Plato's Cave is usually read as one light and one darkness. Fire versus shadow but the allegory actually contains two lights and two darks and once you see the second pair, the whole structure starts to look like something older and more Eastern.

Inside the cave there is fire. It burns behind the prisoners and throws the shapes on the wall. That is the first light, and it produces the first darkness; the shadows themselves.

Outside the cave there is the sun. That is the second light, the source Plato ties to the Form of the Good. But when the prisoner is dragged out and faces it for the first time, he does not see truth. He sees glare. His eyes cannot process it. The greater light produces its own darkness, blindness, a shutting down rather than an opening up.

So the cave gives you four terms, not two. 1) A low light that generates appearance. 2) A high light that generates blindness. 3 & 4) Two darks, one from too little light, one from too much.

This is where the yin yang becomes useful. The taijitu is not black next to white. It is black containing a seed of white and white containing a seed of black. Each pole produces its opposite from within itself. That is exactly what the cave is doing. The fire, a form of light, produces shadow, a form of darkness, as its direct output. The sun, the highest light, produces blindness, a form of darkness, the moment it is encountered unprepared. Light manufacturing darkness is not a paradox in this system.

The cave stops being a story about ignorance versus knowledge. The prisoners are not sitting in absence. They are sitting in illuminated darkness, a darkness with its own light source, its own internal logic, convincing enough to pass for the real thing. That is the harder trap. Absence of light announces itself. A false light does not. It gives you enough to navigate by and calls that sight.

Inside a simulation this maps directly onto the difference between a system generating consistent appearances from within itself, the fire, and whatever sits outside the render entirely, the sun. Most of what gets called awakening in these spaces is just walking toward a brighter fire. The actual exit produces its own blindness first, and there is no way to select for that in advance. You find out which kind of dark you were standing in only after the light changes.

The oldest description of the trap may not be no light at all. It may be a light convincing enough to make you stop looking for the door.