[M]arriage is one of those institutions that we spontaneously see both from outside, in terms of its social function, and from inside, in terms of the moral and spiritual condition that it creates. No honest anthropologist can fail to acknowledge the functional importance of marriage. In all observed societies some form of marriage exists, as the means whereby the work of one generation is dedicated to the well-being of the next. Marriage does not merely protect and nurture children; it is a shield against sexual jealousy, and a unique form of social and economic co-operation, with a mutually supportive division of roles that more than doubles the effectiveness of each partner in their shared bid for security. Marriage fulfils this complex function because it is something more than a contract of mutual co-operation, and something more than an agreement to live together. Hence marriage enjoys—or has until recently enjoyed—a distinct social aura. A wedding is a rite of passage, in which a couple pass from one social condition to another. The ceremony is not the concern of the couple only, but of the entire community that includes them. For this is the way that children are made—made, that is, as new members of society, who will, in their turn, take on the task of social reproduction. Society has a profound interest in marriage, and changes to that institution may alter not merely relations among the living, but also the expectations of those unborn and the legacy of those who predecease them.
(Roger Scruton, A Political Philosophy [London and New York: Continuum, 2006], 82-3)
Note from KBJ: Here is a version of the essay from which this paragraph is taken, in case you want to read it.
Keith Burgess-Jackson, J.D., Ph.D. 