"Human beings cannot be trusted with unbridled power"

"The history of slavery across the centuries and in many countries around the world is a painful history to read-- not only in terms of how slaves have been treated, but because of what that says about the whole human species-- because slaves and enslavers alike have been of every race, religion and nationality.
If the history of slavery ought to teach us anything, it is that human beings cannot be trusted with unbridled power over other human beings-- no matter what color or creed any of them are. The history of ancient despotism and modern totalitarianism practically shouts that same message from the blood-stained pages of history."
http://www.realclearpolitics.com/articles/2010/04/27/filtering_history_105321.html