What does Hank say about human nature at the end of A Connecticut Yankee in King Arthur's Court?
At the end of the book, Hank realizes that he's as much a subject to human nature as anybody else. He had succeeded in transforming the knights from mere fighting machines into men who worked for the good of all people. King Arthur's England, which once had been a feudal kingdom, was now a model of progressive ideas. Slavery was abolished, schools flourished, taxation was "equalized." It sounds like a utopia. And Hank admits that human nature has made him desire to be the first president of this newly formed republic. He says:
Arthur was good for thirty years yet, he being about my own age--that is to say, forty--and I believed that in that time I could easily have the active part of the population of that day ready and eager for an event which should be the first of its kind in the history of the world--a rounded and complete governmental revolution without bloodshed. The result to be a republic. Well, I may as well confess, though I do feel ashamed when I think of it: I was beginning to have a base hankering to be its first president myself. Yes, there was more or less human nature in me; I found that out.
So even though Hank's motive was only to improve the society of Arthur's England, human nature makes him want to be the one in charge. Although things are going well for us, we just can't help wanting something different, something more.
I'm not sure this is what you're looking for, but I hope it helps!