Overview:

What we have depends on what we know, and what we know depends on what we have. How much we have of each mostly depends on our toolbase, physical and mental, which depends on how much we can divide labor, which depends on how literate we are and how much and how fast we can trade. As either trade or literacy grows, communication and division of labor grows. As either grows, our ability to generate reliable knowledge of the world can also grow. As we gain more reliable knowledge, we can use it to build new tools, both physical and mental, which changes our toolbase, which can trigger yet more change. That ecogenetic densification can happen whether we plan for it or not. Europe is a good example. In the swarm view, Europe, and its descendants, rose to power mainly through human action. However, that needn’t imply that Europeans were smarter or harder-working than anyone else, nor did it go according to some plan. Europe benefited from a series of knowledge accidents, but they weren’t wholly random. Each one built up Europe’s overall ability to think and act more effectively in larger groups, and each one made the next one easier. So human action, but not necessarily human design, gave Europe power.

If the steam engine is the iconic invention of our industrial phase change, then the printing press is the equivalent for our mental phase change. Just as the steam engine led to many follow-on changes, so did the printing press. It first led to our printing revolution and that alone led to big changes. But those changes also set up our scientific revolution, our industrial revolution, and our medical revolution, and each of those interacted with each other, and each led to big changes too. All four of those phase changes started in Europe. Today we’re in the midst of another big phase change—our information revolution—and it’s happening even more quickly than those four previous ones. And just as before, we’re not planning it into existence, yet neither is it happening randomly.

Earlier chapters outlined various pieces of that general ecogenetic growth process, with the last chapter sketching the spread of science to medicine. This chapter turns to the rise of science itself. It starts 92 centuries ago, long before we started farming, and touches on a few pivotal events from that time on. About 800 years ago, Europe in particular gained much of Eurasia’s written knowledge to that date. About 500 years ago our species started a printing revolution. About 300 years ago we began a scientific revolution. About 200 years ago we entered an industrial revolution. About 150 years ago we initiated a medical revolution. About 50 years ago we ramped up an information revolution. Today, we’re beginning an intelligence revolution. Our mental resources are expanding. Not only that, their expansion is accelerating.

The Long Chain

It’s 92 centuries ago and a 23-year-old horse hunter has just died in what we today call England, but at the time the British Isles weren’t yet even islands. They were merely the westernmost tip of Eurasia. The last ice age is still ebbing and a lot of water is still locked away as ice, so no sea separates Dover and Calais. The horse hunter’s clan buries him in their cave near today’s Cheddar, 130 miles west of London. The climate is cold and dry, and near his burial cave, horse, reindeer, and arctic fox roam. While hunting them, his migrant kin return to the cave seasonally. They’re about five feet tall, they sometimes starve, and they die young. Much has changed since then. Today, Britain is an island. It’s warm and wet, its reindeer are gone, and no one hunts horse there anymore. Instead of less than 5,000 hunter-gatherers, it now hosts about 60 million grocery-shoppers. But while much has changed, much hasn’t too. In particular, our genes mostly haven’t. A 53-year-old history teacher in Cheddar shows that. He’s taller than that long-ago horse hunter. He’s better and more regularly fed too. He’ll also live longer. But his mitochondrial genes, which we inherit from our mothers, is the same. He and the horse hunter are kin. They both descend from an unknown woman who lived around 500 centuries—50,000 years—ago, when our species first became truly human.

Four centuries after the horse hunter died, the oceans rose with the melting ice and his kin became islanders. Some of them may have then learned about boats. About 55 centuries ago, their island’s climate temporarily warmed enough for farming to worm its way that far north. Some of them may have then learned about plows. About 27 centuries ago, ancestors of the Celts came to the islands. Some of his kin may have then learned about iron weapons—probably pointy end first. Seven centuries later came the Romans, who also brought iron weapons. They garrisoned the whole area around Cheddar, using it for lead mines and farmland. Some of his people may have then learned Latin. Then came the Saxons, the Vikings, the Normans. Then came steam engines, cars, computers. His kin lived through it all until 1996, when one of them, a history teacher, who lived just half a mile from the cave had his mitochondrial genes sequenced. All those changes in climate, tools, and language, all the rape and slaughter and slavery, none of them much mattered to his kin’s genes. Even 500 centuries ago they’d already given all of us all the genetic abilities we needed to survive.

The horse hunter had tracked big mammals, snared small mammals and birds, and gathered wild plants. He didn’t teach history to adolescents in a small English town famed mostly for its cheese. Those two lives, so near in place, so far apart in time, might seem very different, but the differences are smaller than they appear. Today many of us believe that 92 centuries ago we were brutish loners, but that’s unlikely to be so. Hunting horses millennia ago wasn’t simple, nor was survival a solitary sport. You couldn’t simply make a spear one morning, then yawn, step out of the cave, and throw it. You first had to know the best kind of wood to use for your spear. You had to know how to shape the right kinds of flint or obsidian or bone to make its pointy end. You had to know how to use fire to harden your wooden spear, and perhaps how to find and prepare the right poisons for its tip. You had to find your way about by night or day, judge the weather and terrain, and understand the use and range of your weapons. All that you had to learn.

To eat, you also had to put yourself into the mind of the hunted. You had to link a broken twig with a faint hoofprint with knowledge of what plants or streams lie ahead to guess what your prey might do next. You had to work with your hunting party to flush the game, and maximize your kill. Perhaps some of you divided labor by being good trackers while others were accurate spear throwers or strong bowshots. Once you killed your prey, you had to butcher it, and to you everything had a use. Instead of skin you saw clothes, tents, rugs. For bones you saw needles, arrowheads, harpoons. For sinews you saw cord and thread and bow strings. For teeth you saw hacksaws and jewelry. For fat you saw rich food, and also lamps and ointments. Nowadays, butchery might mean remembering to remove the plastic wrap before microwaving, but back then a horse was a department store, and hunting was shopping. All that had to be learned and passed on, just as we learn and pass on history today.

In short, back then your main means of support wasn’t your wit or skill; it was your clan. Nor was your clan acting alone in the middle of nowhere. If you can survive someplace, so can others, so your clan must live with them. Nor were they simply enemies. They could help you learn where the prey is migrating, what climate changes might be coming, where to find suitable mates. And for that valuable information they’ll want something in return, so perhaps all nearby clans now and then come together in big conclaves to trade information, fix matings, and perhaps do some mushrooms and party. Before fridges, the best place to store meat was in friendly bellies. Whether they’re in your own clan or in others, they’ll return the favor when you’re hungry because they know that one day they’ll be hungry again. Perhaps the clans used trade to cement such links. Perhaps that even led one day to money. Tens of centuries ago, flint, shells, amber, and obsidian traveled long distances. We’re economic creatures. We produced, consumed, and traded long before credit cards and stock markets. Wolf-incisor necklaces or mammoth-ivory beads 400 centuries ago, Patek Philippe watches or Manolo Blahnik pumps today—all announce that we would make dangerous enemies, or worthy friends.

All such teamwork needs communication and synchronization. Planning, pooling resources, dividing labor, working together, and trading, they all let us do together what we individually cannot. We’ve always survived together, whether by hunting horses or by teaching history.

Some of us today see our species as a collection of vicious loners. We cut down trees, we foul the air, we’re ignorant, shortsighted, self-deceiving sex maniacs. All true. So they worry that we’ll soon do ourselves in. Well, maybe, but if it happens it won’t be because we’re vicious; it’ll be because we’ll have more power than sense. We’re no more vicious than any other species. To a zoologist, we’re a super-gregarious troop species. We aren’t a collection of angry hermits. We’re far more cooperative than pack mammals like wolves and dogs, or pod mammals like bottle-nosed dolphins and killer whales. We’re more cooperative than even other highly cooperative apes like bonobos and chimpanzees. As with those other mammals, we share food and both nurture and educate our young. But with language we also form intergroup alliances. We’ve never been alone. We all function well only when we form reaction networks with each other. Those few of us who seek to rely only on ourselves rarely last long enough to trouble the rest of us.

All of us, like all living things, are sentenced to death at birth, but we, more than the members of any other species, are also sentenced to love. Our wildly gregarious species cannot exist without bonding. No one has to preach it; no law has to enforce it. Love binds us, and faith in those bonds binds us to the world. Trading, forming groups, educating each other, and so melding ourselves into a swarm, is what we’ve always been best at, going back at least 500 centuries into our past. That’s why we’ve survived without fangs or claws. We’re all driven by a ceaseless hunger for linkage, a greed for each other. Everything we do that lasts, we do together—not this nation or that ideology, but our whole species.

Like the horse hunter and the history teacher, we don’t simply work in groups, we’re also all related—literally. We’re all just beads on a long genetic chain stretching all the way back to the beginning of our species. Not only are we all genetically related, we’re all closely related. With billions of us alive today, we’re by far the most populous group of any physically large animal species on earth. We should be hugely genetically diverse. We aren’t. We share 95 to 98.4 percent of our genome with our nearest living cousins, the chimpanzees, yet compared to their genetic variance we’re almost identical. In our ignorance, we marvel at how similar a herd of gazelles look, never seeing that we’re more similar to each other than they are. Long before the horse hunter was born, our species had already spread to every habitable continent on the planet. But unlike all other species, we mostly didn’t do that by changing our genes. We already had all the genes we needed, and they gave us something unique.

Whatever that unique thing is, we had it first in Africa. All of us alive today descend from one small group of hominids living somewhere in sub-Saharan East Africa around 1.9 million years ago. That group migrated out of and back into Africa in at least three big waves, the last one sometime around 1,300 centuries ago. Each wave scattered around the planet, interbreeding with previous migrants. But all through that time our tools changed only slowly. But by around 500 centuries ago, something unusual happened—we still aren’t sure what. Whatever it was, it phase changed us. Suddenly we had cave art, new jewelry, new burial goods, new shelters, new weapons, new hunting tactics. Everything we made started to change much faster than before just around the time the unknown matrilinear ancestor of the horse hunter and the history teacher was born. By 500 centuries ago we’d become the species we are today.

From then on, all other species paid a heavy price. For example, our first cousins, the Neanderthals, had stone tools and portable fire. They also had bigger brains and bigger bodies than ours. They shared at least 99.5 percent of our genome. Yet they started disappearing 400 centuries ago, then vanished utterly by 270 centuries ago. They’d survived nearly half a million years of volcanoes, asteroids, ice ages, but they didn’t survive us. Maybe we didn’t kill them all. Maybe it’s pure coincidence that 270 centuries ago was also near the peak of the last ice age. Competition with us may have been at its fiercest then. Maybe it’s also pure coincidence that over the last 500 centuries or so many of the world’s largest and tastiest plant-eaters also vanished. Whether or not we’re Cain to the Neanderthal’s Abel, the signals left in our genes and buried artifacts suggest that by about 500 centuries ago we’d become the species we are today. That long-ago horse hunter wasn’t some near-human. He was a man.

We’ve changed a lot of things around us in the 92 centuries since he died, but from our gene pool’s viewpoint, little of it is important. It’s our imagination, our language ability, and our ability to externalize skills in the form of tools that let us synergetically and stigmergically work together to do impossible things. We’ve likely had those abilities for at least the last 500 centuries, so something special must have happened to us around then. Something must have caused that phase change. We still don’t know what it was but perhaps it was the last link in the brain structure needed to support language. Or perhaps that had happened long before then, but it took until then for us to reach the critical mass we needed for that change to start leaving physical traces. Whatever the sequence of events, once we could speak we could pass on second-hand information—and misinformation, and disinformation. (Or, as Caliban remarks to Prospero, “You taught me language; and my profit on’t is, I know how to curse.”) Teaching each other how to hunt horses 92 centuries ago then became as easy as teaching each other how to teach history today. We’ve changed biologically since then. Our teeth, for example, continue to shrink and our brain continues to grow. But our recent genetic changes seem tiny compared to all that we’ve built around us since.

Our mental resources, not our genes, are today the prime mechanisms changing how we live. But language isn’t the only reason that we’re changing our lives so fast today. We could speak for a long time but only recently have we begun to change our tools rapidly. We’re changing fast now because we make things, and some of them help us discover and then pass on new knowledge, from which we make more things. Over our past 500 centuries—50,000 years—we’ve been building up a lot of that information toolbase. For a long time it changed only slowly. Recently though, it started changing quickly, and thus so have we. The most recent strands of that increasing change go back at least eight centuries to the spread of Arabic books in Europe. That’s what set Europe along a path of increasing mental resources, so this story starts there. It’ll end where all things human end, deep in the brain.

