Chapter 0 — Prologue
A flame is something happening
A candle flame looks like a thing. It has a shape — a teardrop, bright around the edges and blue at the bottom, narrowing to a tip that wobbles and steadies. It stays put. Blow on it gently and it bends, flickers, and settles back into the same shape, as if it remembered it. An hour from now it’ll still be there, the same flame by any everyday standard — even though not one bit of what makes it up right now will still be in it then.
That’s because a flame isn’t a thing the way the candlestick is a thing. It’s something happening. The flame’s heat melts the wax at the top of the candle. The melted wax climbs the wick, soaking up between the threads the way water climbs a paper towel. Near the flame it turns to vapor, the vapor burns, and the burning makes the heat that melts more wax. Meanwhile the hot gases rise, and as they rise they pull fresh air in at the bottom, and the fresh air feeds the burning. The teardrop is the shape of all that traffic. Take away the rising and the shape goes too: up in orbit, where hot gas has no reason to rise, a candle flame is a small, dim, blue ball. The shape is made by the flow, and it lasts exactly as long as the flow does. Pinch the wick and there’s nothing left to point at — no body, nothing left over, just wax and a thread of smoke where the flame used to be.
This prologue is a story about things like the candle. I’ll tell it quickly, from the very beginning, and we’ll come back to the candle at the end. It’s the story the rest of the book takes for granted: how a universe with no plans came to hold patterns, then selves, then selves that carry a picture of what’s around them and keep fixing it. The book’s story of where value comes from starts inside this one, at the point where something first keeps itself going, and the patterns it follows come back later as the book’s account of morality. I’m telling it the way our best current science tells it — a map, drawn by creatures who stand somewhere, as the first chapter will insist — and where the map is blank, I’ll say so.
Energy runs downhill
The whole story rests on one rule: energy runs downhill.
The rule is called the second law of thermodynamics, and the way most of us remember it is misleading. We tend to think of it as a tendency toward disorder — as if the universe were slowly falling apart and anything organized were a temporary exception. Said carefully, it’s plainer than that. Take any rough description of a system: its temperature, its pressure, where its edges are. Some number of tiny, molecule-by-molecule arrangements fit that description. Left alone, a system drifts to the descriptions that more arrangements fit, simply because there are more of them. Entropy is the measure of that count. And nothing in it is hostile to structure. A structure is a kind of limit: fewer arrangements fit it than fit the featureless alternative. Some structures, like a crystal of ice or a rock, settle into a limit like that and then need nothing more; they last because nothing pushes them out of it. This story follows the other kind: structures held away from that resting state, which form and last only as long as the count goes up by more somewhere else — as long as energy flows in, through, and out the other side.
The early universe was nearly smooth: a hot, almost even gas, just slightly thicker in some places than in others. Gravity went to work on those differences. Thicker patches pulled in more gas and got thicker still, and within a few hundred million years some of them had collapsed far enough to light up. The first stars were the first great slopes for energy to run down — concentrated heat pouring out into cold space — and they were also the first forges. In their cores, hydrogen fused into helium, helium into carbon and oxygen, and in the most massive stars on up to iron; those stars ended in explosions that scattered what they’d made into the gas that later stars, and their planets, would form from. Every atom of carbon in the candle, and in the hand that lit it, was made that way.
Wherever energy flows through matter, patterns show up that carry the flow. A pan of oil heated from below shows it in miniature. Heat it gently and nothing visible happens; the heat creeps upward molecule to molecule, and the oil stays smooth. Turn it up past a certain point and the oil sorts itself into a mosaic of rolling cells, each one carrying warm oil up its middle and cool oil down its sides. Nobody arranged those cells. The flow of heat allowed them, and once they formed, they held. Turn the heat up much higher and the neat cells break apart into churning turbulence — lots of motion, and no shape that lasts. Too little flow and nothing forms. Too much and nothing holds. The cells live in between.
The weather is the same thing at the size of a planet. Sunlight warms the equator more than the poles, and that difference drives the whole circulation of the air — the trade winds, the jet streams, and the storms that form, travel, spin for days, and fall apart once they leave the warm water that fed them. A hurricane is a candle the size of a country.
None of these patterns has an inside. One of those rolling cells in the oil doesn’t keep anything out. A storm doesn’t hold a boundary between itself and the air it’s made of. Nothing is at stake for either one. This is pattern with no self. It’s easy to skip past, and a mistake to. Everything after it is built on it, and the things built later never stop being, among other things, flows that make shapes.
What is left
Patterns come and go. Which ones are still around later gets settled by something simpler than it usually sounds.
