A lot of things can be said about power but perhaps nothing has the accuracy and longevity of the observation of the English historian, Lord Acton (John Dalberg-Acton) (1834-1902) on the matter. In a 1887 letter he wrote:
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 certainty of corruption by full authority. There is no worse heresy than the fact that the office sanctifies the holder of it.
The first bit quoted above is often misquoted as “power corrupts” — leaving out the operative word tends.. It’s only a tendency, not a certainty. A little bit of power may or may not corrupt, depending on the character of the person. But no matter who, absolute power corrupts extremely and without fail.
Great men are almost always bad men. Try as one might, it is hard to deny that proposition even upon casual observation, let alone after a careful study of history. I cannot resist quoting a few lines preceding “power tends to corrupt.”.