Thinkers aren't limited by what they know, because they can always increase what they know. Rather they're limited by what puzzles them, because there's no way to become curious about something that doesn't puzzle you.

I hope it will not be too long before the technologies that support our population explosion begin to be perceived as no less hazardous to the future of life on this planet than the endless production of radioactive wastes.

There is no one right way to live.

The world of the Takers is one vast prison, and except for a handful of Leavers scattered across the world, the entire human race is now inside that prison.

Pity is always twinged with disgust.

You never actually know how you're going to handle a problem until you actually have it.

[A]ny species that exempts itself from the rules of competition ends up destroying the community in order to support its own expansion.