The Count of Monte Cristo
How we cite our quotes:
"Misfortune is needed to plumb certain mysterious depths in the understanding of men; pressure is needed to explode the charge. My captivity concentrated all my faculties on a single point. They had previously been dispersed, now they clashed in a narrow space; and, as you know, the clash of clouds produces electricity, electricity produces lightning and lightning gives light." (Abbé Faria) (17.45)
As far as Abbé Faria sees it, a man can only truly exert himself – or, rather, he can put his energy to better use – when given something to work against.
"What is truly desirable? A possession that we cannot have. So, my life is devoted to seeing things that I cannot understand and obtaining things that are impossible to have. I succeed by two means: money and will. I am as persevering in the pursuit of my whims as, for example, you are, Monsieur Danglars, in building a railway; or you, Monsieur de Villefort, in condemning a man to death; or you, Monsieur Debray, pacifying a kingdom; you, Monsieur de Château-Renaud, in finding favour with a woman; or you, Monsieur Morrel, in breaking a horse that no one else can ride." (63.7)
Unlike the others, who seem to do things because they love them or what they lead to – for instance, railroads lead to money – Monte Cristo claims to do things for the sake of, well, doing things, like a climber who scales a mountain because it's there.
"Poor young man!" Monte Cristo muttered, so low that even he could not hear these words of compassion as he spoke them. "It is written that the sins of the father shall be visited on the sons, even to the third and forth generation." (85.135)
Because sin itself is able to persist, according to Monte Cristo, and corrupt even the sons of those who sinned, the Count himself must persist in his pursuit of those sinners-by-proxy if he hopes to complete his job.