something that has existed since the beginning of human history as an institution where men and women come together for the purposes of forming a natural relationship as God made it to be...

Two people who may like each other or may love each other who are same-sex, is that a special relationship? Yes it is, but it is not the same relationship that benefits society like a marriage between a man and a woman.

This post is, instead, for anyone who, reading that quote, might disagree with it but think that, even taking away the poisonous argument that only procreative couples "benefit society," Santorum has history on his side.

He does not.

The main difficulty in refuting people who make the claim that "marriage" has "existed since the beginning of human history" for "men and women [to] come together...for the purposes of having children" is actually that there is too much historical fact that refutes it to easily summarize.

As an anthropologist, the temptation is to cite other cultures where institutionalized sexual relations take place between one man with multiple women, or one woman and multiple men. As an archaeologist, one is tempted to cite debates about the origins of pair-bonding and its relationship to the sexual practices of our nearest primate relatives, or recent studies reconstructing the emergence of monogamy (reproductive pairing) in the history of Indo-European languages somewhere between 10,000 and 5,000 years ago. As a gender studies researcher the automatic response is to point to the many cases world wide and historically of people of third or fourth genders engaging in recognized relationships with others with whom they share sexual anatomy.

But I think those responses, while valid, miss the point.

Santorum and others like him don't mean to include the practices of men and women in Native American, South East Asian, or African traditional societies when they say marriage has existed unchanged since "human history" began, and they don't care if primate studies suggest our species might not actually be quite so naturally straight as they imagine. They mean the history that they claim as their own: the one sanctioned by God as continuing "civilization."

But they are still wrong about those historical facts.

"Marriage" in the U.S. today is a civil contractual relationship. That civil contractual relationship has evolved over the history of this country, from inscribing inequality between partners to a contract between equals. Even in the brief history of this country, then, marriage has not been consistently defined and has been constantly evolving, as Charles Kindregan discusses in a paper published in 2011.

"Marriage" is also used in the U.S. today, of course, as the term for a union sacralized by an established religion. But here again, marriage has not been unchanging even within the religious tradition that Santorum implicitly references: Christianity. Marriage in the Christian tradition has changed from a primarily economic contract between two familial groups, a relationship in which the wife was originally understood as subordinate to the husband, to its modern form of relationship between a couple, a relationship in which each partner is understood to have rights and obligations to the other.

Far from Santorum's view of Christianity as timelessly emphasizing procreation through marriage, research by scholars like Duke University's Elizabeth Clark has shown that

Christians of the first to fifth centuries, to the contrary, believed that the renunciation of family, home, marriage, reproduction, and property was the highest ideal. With ingenious arguments and astute Scriptural interpretation, they fervently argued the "anti-marriage" line.

So much for the Christian tradition having enshrined procreative marriage timelessly "as God made it to be."

But then, I am only inferring that Santorum means to limit his claim to the Christian tradition; what he actually said was that this form of social institution "has existed since the beginning of human history."

When is "the beginning of human history?"

Let's assume "history" here is meant to indicate "written records." That would bring us back to the ancient societies of Mesopotamia, Egypt, and the lands between them, where the earliest known written records have been preserved.

In 1994, M.J. Geller of University College London published a superb discussion of some of the insights emerging from study of the Dead Sea Scrolls. The community that wrote these documents, like the early Christians who followed, were at best ambivalent about marriage.

In discussing the background against which the authors of the Dead Sea Scrolls set themselves apart, Geller drew on marriage laws and contracts extending two millennia before the Common Era began. She noted that polygamy (marriage to multiple partners simultaneously) was allowed throughout that history, although it was rare because it required sufficient financial resources for a household to support the multiple contracts involved.

Polygamy was legal in ancient societies of the Levant, including those of the kingdoms of Israel and Judah. Early Christians (and some of their predecessors) thought celibacy and restraining from marriage was superior to engaging in it.

So where has Santorum gotten the idea that marriage has, from the beginning of human history, been a procreative relationship between one man and one woman?

Perhaps his "beginning of history" is more recent. In Medieval Europe, the Catholic Church tightened control over marriage by defining specific circumstances that would invalidate it:

In the first Christian centuries marriage had been a strictly private arrangement. As late as the 10th century, the essential part of the wedding itself took place outside the church door. It was not until the 12th century that a priest became part of the wedding ceremony, and not until the 13th century that he actually took charge of the proceedings.

A history of marriage in the Christian tradition might take us back to the 16th and 17th centuries, when the status of marriage as a religious institution was a topic of debate between Catholics and Protestants: