IN THE BEGINNING, as the Greeks saw it, when chaos settled into form there was a mighty sphere, floating free within the moist, gleaming embrace of the sky and its great swirling drifts of white cloud, a vibrant globe of green and blue and brown and gray, binding together in a holy, deep-breasted synchrony the temperatures of the sun, the gasses of the air, the chemicals of the sea, the minerals of the soil, and bearing the organized, self-contained, and almost purposeful aspect of a single organism, alive, a breathing, pulsing body that was, in the awed words of Plato, "a living creature, one and visible, containing within itself all living creatures."