"Rather than adapting to the limits of the biosphere, humanity should expand beyond it, carrying the living process outward on an odyssey to other worlds.” — Kirby.

“The most difficult transition to make is from a human-centered to a life-centered norm of progress. If there is to be any true progress, then the entire life community must progress. Any ‘progress’ of the human at the expense of the larger life community must ultimately lead to a diminishment of human life itself.” — Berry.

“Thou shalt not exceed the carrying capacity of any environment.” — Hardin.