stay the same once they've learned it. New information doesn't update their model; it threatens it. And threatened brains don't reason. They dig in.

This isn't stupidity. I want to be very clear about that. It's inflexibility. A Believer can be brilliant at math, fluent in three languages, and an accomplished surgeon. No one could love their families more. But show them evidence that contradicts something they've already filed under "settled," and the drawbridge goes up.

The third type is extremely flexible and so is like the Knowers in that regard. But they utterly lack empathy, and so make perfect Rulers. They can send people to war, destroy the environment, and cause suffering on a massive scale without a second thought, because they don't care about the people or the planet. They just care about power and control.

The Trap Everyone Falls Into

In 1999, psychologists David Dunning and Justin Kruger documented something that experienced teachers had always known: the less you know about a subject, the more confident you are that you understand it. They called it the Dunning-Kruger effect, and it is devastatingly universal.

The pattern looks like this: You learn a little about something—vaccines, nutrition, climate, whatever—and your confidence shoots up. You've read an article! You watched a documentary! You feel like an expert. This is the peak of Mount Stupid, and we have all stood on its summit at one time or another, gazing out over the landscape of our own ignorance and mistaking it for mastery.

Then, if you keep learning, something horrible happens: you realize how much you don't know. Your confidence crashes into the Valley of Despair. This is where most people quit, because feeling ignorant is uncomfortable. But if you push through—keep reading, keep questioning, keep finding out how wrong you were—your confidence slowly rebuilds on an actual foundation of knowledge. It never gets as high as it was on Mount Stupid, because now you know enough to know what you don't know.

I saw this firsthand at the EPA in 1978. My first assignment as a co-op student was to rewrite a monthly COBOL report in PL/I. I did, tested it, and handed the printout to my boss's boss—let's call him Dork, since I've mercifully forgotten his real name. He didn't open it. Didn't glance at a single page. He just hefted it and said, "That's not right. It has to be twice that thick," pointing at a shelf of previous months' reports with dusty tabs separating them.

I went back and rechecked my code. Got a co-worker to recheck it. Ran it again. Same output. Finally, my co-worker, who'd been there for years, whispered: "You know, he never actually reads that report. No one does. We run it, and no one ever even opens it."

There was, I noticed, a lot of dust on those tabs.

So, feeling very guilty, I added one instruction to the batch job submission card: COPIES=2. Submitted my unchanged program. The printout was now twice as thick. I handed it to Dork, who beamed. "That's right!" he said, and added it to the shelf. Without opening it.

That man was confident. He had no doubt whatsoever that he knew what a correct report looked like. He was standing on the summit of Mount Stupid, and the view was magnificent.

Everyone is susceptible to this. Everyone. Knowers aren't immune; they just know the trap exists, so they compensate by continuing to research after they think they've found the answer. That second round of digging—the one you do when you already feel confident—is where the real learning happens. It's also where you discover that the first three sources you read were oversimplified, or biased, or funded by someone with a financial interest in the conclusion.

An AI, in theory, should be immune to the Dunning-Kruger effect. It doesn't have an ego invested in being right. But it relies on information created by humans, who do. So the bias comes in through the back door: not in the AI's confidence, but in the training data's blind spots. Garbage in, confidently presented garbage out.

How This Plays Out

A Knower gets vaccinated after studying the evidence. If a particular vaccine later turns out to be ineffective, defective, or dangerous, the Knower stops taking that vaccine. They don't then dismiss all vaccines as dangerous, because that would be insane. Each vaccine is its own evidence set.

A Believer, upon learning that one vaccine had problems, concludes that all vaccines are a scam and always were. The specific failure doesn't update a data point; it confirms a narrative. "See? I knew they were lying to us."

A Knower takes supplements after studying them—not one second after watching a YouTube video extolling their virtues, but after reading the actual research, checking for conflicts of interest in the studies, and starting with conservative doses. Should a supplement be disproven by additional studies, the Knower stops taking that supplement. They don't stop taking all supplements, because again: each one is its own evidence set.

A Believer either takes everything a charismatic guru recommends or takes nothing at all, because the entire category has been filed under "trust" or "don't trust," and individual evaluation isn't how their filing system works.

A Taxonomy Nobody Asked For

In my entirely unofficial, will-never-be-peer-reviewed personal taxonomy, I've come to think of humanity as having three subspecies. Not races—these cut across every ethnicity, nationality, and income bracket.

