The parable of the cave

Parables are useful; they illuminate points well, and they're great for triggering discussion. But most of them are related to a theistic tradition. I haven't heard many written from an atheist viewpoint, but here's one:

I was in a cave, darker than the darkest night. And I was wandering, my hands held out in front of me and my feet lifted hesitantly, for the way was not smooth. I searched, and around me I could hear the footsteps of others searching with me. Eventually I turned a corner, and came across one who held aloft a light. It blinded my eyes, after the long search in the darkness, and I shrank back from the pain of the light, but after a time I grew accustomed. Others among the searchers did not, and some threw rocks at the light-bearer for the pain they brought, but the light-bearer did not obscure the light, nor lower the light to take up the rocks and hurl them back at the rock throwers, for the light-bearer’s only duty was to the light. I saw the walls of the cave, and they were sparkling with beautiful crystals and flowing with the softened curves of water-carved rock, and nothing I had experienced was ever so beautiful. And so it was a long time, revelling in the light held aloft by the light-bearer, before I realized that I too held in my hands a light, and that, by the light held aloft, I could kindle my own light. Others amongst us saw this too, and soon the cavern was blazing with many lights. And some that held lights went and drove back the rock-throwers, and left them in the darkness as they desired, far from the light, so that they ceased to throw their rocks. And then the light-bearers took forth the light, to illuminate other caverns. And I went with them, for I desired to show others the beauty the light could bring, and see the beauty of the other caverns of this cave of ours. And in time my wanderings with the light brought me to the mouth of the cave, where the light was pure and unyielding, and I saw before me the green grass and the blue sky, and all of it lit as the caverns never were. But I saw other caves, and I knew that I must take the light to those who searched there too. For as long as one is without light who desires it, all with the light must seek to take the light to them; for light cannot be held for one or a few alone, but must illuminate the way for all.