The central theme of Howards End revolves around connection—linking personal and public lives, uniting individuals, and the difficulties in creating and sustaining these links. The story focuses on two families: the Schlegels, who represent intellectualism, imagination, and idealism—the inner life of the mind—and the Wilcoxes, who embody English practicality, expansionism, commercialism, and the external world of business and politics. For the Schlegels, personal relationships are more important than public ones, and the individual is more significant than any organization. In contrast, for the Wilcoxes, social etiquette and business norms are of utmost importance.

The marriage between Margaret Schlegel and Henry Wilcox serves as a bridge between these contrasting worlds. Unlike her highly idealistic sister Helen, Margaret comes to understand the Wilcoxes. Helen's initial encounter with the Wilcoxes ends in disaster, but Margaret recognizes that many of the values she holds dear, such as art and culture, depend on the economic and social stability provided by people like the Wilcoxes. "More and more," she reflects, "do I refuse to draw my income and sneer at those who guarantee it."

However, Margaret and Henry's marriage nearly disintegrates when Henry fails to connect his own sexual indiscretion with Jacky Bast to Helen's affair with Leonard Bast. Margaret and Helen wish to spend a night at Howards End before Helen returns to Germany to have her child. Yet, the hypocritical Henry cannot accept the presence of a "fallen woman" on his property and denies them permission to stay. As critic Malcolm Bradbury points out, Margaret upholds the "primacy of the standard of personal sympathy," while Henry focuses on "the standard of social propriety." Defying Henry, Margaret and Helen spend the night at Howards End, rekindling their bond. By the end of the novel, circumstances force Henry to reevaluate his values. He reconciles with Helen, and together with Margaret and Helen's illegitimate son, they establish a home at Howards End under Margaret's care.

A prominent theme in Howards End is the internal struggle and conflict within the middle class. The novel does not feature the aristocracy or the very poor; the author clearly states, "[w]e are not concerned with the very poor," focusing instead on "gentlefolk, or with those who are obliged to pretend that they are gentlefolk." The three families in Howards End illustrate different segments of the middle class. The Schlegels are positioned in the middle, between the Basts, who are on the lower edge of the middle class, and the Wilcoxes, who belong to the upper-middle class. Leonard Bast, a clerk, lives precariously close to poverty, while the Schlegels enjoy a comfortable life from inherited wealth. Meanwhile, Henry Wilcox, a successful businessman, continuously amasses wealth, allowing him to afford "motors" and country estates.

Leonard Bast is preoccupied with class distinctions and aspires to elevate his status by becoming "cultured." He engages with works such as Ruskin's Stones of Venice and attends musical events. At a concert featuring Beethoven's Fifth Symphony, he meets the Schlegel sisters and becomes captivated by them, primarily because they seem to value his intellectual ambitions. The Schlegels, equally intrigued by Leonard and his situation, eventually find their involvement with him disastrous. When Margaret and Helen hear from Mr. Wilcox that Leonard's employer is nearing bankruptcy, they suggest he look for new work. Although this information proves false, Leonard acts on it, obtaining and then losing another job, leaving him and his wife Jacky nearly impoverished. In a dramatic scene where Leonard, Jacky, and Helen crash Evie's extravagant wedding, Forster dramatically illustrates the vast social and economic divide between the struggling Basts and the wealthy Wilcoxes....