In 1940, Jorge Luis Borges published a story about the discovery of an encyclopedia describing an imaginary planet called Tlön. The encyclopedia is fragmentary at first — a single volume, an article on a non-existent country called Uqbar — but more volumes surface over time. The culture, geography, and metaphysics of Tlön are described in meticulous, deadpan detail.
The people of Tlön are idealists in the philosophical sense: they do not believe in material objects. For them, the world is a succession of mental states. A thing exists only while it is perceived, and it ceases to exist when no one is perceiving it. This produces a language with no nouns, a science concerned only with psychology, and a curious form of archaeology in which people manufacture the ancient artefacts they then claim to discover.
The story's culminating move: objects from Tlön begin appearing in the real world. A compass, a small metal cone — things too heavy to be hollow yet somehow impossibly dense. Then the encyclopedia itself begins to replace real reference works in libraries. By the story's end, the narrator predicts, the world will be Tlön. Our reality will have been dissolved and replaced by a fiction we collectively chose to believe.
Borges called this "the audacious and legitimate idea that the world is a fabrication." The dissolution here is ontological: not a thing coming apart but a consensus about what things are coming apart. When the narrator says "the world will be Tlön," he is describing a dissolution of reality so complete that no one will remember what was dissolved.