Though the character of Figaro may be seen as deriving from a variety of stock theatrical types, the single one he relates to most obviously is the "impudent valet" in the classic "guardian and ward" plot—which is always the same: a beautiful girl is being held under lock and key by a ridiculous old man, a dragon, bent on matrimony. Enter a handsome young hero, who is smitten with love at the mere sight of her, and who then uses the devices of his ingenious valet to out-fox the old guardian, and get the girl for himself. This kind of play, as ancient as the Greeks and Romans, had crystalized into a sort of perfection in the modern Classical period, in Molière's hilarious farce, Les Fourberies de Scapin. When we first meet Figaro, in Beaumarchais' Barbier de Séville, he, too, is...