In the case of the recent developments in case law, which have occurred mainly in the US District Court for the Northern District of California in San Francisco but also in the US Court of Appeals for the First Circuit in Boston, the rational basis and compelling state interest tests have been much discussed as regards the institution of civil marriage. The immediate question at hand is ‘Is there a rational basis for or compelling state interest in restricting civil marriage to couples of the opposite sex?’; the broader question that has to be answered first is ‘What is the state’s interest in registering marriages anyway?’
Marriage was for most of human history a distinctly ad-hoc and theocratically organised institution—as, indeed, were most institutions, including government itself (the nation-state emerged as a concept in the sixteenth and seventeenth centuries and was only substantially divorced from the religious authorities of the country in question from the eighteenth century onwards). Religious organisations performed nuptials, which were then granted a certain legal cachet by relevant authorities, chief among which were property exchange and heritability and, in the next generation down, the right to not have to inquire too deeply into who exactly one’s parents were. This system, since it was administered by religious law, was (and in many jurisdictions still is) defined solely in religious terms. Common church interests in marriage (in Europe) included legitimising sexual behaviour, keeping track of family units for the purpose of parish registers, and advancing what was seen as a series of divine mandates related to reproduction and biological parenthood. Obviously, these interests were at the time and to a large extent even to-day only served through the marriage of opposite-sex partners.
