The Cartesian Theatre

For a great deal is said about the forms of the gods, and about their locality, dwelling-places, and mode of life, and these points are disputed with the utmost difference of opinion among philosophers.

— Cicero, On the Nature of the Gods

The whole of the developments and operations of analysis are now capable of being executed by machinery.

— Charles Babbage, 1864

Gentzen trees — concave ocean — paradise regained

Salvation came in the form of algebra. She discovered, in the treasure, a family of string rewriting systems that she used for her own amusement, and later found that these were not logics with sui generis terminology but an algebraic description of human languages. She found, pulling that thread, that there was more than one language, that Hinton Station was not the extent of the universe: that it was one of millions of places where people lived, around a star, and that there were things called stars, planets, flowers and computers. That there existed a universe outside the transparent towers and the words of Gödel and Frege. She found an old network socket and decided to escape.

Sabra was born in the computer. She was made by an algebraist, from a linear combination of six other minds, because the population was held stable at 28 and each departure was followed by the manufacture of a new soul.

Her world had a spartan geometry: bare wireframe walls and eight bit colour. A city of glass buildings, of transparent towers made of logic, floated in the empty space near the origin, its inhabitants were stylized human shapes, empty of texture, their voices were identical.

Hinton Station was a virtual world in six dimensions. Its people were a clade of mathematicians who had gone into the computer to live in the Platonic realm. Gradually they lost sight of the world and disappeared into their own abstractions.

For its people, the acme of life was writing exegeses of Hinton, Cartan, and Poincaré, and debating and dispassionately refuting them. Immense towers of abstraction, crystalline forests of Gentzen trees were built, and then torn down. And this went on forever. And all that is natural — all that is a gift from God — was absent from them. In the computer, all things are a product of human labour, and all exists fleetingly, and is torn down on a whim.

Writing to others on the network she found a charity that printed bodies. She beamed herself to Susa Station, went through the character customization screen, hurriedly accepting defaults on choices she didn’t understand. The surgeon printed a body that could have passed for human, but where there should have been flesh and blood there was diamond and fullerene. And they poured her soul inside.

She opened her eyes and drew breath for the first time, decades after her birth.

Her clade had hammered their minds into abstract shapes, they had pulled them apart and straightened them like circuit routes. Their souls were crystalline like theorems, and the vestigia—the body—were compressed and stored away.

But the body reasserts itself against Cartesianism. Gradually, the autonomic systems rebelled and began to wake, like a mountain rising out of a night ocean. She learned to sleep and blink, to breathe unconsciously. When we dream, our minds are annealed, the old passages are flooded and liquefy and settle in new forms. The rejected atavisms unfolded into a spanning tree of her body. And she dreamt of Hinton Station: a Cartesian grid the colour of argon, forests of proof trees, rivers of ideograms like spiral galaxies.

The world outside Susa was a lenticular cloud of millions of lights, a galaxy in miniature, each a world unto itself. There were clusters of green lights that were comets overgrown with vacuum trees, and plant and animal and human life no Linnaeus would recognize. There were points of dull red light, the reversible computers where bodyless people lived. And there were arcs of blue that were ring habitats: ribbons tied end-to-end, holding concave ocean, and the oceans held continents, islands, mountain ranges, rivers, forests and buried ruins, endless forms of life, cities made of glass, paradise regained. All this had been inanimate dust and cratered wasteland, which human hands had made into an oasis in the sky, where quadrillions live who will never die.

The posthumans who live there called it Ctesiphon. And at times they call it paradise, after the Persian word for garden.

And at the center of the oasis there was a star that travelled backwards across the H-R diagram: already one one-hundredth of it had been whittled away; made into a necklace of artificial gas giants in preparation for the end of time; or sent through reactors where disembodied chemists made protons into carbon, oxygen, lithium and sodium, the vital construction material. And in time nothing would be left but a dim red ember encircled by cryojovian fuel depots. And the habitats would be illuminated by electric diodes.

She saw Hinton Station for the first time, and it was small enough that she could have embraced it: a cubic meter of diamond rod logic, floating in a cheap and distant orbit. Push-rods and cams clicking back and forth in perpetuity, somewhere in that motion was computation, a virtual world, dead souls, the words of Hilbert debated forever.

She found a home with eight refugees like her, people from closed societies, for whom the universe had been bounded by the coordinate system of a virtual world.

She tried to find work as an algebraist.

A comet entered Ctesiphon on an artificial trajectory. It didn’t respond to pings from traffic control. When it was boarded they found, entombed in the ice, a generation ship. The people who lived there had fallen through space for centuries, and over the centuries died out. Nothing remained in the aged computers. There was a chapel carved out of the ice, tablets made of chondrite. And a bounty was posted: decipher the liturgical language. Sabra posted a decipherment to a special interest group on linguistics, and through this she found work.

With newfound income, she found an apartment and lived alone, entombed by concentric layers of work.

When one of the gods dies, the whole pantheon is shaken, and everyone takes notice. Despite her splendid isolation, the news crept in by osmosis: the local deity of Gliese 581 had died, its body had turned off and cooled to thermal equilibrium. The telescope around Ctesiphon had seen it happen. Days passed without activity. Then a woman came to her door, and said that the Miranda Institute was preparing an expedition to sift through the remains, and they needed a linguist.

And why not go? Like Bias of Priene, all she had she carried with her.

In a corridor, a Fedorovist preacher speaks to an unhearing crowd:

“We, all of us, are memories. We, all of us, are being remembered.”

In the transit lounge, a woman with the head of a hyena holds forth on the philosophy of Ernst Mach.