The Foundation

"Please listen to me with an open mind. If you have millions of interacting worlds in the Galaxy, as is, of course, the affil case, and if each is made up entirely of Isolates, as they are, then on each world, human beings are dominant and can force their will on nonhuman life-forms, on the inanimate geological background, and even on each other. The Galaxy is, then, a very primitive and fumbling and misfunctioning Galaxia. The beginnings of a unit. Do you see what I mean?"
"I see what you're trying to say-but that doesn't mean I'm going to agree with you when you're done saying it."
"Just listen to me. Agree or not, as you please, but listen. The only way the Galaxy will work is as a proto-Galaxia, and the less proto and the more Galaxia, the better. The Galactic Empire was an attempt at a strong proto-Galaxia, and when it fell apart, times grew rapidly worse and there was the constant drive to strengthen the proto-Galaxia concept. The Foundation Confederation is such an attempt. So was the Mule's Empire. So is the Empire the Second Foundation is planning. But even if there were no such Empires or Confederations; even if the entire Galaxy were in turmoil, it would be a connected turmoil, with each world interacting, even if only hostilely, with every other. That would, in itself, be a kind of union and it would not yet be the worst case."
"What would be the worst, then?"
"You know the answer to that, Trevize. You've seen it. If a human-inhabited world breaks up completely, is truly Isolate, and if it loses all interaction with other human worlds, it develops-malignantly."
"A cancer, then?"
"Yes. Isn't Solaria just that? Its hand is against all worlds. And on it, the hand of each individual is against those of all others. You've seen it. And if human beings disappear altogether, the last trace of discipline goes. The each-against-each becomes unreasoning, as with the dogs, or is merely an elemental force as with the moss. You see, I suppose, that the closer we are to Galaxia, the better the society. Why, then, stop at anything short of Galaxia?"

(Isaac Asimov, Foundation and Earth, 2001)