End of Days

In 1178 Europe’s mental resources began to change. That year the moon burned. What passed for Europe’s best observers at the time, sober monks, claimed to see flames engulf the moon in the twenty-fourth year of Henry II, king in England. In Canterbury, Gervase, that cathedral’s chronicler, wrote of the moon’s burning, just as in 1170 he’d written of the murder of the cathedral’s archbishop, Thomas Becket, who Henry’s knights had hacked to death in the cathedral. Gervase also wrote of the subsequent miracles at the cathedral plus all the hot water Henry got into. England’s new Norman lords had just invaded Ireland, then the Norse and Scots invaded England, then France and Flanders massed to invade England. For Gervase and his brother monks, Europe in 1178 was a dying world. The moon fire could only be one more sign of the coming end times. Mankind had multiplied too much, the earth was aging, and the Antichrist was near. Six years after the moon burned, a letter predicting the end of the world (based on astrology) caused Canterbury’s archbishop to declare a three-day fast in preparation. A small earthquake in England the next year didn’t help matters. Clearly it was the end times.

In 1178, Europe’s mental resources were small. Gervase was one of a tiny elite in Europe—he could read. He could even write. He was part of Europe’s only literate guild, the Catholic Church. But although he was one of an elite he still lived in a small, poor, closed world where new thought was rare and books were few. Canterbury’s library, one of England’s largest, held only about 600 texts, and most of them were copies of old books—very old books. Those books were filled with sin, penance, and the colorful actions of a few celebs, like Henry and Becket. Written knowledge in Europe, and particularly northern Europe, had barely budged for centuries, and all of it lay in the Church’s hands. In 1178 everything Gervase knew, and thus everything anyone in northern Europe knew, was personal and spiritual. To Gervase and his brothers, Europe’s world was rapidly coming to an end. They were right, too. But not in the way they thought.

What destroyed their world was an tidal wave of new books. While Gervase wrote of a burning moon that warm Sunday night down in Kent in 1178, new Arabic books were trickling into Europe, a trickle that would soon turn into a flood. For the last century, Catholics had been taking both southern Spain and Sicily from the Muslims and the Byzantine Christians. Somehow this time they didn’t sack and rape and burn everything as usual. Well, not everything anyway. Instead, their clerics showed up in the conquered cities and started translating the mounds of books they found. Here was Ibn Gabirol and Ibn Rushd. There was Ibn Sina and Moses Maimonides. And over there, Euclid. Next to him sat Hippocrates, Archimedes, and, above all, Aristotle. Heaps and piles of thinkers—Arabic, Greek, Roman, Jewish, Syriac, Persian, Indian, Egyptian—all poked Europe in the eye, tweaked its nose, and blew its mind. They all had something new to say. (New to northern Europe, anyway.) And much of it was neither personal nor spiritual. Today we would call some of it ‘scientific.’

The Muslims had tech the Christians couldn’t even spell, far less understand. Here, their books talked about math—including an Arabic invention called algebra. Over there, was a Hindu invention called zero. Over yonder, was physics, chemistry, and biology. Optics and astronomy, medicine and anatomy, engineering and meteorology, logic and architecture, all made new. New words also came to Europe with the new books: coffee, sugar, syrup, alcohol, soda, cotton, mattress, talc, plus hundreds of others. All were Arabic. There were strange new things too: compasses, lateen sails, liquor stills. There was even a new thing called a ‘hospital,’ where the sick or wounded went not to die, but to be cured. And all of that sat, row upon row, inside vast libraries in cities with paved streets and streetlights and fountains and baths and huge libraries—things unknown in the north.

The Catholic Church then absorbed that book mound in stages, like a python choking down a pig. Over the next two centuries the Church found ways to reconcile its supernaturalism with Aristotle’s naturalism. It was as if Europe had just struck oil, except instead of energy, the new well spouted geysers of new ideas. And just as the taming of oil in a later age was to lead to the equivalent of a thousand years of summer, this was Europe’s equivalent of a thousand years of thinking. The new thoughts energized Europe. No longer did a few monks in a few scattered monasteries make all Europe’s written lore. No longer was all European knowledge small and local. Brain-dead Europe had gotten an injection of pure adrenaline, mainlined straight into its intellectual heart. Its first wave of universities followed. Europe filled with the sound of excited scribbling as it tried to absorb 15 centuries of human thought.

One of those excited scribblers wrote that “Bernard of Chartres used to compare us to dwarves on the shoulders of giants. He pointed out that we see more and farther than our predecessors, not because we have keener vision or greater height, but because we are lifted up and borne aloft by their gigantic stature.” But excited as he was, he also pined for the good old days. He railed against the decadence of modern times. He deplored the wholesale abandonment of the classics. He denigrated the new narrow specializations. He wailed that today’s students cared only for knowledge they could do something with right then—especially in the new get-rich-quick fields of law and medicine. And he denounced younger teachers for giving in to the new pressures.

But a river of new ideas wasn’t all that was new to twelfth-century Europe. Its climate had been warming for over two centuries. That, plus new farming technology, fed more people. Europe’s numbers rose. Between 1150 and 1300 it would triple. New silver mines in today’s Bohemia and Moravia also changed twelfth-century Europe. For example, England’s silver coinage doubled between 1158 and 1180. By the 1220s, England minted about 4 million silver pennies a year. By the 1240s, it was 10 million. Then 15 million in the 1250s. Then 40 million in 1279-1281.

Plus, over the past century Europe had built up its arms enough to deter the Vikings invading from the north and to attack the Muslims in the south. By 1100, the Vikings had mostly stopped making pests of themselves and turned into taxpayers. By 1200, the Muslims had already lost most of their grip on southern Spain. To the east, the Magyars had already settled in and stopped pillaging. Then the Mongols also called it a day for a bit. (Though they came back for more fun in 1241.) As trade expanded, a new textile technology also came to Europe around then (again via the Muslims): the horizontal loom. Then came the spinning wheel (again via the Muslims). With the new books, trade, money, machines, weather, people—and safety—industry spread. Europeans then put the old Roman waterwheel to new uses—running furnaces and forges, beating textile fibers, fulling cloth, making beer and wine and glass. They even had a few windmills already (in Normandy and England). Towns grew. So did trade. Fat new ships plied fat new trade routes. New roads and bridges appeared. And in rich monasteries like Canterbury, huge new Gothic cathedrals soared. Europe began to make itself an industrial revolution.

All those changes aided literacy, and thus increased Europe’s mental resources. Thanks to the new books, and the new learning they brought, out of wandering traders and town mercers would grow merchants, bankers, magnates. Out of the tonsured clerics scribing at court would grow lawyers, doctors, bureaucrats. And out of the magisters of the new universities would grow academics. They all needed to read, or hire those who could. All those new readers needed new scribes, books, booksellers. Europe’s monks couldn’t keep up, so new players joined the book game. After centuries of inwardness and despair, Europe was blooming.

Today, Europe’s mental changes back then might not seem like much. After all, it only meant that instead of a few men studying a few old hand-copied books, Europe now had a few more men (plus a very few women) studying a few more less-old hand-copied books. The printing press didn’t exist yet. But for Europe that was already a huge step. For the first time ever in Europe, the new books and universities encouraged students to reason about Europe’s age-old belief networks in a new way. For a few, dogma alone was no longer enough. By 1200 in the brand new University of Paris, hotheaded Left-Bank students fought pitched battles in the streets—over logic. Five died. After more riots, the Church banned Aristotle, then it added other works from the new Arabic hoard, condemning clerics who wouldn’t behave. It also burned a few (both books and clerics). But many of us today make far too much of that. It was a mere spanking compared to what the Church did to others that it called heretics. Against the Cathars, a Christian sect, the Church created the Inquisition and declared a Crusade. In 1209 in one French city alone, Catholic warlords murdered everyone there. In one day they killed perhaps 20,000 men, women, children, babies—Cathar and Catholic alike. The saying at the time was: ‘Kill them all. God knows his own.’

New books or no new books, clerics still controlled armies, and heresy was still a fatal offense. Even so, to a suddenly expanding Europe, the new way of knowing remained attractive. The Church was suspicious, but the new ideas were too useful. So instead of doing the usual thing—killing everyone who spread the new way of thought—the Church adopted it. The science that would come centuries later would owe its life to Catholicism, just as the books that set fire to Europe in the first place would owe their lives to Islam. The same is true for Judaism before that—and for the same reason. Never mind that future scientists would call many religious authorities venal, petty, repressive hypocrites. That’s all true, but it’s also just the kind of impertinence that children reserve mainly for their parents. Today’s science grew not in spite of but because of yesterday’s religions.

Nowadays, it’s dogma among many of us in the rich world that the Church not only didn’t help, it actively harmed early science. What bilge. But then, every tribe needs its origin myth. Every religion needs its heathens. In 1178 the Church didn’t feel especially threatened by early science. (Or later science, for that matter.) Too few Europeans understood it, or cared about it. It worried the Church, yes, because it meant change, and any change was bad, but that worry wasn’t some overpowering fear of the new radicals. We can’t transport today’s squabbles over science and politics bodily to the twelfth century. Back then, and for centuries afterward, the Church was far more worried about any threat to its strangehold on spiritual matters, or its linkage of disease and sin. That’s what it killed to protect. But Europe’s physicians grew to do at least as much—and for much the same reasons. The new ideas threatened their livelihood too.

Still, despite Europe’s many changes in physical, and above all mental, resources, little had changed by 1200. It was still poor and ignorant. Most of life in Europe was still the usual shapeless misery. Law, for example, was still a rough-and-ready, tribal affair. While Gervase wrote about a burning moon in 1178, if you were accused of a crime, you often underwent trial by ordeal. In one, you might have to walk barefoot on bars of redhot iron. If you lived, you were innocent. If you didn’t, good riddance. Meanwhile, coffles of slaves were still being chivvied down the muddy streets. Almost no one who watched them shuffle past could read. Almost everyone was dirt poor. War was constant. Open bigotry too was still very much the fashion. In 1189 the English massacred many Jews and simply stole their stuff. (By 1290, they would expel all Jews and steal all their remaining stuff.) And in 1204, Crusaders on their way to attack Islam instead sacked Constantinople, which, oops, was Christian—but Greek not Latin, Byzantine not Roman, Orthodox not Catholic—so somehow it didn’t count. In three days they killed thousands, plundered the city, and raped every woman there, matron, virgin, and nun.

However, while Gervase wrote about slaughtered archbishops, beleagured kings, and burning moons in the 1170s, Europe was catching fire mentally. That bloom would fade as the fourteenth century brought sharply colder weather. The Little Ice Age had come. By 1314, the Great Famine struck. Millions died. By 1337 came the Hundred Years War, then by 1347, the Black Death. More millions died. Europe’s population fell back to what it was in about 1150. Its growing industrial revolution died before making any lasting change. New silver mines petered out. New building projects slowed. Trade collapsed. Learning faltered. Europe’s new burble died back down into its customary mutter. It turned inward again, penitentially whipping itself through its cold, muddy, and nearly deserted streets. But its new books, and the new tools they led to, survived. And yet more books came from crumbling Islamic Spain, then from collapsing Byzantium. Europe’s new universities grew. By the sixteenth century, the flame that had first flared in the twelfth century would return, stronger than before. This time though, it wouldn’t come with Arabic books. It came with the printing press.

The Very Pulse of the Machine

Europe’s mental resources grew a lot in the fifteenth century, thanks to one new tool above all—the printing press. Europe phased changed permanently then. However it was neither planned, nor was it easy to build the press that got the change started. The best way to see why all that is true is to put yourself into the time period. Suppose that you’ve just invented a time machine and you decide to visit Johann Gutenberg to watch him build his printing press. You set your controls for the night of October 16th, 1448, in Mainz. However, your time machine accidentally lands on top of the sleeping Gutenberg, killing him—and irreparably damaging itself. Now you’re stuck in 1448. In Europe, of all places. Cursing your luck, you hide the body, mop up the blood, and make it your task to keep history on the track you know. Somehow you have to invent a printing press in a time when Europeans still write on skins.

