In Nicholas Nickleby, Ralph and Nicholas serve as clear character foils. While other characters in the novel contrast one another in behavior or mien, no two other characters are such evident inverses of one another. The two men are diametric opposites, even in appearance. Note the following excerpt from Chapter 3, in which Dickens compares Ralph and Nicholas:
The face of the old man was stern, hard-featured, and forbidding; that of the young one, open, handsome, and ingenuous. The old man's eye was keen with the twinklings of avarice and cunning; the young man's bright with the light of intelligence and spirit.
Nicholas is the morally upright hero of Dickens's story, while Ralph is the unquestioned villain. In fiction underpinned by simple, straightforward moral philosophies, heroes and villains are often natural foils for one another. Nicholas Nickleby, along with other Dickens novels, tends to ascribe to simpler morality structures and follows this hero/villain foil pattern. Note the association of culturally "unfavorable" aesthetics and attitudes with the "villain" character and the association of culturally "favorable" aesthetics and attitudes with the "hero" character. Nicholas is bright, intelligent, handsome, ingenuous. Ralph is stern, greedy, forbidding, and cunning. In these roles, Nicholas spurns Ralph, as he should; Ralph, in turn, envies Nicholas's better qualities.