THERE WAS ONCE AN ENORMOUS ROCK. It was smooth and round, and the only thing of its kind. As such, the local people loved and adored it. Streams of people came to visit it. Eventually they built homes around it, so that they could be close to it. Gradually a town formed around it. Everybody had the rock in common.
The rock was so perfect and symmetrical that people said it could not possibly be natural. On the other hand, however, just as many people thought that it could not possibly be man-made for the same reasons.