As dusk sets in the Phaedo, soon before he drinks the ending brew, Socrates recounts the structure of the Earth. It’s as if he said we are moles, subsisting in slimy holes. Some are deep, some more shallow. But we can dig farther down, to a land of mirror images which may precede ourselves but cannot measure up to the Forms up high.
But it is hard to tell whether these images or forms down low are more or less perfect. Which way are we to look to gauge our distance to the sky? In every direction, the ground appears to be a perforated noosphere. A planet of negative goose bumps, where each little pebble is a world unto its own. How can the philosopher tell up from down and left from right? Would not a plausible alternative to Socrates's Earth be a cavernous system that never opens up, lit by fires from below? Could it be that our world is an endless maze of tunnels contained by reflective geode walls. Let us explore this mythological universe.
There is no heaven. The walls themselves are pregnant with the Forms, available for those shrewd enough to crack them open in the tunnels' light:
It is a marble whose true grandeur lies within. One sharp cut and the picture is laid bare before my eyes to behold. The image contains a sensible landscape, more perfect than deserves to be in this musty cave. I walk about this cavernous world of apophenia, where all I see and all I build are mere repetitions of buried figures and ancestral worlds, closed in on themselves above my head as underneath my feet. I know, that when I stand before the mirror what I see is a figure stolen from inside my cavern's walls. I am a thief and an unholy architect; a philosopher, in short. In silence, I sand the picture down for I must imbibe its perfect lines.
Even now we have only reckoned with a fraction of the Forms which the Earth withholds from sight, preceding our every thought and every sense. As for the rest, you can only name them from the depths of reverie.
You are Odysseus of the depths. You look in the mirror and you see an imperfect copy, dimly lit in the light of an infinite system of caves. There is nothing new under the absent sun. There is no a sunlight to use for orientation. You traverse the landscape, repeating to yourself, again and again. There is no heaven for the Forms.
You can navigate the caves by abstracting from sensible objects in order to approximate their corresponding Forms. Natured nature is a repository of reason.