The human moral sense can excuse any atrocity in the minds of those who commit it, and it furnishes them with motives for acts of violence that bring them no tangible benefit.
All over the world, belief in the supernatural has authorised the sacrifice of people to propitiate bloodthirsty gods, and the murder of witches for their malevolent powers.
People consider the harms they inflict to be justified and forgettable, and the harms they suffer to be unprovoked and grievous.