Power tends to corrupt, and absolute power corrupts absolutely. is a famous quote of English historian Sir John Dalberg-Acton (1834 - 1902). Of course, Lord Acton was not referring to statistical hypothesis testing when he made the remark in an April 1887 letter to Mandell Creighton. However, the widespread knowledge of the quote by students makes it an interesting way to cover the idea that statistical significance is not the same as practical significance.