What’s making that shadow?
All we can see is the shadow. What's really there?
About 2,400 years ago, in his book the Republic, Plato imagined people chained in a cave all their lives, facing a wall.
Behind them, a fire burned, and things were carried past it. All the prisoners ever saw were the shadows those things cast. So the shadows were their whole world, and they named them as if they were the real things.
For Plato, the story was about learning. Turning around and climbing out into the daylight hurts at first, but it’s how we come to see what’s really there.
People have been asking ever since: how much of what we see is the thing itself, and how much is just where we happen to be standing?