The almost universal opinion and practice of mankind has been on the side of resistance of injury with injury. It has been held justifiable and necessary, for individuals and nations to inflict any amount of injury which would effectually resist a supposed greater injury. The consequence has been universal suspicion, defiance, armament, violence, torture and bloodshed. The earth has been rendered a vast slaughter-field – a theatre of reciprocal cruelty and vengeance – strewn with human skulls, reeking with human blood, resounding with human groans, and steeped with human tears.