But as a perishable perfect man must die, and leave his despotism in the hands of an imperfect successor, an earthly despotism is not merely a bad form of government, it is the worst form that is possible.
 Mark Twain, A Connecticut Yankee in King Arthur's Court (1889). copy citation

Context

“An earthly despotism would be the absolutely perfect earthly government, if the conditions were the same, namely, the despot the perfectest individual of the human race, and his lease of life perpetual. But as a perishable perfect man must die, and leave his despotism in the hands of an imperfect successor, an earthly despotism is not merely a bad form of government, it is the worst form that is possible. My works showed what a despot could do with the resources of a kingdom at his command. Unsuspected by this dark land, I had the civilization of the nineteenth century booming under its very nose! It was fenced away from the public view, but there it was, a gigantic and unassailable fact—and to be heard from, yet, if I lived and had luck.” source