You know you only need four things: something to print on; type that you can combine to form words; ink to swab on the type; and a press to squeeze the printing surface down onto the inked type. But you have no idea how to get those parts in 1448, especially in the higgledy-piggledy haystack of uneasy principalities that isn’t even Germany yet. If you had any sense, you’d skedaddle to a Mediterranean trading city—like Venice or Milan or Paris—where you might stand a chance. But you don’t think of that. You imagine that because you know about microbes and mobile phones, our past problems would be simple for you. So the next morning, as the cocks crow and the cathedral bells clang in the dawn’s chill, you shoulder your way through Mainz’s narrow, crooked, dung-filled alleyways. You’re about to assemble all the pieces you need to change the world. You think it’ll be easy.

First you visit the copyists, who serve the monasteries and cathedral schools. You also talk to the scriveners, who serve any nobles or rich merchants. They also serve university students in Cologne down the Rhine to the north, Heidelberg up the Rhine to the south, or Wurzberg on the Main to the east. They’re all writing on parchment—scoured skins. They’re using an ink containing tannic acid, mixed with gum for viscosity and soot for color. They refer you to the tanners for parchment. As you walk along, you’re getting used to the stench of this place. Like a yapping Aberdeen Terrier, it’s a constant annoyance. But when you reach the tanners’ quarter, you realize the full power of smell because that’s where Mainz keeps its Doberman Pinscher of stink. While you try to hang on to your breakfast, the tanners tell you that the butchers don’t slaughter enough sheep, goats, and calves each week for them to keep your press going. They prefer to sell to the shoe and purse makers. In any case, a single bible needs perhaps 140 skins. Each takes a month to prepare. And only the costliest ones are supple and flat enough to use in a press. To the tanners, a library is really a place to stack hundreds of gutted sheep.

Foiled over using parchment, you next consider papyrus. But you quickly learn that it’s too costly. Supply is also too uncertain so far from the Mediterranean, given the snowed-in mountain passes over the Alps. It’s too glossy to take the ink anyway. Plus it’s too brittle to withstand the press. So you consider paper, made from linen rag. Linen, made from flax plants, had become relatively plentiful in Europe after 1350, when Muslims brought Chinese textile technology to Islamic Spain. That technology then leaked to the rest of Europe. Paper too had been getting cheaper since 1150, when Muslims brought Chinese paper technology to Islamic Spain. At the time, the Chinese and the Muslims have nearly all the money, all the best knowledge workers, and all the coolest high tech.

China had invented paper money nearly 500 years before you arrived in Mainz—and toilet paper some 300 years before that—and paper itself around 400 years before that—yet although there’s some paper in Europe by 1448, it’s not cheap. Demand is near zero. Neither the nobles nor the clerics use it much because it tears too easily and it can’t last as long. Also, good paper comes from Italy or France. Transport costs by mule-train are high. So you try to get a local millwright to switch from grinding grain to pulping rag. But he doesn’t know how. You can’t even bribe him to try to figure out how until you sell some books, none of which you’ve made yet—and no one believes you can. So you sail up the Rhine to the nearest ‘big city,’ Strassburg, to do some discreet spying. At a paper mill that started there in 1430 you buy the chief ingredient you’ll need—wire mesh. But the resulting paper is thick and porous, like a thin felt, or a thick blotting paper. Ink just splotches on it. After months of trials, you get your papermaker to add gum to bind the paper, and clay to give it a gloss.

Now you have a paper source. Next you need type. You first try to whittle letters out of wood, but the too-small pieces often break. When they don’t break, they warp or crack. Besides, as Mainz’s woodcut printers will tell you, wood wears down too quickly. So you visit the goldsmiths to find out how to make metal molds. You need an alloy both soft enough to shape into type easily, yet hard enough for the type to resist wear. While talking to the smiths, you discover another problem. Most metals shrink as they cool. That means you’d lose all your type’s serifs. But you need those serifs to imitate handwriting perfectly, or no one will buy your books. So you tell them that you need an alloy that expands as it cools. When they quit laughing, they tell you that there’s no such thing. After years of trying, you settle on an alloy of tin, antimony, and lead. It miraculously fills in the serifs.

However, no one knows the best proportions for the alloy you need. (Today we know that it’s 62 percent lead, 24 percent antimony, and 14 percent tin.) Metallurgy is hardly an exact science yet. Also, while Mainz’s goldsmiths know how to work many metals, antimony is rare. So sometimes you get good type, but mostly you get soft type. You resign yourself to having to pay for new type often. You also need a metal with a high melting point, like iron, to make the molds. And you need a hard metal, like steel, to cut the type shapes. You also need a soft metal, like copper, to bang the type shapes into to make the intaglio (the impression). You go to the sealcutters to solve those problems. Then you visit the winemakers to see how to make a press.

You soon learn that wine presses are great for squeezing grapes but little else. You need an especially smooth wooden screw to press the paper evenly down on the inked type. If not, your press shreds every sheet of paper fed to it. So you visit the linen makers. They use their presses to make pleats in cloth, which you find works well with your soft, thick paper. But when you try the copyists’ ink, you find that it’s too much like a watercolor. It won’t stay on the upraised metal type long enough to impress on the paper. It’s designed to etch skin, not to stick to both metal and paper. So you visit the painters. They tell you that you can make the ink sticky enough by adding oil. Oil is easy to get, but to bind it to the soot, you must first boil both with soap and gum.

You don’t think that’ll be a problem, but it is. Soap is expensive—even rich Europeans avoid bathing. They think it’s unhealthy. Instead, they try to mask odor with perfume. However, you can get some soap from the chandlers. When not making candles, they make a little soft soap from woodash plus the tallow of slaughtered cattle that they barter from the butchers. (The soft soap is useful for enemas.) You then get linseed oil from the oilmakers. They heat moistened flaxseed then stuff it in woolen bags and crush them in a wooden press. After a devastating fire in your shop, you design cleanup procedures and safety protocols to avoid fire from all the oil, oily rags, and paper. In a crowded town of wood and thatch, fire is a constant fear. As in Rome 1,500 years before, even the theft of a public leather waterbucket is punishable by hanging. Now you must decide how to arrange all the elements in your shop, especially how to arrange the type for easy typesetting. You decide on capital letters in a wooden case above another case holding minuscule letters—an upper case and a lower case. Then you must design your type, and train your typographers and press operators.

It’s now been a decade since you arrived in Mainz. You’ve worked hard, but the townsfolk still think you mad. They scoff that you haven’t done anything new—you’ve just put together several tools made for other purposes by a dozen guilds. Even given your future knowledge, solving the technical problems of mating those pieces has still taken ten years of your life. You’re now decrepit. Many of your teeth have fallen out from recurrent scurvy thanks to the lack of fresh fruit in the Little Ice Age winters. Your skin is pitted from bouts of smallpox, eczema, and psoriasis. You have arthritis thanks to dysentery and poor diet. Your eyesight is failing and spectacles aren’t common yet. You couldn’t afford them anyway. You also now bear scars from knife fights defending your few coins from cutpurses in town and from brigands on your trips outside town. Plus you smell like a horse.

By the standards of the time, you’re ready for the grave. You’re happy though because you’re finally ready to start printing. Except that the sealcutters, making the molds by hand, and knowing nothing of the needs of printing presses, have for their own convenience cut the type too big. You get 18-point type instead of 12-point. That means few words on a page. And that means ludicrously big, and therefore very costly books. In any case, small print can’t get invented until eyeglasses are cheap, since of the few who can read, most are old. Also, the goldsmiths think of themselves as artists, so their molds aren’t all the same size. So when you compose the letters of type, the words aren’t uniform. The molds aren’t all the same depth either. So the upraised type’s height varies in its bed. Some letters press hard while others make no impression. Everyone in the tiny, smelly, wooden town snickers at the childish print of the mad inventor. To them, you’re a hopeless failure.

It only annoys you more to hear rumors of two other idiots—in France and in the Netherlands—who’re working on the same movable-type idea. A European printing press is an idea whose time has come. Determined to succeed first, you start teaching the goldsmiths and sealcutters the bizarre new idea of uniformity of production and interchangeable parts. Now you just need some time to get them to make what you need. Oh, and the money to buy the ingredients and cause them to be built. Plus the money to transport materials and run the press. Not to mention the money for a place to keep it; the money to distribute and sell your books; the money to travel; and the money for room and board for yourself and your apprentices. Don’t forget the money to bribe everyone you need to. So you hock your tools and supplies to a rich merchant who you somehow hypnotize into believing that you can do the crazy thing you claim you can.

Somehow you must also create enough demand for print to make it profitable even though almost no one can read. So you must sell to the few merchants who need everyday printing to run their businesses. You must also sell to the few nobles and clerics who’re literate enough to read, rich enough to buy, and dumb enough to own your expensive fake manuscripts. You must also ensure enough supply of text to print since even fewer can write. So your first products can’t be new books. They must be bibles, missals, breviaries, and indulgences for the clerics and nobles; calendars, grammars, dictionaries, and classics for the universities and cathedral schools; and waybills, handbills, posters, and cyclopedias for the merchants. Plus, if you dare, some under-the-counter pornography.

Now though you have to worry about the Church and the universities. Together they control what could be printed since they control the copyists and the scriveners. By making up the bulk of Europe’s few readers, they’re also your main customers. You also have to worry about the local prince and his brute squad. He won’t like this strange new idea of having his human possessions talking to each other directly through print—who knows what they’ll say. Then you have to worry about the scribes. You’re about to destroy their trade. They may accuse you of dealing with the devil to make such uniform copies at such low cost. That could get you run out of town, or even burned at the stake.

Then your clever backer, scenting money, marries his only daughter to your chief apprentice—an ex-university student from Paris who’s lonely in Mainz. That gets him all your technical secrets. Then he sues you to get your tools and your stock of books. He hires the best lawyer in town. You represent yourself. Soon you’re penniless again. Tempting opportunities for assisted suicide appear daily—hunger riots, random violence, plague, dysentery, typhus, catching leprosy from the pariahs forced to live outside town, the occasional war, a footpad’s knife.

Four more years have oozed by. Somehow you solve your problems and now you finally own a printshop. Everyone stops laughing. Bibles are so rare that they’re deeded on death, like plots of land. They take a scribe nearly a year to copy and they can cost ten times what even a well-to-do merchant could make in that year. Your faux bibles cost a fifth as much. Books at the time are a kind of hugely expensive furniture, and you’ve just built something that can churn them out by the dozen. Everyone thinks you’ve built a machine to do so. In fact, you’ve put together a network of tools. It’s made of all the knowledge, artifacts, and people you’ve had to figure out, buy, bribe, steal, or train, to get just one press working. You’ve now synergetically linked all of them together into a new thing—a printing press. And as soon as it exists, it has stigmergic effects. A reaction network of people then nucleates around it. That’s the very pulse of the machine: not the machine itself but its process of construction, and the network effects it has after construction.

In the streets, instead of spitting on you as usual, everyone now sucks up to you. Even so, you’re still not a runaway success. Your capital outlay for your printshop is far higher than simply hiring some scribes and sticking them in a cowshed. Also, having to renew your too-soft type every few months adds to the cost. Plus paper is still both rare and expensive. Demand is still low. So your printed books are still costly, just not as insanely costly as handwritten ones are. So at first the clergy and nobility would control your printing. Papal indulgences, for example, are big business. They can wash away sin, even future sin. Incest, sodomy, sorcery, murdering your dad or kids, church robbing, all have prices. Thus, even after your costs start to fall, you’ll only have strengthened the Church and the nobles. You’ll also have amplified the number of manuscripts on sex, self-help, social climbing, salvation, witch finding, comedy, and folklore. Television would do the same for similar powers and similar topics in a later age. So even after 14 years of hard work, no new books get written. Little appears to have changed.

Appearances lie. It’s now 1462 and after two centuries as a free city, Mainz is conquered on October 28th. Soldiers led by an archbishop egged on by the pope kill 400 people in Mainz that night. However, had the pope any inkling of the future, he would’ve ordered his pet archbishop to slit everyone’s throats. Instead, two days later the archbishop drives out hundreds of citizens (including the printers). He also steals all their stuff, including your house—Gutenberg’s house—which you’ve been squatting in all this time. The exiled printers then spread the new art of artificial writing up and down the Rhine and Main. From there it spreads all over Europe, from Italy to Iceland, like a fire running up a river of gasoline.

