Novels shouldn’t aspire to answer questions, and I wouldn’t presume to offer advice about love or marriage in any case. What’s fascinating to me about marriage as a subject for fiction—a subject that fiction has taken on with gusto since the 19th century—is how unknowable other people’s relationships are. Even the marriages of your parents, your siblings, your closest friends always remain something of a mystery. Only in fiction can you pretend to know people completely.