"Absolute power corrupts absolutely."
This saying is largely attributed to Shakespeare but was actually first spoken-or written-by Lord Acton-who was a politician & writer-in a letter he wrote to Bishop Mandell Creighton in 1887.
"With great power comes great responsibility."
Most people know this saying from Spider-Man but it has also been attributed to FDR, Winston Churchill, Teddy Roosevelt, the Bible, and controversial French writer & philosopher Voltaire.
"Just 'Cos You Got The Power . . .
. . . That Don't Mean You Got The Right." This is a song by legendary heavy metal group Motorhead fronted by the late Lemmy. It's not as well-known as the others but I feel it's no less poignant.
"Never underestimate the power of stupid people . . .
. . . in large groups." This saying was from comedian the late George Carlin. This is also probably my most favorite "power" saying on this list for, I think, obvious reasons! R.I.P. George!