“‎Using his burgeoning intelligence, this most successful of all mammals has exploited the environment to produce food for an ever increasing population. Instead of controlling the environment for the benefit of the population, perhaps it's time we controlled the population to allow the survival of the environment.”

“The fact is that no species has ever had such wholesale control over everything on earth, living or dead, as we now have. That lays upon us, whether we like it or not, an awesome responsibility. In our hands now lies not only our own future, but that of all other living creatures with whom we share the earth.”

“I don't think whole populations are villainous, but Americans are just extraordinarily unaware of all kinds of things. If you live in the middle of that vast continent, with apparently everything your heart could wish for just because you were born there, then why worry? [...] If people lose knowledge, sympathy and understanding of the natural world, they're going to mistreat it and will not ask their politicians to care for it.”

“The truth is: the natural world is changing. And we are totally dependent on that world. It provides our food, water and air. It is the most precious thing we have and we need to defend it.”

“I don’t know [why we're here]. People sometimes say to me, ‘Why don’t you admit that the humming bird, the butterfly, the Bird of Paradise are proof of the wonderful things produced by Creation?’ And I always say, well, when you say that, you’ve also got to think of a little boy sitting on a river bank, like here, in West Africa, that’s got a little worm, a living organism, in his eye and boring through the eyeball and is slowly turning him blind. The Creator God that you believe in, presumably, also made that little worm. Now I personally find that difficult to accommodate…”

“Human population growth is probably the single most serious long-term threat to survival. We're in for a major disaster if it isn't curbed... We have no option. If it isn't controlled voluntarily, it will be controlled involuntarily by an increase in disease, starvation and war.”

“This last chapter .. may have given the impression that somehow man is the ultimate triumph of evolution, that all these millions of years of development have had no purpose other than to put him on earth. There is no scientific evidence whatever to support such a view and no reason to suppose that our stay here will be any more permanent than that of the dinosaur.”