Knowing that their master would eventually kill, skin, and eat them, the sheep kept trying to run away and proved very troublesome.
At last the shepherd used his magic power to put his sheep into a hypnotic trance and gave them suggestions that would internalize as their own beliefs. He told them they were immortal, so death could do them no harm. He told them to trust their master’s goodness no matter what happened to them. Finally, he told them not to think about their fate at all, because it wouldn’t happen right away. There was no need to anticipate it.
Then the sheep became obedient, and stopped trying to escape. Each one quietly awaited its own death at the master’s hand, believing that it had decided to do so of it’s own free will.
2012 A Space Odyssey 