What is the theme in The Heart Is a Lonely Hunter by Carson McCullers?

Strength and weakness is a theme inthe book. Very early in the book Biff Brannon announces to his wife, "I like freaks." Her response is "I reckon you ought to, Mister Brannon—being as you're one yourself." What Biff has in mind is the affinity he has for the struggling underdog, or, as the book puts it later, "a special feeling for sick people and cripples." Although Brannon himself is physically healthy, his connection to the physically deformed is an indication of the weakness that he sees within himself, a weakness that shows itself in his inability to connect to his wife when she is alive and is even more pronounced in his withdrawal from society after her death. The other main characters display signs of social weakness that range from the obvious to the sublime.