Quotation:

"Power tends to corrupt and absolute power corrupts absolutely."

Long quote:
"Power tends to corrupt and absolute power corrupts absolutely. Great men are almost always bad men, even when they exercise influence and not authority: still more when you superadd the tendency or the certainty of corruption by authority."

Lord Acton (1834-1902) English historian

power (noun): being in a position to control other people; being in government; being the ruler of a country
tend to (verb): be likely to
corrupt (verb): make (someone) act dishonestly
absolute (adjective): total; complete
great men: people of considerable influence or power; people of historic importance
exercise (verb): have; use; apply
influence (noun): the ability to change or persuade (someone)
authority (noun): the ability to make decisions and give orders; the ability to ensure obedience
superadd (verb): add to what has already been added

Contributor: Josef Essberger