We are living in a time of change unprecedented in both extent and rapidity on a planet now so filled by our presence that little further space exists to accommodate serious mistakes. The scale of economic activity, the number of people, environmental degradation, and the power of weaponry raise both the likelihood of conflict and the need for greater cooperation among peoples. The information and communications revolution erases distance. More than ever before, we are truly stuck with each other.

Since the contingencies of history, the complexities of our world, and our own inevitable ignorances make the future impossible to predict in principle, we cannot offer profound advice or definite directions. But perhaps we can suggest some guidelines, based on goodwill and common moral sensibility, for a long and successful human persistence on a well sustained earth.