The earth is what we all have in common. It is what we are made of and what we live from, and we cannot damage it without damaging those with whom we share it. There is an uncanny resemblance between our behavior toward each other and our behavior toward the earth. By some connection we do not recognize, the willingness to exploit one becomes the willingness to exploit the other . . . It is impossible to care for each other more or differently than we care for the earth.