By 1480, at least 110 cities have printing presses. By 1500, 236 do. By then, the new presses have already churned out perhaps 20 million books. That’s more books in a few decades than Europe’s total output for the previous 1,000 years. The new press is already completely out of control. As with computers in a later age, presses got so small that printers became mobile. You could pack a press onto an ox-cart and move it from place to place. Hiding it was equally easy. Books and paper and papermills then worked synergetically with the printing press, just as railroads and coal and mines were to work with the steam engine three centuries later. As presses spread, so did papermills. As the volume of paper rose, its price fell. Then so did the price of books. Finally unchained from the sheep supply, books then further slashed the cost of both bookmaking and papermaking as they spread knowledge about how to improve both trades. They did the same for all other trades too. And that put the first cracks in the monopoly power of the guilds. Suddenly, knowledge in Europe was no longer locked in heads, passed on only from father to son and mother to daughter.

The mighty were petrified. The press brought with it a whole new kind of threat. You can excommunicate, exile, torture, and kill as you like, but how do you trample cheap thought? Bonfires can burn only so many books. If you can’t quash dangerous thoughts at the source, then folks will begin to think anything they want—which is exactly what happened. The small, mobile presses fled and hid like cockroaches. Then they just made more copies. As books and broadsheets mushroomed in Europe’s smelly little towns, the new sea of cheap thoughts made everyone more skeptical of any thought. Even belief networks sanctified by millennia-old authority tottered. Dogmas crumbled. It became possible to make fun of even the pope in print. And if you can do that, you can make fun of anyone and anything. As the number of copies of any one book multiplied, authors raced to be first with a new thought. And instead of buttering up the mighty as before, they started to care more about being correct. Instead of some nitwit noble idly reading for amusement or prestige, their readers might know more than they did. The number of authors mushroomed too. Even the thought-delivery mechanism itself—a uniform, machine-made product—helped remove the person, and thus the unquestioned authority, from the thought being expressed. Every author was now checkable. Every two ideas pairable. Every thought questionable. Thinking exploded.

European demand for print had been growing since the twelfth century, when Arabic books first came to Europe. As Europe’s trade and learning grew, literacy grew. So did the uses that readers could put knowledge to, because the chance of a particular idea landing in front of the right pair of eyes at the right time grew. As more of Europe’s few city dwellers learned to read, the pressure to cheapen bookmaking rose. The ease of cheapening it also rose. By the early 1500s, Europe’s few well-to-do, urban readers could buy many cheap thoughts. And they compared and reassembled them into new thoughts. As that river of new ideas swelled, thinkers found each other more easily through print. That led to more organized professions, more division of labor, more weakening of the Church, the aristocracy, and the guilds. By 1517 came mass protests against authority, religious and civil. By 1527, Rome was burning as Protestant armies sacked it. A century of warfare followed. Millions died. The acrid scent of printer’s ink was the smell of chaos—and of mental freedom. Europe began to phase change. Huge changes in religion, civic order, technology, and science followed. Medieval Europe disintegrated under the relentless hammerblows of print. Printing, and the literacy it brought, just spread and spread and spread. More and yet more of our species got to say what we thought in a communications revolution still ongoing today, half a millennium later.

Organon

Europe’s next jump in mental resources came with the rise of science. That also centered around the development of a tool, but not a physical tool like a printing press, it was a reasoning tool. However, reason seems to be the last thing on the minds of most Europeans in the 1600s. The belief firestorm touched off by the printing press was still burning brightly. The huge wars, and the millions of deaths, were tapering off, but war was still constant. For example, around 1666 England went to war with someone about every three and a half years. Mostly it was about trade routes and land, but many sects all over Europe still quarreled with each other over how God wanted us to live our lives. Some were on the rooftops calling for free enterprise, an end to monarchy, separation of church and state. Others wanted vows of poverty for churchmen, religious freedom, liberty for all (sometimes even for women, sometimes even for slaves). Yet others wanted the vote for all adult males, legal divorce, legal polygamy. It was the ’60s all over again—except three centuries earlier. Over here they shouted for free love. Over there, for no private property. Over yonder, for common male ownership of all property—including sexual access to all nubile females. Then they climbed down and ran away. Some ran as far as British or Dutch America. They ran because if caught, they might be hanged.

But one tiny group that might as well have been a sect didn’t run away. They called themselves natural philosophers, the forerunners of today’s scientists. They weren’t in danger of being hanged. For one thing, just as in 1178, the Church didn’t much care what they thought. They were too few and too hard to understand to matter. Instead of trying to figure out what God wanted, they tried to figure out how God worked—that is, how nature worked—hence the name, natural philosophy. All Europe’s other sects had been growing since Luther’s first printed protest against the pope in 1517, which had triggered the Protestant Reformation. But Europe’s new natural philosophers had been growing since Copernicus’s first handwritten outline of a sun-centered solar system in 1514. Strictly speaking, their big idea wasn’t religious. But over time, all religions would struggle with it. Their big idea was that the cosmos was a machine.

Today that might seem an innocuous enough idea, but in 1666 it was a near unthinkable thought. Think of the universe as a building. Natural philosophers didn’t do what all other European sects did—which was to try to figure out the architect’s mind. Instead, they looked at the building itself and tried to figure out what its parts were made of and how they might have been put together. They thought that the cosmos obeyed recognizable, discoverable, and consistent mechanical rules. There was system behind it. They thought that it would always do the same things in the same circumstances. One of them, Isaac Newton in England, can stand for all the rest. He more than anyone else used the new ideas of to completely reimagine our universe.

Newton, like Aristotle 2,000 years before him, told our species how the cosmos worked. Unlike Aristotle though, he used math. Aristotle was a worthless mathematician. Of course, in his time Arabic-speakers were still a thousand years away from inventing al-jabr. (On the other hand, Archimedes, who lived not too long after Aristotle, did far more than any mathematician until recent times. So Aristotle really was worthless, mathematically speaking.) By Newton’s time, our math had improved enough to be just barely ready for calculus. Newton, and others, improved it still further and then used it to show that both the heavens and the earth obeyed the same mathematical rules. Not only that, but Newton’s ideas, unlike Aristotle’s, led to testable predictions. That testability helps keep us from believing in whatever idea network we want to. For example, Newton’s math showed that the earth should be flattened at the poles. All we had to do was find enough money to go and look to prove him wrong. Such ideas are predictive, and therefore falsifiable—they could be physically tested. And they could fail those tests. Aristotle’s couldn’t.

Aristotle’s ideas were untestable because for him everything had purpose. He thought that everything had been made with a definite idea in mind. So if something didn’t behave as he expected, it only meant that he hadn’t guessed its correct purpose yet. He could always guess again. He also made little distinction between living things and non-living things. All had final causes. (That is, purposes, ends, the things for which they were for). Their final causes made them what they were. So for him, water gushed and rocks rolled for the same reason that eggs hatched and trees grew—those were their natural desires. In his belief network, everything was reaching toward some state—its final cause—its purpose—the end for which it was made. Thus for him, children didn’t grow because of a long sequence of small biological changes. Children grew because that’s what children did. Growing to assume an adult form was their final cause, the end for which they were made. His way of thought was thus all about ‘why’ and not ‘how.’

Looking back from today, Aristotle’s way of thought seems laughable. It’s like playing tennis with the net down. But his work was still crucial. Before you can get today’s science you need yesterday’s science. And for that you first need one important thing, and Aristotle gave it to us. He, and his cohort, ignored magic. Instead, he embraced logic. For instance, he didn’t merely state that the earth was immobile. He deduced why it had to be, given his ideas about motion. He was totally wrong, but he always tried to reason logically. He always strove for generality and consistency. (Of course, and as usual, he didn’t invent all that. He inherited some of it from earlier Greek thinkers. They in turn inherited some of it from earlier Persians, who got some of it from even earlier Egyptians, Indians, and Sumerians. For example, the result that everyone today knows as “the Theorem of Pythagoras” predates him.) Aristotle, heir to centuries of careful thought, called his system of logic the Organon, Greek for The Tool.

Two thousand years later, Newton and others like him used Aristotle’s mental tools, but turned his largely naturalist but still thoroughly animist cosmos inside out. For them, the cosmos was a machine. So they stopped assuming that everything was essentially alive. For them, no longer would something act as it did because it wanted to act that way. Instead they assumed that most everything (except conscious beings, they thought) was essentially dead. Everything acted the way it did because it was uniformly acted on by a few consistent and universal (and testable) forces. For Newton and his ilk, the emphasis shifted from ‘why’ to ‘how.’

For Europeans quarreling about God in the 1600s, that viewpoint brought hard problems. Where does God fit? If we’re all just complex machines, what’s the point of life? And what about sin and free will? If we’re simply acted upon by unwilled forces, how do we assign praise and blame for our actions? What supports our legal system? And what do we tell kids about moral choice? For most Europeans the new belief network was just too much. It wasn’t merely that its results were hard to believe. The method itself meant rejecting everything Europe thought it was sure of. It meant rejecting dogma, authority, and spirits, and replacing them with instruments, mathematics, and tests—none of which we’re good at. We’re good at biology’s four Fs: fighting, fleeing, feeding, and, er, reproduction. And it’s good that we’re good at them. If we weren’t, we wouldn’t be here to whine about not being good at anything other than the four Fs.

The new belief network was even more unappetizing because it didn’t even pretend certainty. It asked us to live in ignorance. Things were no longer to be ‘right’ or ‘wrong.’ They were now to become ‘less wrong’ and ‘more wrong.’ It asked us to throw away everything we thought we knew and live in a fog of uncertainty. But most of us don’t know how to not know. We want certainty. Looking for less wrong facts? Accepting that you don’t know anything for sure? Having to think hard all the time? Coming to conclusions you don’t like? What possible sense could any of that make? If the new method hadn’t gone on to explain so much more of the world than we could have before it could easily have died out. No one liked it much—not even Newton and his bunch. Were they alive today, they’d pray for us.

In any case, most Europeans in the 1600s could care less about the structure of the universe. Even five centuries after 1178 and the translations of Arabic books, most Europeans were still as poor as dirt—and twice as ignorant. They still lived in a violent, ignorant, disease-filled world. So rather than puzzling over whether or not the cosmos was a machine, most Europeans in 1666 worried about more urgent matters—like how to live to reach 20 years old. Plus, even after two centuries of the printing press, at least three in four in England still couldn’t read. And back then England was a nation of bookworms compared to most of Europe. Of the few Europeans who could read, most were clerics and courtiers, or lawyers and physicians. They knew no math—and didn’t want to know any. They preferred reading material that we still prefer today: sex, self-help, and scandal, poetry, piety, and politics.

And so we come to a 23-year-old Newton sitting in his mother’s garden in Woolsthorpe in 1666, having fled there to escape the latest wave of plague. Communication was hard in his time compared to today, but two centuries of the printing press had improved it. Thanks to the press, and the spread of Arabic and Greek ideas, he’d inherited over two millennia of Eurasian thought about nature. Also thanks to the press, and the literacy it spread, he was part of a network of dozens of new philosophers, powered by new books and a growing postal service. Their half-formed musings about the force that kept the heavens together had shaped his thought. Also thanks to the press, he’d been taught the best mathematics available at the time, including an early version of calculus. Armed with all that, and his great genius, as an apple fell he saw into the heart of gravity. In 1666 one of our minds reached out and grasped the entirety of the cosmos—falling apples, circling moons, orbiting planets, shooting comets, spinning suns, spiraling galaxies, everything.

With that, the Copernican cat truly jumped out of the Aristotelian bag. But while we today see Newton’s work as brain-sprainingly clever, Europe at the time didn’t. Nearly no one noticed, and of the few who did, most didn’t understand a word. So don’t imagine that Europe immediately fawned on its new thinkers. Instead, for many, they were figures of fun. What they said, and how they said it, was simply too insane to be taken seriously. In 1664, Samuel Butler made them a sideshow in Hudibras. In 1667, John Milton admonished them for hubris in Paradise Lost. In 1717, John Gay’s farce, Three Hours After Marriage, thoroughly deflated them. In 1726, the year Newton died, Jonathan Swift’s Gulliver’s Travels savaged them some more. Many in England saw their new thinkers not as savants leading Europe into a new age, but as yet more appendages of a rapacious and corrupt state.

