Friendship is one of our most important social institutions. It is the not only the salve for personal loneliness and isolation; it is the glue that binds society together. Yet for a host of reasons--longer hours at work, the Internet, suburban sprawl--many have argued that friendship is on the decline in contemporary America. In social surveys, researchers have found that Americans on average have fewer friends today than in times past. In Friend v. Friend, Ethan J. Leib takes stock of this most ancient of social institutions and its ongoing transformations, and contends that it could benefit from better and more sensitive public policies. Leib shows that the law has not kept up with changes in our society: it sanctifies traditional family structures but has no thoughtful approach to other aspects of our private lives. Leib contrasts our excessive legal sensitivity to marriage and families with the lack of legal attention to friendship, and shows why more legal attention to friendship could actually improve our public institutions and our civil society. He offers a number of practical proposals that can support new patterns of interpersonal affinity without making friendship an onerous legal burden. An elegantly written and highly original account of the changing nature of friendship, Friend v. Friend upends the conventional wisdom that law and friendship are inimical, and shows how we can strengthen both by seeing them as mutually reinforcing.