Over the past year I have followed the debate over gay marriage with interest. Like Sen. John McCain I don’t believe that the majority of American people favor a constitutional ban on such marriages and I doubt that they ever will. But I have been fascinated not only by the passion the subject has generated but also by the arguments which have been set forth. Recently I had lunch with a friend, a historian, who talked about the problem of trying to define “traditional marriage” and the “traditional family” and to use these definitions in arguments to ban new forms of relationships like gay marriage.

Tradition for most of us is a comforting idea. Tradition implies something which we know and which is safe. Through much of history to say that something was new or innovative was to criticize it, not praise it. The trick, of course, is to define what we mean when we say that something is “traditional.”

For example, during the Middle Ages a law was considered to be traditional or customary when it had existed for as long “as man could remember.” In an era of few written records and short life span, this meant that a tradition might be only a few decades old. Memory is an uncertain primary archive of tradition. To discover what is traditional, one must first define the idea with clarity.

Current arguments that the current forms of marriage and family — and nothing else — are traditional, used by proponents of a legal ban against gay marriage, do not work when one looks at history and law. Unlike people in the Middle Ages, we have written records and a good deal of historical knowledge. We can reconstruct with a fair degree of accuracy what our ancestors believed and what was accepted in law and in society. We can ask — and answer — some key questions.

For instance, during the national history of the United States what was marriage like as an institution? Was the notion of family that we accept today the same 100 years ago. Was there, in fact, “gay marriage” and was it accepted?

On the first issue, it is possible, I believe, that one can argue that in the United States during the past two centuries, the predominant form of marriage was one between a man and woman and the predominant form of a nuclear family was one consisting of a husband, a wife, and children. But it’s hard to go much beyond that. In fact, in the 19th century, our ideas about many aspects of marriage and family, which we now consider traditional, were quite different. For instance, in the 19th century, women often married at 12 or 13, an age we would consider unacceptable. Indeed in many states today, such a marriage might lead to the husband’s prosecution for statutory rape.

Further, until the late 19th century, it was both traditional and legal for a husband to have complete control of a wife’s property. In effect, a wife lost virtually all of her property rights and many of her civil rights when she married. Third, in most states, laws banned interracial marriage. Such laws today are unconstitutional and void. I suspect that many today who want to adopt that part of the traditional definition of marriage, which limits it to relationships between men and women, would not be willing to adopt these or other 19th century concepts of marriage and family even though they might well be considered traditional.

A second flaw in the argument is the notion that gay relationships were “traditionally” considered to be unacceptable and not marriages. In fact, in the 19th century, there was a type of relationship known as a “Boston marriage.” The most famous of these relationships was that between the respected writer Sarah Orne Jewitt and Annie Adams Fields. These ladies were not only not treated as social pariahs, they were welcomed into Boston society, a society that was, at the time, one of the most conservative in the United States. Society accepted that they were “married” and treated them as such.

While there is some debate today as to whether such relationships actually involved sex, which some would argue is a key part of traditional marriage, there is no doubt that they were long-term, romantic relationships between two people of the same sex. If one were to disqualify these relationships from being considered marriages solely because the two members of the “marriage” did not have sex, one would also have to disqualify a large number of “traditional” marriages of the Victorian era as well.

The point of this brief history is quite simple. There is, in fact, no simple definition of what is “traditional” in this country as regards the details of the marital relationship or the composition of the family. One can speak of what is and has been most common or what is acceptable according to a particular religious dogma. But to argue that a constitutional ban on gay marriage and the families which result is necessary to preserve “traditional” marriage and the “traditional” family will not survive dispassionate historical analysis.

Mike Hoeflich, a professor in the Kansas University School of Law, writes a regular column for the Journal-World.