The laughter died down though—but not because any of us got any smarter. Soon, the new mechanist view began to bear fruit in practical matters—navigating ocean-going ships, for example. By 1698 came the first prototype steam engine, then by 1712, the first useful one. Only then did a few Europeans outside Europe’s small philosophical sewing circle become interested in the idea of a mechanical cosmos. Newly rich merchants, made fat with Europe’s growing trade, were some of the earliest adopters. They were out shopping for family heirlooms to fake a landed ancestry. They didn’t much care if the new ideas were true or not; pretending to the new way of thought was just one more way to distinguish themselves. Rising with Europe’s rising trade, slave income, finance, and industry, some of them also found the new mechanist view a better way to figure out how to make things—ships, guns, clocks, sextants, telescopes, microscopes, vacuum pumps. The new belief network also fit with their rising aspirations better than did the medieval worldview their lords spiritual and temporal still clung to. So as they gained power in the increasingly wealthy towns, the new ideas spread.

Then, once that idea network reached critical mass in Britain, France, and the Netherlands, tribal pride took over. Soon even politicians and poets were parroting mechanist beliefs. They still had no idea what it was all about, but it became the fashion to say that they did. Suddenly, the names of the new natural philosophers became worth dropping in polite society. The new mechanist attitude spilled out of physics too. For instance, John Locke tried to use it to figure out government in 1690. James Lind tried to use it to figure out scurvy in 1747. Adam Smith tried to use it to figure out economics in 1776. In airy drawing rooms all over Europe, well-dressed lords and ladies began to speak of Newton and Leibniz, Huygens and Wren, Descartes and Boyle, Torricelli and Hooke, just as if they knew what they were talking about. Everywhere, literate Europeans began to turn away from Aristotle. Instead, they started looking at nature as a machine. Europe had begun to give up Aristotle’s ‘why’ for Newton’s ‘how.’

Europe’s new thinkers were unscrewing the back of the world, looking for new ways to explain how it worked—never mind why. However, most of the new tools that later led to Europe’s industrial phase change didn’t come from the genteel natural philosophers. It came from the dirty fingernails brigade. Blacksmiths, plumbers, ironmongers, carpenters, weavers, miners—they were the ones facing concrete industrial problems. Most of Europe’s gentleman thinkers adjusted their powdered wigs, took another pinch of snuff, and continued talking. They mostly ignored those world-changing tools, although after a while their work grew essential to its perfection. What was new wasn’t how helpful they were, but that they existed at all. Even indirect philosophical contributions to material life was a new thing. Previously, philosophers weren’t there to do things. They were there to explain why things couldn’t be done. Now though, a few were hauling away some of the worm-eaten pillars of their crumbling medieval world. They built the rest into new cathedrals of thought. And that went on to change our whole world.

In the summer of 1665, the summer before Newton’s first real insight, London’s weather was hot and dry. That summer the English were at war with the Dutch when plague once again came to London. Everyone who could flee, fled, leaving the poor to die. Perhaps 80,000 did. London remembers it as the Great Plague. That winter, with Europe still in the grip of the Little Ice Age, a cold snap froze the Thames up to London Bridge. It was London’s Great Frost. That in turn stopped London’s lifeblood, river trade. Then another hot, dry summer brought drought. With it, came rising food prices, then starvation. Meanwhile, the heat thoroughly dried out the city’s splay-shouldered, wattle-and-daub buildings. That fall, a burning bakery set fire to the whole city. Perhaps 70,000 Londoners went homeless. It was the Great Fire of London. That winter came another Great Frost, and cheap coal for fuel and grain for food vanished. Tens of thousands of Londoners, freezing, starving, homeless, fled into Moorfields and Finsbury Fields to the north. War, plague, drought, fire, frost—for many Londoners, 1666 signaled the beginning of the end of the world.

On Monday January 22nd, 1666, the Great Plague was still taking lives in London. It was a month after the Great Frost froze the Thames, and eight months before London’s Great Fire. That evening, Samuel Pepys had some drinks at a pub on his way home, his usual practice. Later that night he wrote that: “But what, among other fine discourse pleased me most, was Sir G[eorge] Ent about Respiration; that it is not to this day known, or concluded on among physicians, nor to be done either, how the action is managed by nature, or for what use it is.” Imagine a world where we breathe, but don’t know how, or even why.

While Pepys wrote that frosty night, most well-educated Europeans still lived in a version of Aristotle’s animated, purpose-filled world. For them, metals grew in the ground, like mushrooms. Abandon a silver mine for long enough, and it would simply grow more silver. Heavenly bodies decided what a lump of matter would turn into. Gold came from the sun, silver (the moon), iron (Mars), copper (Venus), and so on. Iron was hard because men were hard. Copper was soft because women were soft. Mars (men, iron) was about war. Venus (women, copper) was about love. (Men from Mars and women from Venus have a long heritage.) The stars ruled daily life. And if your cow died, it may have been because a witch cursed it. In 1666, rich Europeans, despite their airy drawing rooms, might just as well have been dressed in furs, worshiping with frosted breath Odin and Thor and Freya. The old gods still ruled. They just had different names.

But for a few European thinkers in 1666, it was no longer enough to say that we breathed because that was our natural desire. Or that apples fell to earth because that was their natural place. Or that copper was soft because women were soft. Such phrases only sounded like explanations because they contained the word ‘because.’ They seemed to explain ‘why,’ but because they didn’t explain ‘how,’ they really explained nothing at all. On a quest for ‘how,’ Europe’s new thinkers, armed with their new mental tools, tried to understand how blood worked, and what it was for. They wanted to know how tall cedars managed to water themselves. How heavy was the sun? How did the tides work? How can we avoid catching smallpox and plague and the bloody flux? And how does dew form on a tankard of cold water in the summer time? Little by little, they began to believe that our childhood questions were answerable—and that our problems were solvable. One day, they thought, we’d no longer have to fear the plague. No longer would we have to worry that a stray spark could set a whole city ablaze. And if our rivers froze solid, we’d at least know why.

By candlelight they did their philosophizing with quills ripped from dead geese. They scratched their lice and scrawled their thoughts in a world whose always night-dark streets were full of both cutthroats and dead animals. They were the first of us to see that our usual way of thinking—simply musing about a problem then inventing good-sounding, sympathetic-magic, Aristotelian final causes—was worthless. It might give us some idea of how we think—or, rather, how we think we think—but it can’t yield reliable knowledge of the world around us. They were the first among us with sharp enough tools, mental and physical, to begin to find yet sharper tools, a more reliable organon. Today we call it science. Passed from hand to hand over millennia by many of us in many places, and sculpted in blood and frost and fire during a trying time in Europe, that new organon let us change our world. As it grew in power, we didn’t only change how we fed ourselves, made a living, made new resources, made more energy, cured ourselves, rearranged our planet. With it some of us began to see a much deeper beauty in ourselves, and in the cosmos around us. But all that took time, a great deal of time, because we fought it. We’re still fighting it today. None of our belief networks die easily.

Dying To Have a Baby

In 1665 natural philosophers in London might have been clambering over mounds of rotting, blackened corpses in the streets. A year later, they might have been burned out of their homes. A few years before or after, they might have gone hungry in the famines caused by war or weather. By the 1760s though, England was a different world. By the 1860s, a new body of people, by then calling themselves ‘scientists,’ had already separated themselves almost entirely from philosophy. They asked the universe direct questions with ever better tools and ever greater mathematical sophistication. That more rapidly led to reliable knowledge than our previous fruitless search for Aristotelian final causes. After physics in the seventeenth century, chemistry began to solidify in the next century, then biology in the following century. Then as we built more sophisticated tools, more fields crystallized into reliable sciences as our new tools, physical and mental, let us move away from our usual folktales and toward mathematics, direct low-level observation, and repeatable experiment.

But it wasn’t, and still isn’t, easy, despite the facile stories we like to tell ourselves today. For example, today it’s dogma to believe that the earth circles the sun. We today make ourselves feel good by making fun of our earlier selves for believing otherwise. We also point to Copernicus as the father of that idea. But the idea far predates him. Aristarchus of Samos is its first (known) proponent, 2,200 years ago. If it’s so obvious that the earth circles the sun, why didn’t the idea take the world by storm back then? Further, in our simple versions of this particular folktale, we say that Copernicus came up with the stellar idea we hold today. Not so. His scheme was just as wrong, and even more intricate than the one it supposedly supplanted. (Which was Ptolemy’s, based on Aristotle’s ideas of how the heavens worked.) Plus, we today like to blather on about how he had to defy the Church to get his scheme published. Again not so. In short, today we’ve streamlined a complex story into a simple one we can tell to kids. It has far more to do with emotion than with truth.

Our mental resources have grown over the millennia, and particularly since the spread of early science to Europe in the twelfth century, then Europe’s printing revolution in the fifteenth century, then Europe’s scientific revolution in the seventeenth century, then Europe’s industrial revolution in the eighteenth century. But even today it still grows only slowly. When any change threatens our most closed and synergetic belief networks, we fight it. That wouldn’t be a problem except that much of what we believe is wrong. Much of how we think we think is wrong too. A disease we used to call ‘childbed fever’ is a good example. It kills women in childbirth and it’s very old. Twenty-four centuries ago, Hippocrates, in the midst of a great epidemic, treated ‘the wife of Philinus.’ Then, two weeks after giving birth, she had a fever. Then, “pains of the head, neck, and loins.” Then, “no sleep... extremities cold... thirst... bowels in a hot state.” By the seventeenth day she couldn’t speak. She died three days later. Hippocrates never knew that he himself may have killed her.

Childbed fever is really blood poisoning (septicemia). Microbes multiplying in the blood stream cause it, and they can get in when childbirth tears up the birth canal. So until recently, childbirth was dangerous. In nineteenth-century Europe, one new mother out of every five might die, and, at the time, constant pregnancy, even in rich countries, was still normal. At those odds, of every 100 women each attempting six births in a row, 74 would die. An 1853 tombstone sums up many women’s lives back then: “Twenty years I was a maid, / One year I was a wife, / Eighteen hours a mother, / And then departed life.”

In 1846, Ignác Semmelweis, a Hungarian doctor of Germanic extraction, started work at Vienna General Hospital as assistant to the head of the maternity wards. The wards gave free care to poor or unwed women. Split into two wings, they were divided by caregiver sex. Obstetricians and their students (all male) managed one wing. Midwives and their students (all female) managed the other. Each wing delivered about 3,000 babies a year. During his first month on the job, 36 out of 208 new mothers died. Childbed fever killed them.

The problem was common in our industrializing countries as both populations and large hospitals grew. Over in Philadelphia, one doctor wrote that “Sometimes the pain... is too intense to be borne by any human patience; and no exhortation or recommendation can prevent the woman from crying aloud, or even screaming in her agony.” Semmelweis, sensitive to the cries of the motherless newborns, the grieving relatives, and the women’s dying screams, tried to find out what was killing them. He stepped up his examinations of both the women and the bodies of the dead. The obstetrics students followed his example. More women died.

The next year, 1847, he tabulated births and deaths for the past six years, looking for a pattern. Between three and four times as many died in his wing as in the other. Pregnant women routinely got down on their knees and begged to leave. That preyed on his mind. He even began to suspect that he may have helped kill some of them. But other doctors didn’t worry. They put down the excess deaths to many causes. The emotional strain of being examined by males was one popular one. Another was overly rough examination by foreign students. Then there was delivering on their sides versus on their backs. Or terror of the priest who rang the death knell. Or overcrowding. To those they added the catch-all ‘atmospheric cosmic telluric changes,’ and ‘miasma’ (a disease-ridden vapor striking down the weak or dissolute).

Semmelweis could make nothing of those ideas. The weather hadn’t changed. The two wings were in the same hospital. The second wing was more crowded. Varying the delivery position changed nothing. So did banning foreign students. Muffling the priest’s bell didn’t help either. Also, childbed deaths were low for home delivery even when they were raging in the hospital. A few women lived far from the hospital and some had even given birth in the streets of Vienna on their way there. Yet still their deathrate was lower than his wing’s.

Semmelweis couldn’t make sense of his data. Then, during a dissection, an awkward student accidentally nicked the finger of the presiding pathologist (a male), who was also Semmelweis’ mentor and friend. He died in agony five days later. Semmelweis, putting aside his grief, noted that the body looked like it had died from childbed fever. But that was impossible. Everyone knew that was a female ailment. So what had killed his friend? Midwives didn’t do dissections, he knew. So he guessed that something to do with cadavers could kill anyone, not just women and babies. He called the invisible somethings ‘cadaveric particles.’ He thought that doctors, who sometimes handled corpses right before delivering babies, were ferrying them around. He tested that by bruising the vaginas of some female rabbits and rubbing in ‘cadaveric matter.’ They rotted away inside, then died, much as childbed fever victims—and his friend—had died.

