A river that has slowly been polluted suddenly becomes toxic; most of the fish perish; swimming becomes a danger to health. But even then, the river may look the same and one may still take a boat ride on it. In other words, even when life has been taken from it, the river does not disappear, nor do all of its uses, but its value has been seriously diminished and its degraded condition will have harmful effects throughout the landscape. It is this way with our symbolic environment.
