"Shouldn't bother trying to saw through hand-cuffs. Never make it in time."
— Rorschach, Watchmen
He doesn't want us to cut through our chains. He wants us to cut through our feet.
— Dr Gordon, Saw
Stiles: Look, I don't know if I can do this.
Derek: Why not?
Stiles: Well, because of the cutting through the flesh, the sawing of the bone, and especially the blood.
Derek: You faint at the sight of blood?
Stiles: No, but I might at the sight of a chopped off arm!
Reverend Mother Mohiam: You've heard of animals chewing off a leg to escape a trap? There's an animal kind of trick. A human would remain in in the trap, endure the pain, feigning death that he might kill the trapper and remove a threat to his kind.
Paul: Why are you doing this?
Mohiam: To see if you're human.
— Dune, following the Gom Jabbar note test.