Whenever I refer to sexual intercourse in teaching my classes, I refer to it as “the marital act,” largely because sex is unitive and marriageis about union. Truth about human sexuality sees that its unitive nature completes husband and wife as persons, as couples and as a people. Likewise, to live it incompletely renders us incomplete and divided.
My review of Humanae Vitae centered on the reality that sexual intercourse between husband and wife is both unitive and procreative. In my experience what Catholics and others fail to understand is that in recognizing the unitive nature of sex as different from its procreative nature, Humanae Vitae did not separate the two. The Holy Father wrote that the traditional doctrine taught within it “… is based on the inseparable connection … between the unitive significance and the procreative significance which are both inherent to the marriage act”. As outlined in TheSmoke of Satan, dissenters from Humanae, lay and clerical separated the two, claiming the unitive nature of sex remains genuine when distanced from the procreative. Quite simply, the Pope’s point was that sex that is not open to procreation, sex that is shut off from its very nature, cannot be unitive. Just look about our overexcited sexualized world and see—there is no intrinsic unitive value in sex divorced from its natural end. Humanae Vitae posits truth in connecting the unitive nature of sex to its procreative nature. A marriage that accepts in every marital act the possibility of a child with its own needs, changes the nature of a relationship into something more than the husband and wife. In considering the yet to be conceived child, a man and wife subordinate their lives to another. Their love for each other is no longer solely about themselves but a gift to their child not yet conceived. It is this love, rooted in the creative nature of the sexual act, that makes it unitive.
Untying the procreative nature of our sexuality from its unitive nature, as we have done, extinguishes the very thing that makes it unitive. Contraception fundamentally changes the marital act, changing it into something completely different. Sex open to new life and deliberately sterile sex are wholly different acts. Using “sex” to refer to both of these is deceptive, for intercourse open to life changes the lives of husband and wife beyond themselves.