Power Corrupts

The 4-1-1 on the man who said it, the full,
correct quote, and the instance of its use.

      John Emerich Edward Dalberg-Acton, 1st Baron Acton, KCVO,
      DL (10 January 1834 - 19 June 1902), known as Sir John
      Dalberg-Acton, 8th Baronet from 1837 to 1869 and usually
      referred to simply as Lord Acton, was an English Catholic
      historian, politician, and writer. -

In 1870 came the great crisis in Catholicism over the First Vatican Council's promulgation of the doctrine of papal infallibility. Lord Acton, who was in complete sympathy on this subject with Döllinger, went to Rome in order to throw all his influence against it, but the step he so much dreaded was not to be averted. The Old Catholic separation followed, but Acton did not personally join the seceders, and the authorities prudently refrained from forcing the hand of so competent and influential an English layman. It was in this context that, in a letter he wrote to scholar and ecclesiastic Mandell Creighton, dated April 1887, Acton made his most famous pronouncement:

But if we might discuss this point until we found that we nearly agreed, and if we do agree thoroughly about the impropriety of Carlylese denunciations and Pharisaism in history, I cannot accept your canon that we are to judge Pope and King unlike other men, with a favourable presumption that they did no wrong. If there is any presumption it is the other way, against the holders of power, increasing as the power increases. Historic responsibility has to make up for the want of legal responsibility. 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 negation of Catholicism and the negation of Liberalism meet and keep high festival, and the end learns to justify the means. You would hang a man of no position like Ravaillac; but if what one hears is true, then Elizabeth asked the gaoler to murder Mary, and William III. ordered his Scots minister to extirpate a clan. Here are the greatest names coupled with the greatest crimes; you would spare those criminals, for some mysterious reason. I would hang them higher than Haman, for reasons of quite obvious justice, still more, still higher for the sake of historical science.