Now he thought he had the answer, but he couldn’t convince everyone of it. He couldn’t display his mysterious ‘cadaveric particles,’ nor could he explain how they killed. But he could smell them, he thought, in the morgue’s foul, clinging odor. He then tried various ways to remove it. Soap and water didn’t work. But a toilet cleanser, calcium hypochlorite, did. So on Saturday May 15th, 1847, without asking his hidebound boss, he posted a notice about hand washing. After dissections, students now had to wash their hands in the cleanser until there was no “smell of cadaver.” Many ignored the notice. So he stood guard over the wards, bullying compliance. Everyone was furious. They grew even more angry when he and some students examined a dying woman then 11 healthy ones. All but one promptly died.

That might have killed his idea, but, driven by the daily agony, he refused to give up. He guessed that even though he and the students had washed their hands before the first examination, they still carried “putrid matter derived from living organisms” from the first woman to the other 11. So he told students to wash their hands before every examination. It no longer mattered what they were doing before. He also wrote the names of each attending student and midwife above each woman’s bed. If she died, everyone would know who to shun. His wing’s deathrate then plunged by two-thirds (to 3.8 percent). The next year, it fell to 1.27 percent. That was lower even than the other wing’s 1.33 percent. He now knew what had killed those hundreds of women and infants. He also knew that many had died at his hands, just as surely as if he’d strangled them in their beds.

It was now 1848, called ‘The Year of Revolutions’ in Europe. Much unrest, spurred on by the industrial revolution, which was then boiling away, had led to revolt all over Europe. Semmelweis supported the rebels. The next year, with the rebellions crushed, the backlash began. Most of the older staff plotted against him. They disliked the inconvenience of his new hand-washing protocol—and what it implied about them. They also feared his politics. So when his two-year appointment ran out, his boss refused to renew it. He fled Vienna, running home to Pest. In Hungary, he repeated his protocols at Saint Rókus Hospital. Conditions there were even worse than at Vienna General. Sheets stained with pus from the last woman to die were being laid for new deliveries. After a string of deaths, he guessed that even dirty linen could carry contagion. After much fighting with the staff, and paying for laundering out of his own money, he changed that. Once again, everyone was furious. But childbed fever deaths then dropped to eight women in 933 deliveries. That was just 0.85 percent, a record low for Europe.

In 1861 he published a dense, rambling, tactless book about his work. It savaged many eminent doctors, some of whose childbed deathrates were as high as one in four. He was savaged in return. At a medical conference in Paris, his technique was said to belong in a factory, not a hospital. An eminent Berlin pathologist ridiculed him. A respected Viennese medical weekly said that it was time to stop the nonsense about the chlorine wash. Graybeards in Prague, Munich, Würzburg, and Erlangen all agreed. Meanwhile, the deathrate back at Vienna General was back to all-time highs. That’s one of the great things about our species: we believe in striking when the irony is hot.

To many doctors his idea was absurd. Even if his ‘particles’ existed, how do we know they’re harmful? And even if they were, how could so little poison kill? Besides, Europe’s well-accepted miasma theory already explained everything. It also placed blame in convenient places—on the air and on the patient. Europe’s religious teachings at the time said as much too. Christians said that in sorrow thou shalt bring forth children. Jews said that women died in childbirth because they hadn’t properly obeyed the menstrual laws, hadn’t properly done the dough offering, or hadn’t properly lit the sabbath lamp. Each of our religions had a story. Somehow all those deaths had to be explained, and how else but via some hidden sin? Europe’s network of beliefs tied together. Everything made sense.

Semmelweis’ model didn’t. It couldn’t explain why deathrates varied from hospital to hospital. Nor could it explain why they changed with the seasons. (No one, not even Semmelweis, noticed that childbed deaths vanished when the students had been out in the streets protesting in 1848.) It also implied that doctors were unclean. If it were true, then socially they’d be no better than toilet cleaners. That can’t be right. Plus they’d then be killers. That can’t be right either. They saved lives; they didn’t take them. Besides, the dying were only women—and poor women at that. Many were so morally weak that they got pregnant without first getting married. Naturally miasmas then killed them. Everyone knew that moral weakness was a sure way to invite disease. So was poverty. It’s thus not surprising that so many fell ill. Poor women of easy virtue or weak constitution simply died in childbirth, that’s all.

So many doctors simply ignored him. Others damaged his credibility by failing to repeat his protocol correctly. That was partly his fault. He was slow to publish, and when he did, he larded his book with libel. Plus he was a bad writer. But it was mostly the doctors’ fault. For instance, some eminent Prague doctors said that they’d tried his cleanser and it didn’t work. But what they didn’t say was that they used the same basin of it for many days. It itself grew foul. They also didn’t say that they only dipped their fingertips. Nor did they say that they soon replaced it with a basin of plain water. And that was straight after coming from the morgue.

A few younger doctors were more open-minded. They adopted Semmelweis’ ideas, but their stories didn’t always inspire mimicry either. For example, one of them had earlier attended his own cousin as she gave birth. She later died of childbed fever. Then he tried the new cleanser in his practice. After he saw the huge change it made, he realized what had killed his cousin. So he threw himself under a train.

As Semmelweis’ frustrations mounted, he grew more and more erratic. By 1864, his mind broke. He drank heavily. He grew sexually disturbed. He called eminent doctors ‘assassins.’ During his lectures he raged, then wept. He accosted lovers on the street. He handed out leaflets, screaming that doctors were murderers. Pest University fired him, then his wife, afraid for their children, tricked him into an asylum. Two weeks later, on Sunday August 13th, 1865, age 47, he died. Apparently, his guards tied him down and trampled him.

Today, ‘childbed fever’ is down to three women in 100,000 births. That is, in our rich countries. In our poor ones, it still kills many of us. Even in our rich countries, dirty hands still kill. They’re the single largest source of hospital infections. Nurses, orderlies, and especially doctors, don’t wash their hands often enough. Doctors say they’re too busy. Plus, soap dries their skin too much. In 1995, several outbreaks in the United States ended only after the introduction of a new soap. It was antiseptic, but more importantly it smelled good and didn’t dry the skin. In 1996, in an Australian intensive care unit for children, only 12 percent of doctors washed their hands after seeing a sick child. Researchers then mounted an educational program. It had in-service teaching rounds, poster displays, and specific requests to wash. The hand washing rate then rose—to 17 percent. Some of the doctors were then asked what their hand washing rate was. Their average estimate was 73 percent. Those doctors were then secretly followed. Their actual hand washing rate was ten percent. Nothing had changed in another study in 1999. Even when doctors did wash their hands, their average washing time was only nine seconds. In the United States in 1998, 41,737 people died of breast cancer, and 13,426 died of AIDS. Such diseases make headlines. That same year, hospital staff infected about two million of their patients, which is about five percent, or one in every 20 admissions. Of those, at least 80,000 died. By 2002, 99,000 a year died. Those deaths don’t make headlines. Today, hospital infection is still among our top ten killers, even in our richest countries.

Changing Our Minds

Why did Semmelweis have so much trouble? Why wasn’t it enough for him to state his idea, show how to test for it, then watch it spread easily and naturally? That question is tied into bigger ones about how we change our belief networks. Even with today’s science, changing our minds about anything is often hard for us. Whether we live in huts or skyscrapers, we always have an ‘idea toolbase,’ just as we have a physical and institutional toolbase. We don’t live by bread and batteries alone. Even though our ideas are intangible, and thus don’t need much matter or energy, changing them isn’t easy. Our belief networks always grow until they can withstand almost any attack, even if you use a pair of pliers and a blowtorch. And they’re that way for good reason. They exist because they explain the world to us and they give us importance, They’re not merely mental vampires; they’re mind symbionts. In exchange for belief, they give us emotional sustenance. Each one serves at least some of our emotional needs.

The scientific revolution is the single largest recent change in how we think. But it didn’t happen easily. It didn’t happen because after it we could figure more stuff out, or save more lives, or live better, or whatever. Nor did it happen because some Europeans were sitting around one day when one of them said: ‘Hey! Enough of this aimless woolgathering! Let’s think for a change!’ Instead, it happened in ecogenetic stages, one little change at a time.

For instance, Tycho Brahe was our first significant astronomer after Copernicus. Without his enormous mound of careful data (amassed over decades), Kepler couldn’t have done what he did. And without Kepler, Newton might not have done everything he did. But why did Brahe watch the sky so carefully—and for decades? We might simply say that he was a genius and leave it at that. From that we might build a theory of history as a series of random turns where anything could happen at any time. Alternately, we might say that he was a genius, but then explain that by saying that he was European. From that we might build a theory of history where Europeans did what they did because, of all our groups, they’re the smartest, bravest, nicest—or meanest, cruelest, greediest. Or perhaps because they were the first to adopt today’s forms of capitalism, or democracy, or hair-care products, or whatever. With enough effort we could make either kind of theory work.

But we needn’t assume any of that. The printing press made Brahe one of our first astronomers—anywhere in the world—to have printed copies of two different star charts in his hands. One was based on Copernicus’ new theory and the other on Ptolemy’s old one. Brahe was perhaps our first sky-watcher anywhere who was competent to understand what he had. He could see that we had two ideas about the stars. They differed. And both differed from the actual night sky. Both were wrong. So perhaps that’s why he ignored what everyone before him had said and simply recorded the heavens. Then he published. The new data then spread so that others no longer had to do that work. Their star-gazing, and their ideas about the sky, could build on his because his were provably more reliable than what came before. Europe’s new printing press didn’t force such developments, but it acted as a catalyst to aid them. The printing press thus gave Europe a huge thinking advantage. With it, Europe could more easily and cheaply produce and spread more reliable knowledge than before.

Our idea toolbase grows ecogenetically, just like our physical and institutional toolbase. Once any of our groups builds up any closed and synergetic network of ideas about how the world works, it perpetuates itself. It doesn’t matter whether it’s about a turtle supporting four elephants supporting a discworld, or about molecules evolving until they invent mobile phones, each of our belief networks always grows to be self-consistent and self-reinforcing. Think of how much synergetic and stigmergic support any old and popular idea must have. Since it’s persisted for a long time in many of our heads, we would’ve embodied it long ago. Several of our rituals and institutions will both assume it and perpetuate it. Much of our physical toolbase will support it and channel it. Many of our physical tools will reflect it and enhance it. We can’t make it go away just like that—unless we adopt the methods of the Khmer Rouge. And even that extremity usually fails too.

Many of us today, whether in rich or poor lands, don’t see our species that way. We thus imagine that education is a simple task. All we have to do is proclaim some new idea, and that’s that. But that’s ridiculous. Dislodging an entrenched belief network can’t ever be a matter of simply talking about making a change. Talk is always cheap. No book, not this one, and not even the Little Red Book or Mein Kampf, will change much of anything, unless it’s backed by something more persuasive—like 48 panzer divisions.

In rich lands today it’s true though that we change our minds more quickly today than before, but change is still slow. Mainly, we can change our minds more rapidly today only when we mostly don’t have to. As we’ve gotten richer over time, we’ve given over more power to a few specialist in each field, who then make judgments for us. Thus, we mostly no longer make direct decisions about, for example, public health; public health officials do, aided by experts in the field. We’ve given them power to make such decisions for us. Even so, we still often protest decisions we don’t understand or don’t like—like water flouridation. Choosing the right balance between the power of our officials and experts and our power to countermand them is still an unsolved political problem. It might always be one.

So, back to Semmelweis. First of all, he could notice a pattern in maternal deaths only because Vienna General kept good records. No other European hospital at the time did. His simple table of deaths then immunized him from the inherited belief networks that other doctors could fall back on or hide behind. He also had enough power to test his pattern, but not enough to make it stick. Further, even two centuries after Newton and his bunch, we still misused the scientific method, especially in medicine. So Semmelweis didn’t test his model as well as we today would. Nor did he publish as well, or as quickly, or as widely, as we today might. And when he did publish, his book was too hard to understand. And what he did publish, his peers didn’t repeat well. In fact, they mostly didn’t repeat his tests at all. His new belief network was too hateful. But what has changed today? As we see with today’s hospital hand washing, even when we both notice a pattern, and verify it well, and broadcast it, we still don’t always do anything until doing something is made easy. And rather than face that, many of us simply ignore all those deaths. So we imagine we live in a world where they simply don’t happen.

