Power Corrupts?

"Power corrupts, and absolute power corrupts absolutely."
I can't remember to whom this quote should be attributed. Could someone help me?

I have been pondering this statement often lately as it relates to the local and national political processes as well as to the events of Roman rulers and Jesus' crucifixion.

In an interview with HarperOne about his newest book Thich Nhat Hanh reminds us that power does not necessarily need to corrupt. Power, when coupled with love and compassion, can be a tremendous healing and unifying force in our world/universe.

Here's the interview from Beliefnet today.