Monsters

"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you."
--Friedrich Nietzsche, Beyond Good and Evil, Aphorism 146
German philosopher (1844 - 1900)

"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf."
--George Orwell