Today we both know far more and have far more than Semmelweis did. Both our mental and physical toolbases have grown. But talk will always be cheap. And science can only do so much. As our mental resources have grown over the millennia, we’ve figured out more reliable information. What we could build changed. How we lived and died changed. But before any of that could happen, more had to change than just our knowledge. Our rituals, behaviors, institutions, and physical tools had to change too. And for that to happen, what we made next had to have changed. Whatever our next potential change might be, until we have the enabling tools, mental as well as physical, to make it easy, it likely won’t happen. We today, just as we yesterday, still mostly believe the simplest, most emotionally supportive thing we can believe. We’re still wolf children, still stumbling into new ways to be, ways that won’t dry our skin or take any time. That may become more clear to us as our mental resources keep growing across the rest of this century.

Wiring the World

The amount of our mental resources is one of the central things, if not the central thing, limiting the growth of our physical resources, although other things, like climate change, do matter as well. But our belief networks resist change. So if growth in our physical toolbase depends on them changing, how is it that we change at all? Change has often been forced on us by one circumstance or another over the millennia. Are there some general rules that include many of those special cases?

These days it’s popular to ascribe our differences across nations to endowments—geographic resources, the distribution of hoofed mammals, the shape of continents, and so forth. These are good general arguments. For instance, they can explain why Eurasia had a tool advantage over Africa. Eurasia is wider than it is long, so you can move east or west yet still keep the same food plants and animals. That in turn increases tribal mixing, which speeds up invention. Such ideas can also explain, for example, why Americans didn’t invent the wheel (lack of hoofed mammals to pull carts). So such ideas can fill in many broad strokes about the general conditions that shape our species. But they don’t handle specifics well.

For instance, if Eurasia always had a geographic advantage over America, why did the Iberians conquer the Americans in the 1500s when the Scandinavians, who went five centuries earlier, failed to conquer them? If Eurasia always had an advantage over Africa, why did no Balkan nation establish African colonies? Why was tiny Britain to become a world power so early when huge Germany didn’t until much later? Is it just because of Britain’s coal deposits? But Germany has coal deposits too. Why is small and resource-poor Japan today one of our richest economies? Is it because of its coastline? Similarly, why are South Korea, Taiwan, Hong Kong, and Israel relatively rich today? They have few resources. They should be poor. Then too, why is Angola so far behind Luxembourg? One has vast natural resources while the other only had some iron ore, which is now exhausted. Yet today Luxembourgers have the world’s highest income per person. Angolans have the 120th.

Again, why, over the past 1,500 years, was southern Spain poor, then rich, then poor, then rich again? (Relatively speaking, and taking urban density as a proxy for wealth.) Did rivers repeatedly change course there? Was it invaded by new kinds of bugs in succession? Did weather patterns change, then change again, then change again? Why are India and China gaining wealth so fast today after about five centuries of relative stagnation? Why did Europe change so much after centuries of relative stagnation? Is it because Europe is mountainous and rainy and so has many fast rivers and those encouraged use of waterwheels, then later steam engines? If so, then why didn’t the same thing happen in Papua New Guinea? It’s just as mountainous; and it’s even rainier. And why did Europe gain so much power in just the last two centuries? A thousand years ago it was a miserable festering pit of famine, disease, slavery, war, and ignorance. Europe is indeed unusual, but perhaps not just because of its guns, germs, and steel.

While endowments and climate and such do matter, our accumulation and application of reliable information is at least as important. Anything we invent that expands our trade or expands our communications can lead to new thought and increasing mental resources. Both rules can be expressed with one idea: anything that increases our flow of reliable data can potentially change us a lot.

That growing data accumulation and flow started with changes in our food technology about 95 centuries ago. In Sumeria we baked marble-sized clay tokens to stand for a goat, a bushel of grain, a jar of oil. Now we could count a flock of sheep or a load of grain—perhaps for tax purposes. By about 55 centuries ago we’d put those tokens inside hollow clay balls and baked them to make a record. We’d gone from counting to recording. But what was inside the hollow ball? To keep track of that, before putting in the tokens we pressed them into the ball’s wet surface. Over time our technology grew enough to support towns. The number of our tokens shot up as we tracked all the new things we made in our new workshops. It was getting hard to tell what the various little token-shaped dents on the outside of our clay balls stood for. So besides pressing our tokens into the wet ball before sealing them in we also drew little pictures on the ball to clarify the tokens it contained. Two centuries later, we saw that we didn’t need to put in the tokens anymore. We then flattened our balls into tablets, but we still pressed our tokens in its surface as before. A couple centuries later we started drawing pictures on the tablet to stand for the token impressions. We then extended that marked-tablet idea to our contracts. The first known one is 51 centuries old. A trader named Ur-Ningal gave a money-back guarantee on the sale of some slaves. We expanded the idea to funeral inscriptions, lawsuits, tax records. One from 40 centuries ago records a herdsman named Ur-Kanara who died before paying his taxes of cheese and clarified butter. His five children were enslaved to cover his debt. We’d gone from recording to accounting. But as life’s complexity increased, we needed yet more drawings. As their number increased, we simplified our drawings until they were just abstract marks. At first, those marks stood for our old token-drawings, which stood for our old token-impressions, which stood for our old tokens, which stood for our goods. But then we used our new marks to tell stories. At first they were pretty boring. ‘Aram owed Esau five sheep, but didn’t pay, haha’ was about it. But by about 44 centuries ago we’d brought in gods and monsters, mountain men and temple whores, heroes and ziggurats. We’d gone from accounting to writing.

Writing was a huge leap for us. Imagine you’re an Assyrian reader visiting Assurbanipal’s library 26 centuries ago. There, among thousands upon thousands of tablets, you’d find this: “Go up on to the ancient ruin heaps and walk about; / See the skulls of high and low. / Which is the malefactor, and which is the benefactor?” Part of a comedy sketch, someone composed that perhaps 30 centuries ago. By then, we’d already been writing for over 20 centuries. Shakespeare’s Yorick, that fellow of infinite jest, was merely an extension of the same idea—26 centuries further down the timestream. Another tablet runs thus: “Who has much silver may be happy. / Who has much barley may be happy. / But who has nothing at all may sleep.” Instead of being limited to the few decades of our lives, our little voices began to echo down the millennia.

But the things we said were much the same for all those millennia. Here’s a little of what we scratched or painted all over Pompeii almost 20 centuries ago. In a tavern: “Restituta, drop your tunic, I beg you, [and] show [your] [bleep].” In a bar: “I [bleep]ed the barmaid.” In a gladiator barracks: “Antiochus spent time here with his [girlfriend] Cithera.” On a wall: “The petty thieves support Vatia for the aedilship.” Near a home: “At Nuceria, look for Novellia Primigenia near the Roman gate in the prostitute’s district.” On a street: “Traveler, eat bread in Pompeii but go to Nuceria to drink.” On a block of flats: “For rent from July 1st. Streetfront shops with counter space, classy second-story rooms, and one townhouse. Renters, contact Primus, slave of Gnaeus Alleius Nigidius Maius.” In a basilica: “I wonder, o wall, that you haven’t collapsed in ruin with the tedious scribbles of so many writers.”

With writing, the ease with which we could store, transport, and recombine ideas rose. Our ideas spread more easily, and as they did, our pace of change picked up, first slowly then more and more quickly. By the fifteenth century it had gotten so fast that we noticed. We called part of it ‘the print revolution.’ By the seventeenth century, the newly jerky speed helped us see another piece of it as ‘the scientific revolution.’ Then, by the nineteenth century, it sped up so much more that we called another part of it ‘the industrial revolution.’ Then last century came ‘the medical revolution.’ We’re now in a computational revolution.

We’ve thus been reducing the cost of data flow amongst ourselves for perhaps all of our species existence. Spoken language came maybe 50,000 years ago with the birth of our species. Writing came roughly 5,000 years ago. Printing, around 500 years ago. Computing, about 50 years ago. Each came about ten times faster than the last. Also, starting about 150 years ago, came a whole bunch: the telegraph, typewriter, telephone, radio, phonograph, photograph, movie camera, television, satellites, mobile phones.... As each wave hit, data spread faster, more widely, and more cheaply. It also spread with higher fidelity and greater volume. With cheaper data storage and flow, plus cheaper knowledge creation and transport, our ideas grew easier to store, spread, and recombine. They also grew harder to forget, misunderstand, misinterpret, or misrepresent. Today we can store, copy, analyze, and recombine larger, stabler, and higher-fidelity amounts of data outside our brains and across time and space.

Normally we think of all those changes as either physical or institutional. The steam engine, for example, is a physical thing. Without it we’d have no railroads. Without them, today’s industrial synergies couldn’t have happened. Similarly, a credit system needs banks and insurance, companies and governments, law books and armies, and so on. But all those physical things, and the ways we arrange and rearrange them, ultimately rest on a network of ideas. Behind every physical thing or system we make or organize lies the idea of that thing. And getting, testing, and then spreading such ideas is what our increasing data flow aids. Those ideas may be wrong, or they might change, or their effect may be nothing like we expected, but many, perhaps all, of our changes over the millennia are due to our increasing ability to create, test, store, recombine, and spread data. That’s not to say that we planned any of that. We can’t foretell the many non-linear ways in which the things we invent then go on to network, thus producing new synergies.

We usually take ‘communication’ to mean transport of text, images, speech, music, or video. That’s too narrow. It looks at data flow only in terms of the data we’ve so far managed to package into a data-holding artifact: a piece of paper, a tape, a data disk. But our brains are data-holders too, as are the walls we write on, the road signs we make, the labels we attach to our goods. When we transport ourselves or our goods we’re also transporting attitudes, rituals, ideas. So data flow includes physical transport, and it includes trade. Tools as seemingly remote from communication as compasses, geared clocks, and carbon-arc lights (for use in lighthouses), all increased our trade. With a compass, for example, you could leave port whenever you wanted—not just when it wasn’t cloudy. So compasses increased trade. With a sextant and a chart you could leave port at night too, not just during the day. Lemons to cure scurvy and pitch to protect ships from woodworms also increased trade. So did limited liability companies and lateen sails and bills of exchange. As our tools increased our trade our data flow increased. More and more of us became linked. Similar technology halos surround railroads, airplanes, steamships, satellites, and many other of our tools. They all aid our unconscious networking.

As we unfolded all those networking tools, and all the ones supporting them, separations between us, both in time and space, mattered less and less. Even though we indivdually remained as stupid as ever, our swarm grew smarter and smarter. When more of us can talk to each other than before, more of us can attack the same problems in concert. Each of us can add our insights to help solve them more quickly than before. But how we’re linked matters too. Over time we stumbled over more accurate ways of checking and spreading information and of thinking more reliably together.

When we’re disconnected, we all must face our problems alone. It takes a superbright to do anything really new. But it’s not enough for us simply to link up. Some network linkages aid problem-solving more than others. We don’t know what the best ones might be, but we do know that some typical ones are bad. A typical fascist style, for example, links everyone to Fearless Leader. But Fearless Leaders are good at seizing and keeping power in Pottsylvania, not at thinking up clever ways for Boris and Natasha to keel Moose und Sqvirrel in Frostbite Falls. On the other hand, the democratic ideal of linking everyone to everyone else is equally dumb. Too much information and no focus is just as useless for problem-solving as no information and a single focus.

A hierarchical linkage scheme—with one Fearless Leader, then minions, then minions for the minions, and so on—is better than either approach, but it has many decision problems too. The best linkage strategy we’ve found so far is to have many local hubs with a few longer-range links between them. When we’re arranged in such networks different groups of us can over time coalesce around each hub. We can then focus on different but related problems. Solutions to those problems can then change to fit together better. Groups can thus knit tightly while still linking loosely to other groups. Each group thus has many different sources of information but still can be focused on a small set of problems. Each of us in any group is only a few links away from anyone else, anywhere. And a few of us (for example, traders) link to many such groups.

