A story about a skeleton so big that nobody knows it's one thing. It’s the frame-story for the whole Principia: every science is a dig site, every vocabulary is a placard, and the bones — entropy, information, selection, surprise — all belong to the same dragon.
Under the ground — under the deserts and forests and the oceans and cities and the school parking lots — lies a skeleton. It’s the skeleton of a dragon, and the dragon is the size of the world.
That’s not an exaggeration. One of its ribs runs beneath an entire continent. You could hike along it for a year and call it a mountain range. Its backbone wraps around the planet like a sleeping cat's tail.
And here’s the strange part: nobody knows the dragon is there. Not because it’s buried too deep — bones poke out of the ground all over the place, and people find them all the time. Nobody knows because the dragon is too big to notice. It turns out you can stand on a thing your whole life and never guess that there’s more to it than you can see.
The dig sites
For hundreds of years, all over the world, people have been digging up pieces of the dragon.
In fact, long, long before museums, before placards, when shovels were made from the scapula of an ox — a wise old digger in China named Lao Tzu saw something white sticking out of a riverbank and brushed it clean. It was a tooth, taller than he was. He looked at it for a long while. Then he smiled, patted it once, and wisely declined to name it. "The dragon you can name," he said instead, "is never the whole dragon."
In other places, people told stories about the dragon. In the far north, the Norse told of a serpent so long it circled the entire world and held its own tail in its mouth. They even thought they had invented it.
One day many years later, a digger named Spencer-Brown noticed a piece of one finger bone sticking out of the ground. He didn’t have a shovel, so he picked up a stick and scratched a line in the dirt around the bone to enclose it so he would know where to come back and dig later. But the whole dragon was bigger than the circle.
In Austria, a digger named Ludwig Boltzmann uncovered a vertebra — but it was shattered into a thousand pieces. He had to examine all the possible ways it could be put back together to find the one that worked. He gave it a name: ENTROPY. It went into a museum with a beautiful placard.
An ocean away and a lifetime later, a digger named Claude Shannon found an intact vertebra, a piece of the spine with a channel through the middle to hold the spinal cord. He gave it a name too: INFORMATION. Different museum. Different placard.
In Germany, two very careful diggers named Weber and Fechner found the tiniest bone of all — an ear-bone. It was just barely sticking out of the ground. If it had been any smaller, they would have missed it. They called it the JND bone for JUST-NOTICEABLE DRAGON BONE.
In England, Charles Darwin patiently and meticulously chipped a piece of the pelvis, the dragon’s foundation, out of a hillside: SELECTION.
In London, a digger named Karl Friston uncovered a piece of the skull — the hard boundary that separates the brain from the world outside it. He labeled it the FEP for FIRST EVER PREDICTOR, since he realized that the dragon’s brain would have to be capable of predicting what would happen next in its world.
The man who knew better
The scientist who found the most pieces was named John von Neumann. Von Neumann was famous for having one of the fastest minds on Earth. People said he could see the whole of a problem while everyone else was still squinting at its corners.
One bright and sunny morning, Von Neumann was walking to one of his digsites.
On his way, he passed six blind men standing around an elephant, arguing.