Since the Church says that having children is intrinsic to sex and marriage, should we just strip the sterile and older people of their right to marriage?
The Catechism says that sex must be ordered per se to the procreation of human life (# 2366). “Per se” does not mean every act can be fertile but only that “by itself” (i.e. per se) the act is not intentionally hindered from its natural ends. This is what contraception, homosexual acts, and certain heterosexual practices, that do not complete or naturally render the marital act, do. But it is clear to any biology novice that not every sexual act results in conception.
Consider by analogy, that I call a friend, and this might result in speaking with her, or perhaps being sent to a voice mail. Whatever the final result, my reason and purpose for calling was to try to reach my friend. One would likely consider me a madman if, in dialing the numbers, I had no intent of reaching my friend, and was angry if she did pick up the phone and begin to speak. Whatever the final result, the calling of my friend is per se related to speaking with her.
And this is what it means that marriage, and sexual activity, must be “per se” related to the procreation of children, even if the results of that activity do not always attain the full purpose of that action.
Older and/or sterile people do not intentionally exclude one of the two fundamental reasons for marriage and sexual activity.
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