A physicist might call a network linked in that division-of-labor way a scale-free network. When we’re linked in a scale-free way, we don’t need superbrights quite as much. Nor do we need Fearless Leaders. Groups of us can together do roughly the same job that before only isolated superbrights could. Someone might say “Hey, I’ve just invented a new kind of steam engine. But I don’t know how to make the precision cylinders it needs. Does anyone know? There’s money in it!” That query can then spread out within a diverse and dense local subnetwork instead of always having to go straight to Fearless Leader—or diffusing out to everyone, thus cluttering everyone’s in-box. Further, as our densely linked networks broaden, once we solve a problem, its solution spreads more quickly, and more widely. An idea originating in Britain, for example, may fail there yet flourish in the United States, or Nigeria, or China. Our ideas are no longer limited to those of us living nearby in time and space. Nor do horses and sailing ships limit their diffusion speed.

There’s still further to go though. Linking more of us together means that more of our brains could settle around solving the same related set of problems, but it can also lead to problems of its own. Linking at higher speed and volume means not only more trading, it also means more raiding. Increasing the speed and volume of information flow among us also increases the speed and volume of misinformation flow among us. Having more of us think together doesn’t of itself mean that we think any better. In fact, often we think worse because of groupthink. Our only protection against error comes when we increase the reliability of our data-checking processes, and that took a long time to figure out. Our swarm can increase its overall smartness not just by creating more of us, linking more of us, and arranging for that linkage to be scale-free, but also by increasing the data-checking ability of its local hubs. The best way we’ve found to do that so far is science.

To some of us today, a science looks like a series of random facts. It might even appear to be a bunch of made-up stuff dressed up in big words and math to impress the rubes. But science isn’t a mere list of facts. It’s a large belief network about the world, plus a much smaller belief network about how to look at the world. That small belief network is what matters. A science like chemistry isn’t a mere jumble of laws. To be called ‘scientific,’ those laws must be few, testable, uniform, general, and consistent. Each law must also pass many tests, and it must always be available to be retested. A law also can’t be arbitrary. It must also apply the same way everywhere. And it must be consistent with all other known laws. That’s the ideal, anyway. So a science isn’t merely a grab bag of rituals and institutions and tools. It’s a philosophy. It’s a point of view.

That point of view can help drag us out of our old ideas and old ways. But for it to have a physical effect on our lives we must do four things. We must notice a pattern. We must test that pattern. We must communicate what we’ve found. And we must do something with our new knowledge. All four are hard for us. We haven’t yet built enough mental, institutional, and physical toolbases to make any of them easy to do.

Today many non-scientists think that scientists coolly engage in a disinterested search for truth, as if they were idly looking for a matching pair of socks on a rainy afternoon. Well, maybe they do on TV, but what they actually do, mostly, is bicker—and gossip, and show off to each other, but mostly they bicker. Science is one long argument. Oh yes, scientists shrug a lot too. That’s because mostly all they know for sure is that they don’t know much for sure. But their bickering isn’t random. If it’s to achieve anything it must be highly structured. Students suffer through years of simply learning how to bicker properly. It all works not because scientists all think the same but because they all accept that the same bickering process will over time reduce nearly any kind of error. It’s that self-correctiveness, arising from the endless bickering within an accepted way to bicker, that gives science its special strength. Of course, bickering isn’t limited to science. But fields that allow any kind of bickering at all, or that don’t allow bickering, or that habitually hide data over which we could bicker, aren’t science. None of them have proved to be as self-corrective as science.

However, even large numbers, distributed linkage, open information, and precision bickering isn’t enough. There’s also the meta-problem of what catalysts aid the spread of that special kind of linkage and bickering within our network. (And the meta-meta-problem of what catalysts aid the spread of those catalysts, and so on.) Scientists succeed mostly when they keep their eye on nature, and not just on what each other says about nature. Thus, what killed our early science in various places wasn’t that we grew smarter before it, then stupider after it, but that after each flowering, we stopped looking at nature. Instead, we looked at the writings of those who had looked at nature. We took their thoughts as gospel. It happened in Egypt five millennia ago. It happened in Greece. It happened in India, Persia, and so on. Take Aristotle. He was a clever guy. He looked at nature and came up with a scheme to understand it. But many of his successors looked not to nature, but to him. Why? When books are rare, idea spread is low. So we assumed that only a few of us could have them or share in them. Today’s science isn’t like that. But that’s a logjam that broke only after the printing press. Once millions of books were in print, authority’s power waned. But that alone didn’t give us the mental tools we have today. We also needed a new bickering scheme that many of us could use to create, verify, and share more reliable knowledge. New ways of looking at nature then expanded. The computer in particular expanded just about every mental power we had. With science booming today, and with our computers just getting better and better, we’re getting better at precision bickering and thus are now getting more things less wrong than in the past.

That millennia-long rising flow of more reliable data explains a fair amount about how we change, but change is still not easy for us, and permanent change even more so. Europe’s early kick-start toward literacy began around 1178 with Latin translations of Arabic books, but a climate change that began centuries before that is probably what started it. Another climate change, which came centuries after that, is probably what ended it. The literacy spike did make a difference though. If nothing else, it led to Europe’s first wave of universities. But it wasn’t big enough for long enough to make much of a difference against the usual ups and downs of life when Europe was so mired in poverty. Europe’s next big literacy spike came around 1452 with the printing press. That one lasted, but Europe still had far to go before literacy became universal. Another big spike for Europe came around 1666 with the scientific revolution. But again that might have died out had not the industrial revolution followed it a century or so later. (China, and perhaps Dar al-Islam, also had glimmerings of today’s science at the time, but with no printing press, and with no industrial revolution to follow, it didn’t get very far.) Each literacy spike made a difference. But how big a change it made was ecogenetic.

When none of us can read, little can change. Almost no knowledge is reliable. Or rather, all our knowledge is equally reliable—we just don’t know that it’s actually rubbish. Then when only a few of us can read, we hoard knowledge. It’s both precious and rare. It’s a source of power, and, often, wealth. If you can figure out when the Nile will next flood based on past records and no one else can, you have power. Then when many of us can read, knowledge is no longer rare, but it’s even more valuable because network effects multiply its value. Many of us can check it, recombine it, spread it. If you can figure out how high the Nile will flood, and I can figure out what stars are in the sky then, together we can make a calendar. With a calendar we can organize to do things at specific dates. Then when all of us can read, we become capable of even more things. Reliable documents, for example, become possible. We can then use such documents to certify or verify identity, ability, possessions, acquisition, exchange. Once that happens, we can band together and verify each other’s wealth outside of just our neighborhoods. Long-distance property rights become possible. With those, we can share risk. We can build more complex things. We can compute harder things. We can have more uniform law. We can trade over longer distances. We can have banks and contracts and insurance and corporations and newspapers and textbooks. We can more easily build on each other’s mental work. All that helps us pool our efforts, even without our planning it—or even wishing it—or even noticing it. That helps us grow our base of reliable knowledge, and thus our power over nature. And that helps more of us do more with less. Literacy, and now network bandwidth, becomes both the source of our power and the source of our changes. All that power seems like it’s a long, long way from making little clay tokens 95 centuries ago, but the game has remained the same all this time.

In sum, the more ideas we have, the easier it is to discover new ideas. The more ideas we have, the more folks we can recruit, train, and equip to discover new ideas. The more ideas we have, and the more equipped folks we have to produce them, the better tech we can produce to link equipped folks to promote the discovery of yet more ideas. Plus, each of those three autocatalytic cycles has catalytic side-effects that affect the other cycles. For example, the more ideas we have the more people we can feed, so the larger our population. The larger our population, the more people we can recruit to generate more ideas. The more ideas we have, the more people we can recruit to generate better ways of linking to generate ideas. Knowledge is thus strongly catalytic—much more so than any other catalyst we know. Once it grows beyond a certain level it quickly becomes autocatalytic, thus catalyzing its own growth. The more we learn, the more we learn next. That rising flood of reliable data has changed our world again and again. Where we once saw desolate prairies, we today see amber waves of grain. Where we once saw food-destroying fungi, we today see life-giving antibiotics. Where we once saw barren beaches, we today see groves of silicon. And where we once saw only enemies or victims or future masters or slaves, we today (sometimes) see mates and friends and business partners. The world didn’t change; our belief networks did. Today, more than ever, we flourish by our wit.

Liquefying Everything

Our millennia-long growth in data flow is a big part of what we do as a species, but even it is only part of an even broader set of network changes that we’ve been unconsciously pushing along for millennia. Once again, it began with changes in our food supply. Around 100 centuries ago we traded cattle and grain for goods and services (and taxes). We used clay tokens to keep our accounts (in Sumeria). We switched to metal coins 27 centuries ago (in Western Asia). We moved to printed paper slips about ten centuries ago (in China). Then about seven centuries ago we used signed paper slips to stand for those printed slips (in Europe). In the twentieth century, we made plastic cards stand for those signed slips. Today, many of us use mere numbers to stand for the plastic cards. Passing around numbers is a long way from having to haul cattle and grain to market.

Challenged by obstacles to our desires over the millennia, our species has liquefied not just our data but also our goods and services. That is, we’ve lowered barriers to their flow, granularity, ownership change, and conversion. Each time that changed, supply better fit demand. To support those millennia-long liquefactions we changed many things. For example, we invented insurance policies. (One early one is dated May 8th, 1401. It was for the transport of a slave girl from Pisa to Barcelona.) We also invented property rights, courts to uphold them, and militias to enforce them. Stock markets, banks, credit systems, and such, all helped liquefy our goods and services further. Today, over a billion of us can trade nearly any amount of nearly anything nearly anywhere anytime. And that figure is likely to rise by another half billion by 2015. Many of us no longer have to worry about our cattle dying on the way to market. Nor do we have to barter for a whole cow’s worth of stuff at a time once we get there. Nor do we have to wait until the floods die down to go in the first place.

We’ve done much the same with energy too. Over at least our past five millennia, we harnessed our bodies, then livestock, then windmills and watermills, and now power plants and power grids. Today, over a billion of us can call on energy anytime and in many places, although not yet everywhere and not yet in any amount. We can now also call upon mechanical work in many more places, much more often, and in many more gradations, than before. But mechanical work isn’t yet as liquid as data, credit, or energy. However, once our robots become cheap, smart, and mobile, and globally available labor maximizes, it too will liquefy further.

As those examples show, liquefying a thing banishes time and space and bulk and other limits to its flow. As we drive the chunk size of things down, we increase their convertibility and recombinability. Thus, more of the value that our species has created over the millennia becomes available to more of us more often and more easily in more places. We can do more with it, too, since it’s available to us in smaller, more widely accessible, more easily recombinable pieces. And that speeds up its flow and widens its reach even without changing its volume. That then makes it more reliable. And that makes it grow faster. All those liquefactions change us.

The printing press, for example, didn’t merely help us make more books. It helped us liquefy thought itself. After it, more of us could benefit from thinkers without having to be alive when they were alive. We no longer had to live in the same place, belong to the same circles, share the same religion. We didn’t have to be the same age or sex or have the same skin color. Over time, we didn’t even have to speak the same language. The same goes for the computer today. The same goes for food, with inventions like the railroad, the tin can, and the fridge. The same goes for energy. Once we standardized on electricity, our fuel sources no longer mattered as much as they did before. We could feed any energy-releasing material in and get energy out. So we could spread it more cheaply and distribute it more widely. We’ve even liquefied land and other immovables as well as rights of way and other intangibles. We used mortgages and rights like copyrights and trademarks to do so. Once we did, we no longer had to sell our house to leverage some of its economic value. We could get a mortgage and use a piece of that instead. (Getting a mortgage is like chopping up your land into penny-sized lots then potentially renting each lot separately.) We could also combine different pieces. We could use a piece of our car and a piece of our house to finance things we couldn’t otherwise have. We could combine those liquefactions too. For instance, we can take an idea from Britain and an institution from Brazil plus a machine from Belgium and make things not possible before.

All our many liquefactions are also linked to each other synergetically. So liquefying any one thing helps liquefy others. Banking, for example, helped us build electrical power stations. Those then helped us build fridges. Which let us build refrigerated railroad cars. Which let us build mass food distribution rail networks. And those let us spread food and perishable goods more widely, more easily, more cheaply. That stigmergically bootstrapping network in turn helped cities grow. Before either railroads or fridges, cities could grow to only a certain size before they starved. Before 1841, no one had seen real milk in New York in decades. And before sewage treatment, today’s megacities simply couldn’t exist at all.

However, liquefying something needn’t mean that it then becomes more evenly spread. If anything, liquefying a thing lets it concentrate more easily. Both power and powerlessness concentrate too. Take big cities