Idealism can be transferred from one person to another on a vehicle called revenge.

[from Wikipedia:
Scaramouche tells the story of a young lawyer during the French Revolution. In the course of his adventures he becomes an actor portraying "Scaramouche" (a roguish buffoon character in the commedia dell'arte). He also becomes a revolutionary, politician, and fencing-master, confounding his enemies with his powerful orations and swordsmanship. He is forced by circumstances to change sides several times. The book also depicts his transformation from cynic to idealist.]