A civilian sheepdog is not a dog breed, but rather a concept started by former psychology professor and army ranger, Lt. Col. Dave Grossman. He breaks down society into three categories: sheep, wolf and sheepdog. The sheepdog's role is to protect the sheep from the wolf.
According to this concept, most people in the world are sheep. These people are calm and gentle most of the time and can only hurt other sheep by accident. Then, there are the wolves, who feed on the sheep without mercy. Finally, the sheepdogs live to protect the flock and confront the wolf. The Sheepdog Concept labels the sheepdog as having the capacity for violence and a deep love for its fellow human beings, with the sheep being incapable of violence and the wolf incapable of love.