"We travel together, passengers on a little space ship .... We cannot maintain it half fortunate, half miserable, half confident, half despairing, half slave - to the ancient enemies of man - half free in a liberation of resources undreamed of until this day. No craft, no crew can travel safely with such vast contradictions. On their resolution depends the survival of us all." - Adlai Stevenson, shortly before his death.

"Ecological considerations have made us all more aware of the interdependence of the political and geographical entities of our world. We have come to see our planet as 'Spaceship Earth.' But we must not forget that one-quarter of the passengers on that ship have luxurious first-class accommodations and the remaining three-quarters are traveling in steerage. That does not make for a happy ship - in space or anywhere else. All the less so when the steerage passengers realize that the means are at hand to make the accommodations reasonably comfortable for everyone" - Robert Mcnamara, in One Hundred Countries, Two Billion People: The Dimensions of Development, 1973.