The Count of Monte Cristo
How we cite our quotes:
"Indeed," said Danglars, casting a sidelong glance at Dantès with a flash of hatred in his eyes. "Yes indeed, he is young and full of self-confidence. The captain was hardly dead before he had taken command without asking anyone, and made us lose a day and a half on the island of Elba, instead of returning directly to Marseille. (1.30)
Here we see a conflict of ambitions. Danglars wants what Edmond has worked hard to earn. This small-scale conflict of interest leads to, well, everything.
"Father! Will you always be an obstacle to my happiness in this world, and shall I always have to contend with your past?"
Then, suddenly, it seemed as though a light had unexpectedly passed through his mind and lit up his face. A smile rose to his clenched lips, while his distraught look became a stare and his mind appeared to concentrate on a single idea.
"That's it," he said. "This letter, which should have destroyed me, might perhaps make my fortune. Come, Villefort, to work!" (7.121-123)
Ambition can turn even the most dire of situations into the greatest of boons.
"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." (17.45)
Abbé Faria suggests that ambition can feed on adversity.