Most of the people in our society are sheep. They are kind, gentle, productive creatures who can only hurt one another by accident. Then there are wolves and the wolves feed on the sheep without mercy. Finally there are sheepdogs, and I am a sheepdog. I live to protect the flock and to confront the wolf.
On Sheep, Wolves and Sheepdogs
(From the book, On Combat : The Psychology and Physiology of Deadly 2008, by Lt. Col. Dave Grossman)