Hidden behind the stock Western novel device of the epic trail drive are basic themes of the novel, love and death. Several of the characters are either seeking lovers or are haunted by absent lovers. (This motif explains the title; doves mate for life, and a lonesome dove is one that has lost or is searching for its partner.) Elmira thinks that she can find happiness with Dee Boot, and she leaves both husband and baby in a search for a reprobate who will be hanged the day after she is reunited with him. Dish Boggett hangs around Lorena, to whom he is devoted, like a panting puppy. Even the remarkably resourceful and self-contained Augustus rides hundreds of miles to plead his case to Clara. Although Lorena reveres Augustus as a rescuing knight, she fails to understand that Augustus really is a knight: He helps her not because he has designs on her body or soul but because she is in danger, so he saves her as a good knight or Texas Ranger should. Dish Boggett’s passion for Lorena is a reminder that emotion alone cannot sustain deep love. Lorena’s attitude toward Dish passes from indifference to annoyance to scorn, perhaps because in Boggett she sees a reflection of her own moon-eyed pining over Augustus. Lorena is too weak to inspire more than affection in Augustus. He can only love someone who is as strong and independent as himself—and for that reason, ironically, there can be no permanent relationship between Clara and Augustus, since they are too strong for each other.
Lonesome Dove is also a reminder of mortality. The deaths begin as soon as the drive begins, when the O’Brien brother is bitten by the snakes. Because this character had scarcely been introduced, his death is more shocking than affecting. The deaths continue to come, however, and to characters of more significance; the deaths of Deets and Augustus are almost unbearable. Since the drive itself moves through ever-changing and unpredictable circumstances, the deaths are the final test of the characters’ ability to change and adapt. The novel thus is an account of what happens when a group of people whose characters and relationships are fixed are placed in new circumstances and forced to adjust. Malleable and fluid characters such as Augustus thrive; those whose characteristics are set and unchangeable are destroyed or suffer reduction.