The main theme of Little Lord Fauntleroy is the meaning of true nobility. Burnett uses Dorincourt as a foil to Fauntleroy to dramatize the contrast between the two competing ideas of nobility that clash over the course of the novel. On the one hand, there is the superficial, self-interested idea personified by Dorincourt, a man with all the trappings of nobility but none of the character, and on the other, the thoughtful, generous idea personified by Cedric, a boy who knows nothing of the aristocracy, yet interacts with those less fortunate than him with a natural noblesse oblige.

A truly noble person is a happy person. The proof of this truth lies in the happiness it brings. That the proof is a feeling is typical to sentimental novels, which upheld deep knowledge and trust of emotions over emotionless rationality. The contrast between Dorincourt and Fauntleroy isn’t so much one of reason versus emotion, but of selfishness versus generosity. Dorincourt lived according to the rule of selfish pleasure, using his “wealth and power only to please himself and kill time” (152). In contrast, Cedric’s first impulse after learning of his newfound wealth isn’t to buy toys for himself, like a typical seven-year-old boy, but rather to help his friends and family and those who have been kind to him, such as the apple seller and the woman whose husband is sick.