We thus can see that there are two kinds of human economy. There is the kind of economy that exists to protect the "right" of profit, as does our present public economy; this sort of economy will inevitably gravitate toward protection of the "rights" of those who profit most. Our present public economy is really a political system that safeguards the private exploitation of the public health and wealth. The other kind of economy exists for the protection of gifts, beginning with the "giving in marriage," and this is the economy of community, which now has been nearly destroyed by the public economy.
There are two kinds of sexuality that correspond to the two kinds of economy. The sexuality of community life, whatever its inevitable vagaries, is centered on marriage, which joins two living souls as closely as, in this world, they can be joined. This joining of two who know, love, and trust one another brings them in the same breath into the freedom of sexual consent and into the fullest earthly realization of the image of God. From their joining, other living souls come into being, and with them great responsibilities that are unending, fearful, and joyful. The marriage of two lovers joins them to one another, to forebears, to descendants, to the community, to Heaven and earth. It is the fundamental connection without which nothing holds, and trust is its necessity.
Our present sexual conduct, on the other hand, having "liberated" itself from the several trusts of community life, is public, like our present economy. It has forsaken trust, for it rests on the easy giving and breaking of promises. And having forsaken trust, it has predictably become political. . . .
This quote from Wendell Berry points up the incongruity that many of those who defend the traditional definition of marriage are unabashed cheerleaders for a liberated "public economy" (as described by Berry) that by its logic inexorably undermines traditional marriage. Once we adopt the language of "rights" and "self-fulfillment" to talk about marriage the battle is already lost. And I fear it was lost long ago.
Quote from pp. 138-9 of Sex, Economy, Freedom & Community (Pantheon Books, 1993)