It is not true that half of all marriages end in divorce. That false statistic was arrived at by comparing marriages in the general population and finding that they were twice as numerous as divorces in the general population. But correct for the fact that the marriage rate is declining and population growth slowing. Correct also for the fact that many divorces are by people in their second or third marriages. And then you find that about 25 percent of first marriages among the college-educated end in divorce, and, among devout Catholics, an even smaller percentage than that (the exact number seems to be unknown).

Still, we all know Catholic couples who have broken up after sometimes many years of marriage. Sometimes just one person goes AWOL and nothing can be done about that. Each of us is capable of acting treacherously without any provocation. But here are seven rules for couples to follow so that in ordinary circumstances they have the most reasonable chances of persevering in their marriage.

1. The most important basis for a stable marriage is the firm acceptance by both husband and wife of marriage as a one-flesh, indissoluble relationship, such that so-called "divorce" is an impossibility and a human fiction. The bond of marriage must be regarded as actually closer than that of parent to child, and sibling to sibling, as it is the relationship which is meant to be the foundation for those others. "Blood is thicker than water": marriage is a "blood" relationship and not merely a juridical "water" relationship. Every child has this ideal naturally but in an adult it hardly can survive today without the illumination of the Gospel from the Church.

2. In the act of marriage, husband and wife must each die to self, so that from that point onward neither has an individual good ("my career," "my time," "my friends," "my money"); rather, the good of each is through and in the marriage. In a marriage ceremony, two individuals go in and a single social entity comes out. A sign that a couple has effected this self-renunciation is their openness to children, because the lifelong commitment required to raise a child should look like a relatively slight thing after they each have giving up their lives for the other.

3. After they get married, husband and wife must both agree that the health and goodness of their marriage is the most important achievement of their life. Every other goal and pursuit -- career, wealth, education, prestige -- takes second place. If their marriage is a success (insofar as it is in their power), they are a success; if not, they are not. For each, the path to heaven has a name -- the name of their spouse.

4. Husband and wife should communicate regularly to foster their relationship. Here the pattern husband and wife must follow closely matches that which is necessary in the interior life. They should spend some time each day, 15-30 minutes at least, simply talking; then a "date" every week or so; and a "getaway" every year or so. This is exactly like: a Christian needs to pray (converse with God) for 30 minutes or so each day; join with the sacrifice of Christ at least once a week; and go on a yearly retreat. No surprise that they are similar: both involve the deepening of a relationship with a person.

5. The exhilaration and extremes of passion which the couple felt when they first fell in love will moderate over time, becoming subtle and refined, just as wine develops "structure" as it matures. C.S. Lewis observed that you cannot cook on a fire until the flames have died down and one is left with steadily burning charcoal--and marriage is for "cooking." Romance, however, should never die. But romance is the effect of "courtship," and courtship implies that husband and wife understand and receive each other as a gift.

6. Naturally, such courtship is incompatible with harsh criticism or domination by the man; equally, the wife's appearing as a gift is incompatible with her being bitter or seeming a nag. The simple tact and kindness that one shows to strangers is usually enough here. (And hold your tongue rather than complain.)

7. Finally, the couple should show prudence in safeguarding their hearts. Professional relationships are necessary, but neither husband nor wife should have just on their own any personal friendships with a member of the opposite sex. Always it should be the married couple together which is friends with the other. Be transparent about meetings with a member of the opposite sex. Again, do not unburden your heart to anyone except your spouse or spiritual director. Do not criticize your spouse before others, especially to members of the opposite sex. Do not seek consolations on the Internet.

Michael Pakaluk is Chairman and Professor of the Philosophy Department at Ave Maria University and an Ordinarius of the Pontifical Academy of St. Thomas Aquinas.