The obvious can sometimes be illuminating when perceived in an unhabitual way.

Man's destiny was to conquer and rule the world, and this is what he's done.. almost. He hasn't quite made it, and it looks as though this may be his undoing. The problem is that man's conquest of the world has itself devastated the world. And in spite of all the mastery we've attained, we don't have enough mastery to stop devastating the world.. or to repair the devastation we've already wrought.

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.

five severed fingers do not make a hand

The premise of the Taker story is 'the world belongs to man'. … The premise of the Leaver story is 'man belongs to the world'.

If the world is saved, it will not be by old minds with new programs but by new minds with no programs at all. Why not new minds with new programs? Because where you find people working on programs, you don't find new minds, you find old ones. Programs and old minds go together like buggy whips and buggies.

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.