Excerpted from Marriage: The Dream That Refuses To Die (Wilmington, DE: ISI Books, 2008), 225 pages, $25.00. This title will be published in May 2008 by ISI Books, where it will be featured as the Book of the Month.

The combined weight of the social, political, and economic functions of marriage underscores its significance as the foundational social unit. To grasp the relevant perspective demands an extraordinary effort of imagination from those steeped in modern and postmodern assumptions about the nature of the human person and human relations. Some, notably the historian Colin Morris, argue that the individual and a conception of individualism appeared in England as early as the eleventh and twelfth centuries. And there are strong arguments, although not those upon which Morris relies, that Christianity nurtured a specific conception of the individual both with respect to the quest for personal holiness and the sense of individual moral responsibility. Because of the slippery nature of definitions, it is ultimately pointless to quarrel with Morris, but it is essential to understand that most people in Britain, Europe, and throughout the world saw themselves primarily, if not exclusively, as the member of a group, usually a family first and beyond it a clan, tribe, community, or people—a race, as many of them would have said.

When so large a share of social order depended upon marriage, love could only be viewed as disruptive. Like Greek and Roman myths, medieval European culture abounded with tales of unruly and untamable passions, just as the more popular culture delighted in tales of cuckolded husbands. In Romeo and Juliet, William Shakespeare drew upon a rich tradition of consuming loves that defied the exigencies of political order and political enmities. The middle of the twelfth century witnessed the emergence of a tradition of courtly love that would culminate in the thirteenth and persist into the fourteenth century. Intended to soften and civilize the brutality of early medieval culture, courtly love inaugurated a new vision of love and prescriptions for the ways in which a proper knight should treat his lady. By definition, this lady, the knight’s true love, was not his wife, but a lady of beauty and social position whom he served through acts of fealty and valor.

The cycle of Arthurian legends rapidly became a central piece of the culture of courtly love. Sir Lancelot’s love for Guinevere, the wife of King Arthur, figures prominently in the cycle and doubtless influenced the other legends included within it. Among these, a special place belongs to the story of Tristan and Isolde, which did not originate in the cycle but was absorbed into it. According to the best-known version of the tale, written by Gottfried von Strassburg in the first decade of the thirteenth century, Sir Tristan is entrusted by his uncle, King Mark of Cornwall, to go to Ireland to escort the king’s prospective bride, the Irish Isolde, to Cornwall. During the voyage, her attendant gives them a love potion, which instills in them an undying passion. Respecting the claims of kinship as well as social and political obligation, they remain on their assigned course: Isolde marries King Mark, and Tristan marries another, also named Isolde, but never consummates the marriage. Tristan’s military responsibilities take him away, but after receiving a fatal wound he returns to Cornwall to seek Isolde, who had twice previously saved him from death. His jealous wife foils the plan. Tristan dies desolate, and Isolde, who arrives minutes too late to save him, lays down in his arms and dies with him.

Few tales better or more poignantly illustrate the potential conflict between love and marriage, which helps to explain why it has been so frequently retold. Among the many who have done so, we may note Paul Hamilton Hayne, Frederic Manning, William Morris, Algernon Charles Swinburne, Alfred Lord Tennyson, and Thomas Mann. Towering above all, Richard Wagner’s opera, Tristan und Isolde, powerfully affected countless writers and painters in various countries and helped to consolidate the modern myth of liebestod—death for or through love. However flamboyant and informed by modern themes, Wagner’s treatment captures the essence of the original medieval sensibility: Love is inherently dangerous and usually deadly. It is not compatible with social order and has nothing to do with the rearing of children, the predictable appearance of meals, or the observance of basic social conventions. Georges Bizet memorably captures the sensibility in Carmen’s “Habanera,” in which she announces that love is a rebellious bird—a child of the Bohemia—that has never, never known any kind of law: “If you do not love me, I love you. If I love you, watch out for yourself.” And Carmen’s love, like that of Tristan and Isolde, ends in death. How could it be otherwise? Consuming, all-absorbing passion is inherently at odds with any form of authority, which its very nature defies.