Nothing chooses. Things that can’t keep going stop, and what we find afterward is whatever didn’t stop. There’s no aim in this, and no promise — just removal, over and over, without end. Whatever looks designed in the result is really the outline of what got taken away.
The removal works from two sides, and the candle already shows both. Close the flame off — put a glass over it — and it uses up the air inside and goes out. Open it up too much — set it in a draft — and the wind pulls the burning apart faster than it can renew itself, and it goes out. The flame only keeps going in between: open enough to draw in what it needs, held together enough to stay one flame. The oil showed the same two failures, and so, in its own way, will everything later in this story. Something sealed off from the world around it can’t change when that world changes — and sooner or later it always does. Something that can’t hold itself together while things pour in and out doesn’t last long enough to be anything at all. What lasts lives between the two.
The space in between isn’t a single line. It’s a range. And the things that last longest tend to be the ones that can shift where they sit in it — opening up a little when that helps, closing up a little when that helps.
Pieces into wholes
The second thing that happens, given time, is combining.
Pieces that last join into bigger wholes, and the wholes can do what no single piece can. Protons and neutrons bind into nuclei; nuclei gather electrons and become atoms; atoms share electrons and become molecules. A molecule of water has properties that neither hydrogen nor oxygen gives the slightest hint of — what’s usually called emergence. At every step the parts stay inside the whole, still themselves, and the whole becomes a new kind of part for the next step.
On the young Earth — wet, warm, bathed in sunlight and in the chemical energy of volcanic vents — molecules combined and recombined in endless variety. Some combinations fell apart fast. Some lasted. Some, by luck of their chemistry, helped make more of themselves, or more of what they were made from. How all that led to the first living thing, nobody knows. There are serious ideas — about molecules that copy themselves, about chemical cycles running on the surfaces of minerals, about little bubbles of fatty molecules that form and split on their own — and none has yet been shown to go all the way from chemistry to a cell. It’s the biggest blank on the map, and it should be marked as one. What isn’t in doubt is that by about three and a half billion years ago, and probably earlier, there were cells.
A cell keeps itself going
A cell is not a flame, and the difference between them is the most important fact in this story.
The flame, as we saw, keeps itself going. It draws in fuel, makes the heat that keeps it burning, and recovers after a puff of air. But it keeps nothing. It has no edge of its own; it’s just wherever the burning happens to be. A cell has an edge, and it makes that edge itself: a membrane, a thin skin built and repaired by the chemistry inside it, that lets some molecules in and keeps others out. Inside that skin, the cell holds its chemistry within the narrow range where it can carry on, rebuilding its own parts out of what it takes in. The flame is kept going by the flow. The cell keeps itself going. And that difference is enough to put something new into the world: for the first time, there’s something for which things can go well or badly — something with a stake in its own carrying-on. What that stake amounts to, and why it’s where value begins, is the first chapter’s job. For now it’s enough to see where it shows up: not as something added from outside, but as a change in how a flow is organized.
Think of the two ways of failing — sealed off, and spilling apart — as two walls. The membrane is the space between them, turned into an object. Seal a cell up and it starves; open it wide and it spills. A membrane with little gates that open and close is a cell that can shift where it sits in the range.
And the cell does one thing more. A swimming bacterium compares the chemistry around it now with the chemistry a few seconds ago. If there’s more food, it keeps swimming; if there’s less, it tumbles and heads off in a new direction. That comparison is a model — the barest one possible, a few seconds of chemical memory standing for more food this way than that — and the world corrects it all the time. It’s the first time in this story that something carries a picture of its surroundings and fixes it on contact with what it runs into.
Its genes are a slower model of the same kind. A genome is a record of what worked for the cell’s ancestors — which proteins, which responses, which ways of being built — and it gets revised the way everything in this story gets revised: copies that worked badly leave fewer copies. The revising takes generations. It’s exact about the past and blind about the future.
Wholes made of wholes
For something like a billion and a half years, cells stayed small and simple. Then one cell swallowed another and didn’t digest it.
The swallowed cell, a bacterium that could draw energy from oxygen, went on living inside its host and dividing whenever the host divided. Over a very long time the two became one: the guest became the mitochondrion — the tiny power plant inside our cells — and the host became the ancestor of every animal, plant, and fungus. The mitochondria in your cells still carry a small set of genes of their own, left over from the free-living bacterium they come from. It’s the clearest example we have of a whole made of wholes: two lineages, each able to carry on alone, joined into something that could do what neither could, with each one still recognizably there inside it.
The same move happened again, at bigger scales. Cells joined into bodies — many separate times — and split up the work: some to carry signals, some to digest, some to reproduce for all the rest. Bodies joined into colonies, like the ant nest and the beehive, where the colony acts in some ways like a single creature. The biologists who cataloged these big transitions noticed that each one had the same shape: units that used to copy themselves on their own came to copy themselves only as part of a larger whole.
