"Power tends to corrupt, and absolute power corrupts absolutely." Lord Acton
"Nearly all men can stand adversity. But if you want to test a man's character - give him power." US President Abraham Lincoln
"Das Experiment" (The Experiment) A good German movie showing how power can bring out the worst in our character.
Nobody heard him, the dead man, but still he lay moaning: I was much further out than you thought. And not waving but drowning. (Stevie Smith)