"Power corrupts; absolute power corrupts absolutely"
"Absolute power corrupts absolutely" is the best known quotation of the 19th century British politician Lord Acton. He borrowed the idea from several other writers who had previously expressed the same thought in different words.
Absolute monarchies are those in which all power is given to or, as is more often the case, taken by, the monarch. Examples of absolute power having a corrupting influence are Roman emperors (who declared themselves gods) and Napoleon Bonaparte (who declared himself an emperor).
"Absolute power corrupts absolutely" arose as part of a quotation by the expansively named and impressively hirsute
John Emerich Edward Dalberg Acton, first Baron Acton (1834–1902). The historian and moralist, who was otherwise known simply as Lord Acton, expressed this opinion in a letter to Bishop Mandell Creighton in 1887:
"Power tends to corrupt, and absolute power corrupts absolutely. Great men are almost always bad men."
The text is a favourite of collectors of quotations and is always included in anthologies. If you are looking for the exact "power tends to corrupt, and absolute power corrupts absolutely" wording, then Acton is your man. He coined the phrase but he didn't invent the idea; quotations very like it had been uttered by several authors well before 1887. Primary amongst them was another English politician with no shortage of names -
William Pitt the Elder, Earl of Chatham and British Prime Minister from 1766 to 1778. Pitt said something similar in a speech to the UK House of Lords in 1770:
"Unlimited power is apt to corrupt the minds of those who possess it"
Acton is likely to have taken his lead from the writings of the French republican poet and politician, again a generously titled individual -
Alphonse Marie Louis de Prat de Lamartine. An English translation of Lamartine's essay
France and England: a Vision of the Future was published in London in 1848 and included this text:
It is not only the slave or serf who is ameliorated in becoming free. The master himself did not gain less in every point of view, for absolute power corrupts the best natures.
Whether it is Lamartine or his anonymous English translator who can claim to have coined 'absolute power corrupts' we can't be sure. What we can be sure about is that it came before Lord Acton's more famous version. Whether Acton was aware of Lamartine's essay we can't now tell.
Conclusion
"Absolute power corrupts absolutely" is one of the proverbial sayings that seems to be proved correct by experience of people's actual behaviour.
It was coined by the English nobleman Lord Acton in 1857, using similar ideas expressed by several of his contemporaries.
The meaning and origin of the phrase 'Power corrupts; absolute power corrupts absolutely'.
www.phrases.org.uk