"A universe comes into being when a space is severed or taken apart. The skin of a living organism cuts off an outside from an inside. So does the circumference of a circle in a plane. By tracing the way we represent such a severance, we can begin to reconstruct, with an accuracy and coverage that appear almost uncanny, the basic forms underlying linguistic, mathematical, physical, and biological science, and can begin to see how the familiar laws of our own experience follow inexorably from the original act of severance. The act is itself already remembered, even if unconsciously, as our first attempt to distinguish different things in a world where, in the first place, the boundaries can be drawn anywhere we please. At this stage the universe cannot be distinguished from how we act upon it, and the world may seem like shifting sand beneath our feet.
Although all forms, and thus all universes, are possible, and any particular form is mutable, it becomes evident that the laws relating such forms are the same in any universe. It is this sameness, the idea that we can find a reality independent of how the universe actually appears, that lends such fascination to the study of mathematics. That mathematics, in common with other art forms, can lead us beyond ordinary existence, and can show us something of the structure in which all creation hangs together, is no new idea. But mathematical texts generally begin the story somewhere in the middle, leaving the reader to pick up the threads as best he can. Here is the story traced from the beginning."
Postscript. This simple "point and shoot" image (albeit with an assist from Photoshop's perspective-crop tool) was taken with my iPhone as my wife and I were waiting for yesterday's matinee of Les Mesirables to start at the Kenney Center in Washington, DC. I have been drawn to mirrors and reflections ever since my teenaged-self stumbled across their deep mysteries through Borges' stories. Objectively speaking, the image is composed of nothing but metal, glass, some branches and leaves, and just a hint of a massive chandelier hanging just inside the Kennedy Center. But, as all Borgesian souls know, this "objectively banal reality" is but a shadow of the dynamic undulating froth of invisible universes! The first step toward catching a glimpse of these other realities is - as G. Spencer Brown reminds us - to draw a subjective distinction.