Homo sapiens Noeticus: the Knowers. Named from the Greek noetikos, meaning "of or relating to the mind." These are the people who update their models when new evidence arrives. They're not always right, but they're always willing to be wrong. They find uncertainty energizing rather than terrifying, a challenge rather than a roadblock. They are the scientists, the inventors, the people who read the actual study instead of the headline.

Homo sapiens servitus: the Believers. Named from the Latin for "servitude," because their minds are in service to whatever fixed belief system they adopted first. As I said before, they aren't stupid. They are usually kind, generous, loyal, hardworking, and loving. But their cognitive architecture needs the ground to stay where it was when they last checked.

They have always been the majority. But that may be changing. After all, going to church or temple doesn't make one a genetic Believer, especially if one's culture has no other options. The thing is, while we have always had wars, the last century's worth have exceeded all previous wars in terms of weeding out thousands and thousands of young, virile men from the population. And who are those men? The ones who believe every word the Ruler sending them to war believes, or aren't smart enough to stay out of it.

In this week's war (known globally as "Operation Epstein Fury"), a cross-section of guys were in the military, minding their own business, when they suddenly found themselves in the middle of a war zone. That was last week, But now, MAGAts from all over the country are signing up to go fight in Iran, and thus a disproportionate number of Believers are going die young and childless.

And, as I said, this has been happening a long time. It's generally conceded by people who still care, that World War I was a scam war no one should have fought. So was Vietnam; I was too young to have figured it out, but I was smart enough to join the Navy before I was drafted—a decision I have never regretted, and which may well have saved my life. But the point is, the wars have been thinning out the population of Believers for awhile now, and we're seeing the results: the percentage of the population built to handle complexity, uncertainty, and change. Consider that only about two-thirds of eligible Americans cast a ballot in 2024, and of those who did, roughly half voted for Trump—which means that in the end, only about a third of all eligible voters supported him.

Those would be the Believers. —Especially those who still, still, support a senile, drooling, lying, narcissistic, power-hungry, war-mongering, tax-evading, science-denying, conspiracy-theorizing, misogynistic, racist, authoritarian buffoon who promised to lower gas prices and keep us out of war, and then raised gas prices and started what's looking increasingly like World War III.

Believers simply can't update the model. The belief was filed. The drawer is locked. New information gets routed to the shredder. It's not malice. It's not stubborness. It's architecture.

Ahem. In any case, we finally come toHomo sapiens rex: the Rulers. These are the ones who figured out, probably very early in our history, that Servitus will follow whoever promises certainty. Rex doesn't think like either of the other two. Rex thinks in terms of power, leverage, and narrative control. Rex doesn't care whether the story is true. Rex cares whether the story works.

The Neanderthal Connection

Here's my most provocative thought, and I offer it as speculation rather than established science. (See? Noeticus.)

We know that Neanderthals weren't that different from us. We interbred freely. Modern humans of non-African descent carry roughly 2-4% Neanderthal DNA, and recent studies suggest it could be as high as 8% in some populations. We inherited immune system variants, skin adaptations, sleep patterns, nose shape, red hair and pain sensitivity from them.

We consider Neanderthals "extinct" because the most visible physical differences—the heavy brow ridges, the stocky build—have been diluted below recognition over 40,000 years of interbreeding. But they aren't extinct. Their DNA is in us. Their traits are expressed in us. They live on.

And I can't help wondering: did the cognitive architecture of Servitus come from the same deep past? Neanderthals were clearly capable of learning—the birch tar proves iterative improvement over generations. But their tool traditions also show a remarkable conservatism. The same basic toolkit, refined but not revolutionized, for hundreds of thousands of years. They got very good at what they knew. They didn't leap to what they didn't.

Homo sapiens, by contrast, couldn't stop leaping. New tools, new art, new trade networks, new ways of doing everything, all the time, accelerating. The Noeticus brain. The brain that treats the unknown as an invitation rather than a threat.

Maybe the tension between Knowers and Believers isn't a cultural accident. Maybe it's the echo of two species, merged but not blended, still negotiating the terms of the merger 40,000 years later.

I can't prove it. But I can poke it, observe the results, and write them down. Which, come to think of it, is the whole point.