Terror made me cruel; and finding it useless to attempt shaking the creature off, I pulled its wrist on to the broken pane, and rubbed it to and fro till the blood ran down and soaked the bedclothes.
I'm one-hundred-fifty miles off Cape Horn, both autopilots are broken, and my boat is drifting toward one of the nastiest chunks of ocean on the face of the earth.
Obviously if any actions, even a lunatic's, can be causeless, determinism is done for. If the chain of causation can be broken for a madman, it can be broken for a man.