Plato initiated the view that possession of absolute power inevitably has a corrupting effect.
Probably the most ancient expression of the idea that power has a corruptive effect appears in the parable of the Ring of Gyges in The Republic (c. 360 BCE) by Plato (c. 424-c. 348 BCE). In the parable, the otherwise virtuous Gyges indulges in corrupt behavior after finding a magic ring that renders him invisible.
However, the maxim “absolute power corrupts absolutely” originates much later, being a paraphrase of a letter written by Sir John Dalberg-Acton (1834–1902), a British Catholic historian better known as Lord Acton, to Bishop Mandell Creighton in 1887. Acton scolds Creighton in the letter for his suggestion, in previous correspondence, that the pope, king, or any other person holding comparably high station ought to be judged according to standards different to those applied to common men. Acton argues that, quite to the contrary, “Historic responsibility has to make up for the want of legal responsibility. Power tends to corrupt, and absolute power corrupts absolutely.”
The British politician and historian Lord John Dalberg-Acton famously wrote in a letter to Bishop Mandell Creighton (1887):
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. There is no worse heresy than that the office sanctifies the holder of it. That is the point at which … the end learns to justify the means.
Acton, however, followed at least two distinguished persons in associating power with corruption: in a speech that was delivered in the British House of Commons in 1770, Prime Minister William Pitt, Earl of Chatham (1708–78), had claimed that, “Unlimited power is apt to corrupt the minds of those who possess it; and this I know, my Lords, that where law ends, tyranny beginsl” Acton’s observation was also anticipated by French writer, poet, and politician Alphonse Marie Louis de Prat de Lamartine (1790– 1869), who, in his essay France and England: a Vision of the Future (1848), had claimed “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.” Acton, too, believed that few could resist power’s corrupting effect, asserting, “Great men are almost always bad men.”