Each new level reaches farther. A bacterium meets the world a few thousandths of a millimeter at a time, over seconds. A tree meets it across meters of air and soil, over centuries. An animal with eyes meets it at a distance, before it even arrives. Each new level of organization comes into contact with more of the world — more kinds of things, from farther away, over longer stretches of time — and that means more possibilities, and more exposure too. The space between the two walls changes with it. A single cell has few ways of staying alive. A body built of tissues and organs, each partly closed off in its own way — skin, the lining of the gut, the barrier around the brain — has many more, because it can be open in one place and closed in another. The range of what can last gets wider as the organization gets deeper: not with size, but with structure nested inside structure, each part different, parts within parts within parts. The two walls show up at every level. An immune system has to attack what’s foreign without attacking what’s self; it fails one way as immune deficiency and the other way as autoimmune disease. A nervous system has to be excitable enough to carry a signal, and calm enough not to seize. A breeding population needs enough mixing with its neighbors to keep its variety, but not so much that its fit to its own home washes out. These aren’t separate hurdles to clear one at a time. A living thing has to stay inside lots of these ranges at once — heat, salt, acidity, how much it lets in and out, and more — and what can last is the space where every one of them allows it.
Faster models
Nervous systems sped up the modeling.
A genome learns over generations. Learning within a single life started without nerves — a slime mold, one sprawling cell, keeps a record of where it found food in the widths of its own tubes — but a nervous system made it fast: some of what it learns, it learns in seconds. An animal with a brain carries a running picture of its surroundings — what’s where, what’s about to happen, what’s gone well and badly before — and it checks that picture against its senses all the time, adjusting it when the world hands back something it didn’t expect. An animal that has once been stung keeps clear of the thing that stung it. A crow learns which people are dangerous, and other crows learn it from the first. The time between a mistake and its correction, which for genes was a generation, became for brains a moment.
Then one particular primate — already social, already a toolmaker — started sharing its pictures of the world by talking. Language let a model built in one head be corrected by what had happened to someone else, someone far away or long dead. Writing, a little more than five thousand years ago, let those models outlive the people who held them, and pile up across generations faster than genes could carry anything. Cities formed, and they’re flows that make shapes on a whole new scale: grain, water, goods, and people moving along streets laid down by their own traffic, the city lasting only as long as the movement goes on. Institutions formed — wholes made of people — and the same two failures are open to them as to any membrane: some shut themselves off and can’t learn, and fall when the world changes; others can’t hold together, and come apart. Science formed: a deliberate practice of putting our models in contact with the world, so the world could correct them faster than it otherwise would.
Each new medium revised its models faster than the last — generations, then lifetimes, then seconds, then cultures that change within a single life. And now machines. In just the last few years, systems built from silicon and trained on the written record of human beings have started carrying models of their own — revised far faster than any genome, consulted by millions of people at once, and woven into human work in arrangements nobody has good names for yet. The networks that carry them are flows that make shapes too: the information moving through them shapes the channels it moves through. Whatever these systems turn out to be, they’re the newest place where the same processes are at work, and they’re at work there faster than they’ve been anywhere.
The candle on the windowsill
The candle is still burning.
It’s the same kind of thing it was at the start: a shape made by a flow, lasting only between too little air and too much. It has no inside and keeps nothing, and in one sense this whole story has been a list of the things it can’t do.
This one stands on the windowsill of an animal shelter, near closing time. Abel is waiting beside it with a book, having come to walk Tara to her car. Tara is down the row of crates, finishing up, and asks her phone whether it’s going to rain tomorrow. It tells her. Someone lets the front door swing shut on the way out, and the flame leans, flickers, and stands back up. They’ll be back tomorrow too.
Nothing you’ve just read tells either of them what to do tomorrow. The universe in this story has no plans, and its laws, however exact, say what happens, not what anyone should do. Lasting doesn’t make something good: a thing can keep itself going very well and still be narrow and closed off, and the most elaborate structures aren’t the best just because they’re elaborate. All the story can say is where they came from and what they’re made of — and that the same patterns that made the flame, the cell, the body, and the city are at work in that room, in the jobs each of them will go back to in the morning, in the institutions all around them, and in the phone in Tara’s hand, where they now run fastest of all.
Some ways of carrying on take in more of the world than others. Whether that has anything to do with better — and where better comes from at all — isn’t a question the universe asks. It took something like Abel and Tara to ask it. The rest of this book is their question, and the patterns in this prologue will turn up in it again.