The contrast between the two families is one of the most important thematic devices of the novel. Historically, the Schlegels represent the liberal social attitudes of the Edwardian era then emerging in England after the death of Queen Victoria. They are intellectual, cultured, talkative, and somewhat flighty, believing that their relationships with other people are the most important priorities on Earth. The Wilcoxes, on the other hand, represent a more conventional social morality received from the Victorian 19th century: they are pragmatic, materialistic, moralistic, and chauvinistic. What unites the two families thematically is money: They are both in the upper strata of the English class system, and are used by Forster to represent different aspects of the English class system in the early years of the 20th century.
Though Tibby, to his credit, shows a great deal of personal improvement in the novel, it is fair to say that Tibby and Charles represent the worst flaws of their respective family tendencies. Tibby, from the intellectual Schlegel family, is dry, academic, snobbish, peevish, frail, and uninterested in human beings; Charles, from the materialistic Wilcox family, is greedy, suspicious, bullying, and aggressive. Their contrast is illuminating because it enables Forster to expose the hypocrisies and flaws of each class position without turning the reader too far against the more important characters of the novel, such as Margaret, Helen, and Henry.