The logical case for same-sex marriages seems nearly ineluctable today. In the course of the past three decades, American state laws have effectively reduced marriage to a terminal sexual contract between consenting adults. But "[a] page of history is worth a volume of logic," Oliver Wendell Holmes, Jr. reminds us, and Western history provides very little support for extending the legal category of marriage to include same-sex unions. For nearly two millennia, the Western legal tradition defined marriage as a heterosexual, monogamous union, designed for the procreation and nurture of children, the mutual help and companionship of husband and wife, and the mutual protection of both parties from sexual sin and instability. Though, to be sure, the Western legal tradition has undergone radical transformation and equitable tinkering, it has not extended the legal category of marriage to include same-sex unions. History alone, of course, is not reason enough to maintain traditional marriage laws. But history must be an essential part of any serious arguments for the maintenance of traditional marriage. And the enduring traditional arguments about the origin, nature, and purpose of marriage must be the starting point for any serious debate about the propriety of legalizing same-sex marriages.  In this chapter, I join the volume's candid conversation on the legal status of same-sex unions by offering a quick tour of some of the main texts that have informed our Western legal understandings of traditional marriage and a quick distillation of some of their enduring teachings on the origin, nature, and purpose of marriage.